Having been requested to
supply articles on bloat/torsion/volvulus, and on megaesophagus, I decided
to revise an article formerly published as “Digestive Tract Disorders”,
and combine it with other articles, giving it a new name. My favorite
breed is susceptible to many gastrointestinal problems. There are a great
number of causes for stomach and intestinal problems. When these two
organs in the alimentary canal are considered together, we refer to a
syndrome as gastro-intestinal. For no other reason than whim, let’s start
at or near the beginning of this tract, where the esophagus meets the
stomach. This is where a sphincter exists, that is supposed to keep
digesting stomach contents from refluxing back up the tube into the mouth
(or worse, sidetracked into the lungs). Peristaltic action (a progressive
squeezing, analogous to milking a cow, forces food boluses down from the
mouth and throat to where they can be digested in the stomach and
intestines.
Esophagus
Affliction— Congenital esophageal achalasia is also known by many other
names such as cardiospasm, megaesophagus, dilated esophagus, and ectasia.
The disorder appears to be caused by a simple autosomal recessive in
German Shepherds, although it is highly variable in expression. After
briefly consulting me, genetics worker Danielle LaGrave wrote an article
for the November 2002 GSDCA Review on this subject, and concluded, “I had
hoped to have a definitive answer as to how megaesophagus in the GSD is
inherited. But regrettably, I was unable to.” My example of a pedigree
study in “The Total German Shepherd Dog” (www.hoflin.com) apparently was
not convincing enough for her. While reportedly only about one percent of
the dog population may be involved, mortality rate in pups is fairly high.
Even when PRAA (Persistent Right Aortic Arch) has been ruled out as the
cause, I believe the percentage in German Shepherds is quite a bit higher
than that reported one percent. Correspondents in the late 1990s have
given me testimonial comments that they believe the incidence is on the
rise, but this, too, may be more a matter of greater awareness. This
abnormally large and flaccid “food-pipe” between the mouth and the stomach
can be found in adults, but the most heartbreaking and serious cases are
in pups early in the weaning and solid-food stage. The ballooning out
reminds one of the extensibility of a pelican’s pouch. The more severe the
expression, the earlier it manifests itself.
GSDs,
Goldens, and Irish Setters seem most at risk, and if a pup survives to
adulthood, the condition often causes or is associated with other
esophagus problems, peripheral neuropathies, gastric dilation with or
without torsion, and especially myasthenia gravis. Even in adults, many
are euthanized or asphyxiate, due to progressive malnutrition, aspiration
pneumonia, vomitus obstructing the air passage, and owner frustration over
the regurgitation. Most adult cases that are presumed to be acquired have
no cause discovered, which leads me to believe it is simply a milder form
of the genetic problem that causes death by starvation in most pups
between 5 and 8 weeks of age. Some veterinary references, however, stoutly
consider these genetically/environmentally different disorders. A loss of
peristaltic action is probably due to a disorder of the afferent nerves.
This is why there is no successful medical, pharmaceutical, or surgical
treatment. There may be a connection with other nerve disorders, even
giant axonal neuropathy, which mimics HD and GSD myelopathy. Some have
gone so far as to hint that a general immune system deficiency is at the
root of this problem, as it appears to be in so many disorders: pannus,
Demodex susceptibility, DM, and more.
Symptoms of megaesophagus
include slow or halted growth, weight loss, dehydration, water in the
lungs, and persistent and progressively worse vomiting of food minutes
after swallowing. The disorder usually is detected at or slightly after
the commencement of weaning. As food slightly stretches the esophagus on
the way down, an affected pup’s muscles apparently fail to contract enough
to prevent the food bolus from staying in a pouch just in front of the
entrance to the stomach. In time, the muscles become progressively weaker
and less able to squeeze the food ball, and even liquid food remains in a
hanging “pelican pouch” forward of and below the stomach entrance. As with
PRAA, the pup becomes emaciated and listless, often dying of starvation.
In fact, the two conditions may be indistinguishable without autopsy. The
pedigree study in my GSD book gives food for thought.
A definitive diagnosis
can be obtained by giving a “barium swallow”, a concoction that contains
heavy barium sulfate in emulsion or suspension, like a chalky milkshake. A
radiograph is taken or fluoroscopy performed immediately afterwards, and
the opacity of the cocktail clearly shows where it is. In the normal pup,
it will be moving into and through the stomach, but in the dog with
megaesophagus, most of it will be seen collected in that pouch ahead of
the stomach. An experienced breeder or dog watcher may be able to save you
a trip to the vet, but it is a good idea to make sure with a professional
evaluation, so you can better plan the next breeding.
Megaesophagus
signs appearing at old age are not typical, but dogs with “very mild
cases” may not present with noticeable signs until older, when the owner
perhaps is watching more during and after meals. Also, similar symptoms
can be caused by other disorders. One correspondent, when pressed on the
issue of her 8 year-old “suddenly” showing signs, admitted that he had
classic symptoms at 7-8 weeks (not long after weaning onto solid food),
which points toward megaesophagus. A second opinion from a veterinarian
who has a lot more experience in megaesophagus may have been needed, and
that is what I advised her to get. I told her that there is a late-onset
form that may be related to other disease states, but I was suspicious
because of the history at age 7-8 weeks.
Mild or moderate
expression of megaesophagus should not be a problem in the individual,
non-breedable pet except after eating — which could be for many hours,
though. If it is megaesophagus (inherited or acquired esophageal dilation)
you might better control it by having the dog eat more-liquid-like meals,
small servings, many times a day, and standing on his hind legs such as
eating/drinking from a table with his front feet up where the bowl is.
Also keep him as upright as you can for a while after meals. This might be
the wisest management method. I suggested she might consult with a vet who
would not advise surgery at this age — most surgical procedures to
“correct” megaesophagus are not satisfactory. It is a very involved
operation, with very low rates of success, and is highly expensive.
Congenital pyloric
stenosis is a similar disorder but is mostly found in Boxers and other
short faced breeds; it is very rare in the German Shepherd. Spasm of the
pyloric sphincter in excitable dogs, especially toys and miniatures, is
also uncommon in the Shepherd Dog. There may be several other causes of
esophageal dilation, affecting various breeds to different extents.
However, German Shepherds have over thirteen times the incidence of
esophageal disorders of all other breeds combined, although PRAA may be
part of this statistic.
Following is an excerpt
from an article prepared by my young geneticist friend Danielle, for an
American magazine. I have condensed it because of some parts being either
obvious or redundant for an introduction. Remember that she is not a
breeder, and did not have first-hand familiarity with the pedigree study I
presented in my book, some generations of my own breeding a few decades
ago. My comments are in brackets. “I am flattered that you want to include
the article on the website. Please feel free to quote whatever parts you
feel are applicable.” Respectfully, Danielle.
The answer to many
questions depends on how “Mega” is inherited. There are two ways in which
it might be inherited. The first is via an Autosomal Dominant (AD) gene. [Autosomal
means that the trait is carried on some chromosome other than the X/Y
sex-determining ones.] If the disease is AD, then only one parent needs to
carry the mutated gene in order to have affected puppies, and would be
affected itself. [Danielle says:] Approximately 50% of the pups in the
litter should be affected, although that can vary from all to none based
on chance. [Fred’s comment: this might be true only if the condition were
a dominant trait with inhibited or partial penetrance, and I do not
believe that to be the case, based on what I have seen; Danielle has not
my breeding and observation experience, just the schooling.] Penetrance is
the probability that a gene will have any phenotypic expression at all.
When an individual with the appropriate genotype fails to express that
genotype, you have a gene that shows “reduced penetrance”.
The second likely way
Mega can be inherited is via an Autosomal Recessive (AR) gene. If the
disease is AR, then both parents would have to be carriers (have one
normal Mega gene and one mutated Mega gene). They would be phenotypically
normal, and indistinguishable from a dog that does not carry the abnormal
gene. However, when two carrier dogs are mated together, each pup they
conceive, will have a 25% risk of inheriting the mutated gene from both
parents, therefore having no normal version of the gene, and being
affected. [Again, Fred’s comments: actually, 75% of the pups, on average,
will inherit the defective gene; 50% of the offspring would be expected to
be carriers and 25% would have a double dose and therefore clearly show
the symptoms. The other 25% would be normal in both phenotype and
genotype.]
So, if the disease is AD
and the female has Mega herself then, yes, she can have affected pups even
if the male does not carry the mutated gene. However, if the disease is
inherited in an AR fashion, then both parents need to be carriers for the
pups to be at risk. So she would not have affected offspring if the sire
were not a carrier for the disease, even if she were a carrier. The
problem here lies in that if she is a carrier, while she may not have
affected puppies, on average 50% of her offspring [sired by a normal male]
will also be carriers for the disease, perpetuating the abnormal gene in
the GSD population. It takes both the sire and the dam to produce [overt]
Megaesophagus in the litter if the disorder is inherited in an AR fashion.
At this time, there is no
way to tell which pups are carriers. So you have a 2 out of 3 chance that
the pup you choose to show and breed is a carrier for Megaesophagus. If
you [in North America, anyway] breed the pup to another carrier (very
likely if you line-breed) then your risk of having affected pups depends
on the closeness of the relationship and whether the other dog has
affected littermates or offspring (a fact you may never know). The math is
simple. Let’s say you breed a bitch with affected littermates. Her risk to
be a carrier is 2/3. You decide to breed her back to her paternal
grandsire. His risk to be a carrier is ½ (Her sire must be carrier in this
scenario (risk = 1) and he shares ½ of his genes with his father – ½ x 1 =
½ = granddad’s risk to be a carrier). This assumes that the grandsire has
no affected littermates or offspring. So the chance for each pup produced
by this mating to be affected is: bitch’s risk to be a carrier x dog’s
risk to be a carrier x ¼ (each pup’s chance of being affected if both
parents are carriers). In the above scenario this works out as follows:
2/3 x ½ x ¼ = 1/12. This is each puppy’s chance of being affected. The
chance of at least one pup in the litter being affected would be higher,
and would depend on the number of puppies.
[Danielle’s math is OK,
but the statement that a show-pick pup from the bitch who had affected
littermates had a carrier risk of 2 out of three is not a good way to
express this. Make a Punnett square or other diagram and you will see that
of four genotypes in her offspring (sire is normal, remember) one is
homozygous-normal, one is homozygous-affected, and 2 are
heterozygous-normal but carrying the recessive defect.]
If you outcrossed her,
your risk to have affected pups would decrease, but since the carrier rate
in the population is not known, the chance of having affected puppies
cannot be calculated. Things get a little more convoluted when we address
this question using the AD scenario. If Mega is a dominant disease it
shows what is called reduced penetrance. Penetrance is the percentage of
animals with the Mega genotype that demonstrate the Mega phenotype (are
symptomatic). For example, in a [dominant] disorder with 75% penetrance,
only 75% of the affected pups would be expected to show symptoms, so it is
possible that an “unaffected” littermate is really affected but
asymptomatic, and could still have affected pups. Therefore, the risk that
one of the unaffected littermates could have affected puppies depends on
the penetrance. The penetrance of the disease cannot be calculated until
it is known that it is inherited in a dominant fashion. [Even then!]
Dominant diseases often also show a trait called variable expressivity.
What this means is that each dog which has the Mega genotype can express
the phenotype to varying degrees. Some dogs may have the full-blown
disorder with vomiting of solids and liquids and may need special
assistance in eating (chairs to hold them upright, etc.). Others may only
vomit solids and get by on soft diets. Some may grow out of the vomiting
stage. And still others may barely be symptomatic at all and may never be
diagnosed at all. These varying phenotypes may all be present in the same
litter. So the pup that came to your attention due to vomiting and weight
loss might have a brother who is gaining weight just fine, never vomits,
and seems perfectly normal. However, if this pup had a [barium] swallow
test at the vet, it would [might] be determined that this pup had Mega as
well. So it is important when one pup in a litter is diagnosed with Mega,
that a vet with knowledge and experience in diagnosing Megaesophagus
examine all the pups. If you bred this “normal” pup, he would be expected
to sire pups with Mega.
[Unfortunately, the same
scene can is, and I believe definitely is, painted with the AR (recessive
theory) brush. What we breeders have seen is that there are “modifier
genes” located either close to or far from the major gene responsible for
a recessive trait, on the same or different chromosomes. These account for
such differences between littermates as amount of gray grizzling in the
saddle, relative darkness of the iris, amount of hip joint laxity, etc. I
believe such modifiers are most likely the primary cause of differences
between affected (homozygous-recessive) littermates with megaesophagus.
Further, the effect of environment cannot be ignored; I believe there is a
substantial contribution to phenotype there. Some pups with a borderline
condition, held in check for a while by those modifiers, could be pushed
over the line into obvious pouch dilation by feeding techniques.
Conversely, a pup with a mild form might grow up to have stronger muscles
around the length of the esophagus, if it had been fed small frequent
quantities of soft mush, while standing on its rear legs, and handled in
other manners designed to prevent stretching of the esophageal tissues.
Other pups will vary even if the same treatment is given to all.]
If the goal of the
breeder is to eliminate this disease from their line (and ultimately from
Germans Shepherd Dogs, entirely), then dogs that have affected offspring
or have affected littermates should not be bred; we would greatly reduce
the number of affected alleles in the breeding population. If the disease
is [recessive], then it will take a while due to those pesky carriers that
never had an affected litter [to tell us] they are carriers) until genetic
testing is available that can detect carriers. If it is AD, it can be
eliminated in a very few generations, even with reduced penetrance. [The
condition is more common in the U.S. than hemophilia or epilepsy was in
England just a couple decades ago, and since it has not noticeably
diminished in linebred American-AKC type dogs, this is another strong hint
that it is a recessive trait.]
If your goal as a breeder
is to not eliminate the gene, but to only avoid affected pups, then it is
necessary that you perform in-depth research into the lines of the males
you choose for her. The same logic applies to stud dogs as to the bitches;
the main difference is that some studs contribute their genes to a larger
proportion of the next generation(s). If you feel that your bitch’s
positive contributions to the breed far outweigh her negative contribution
(the Megaesophagus gene), and you do decide to breed her, you need to
determine that the potential sires have no offspring [or relatives] with
the disease and have every puppy checked for Mega by a vet. If the disease
is inherited in an AR fashion, then you are breeding a known carrier
(having affected offspring is a very accurate test for carrier status!).
Remember that ½ of her pups would be carriers and we can’t tell which.
[Actually, your Punnett square will show half to be apparently normal but
carriers, 25% will be overtly affected, and 25% genotypically normal.]
If a very popular male is
a carrier of Mega, he can have a devastating effect on the allele
frequency in the population. His popularity can cause the number of
carriers in the population to rise sharply. Then, as these dogs are bred
(and often line bred) the number of affected pups jumps. A female has
fewer chances to contribute her genes to the next generation. [This has
happened. The pedigree study in “The Total German Shepherd Dog” (www.Hoflin.com)
indicates that both Bernd Kallengarten and Lance of Fran-Jo were suspects
in carrying the recessive for megaesophagus. The popularity of combining
these lines for success in the show ring was mirrored by a large number of
affected pups. Most died at or shortly after weaning age (5 to 9 weeks)
despite attempts to save them. A good friend who had carriers and affected
dogs had an attitude that was typical of many: he felt that the worst ones
would self-cull by dying, and those that survived would be as acceptable
for breeding as their show-successful parents.]
In the AR scenario, a dog
with a genotype of mm [homozygous and affected, even if not obvious], can
only contribute mutated genes. 100% of [its] offspring will at least be
carriers of the disease. Some percentage will be affected as well,
depending on the carrier status of the other parent. In the AD scenario,
each pup will have a 50% risk of being affected. Even the ones that do not
show signs of disease may have affected offspring due to reduced
penetrance. [I disagree, and feel these last two sentences are potentially
confusing; in my experience, 100% of the pups in a litter with one
dominant-gene parent (or both) will be affected. Modifier genes can indeed
cause phenotype variability. But it is less than academic, since I am
quite sure that megaesophagus is recessive. Besides the litters I’ve seen,
other weight is given by the fact that most disorders are recessive in
essence. Nature tends to weed out defects through the laws of natural
selection and “survival of the fittest”. It is man that has created, by
protective and selective measures, such defects as are now accepted as
“desirable”, such as pushed-in faces, dwarfed legs, extreme size, and
other anatomical and behavioral features. Likewise, by benign neglect, man
has also interfered with Nature’s tendency to keep defects at their lowest
incidences.]
Never breed an affected
dog; even an affected dog who “has recovered” should be neutered and all
littermates tested. If the goal is to eliminate the disease, then any
carrier risk should not be bred. Of course, this applies to the parents as
well. They are “obligate carriers”, and will continue to contribute the
gene to their offspring even if they never have another affected puppy.
One source states that the incidence of Mega-esophagus in the GSD
population in the US is approximately 1%, although the author [LaGrave]
speculates that it may even be higher. If 1%, then about 18% of US German
Shepherd Dogs are carriers of the altered gene (assuming AR inheritance).
With 18%, the [risk], even if you avoid line breeding and stay completely
away from all the [known] lines is extremely high. [Fred adds: I do not
see the occurrence of megaesophagus in other countries where I have
judged, as being anywhere near the magnitude as it has been and probably
still is in the U.S. The reason? Bloodlines. After the mid-1960s, the
lines diverged tremendously from those in the rest of the world, those
being primarily in close alignment with current German genes. Some were
isolated by government quarantine and that included the “Alsatian” in the
U.K., and the lines in Australasia. The relative isolation in North
America was one of breeders’ choice and fad preferences as much as it was
the control by a powerful political clique.]
*********************************************************
Vomiting and gastritis —
Vomiting comes easily to dogs. Grass eating and subsequent vomiting give
rise to all sorts of explanations, the most popular being that the dog was
sick and ate the grass to help him throw up. Actually, excess grass is
more likely the reason for the reflex action. Dogs mostly eat grass
because they like the taste of it, just as with the case of garbage, but
it does appear that individuals learn that too much can cause vomiting, so
the intentional eating of grass to induce vomiting may come after
experience. Gastritis, an inflammation of the stomach lining, can be
caused by the ingestion of too much grass, garbage, or indigestible
materials. It can also be caused by viral or bacterial invasion, but much
more common, especially in pups, is the presence of endoparasites:
tapeworms, roundworms, hookworms, whipworms, and coccidia. Actually,
tapeworms or roundworms can fill up the belly to the extent that they back
up and cause vomiting from sheer bulk. The initial treatment for gastritis
or vomiting may be the withholding of food and administration of
Kaopectate every four hours.
Torsion — Commonly called
bloat, sometimes described as gastric dilation/volvulus (GDV), this is a
terrifying and frequently fatal disorder that German Shepherds and many
other deep chested dogs experience. A twisting of the entrance and exit to
the stomach traps the food and gas. As the stomach swells, the twist is
more unlikely to be relieved without veterinary help. Great strides in
surgical treatment have been made, but the key to reducing the high
mortality is still time. Recognize the symptoms and get the dog to a
veterinary surgeon, preferably an emergency or trauma-oriented hospital.
Simple dilation (swelling due to gas) may not be serious as long as the
dog is able to pass food into the duodenum, but it has been estimated that
80 percent of all dogs that experience simple dilation will someday also
have torsion.
Symptoms of torsion
include a swollen, turgid abdomen; the sluggish action of the dog; his
white, frothy, unsuccessful attempts at vomiting; and perhaps his
scratching in the dirt to make a cool hole in which to lie down. Also, the
spleen will feel like a hard lump. The spleen is normally wrapped around
some of the stomach and therefore splenic torsion usually accompanies
gastric torsion, sometimes occurs without stomach torsion. When either
happens, the return of the blood that flows through the spleen is shut
off, causing shock, the “immediate” killer.
The first thing your vet
is likely to do is attempt to push a tube down the throat into the stomach
so the gas pressure can be relieved. If he cannot get past the twisted
part of the alimentary canal, he may opt for immediate surgery so he can
untwist the organs. One emergency veterinary service in the Detroit area
uses a different kind of lavage tube in their treatment of acute torsion.
The large diameter, stiff, black polyethylene pipe has a smaller, flexible
tube inserted into it. This smaller tube is for warm water so that the
stomach contents can be flushed out of the larger one for about fifteen
minutes. In either case, once the dog has been stabilized, decisions can
be made about whether to operate, or untwist a stomach or spleen still in
volvulus.
Follow up surgical
techniques are numerous, but perhaps the one with the most success in
preventing future torsion is a tube gastrostomy. In this procedure, a
rubber or vinyl tube is put into the stomach through the abdominal wall,
and in a week the stomach wall at that point becomes attached with scar
tissue to the peritoneum and abdominal wall. The tube is then pulled out.
The surgical opening seals off in a few days, and since the stomach is
fused to the abdominal wall, it is prevented from again twisting out of
position. Regular gastroplexy, which is suturing the stomach to the
abdominal cavity, is also widely performed. Because of these and other
techniques, especially the rise of emergency clinics, the mortality rates
among those that make it to the clinic while still alive has plummeted to
about 15 percent. Another 15 percent or so die without being seen by the
vet first.
Groups of scientists at
many locations have been studying bloat for a long time, partly with help
from such as Morris Animal Foundation, the GSDCA, and many others. So far,
they have identified a number of likely causative factors, including
behavioral traits. Breed susceptibility is pretty obvious, with 25 percent
or more of Great Danes, Saint Bernards, Weimaraners, and Irish Setters
expected to suffer from bloat sometime during their lives. German Shepherd
Dogs, Standard Poodles, Collies, and Gordon Setters are fairly high on the
incidence lists, also. Some of the characteristics seen most often in dogs
that had bloated include some stressful event, even minor, in
approximately the eight hours prior to the incident, a fearful
temperament, and consumption of fairly large quantities of non-food
material. The only dogs I’ve had direct contact with that bloated were of
impeccable character, but those may have been in the minority. Purdue
researchers found no pattern in presoaking dry food or not, but a slight
correlation between several smaller meals and less bloat. Others found no
relation to soybean meal in the food, an early target of breeders looking
for a primary cause. Adding vegetables and canned or meat scraps appears
to help lower incidence. Most dogs (60%) bloated not immediately after
vigorous exercise soon after a meal, but in mid- to late evening when
resting or sleeping.
Less likely are other
types of torsion, but they can be as life-threatening. Splenic torsion can
occur without gastric twisting, and an even more rare disorder is
mesenteric root torsion. The mesentery is the white, fibrous, web-like or
film-like tissue that connects the various sections of intestines to each
other and to the abdominal wall. Blood vessels travel through the
mesentery, and if there is a twisting there, regardless of whether the
intestine itself is closed off, the blood supply can be halted and the
intestinal tissue can become necrotic. Bloody diarrhea, vomiting,
abdominal swelling and/or pain, and shock or general collapse can be
symptomatic. It may be the same as what some call “twisted intestines”. So
few dogs survive that it is impossible to prevent recurrence or
conclusively predict whether those are at greater risk for another attack
than any other dog is.
There is a familial
element in torsion/volvulus in many, similar to the way cancer “runs in
families”, but most cases don’t give a clue to hereditary factors. As in
“toxic gut syndrome” which is also seen a lot in some GSD lines, it is
almost impossible to tell which came first, the presence of abnormal
bacterial populations and irritated intestinal or stomach linings, or the
bloat itself. Which is cause and which is effect is not going to be easy
or even possible to determine. Some investigators suspect that breeders
may be stuffing their small, young puppies’ stomachs too much, with
results that show up only later in life. Work goes on. Dr. Larry Glickman
and his group at Purdue University as well as others have published
several papers on this syndrome. Dr. Glickman commented that the supposed
claim that raised bowls are correlated with increased incidence in
torsion/bloat may just mean that this allows a dog to swallow more food
(and air?) more quickly than if they were on the floor. A couple of
website references, such as <http://www.vet.purdue.edu/epi/bloat.htm>, had
some info, including from JAVMA’s Nov 15, 2000 issue. An abstract follows:
Canine Gastric
Dilatation-Volvulus (Bloat)
School of Veterinary Medicine, Purdue University, West Lafayette, IN
47907-1243
Non-dietary risk factors for gastric dilatation-volvulus in large and
giant breed dogs. Lawrence Glickman, VMD, DrPH; N.W. Glickman, MS, MPH;
D.B. Schellenberg, MS; M. Raghavan, DVM, MS; T. Lee, BA
Summary of findings (references 1 & 2) -A 5-year prospective study was
conducted to determine the incidence and non-dietary risk factors for
gastric dilatation-volvulus (GDV) in 11 large- and giant-breed dogs and to
assess current recommendations to prevent GDV. During the study, 21 (2.4%)
and 20 (2.7%) of the large and giant breed dogs, respectively, had at
least 1 episode of GDV per year of observation and 29.6% of these dogs
died. Increasing age, increasing thorax depth/width ratio, having a first
degree relative with a history of GDV, a faster speed of eating, and using
a raised feed bowl, were associated with an increased incidence of GDV.
Table 1 summarizes the magnitude and direction of GDV risk associated with
having each of these factors. The relative risk (RR) indicates the
likelihood of developing the disease in the exposed group (risk factor
present) relative to those who are not exposed (risk factor absent). For
example, a dog with a first degree relative with a history of GDV is 1.63
times (63%) more likely to develop GDV than a dog without a history of GDV.
As another example, if dog ‘A’ is a year older than dog ‘B’, then dog ‘A’
is 1.20 times (20%) more likely to develop GDV than dog ‘B’.
|
Risk Factor |
Relative Risk |
Interpretation
|
|
Age |
1.20 |
20% increase in risk for each year increase in age |
|
Chest depth/width ratio
(1.0 to 2.4) |
2.70 |
170% increase in risk for each unit increase in chest
depth/width ratio |
|
First degree relative with GDV
(yes vs. no) |
1.63 |
63% increase in risk associated with having a first-degree
relative with GDV |
|
Using a raised feed bowl
(yes vs. no) |
2.10 |
110% increase in risk associated with using a raised
food bowl, contrary to popular opinion! |
|
Speed of eating (1-10 scale)
[for Large dogs only] |
1.15 |
15% increase in risk for each unit increase in speed-of-eating
score for large dogs |
|
Most of the popular
methods currently recommended to prevent GDV did not appear to be
effective, and one of these, raising the feed bowl, may actually be
detrimental in the breeds studied. In order to decrease the incidence of
GDV, we suggest that dogs having a first degree relative with a history of
GDV should not be bred. Prophylactic gastroplexy appears indicated for
breeds at the highest risk of GDV, such as the Great Dane.
OBJECTIVE: To identify non-dietary risk factors for gastric dilatation-volvulus
(GDV) in large breed and giant breed dogs. DESIGN: Prospective cohort
study. ANIMALS: 1,637 dogs 6 months or older, of the following breeds:
Akita, Bloodhound, Collie, Great Dane, Irish Setter, Irish Wolfhound,
Newfoundland, Rottweiler, Saint Bernard, Standard Poodle, and Weimaraner.
PROCEDURE: Owners of dogs that did not have a history of GDV were
recruited at dog shows, and the dog’s length and height and the depth and
width of its thorax and abdomen were measured. Information concerning the
dog’s medical history, genetic background, personality, and diet was
obtained from the owners, and owners were contacted by mail and telephone
at approximately 1-year intervals to determine whether dogs had developed
GDV or died. Incidence of GDV, calculated on the basis of dog-years at
risk for dogs that were or were not exposed to potential risk factors, was
used to calculate the relative risk of GDV.
RESULTS AND CLINICAL RELEVANCE: Cumulative incidence of GDV during the
study was 6% for large breed and giant breed dogs. Factors significantly
associated with an increased risk of GDV were increasing age, having a
first-degree relative with a history of GDV, having a faster speed of
eating, and having a raised feeding bowl. Approximately 20 and 52% of
cases of GDV among the large breed and giant breed dogs, respectively,
were attributed to having a raised feed bowl.
Another article based on
the same research but with slightly different data pulled out for the
particular subject matter, was published in 1997: Multiple risk factors
for the gastric dilatation-volvulus syndrome in dogs: a practitioner/owner
case-control study (by): Glickman LT, Glickman NW, Schellenberg DB,
Simpson K, Lantz GC. JAAHA, May-Jun., 1997. ABSTRACT: A study was
conducted of 101 dogs (i.e., case dogs) that had acute episodes of gastric
dilatation-volvulus (GDV) and 101 dogs (i.e., control dogs) with non-GDV-related
problems. The control dogs were matched individually to case dogs by breed
or size, and age. Predisposing factors that significantly (p less than
0.10) increased a dog’s risk of GDV were male gender, being underweight,
eating one meal daily, eating rapidly, and a fearful temperament.
Predisposing factors that decreased the risk of GDV significantly were a
“happy” temperament and inclusion of table foods in a usual diet
consisting primarily of dry dog food. The only factor that appeared to
precipitate an acute episode of GDV [in their observations] was stress.
This contradicted the
early-1990s study that indicated the opposite: that raised bowls should
reduce the incidence of torsion/bloat. An article in “Bloat News”
indicated a possible link that raised feeders might help prevent future
episodes in a dog susceptible to “aerophagic” bloat (linked to swallowing
too much air with the food, a commonly blamed cause at the time. Another
issue of the same periodical indicated the single highest correlating
factor was morphology (body type). A graph showed a sharp incidence
increase as the depth of the chest exceeded its width and a strong
correlation with body condition and temperament (weak nerves vs. calm,
unstressed dogs). It may be good to select dogs that have strong, calm
nerves, and are not slab-sided!
An article on the Foster
and Smith Pet Education site, “Interpret Findings of a New Study on Bloat
(Gastric Dilatation/Volvulus - GDV) with Caution”, December 2000, at:
<http://www.peteducation.com:80/article.cfm?cls>, starting with a
subheading, “The Question of Raised Food Bowls” circulated among fanciers.
An excerpt: “In this study, when analyzing the association between the
rate of GDV and the height of the food bowl some questions arise. First,
the study found that large breed dogs whose food bowls are not elevated
have the lowest risk of GDV. A confusing finding is that large breed dogs
who have their bowl raised over 1 foot have the next lowest risk, and
those who have their food bowl raised somewhere between the floor and one
foot have the highest risk. So, the risk of GDV is not proportional to the
height of the food bowl. If height of the food bowl is important, why
doesn’t the risk steadily increase, the higher the food bowl is raised?
Secondly, it appears that the researchers did not consider the height of
the animal in relationship to the height of the bowl when looking for an
association between food bowl height and prevalence of GDV. It would be of
interest to compare the height of the bowl to the height of the dog, since
dogs in this study varied widely in height due to breed differences and
age (some were only 6 months old).
The third question is,
‘why weren’t similar findings obtained in giant breed dogs?’ In giant
breeds, dogs with food bowls raised less than one foot had the same
incidence of GDV as those dogs who did not have their dishes raised at
all. Finally, it is unclear if the researchers also analyzed whether the
elevated feeders were being used because other medical problems were
present or if the elevated feeders could influence other factors such as
the speed of eating. Could these medical problems or other factors, rather
than the elevated feeders, have contributed to the increase in GDV in this
group? A second subheading was ‘Comparison to Other Studies’: The results
of this study agree with most previous studies, which also found that GDV
increases with age. On the other hand, in several studies, dogs who ate
faster had higher rates of GDV. In this study, we had a peculiar finding:
eating at a fast rate was associated with an increased rate of GDV in
large breed dogs, but a decreased rate in giant breed dogs. There have
been other contradictory findings in research on GDV. In some studies it
was found that overweight dogs had higher rates of GDV, and in other
studies, lean dogs had higher rates. In this study, weight did not seem to
make a difference. In most studies, including this one, the rate of GDV
between males and females were similar; in one study, however, males had
an appreciably higher rate.”
One other item that was
brought to light on a “VetMed” e-mail discussion list, was that there is
no proven advantage to raised feeders, and that the Foster and Smith
company which runs the Pet Education website sells many types of elevated
feeders.
While some excellent work
on GDV has been carried out at Purdue, some feel that very little research
has been done in the US on canine torsion/volvulus. Here are websites I
was told will give information on GDV; I have not checked these out, so I
cannot verify their usefulness. Some may be “foreign links, as well as
human links and livestock links” as the person who gave me this list said:
http://www.editoraguara.com.br/cv/ano5/cv29/cv29.htm#tormes
http://www.vetinfo.com/dbloat.html#MesentericVolvulus
http://www.canismajor.com/dog/bloat.html
http://www.harkleen.com/Chimo.htm
http://search.atomz.com/search/?sp-q=mesenteric&sp-a=000608a5-sp00000000
http://www.emedicine.com/emerg/topic311.htm
The huge retrospective epidemiological study of GDV, as I mentioned above,
is at Purdue, run by Larry Glickman.
http://www.vet.purdue.edu/epi/bloat.htm The project was funded by the
AKC Health Foundation and by breed clubs.
****************************************************************
Pancreatic Disorders
—Very close to where the stomach empties its contents into the small
intestine, ducts contribute secretions from the gall bladder and pancreas,
mostly to aid in the metabolism of fats, which are fairly resistant to
action by gastric acid. If either gland does not function properly, this
can result in loose stools, and inefficient absorption of nutrients with
highly variable severity.
The pancreas is a rather
long, V-shaped gland located near the stomach, and aids the digestion of
food. It has two major types of cells or tissues. One group is endocrine
in nature, which means it secretes hormones into the circulatory system,
which in turn transports them to other glands and body parts. The
endocrine activity of this gland serves to control blood sugar level, and
when defective, results in diabetes. The other part empties a group of
biochemicals into the digestive tract. It produces enzymes and
bicarbonate, and excretes these into the duodenum. One major enzyme,
amylase, breaks down the long starch macromolecules, while others break
down fats and proteins. Most GSD people, in America, at least, are
concerned more with the digestive function than with diabetes. I have
corresponded with fanciers in England who are concerned about pancreatic
insufficiency, and since many of their lines are from recent German
imports, this is possibly a more widespread problem there than I had
earlier suspected.
Clinical pancreatitis —
The word clinical may be used to mean “frank” or “obvious”, at least to a
veterinarian with the training and equipment. Any disorder with “-itis” on
the end refers to an inflammation. Most causes of this disorder are of
unproven origin, but “bad genes” must be the prime suspect. Adult clinical
pancreatitis is not tremendously common in the German Shepherd Dog, but
when it does occur it is usually the middle aged, obese bitch on a fatty
diet that has it. Chronic pancreatitis symptoms include emaciation, dull
dry coat, and high appetite with poor digestion as seen by fatty, loose
stools containing undigested starches. Treatment is aimed mainly at
correcting the diet, but it is very difficult to control.
Pancreatic atrophy — On
the other hand, German Shepherd Dogs seem to have a considerable
predisposition to pancreatic atrophy, also known as juvenile atrophy or
pancreatic insufficiency (PI), and certain bloodlines have been much more
associated with it than others. For years I have referred to the milder
manifestations as subclinical pancreatitis, because people who are not
familiar with familial and breed tendencies are likely to miss the subtle
signs, and I had suspected the two forms were variations of one basic
problem. The disease usually starts before the dog is one year old, though
many are three before symptoms are noticed. When lack of “drive”,
diminished coat lustre, coprophagia, and/or poor weight are seen, have the
stool examined by your veterinarian for abnormal fat level and absence or
low level of the trypsin enzyme. If the problem is discovered before it
becomes severe and chronic, Viokase™, a brand of powdered raw pancreas,
added to the food half an hour or more before feeding usually produces
good results. Other similar products that I am familiar with are called
Pancreazyme™ and Prozyme™. I have heard of a British product called
Tryplase as well. I was told, but have not verified this, that Prozyme “is
not the medication of choice as it only contains the vegetable type
enzymes.” Costs vary widely among these. Getting enough to do the job
without making the owner go broke is a tough balancing act, though. By the
way, these types of preparations also appear to be good for non specific
diarrhea. I believe there is a strong possibility that subclinical
pancreatitis can worsen with neglect into an acute attack by enzymes on
the pancreatic and surrounding tissues themselves, and that this condition
may be the cause of many instances of diagnosed perforated ulcers. Texas
A&M vet school at one time was trying to get AKC and GSDCA funding to
study and possibly identify a genetic marker for pancreatic acinar atrophy
in the breed.
The Animal Health section
of HelpLine (UK), autumn 1999 issue had several articles on frank pancreas
insufficiency and malabsorption. That reported on a test for the specific
detection of pancreatic insufficiency, using a trypsin method (TLI) from a
single blood sample. This replaced the fecal test, which had proved
inaccurate. Differential diagnosis of pancreatic insufficiency and other
small intestine disease are sometimes difficult since clinical signs can
be similar. Many problems that befall the GSD point to autoimmune
conditions; research was carried out by Dr. D. Williams in the U.K.
Pedigrees have been requested by veterinarians working on this problem,
and a clearinghouse for information has been set up by Dorothy Cullum, 15
North Road, Brentwood, Essex, England. Chronic intestinal disease, called
overgrowth of intestinal bacteria in the UK, and probably the same thing
that the U.S.’ Dr. Chuck Kruger dubbed “toxic gut syndrome”, is also being
studied in Britain, and has been found to be a particular problem in young
dogs. Treatment with high dosage of antibiotics over a long term has been
claimed to have a good success rate.
Malabsorption or poor
digestion and stool condition are frequently seen in the GSD, and in my
experience, has been more so in the heavily linebred typical lines in
American-bred dogs since the 1970s. These symptoms can be caused or
exacerbated by physical or emotional stress, change of food, and other
things. I suspect that dogs with subclinical weakness in immune systems or
pancreatic function may be most likely to show these reactions. I know
that my strongest-character dogs over the years have also been able to eat
almost anything without diarrhea. Others have also proffered the theory of
an abnormality in the immune system. Such dogs are apparently more likely
to show symptoms like increased susceptibility to bacteria, intolerance to
change in diets, ravenous appetite, reduction in body weight or failure to
gain, diarrhea, greasy-looking feces with possibly undigested cellulose as
well, and an “unthrifty” dry coat. The usual response by breeders and vets
is to try the enzyme supplements and/or something like Hills Prescription
Diet. But there are about as many stories of failure as there are of
successful (though tricky, difficult) control. Some believe that an
increase in roughage or “bulk” is needed in order to “keep the food in the
system” long enough for the digestive system to do its work, but others
say that more bulk or roughage tends to move the contents along a little
faster. Also, we are told to feed our affected dogs low-fat foods.
Some owners with access
to slaughterhouses claim some benefit from feeding raw pancreas, but there
is not enough data with scientific controls to consider this anything more
than anecdotal testimony. This is not to discount testimonials, though, as
these can lead to success and may be incentive for scientific
corroboration. One reader in the UK tried the natural pig pancreas plus
roughage route, and said, “It [pancreas from the abattoir] is no more
unpleasant to handle than any other meat from the freezer, costs half the
price of powdered enzymes, the dog absolutely loves it and appears to be
more effective than any man made preparation on the market! He is not
requiring as much food, as he is obviously absorbing what he needs from
his diet now. He is not full of wind, and he is now producing approx. 1/3
of the amount of faeces that he did on the powders. I have also noticed
that he is no longer ravenously hungry and has actually left some of his
dinner on a few occasions.” On the other hand, many experts say that you
should reduce the amount of non-digestible fiber in the diet for dogs with
pancreas problems.
If you choose the
expensive specialized EPI diet foods from Hills, Eukanuba, or others,
check the labels and prices — they are “out of sight”. People who treat
their EPI dogs for the rest of the dogs’ lives can spend about $1,000 to
$1,500 annually for the enzymes alone. If you go along this road, you will
have to “soak” the ration for a while, to give the enzymes time to work —
longer for the dry rations than for the canned. The enzymes have their
greatest effect after about 20 minutes.
Warning: you can spin
your wheels for years on the abundance and infinite variety of nutritional
advice. Many claims are entirely unrelated and coincidental to results,
but people who are desperate will tend to try them all. One correspondent
told me that, after initial help, she was no longer getting satisfaction
by using just the enzymes; her dog’s stools were getting poor again.
Later, she found good maintenance results by supplementing with folate,
vitamin B-12, banana, live-culture yogurt, oatmeal, baked yams, and
flaxseed oil twice a day, in addition to “one Cimitadine tablet (brand
name is Tagamet) morning and evening three times a week”. (Cephaloxin
500mg two or three times daily, depending on the situation, is sometimes
administered for two weeks.) This diet change had followed the Texas A&M
College of Vet Medicine’s suggested treatment with cobalamine folate.
Cobalamine is vitamin B-12, and folic acid (obtained synthetically or in
liver, green leaves, and yeast) is essential to the friendly lactobacillus
in the gut, in combination with which it inhibits malabsorption. That lady
did not see a turn-around in condition until more B-12 was added to the
vet school’s recommended treatment. She found that 2,000 milligrams of
folate and a fourth-teaspoonful of liquid B-12 with the dog’s light meals
three times a day gave marked improvement It appears that occasional
(quarterly, for example) antibiotic treatment to kill unfriendly bacteria,
followed by folate and yogurt to encourage the lactobacillus, is highly
thought of by veterinary nutritional specialists. I am a fan of vitamin E,
having seen benefits in many areas, so I always recommend that people also
give one or two 400-IU capsules a day of Vitamin E to help boost the
immune system.
Most people make a
distinction between EPI (Exocrine Pancreatic Insufficiency) and
pancreatitis, some saying that dogs can recover from pancreatitis, rather
simple inflammation of the pancreas, and that when the pancreas begins to
atrophy, the only thing you can do is supplement with digestive enzymes
like Viokase V or with Pancreazyme. I tend to believe the two conditions
are more intrinsically linked. Canned dog foods, even the non-prescription
brands, are said to be easier for the EPI dogs to digest than is dry
kibble. The EPI dog is unable to efficiently digest carbohydrates, protein
and especially fat. The condition is also called acinar atrophy, the word
“acinar” referring to the physical tissue structures that make up lobules
in the gland. When the pancreas atrophies, it loses ability to function in
its digestive mode; it apparently does not interfere with insulin
production, which is its endocrine function carried on by different types
of cells. Some dogs do become diabetic as well, but this may be entirely
unrelated.
I have been told that the
statistics on EPI dogs indicated that 1 in 5 pups born to an EPI-affected
dam would eventually show signs of EPI. There seem to be a higher than
average number of stillborn pups, as well. Whether this has anything
directly (genetically) to do with EPI, or is a reflection on the poorer
physical condition that leads to uterine inertia, is hard to say. By the
way, on this website you are now surfing, you might also find my article
on uterine inertia and the use of oxytocin.
The test that your vet or
his contracted lab will perform will give you a reading of what is called
Tli. This is an enzyme blood test that determines the level of digestive
enzymes present. It can vary from day to day, increasing and decreasing
and varying within the same day. The scale on this test from low to high,
is 5.0 to 35.0 while GSD’s rarely test over the 5.0 to 8.0 range. At Texas
A&M, the Researcher told me that they have found that dogs that normally
test below 8.0 will most probably become EPI positive. Of course they are
talking about all breeds, and we must remember that there are breed
differences. The GSD, for example, has a higher packed-cell volume than
other breeds, and it is likely the Tli range that is abnormal for others
might be more normal for GSDs. The disorder might remain fairly unnoticed
or asymptomatic until it reaches a Tli much below 5.0, then the dog
typically begins to get voraciously hungry and has terrible diarrhea with
a sour odor, many times a day. Severe weight loss is an indication that
the dog is starving to death. The fur loses pigment and gloss, becomes dry
and brittle and often is lost to some extent, and Staphylococcus infection
scabs may appear on the skin, because the compromised immune system
doesn’t allow the dog to fight off the infection. The symptoms of EPI
mostly show up when the TLi is down around 2.5 to 3.0. In most breeds
perhaps, any dog that tests at even an 8.0 will be at high risk for EPI.
So, most dogs will be diagnosed with EPI when Tli is at 8.0 or less, and
perhaps 0.4 or lower for GSDs. If a dog is found to be within the normal
Tli range (for GSD’s 5.0 to 8.0) but exhibits symptoms such as much
flatulence, diarrhea that is light brown/yellow to clay color from time to
time, the dog should be tested for levels of Lipase, Protease and Amylase.
The genetics of
pancreatic disorders may confuse, because the expressions are highly
variable. Some can carry the trait and never develop EPI, while others
show symptoms, although the genotype may be similar. The wisest
recommendation is that such dogs not be bred as they most certainly carry
the recessive gene. They are currently looking for a “marker” in the
families of dogs they’ve been working with over the last couple of years.
Before breeding, one perhaps should have the TLi test done, and get a hint
of the possibility of carrying the gene. If you breed two that are
carriers together, you risk as much as the entire litter having EPI. I
once bought a full brother of a famous champion named Shiloh; My “Harry”
was a beautiful animal with excellent hips, but he developed the
pancreatic disorder and had to be controlled as much as possible with the
enzyme powder. I had sold a co-ownership in him before the disorder
developed, and he was killed in a car crash before years of treatment and
follow-up would have been completed. Some others with close relatives also
reported pancreatic insufficiency in their dogs. One vet I know of told
his client that EPI “is not considered being ill — merely a genetic
condition.” Merely a matter of semantics? To me, pancreatic insufficiency
is an abnormality that calls for removal from the gene pool, whether the
dog has a mild case or asymptomatic most of the time. I have found that
most vets take but a modicum of hours of nutrition and practical genetics
classes in vet school, and then forget most because they don’t use it
every day. Breeders, especially those with a science background, are more
reliable sources of information, I think. Unfortunately, not many people
who offer their EPI males at stud admit or declare any cautions about
their dogs. As one observer quipped, “It’s funny isn’t it, that those who
deny all those things have Viokase-V on the shelf in their back rooms?”
Yes, in spite of the fact it is good for various causes of diarrhea, it is
so much more expensive than Kaopectate, that it makes you wonder.
Connection between PI and
GDV? — There have been reports from dog owners indicating that many
episodes of EPI begin with a bloating incident, or with a gastroenteritis,
marked by vomiting and blood tinged diarrhea. One who had “chatted” on the
Internet with many GSD owners in the UK and the USA said, “From the
general info collected, the dog first bloats, which often leads to torsion
of the gut, which of course requires surgery for a tacking of the stomach,
and this is usually followed by a full blown episode of EPI within a few
months of the surgery.”
Intussusception — In very
young pups (and other animals including humans) the intestine can
invaginate (one part slips inside another). The condition, also referred
to as “telescoping intestines”, also occurs in adults, but not as
frequently. Most common immediate causes include worms, obstruction by
indigestible materials, garbage, or toxic substances. The German Shepherd
seems to experience a high incidence of this disorder and I believe there
is a genetic propensity, a familial trait, in certain bloodlines.
Diarrhea and soft stool —
Diarrhea can be a symptom of any number of disorders from cancer to
overeating, but is most often associated with disease or parasitism of the
small intestine. Diarrhea or loose stool is quite common in the German
Shepherd Dog, even when no physiological disease has been identified.
However, since this is not a normal condition, the owner should make a
sincere attempt to find and attack the cause. Some of the causative
factors in true diarrhea are: pancreatic insufficiency, chemical or
mechanical irritation of intestinal linings, parasites, microorganisms,
and a psychosomatic condition related to the “high-strung,” emotional
make-up of the German Shepherd Dog. Foods that can cause loose stool
include milk (if suddenly introduced into the diet), excessive liver,
fats, and those with a high fiber content. However, simple overeating is
perhaps the most frequent culprit. Most people overfeed their dogs.
Soft to runny stools may
be an indication of a general inflammation of the stomach and intestines
known as eosinophilic gastroenteritis. It is treated symptomatically with
something to coat the lining, plus perhaps a steroid and Kaopectate, until
the dog “heals itself.” Many veterinarians and owners administer
Pepto-Bismol, also. In the case of very young puppies with watery stool or
repeated diarrhea, rush to your veterinary clinic with the pup and the
stool samples. Most of the time the cause of diarrhea in a young puppy is
serious, such as parvo or coccidiosis, perhaps with hookworm as well. The
Campylobacter bacteria cause some cases of acute or chronic diarrhea, and
most labs would have no trouble identifying this infection. Generally
watery diarrhea is not an indicator of “campy”. Erythromycin antibiotic is
90% effective, although resistant strains may be evolving.
Even giardia can be quite
dangerous, if the pup is young and has been exposed to other challenges,
such as being wormy, stressed, or otherwise weakened. Giardiasis is marked
by watery diarrhea with a uniquely acrid “bloody” odor, that experienced
breeders can identify quite easily even before a stool sample is analyzed.
Giardia is a protozoan disease; i.e., it is caused by a single-celled
“animal” flagellate parasite, so-called because it is highly motile,
having a tail. The Merck Veterinary Manual describes it: “Transmission
occurs in the cyst stage by the fecal-oral route. Incubation and
pre-patent periods are generally 5 to 14 days. Giardia cysts survive in
the environment and thus are a source of infection and reinfection for
animals, particularly those in crowded conditions... prompt removal of
feces from cages, runs, and yards will limit environmental contamination.
Cysts contaminating the hair of dogs and cats may be a source of
reinfection.” Regarding treatment, the manual says “Flagyl ™ (metronidazole)
is about 65% effective” (in removing cysts from feces) and if administered
“for 3 days, effectively removes giardia cysts from feces of dogs; no side
effects are reported.” By the way, these oocysts are much smaller than
worm eggs, and require much higher magnification to find them; still, they
are not shed every day, so it may be wise to start treatment and then wait
for a three-to-five-day combined stool sample to be checked by your vet.
Despite the “low” rate or ridding the body of cysts, many vets prefer
Flagyl. The success rate is reportedly declining as giardia is now
demonstrating resistance to the drug. In addition, it may be a little hard
on young puppies, with some neurological side effects.
Panacur (fenbendazole) is
relatively pricey and seems to be sold only in large-volume jars from the
usual vet supply catalogs. For giardia, Panacur is considered a static
drug, 100% effective in clearing cysts from feces in 3 days (the cysts are
the infective part), with no side effects reported, and is safe for
pregnant and lactating animals. In the lab, giardia did not develop
resistance to fenbendazole. It does not have a repelling taste. A field
representative for Intervet, the company that manufactures Panacur,
admitted that Flagyl may be preferable for the occasional dog that has
general stomach distress. With either one, a 5-day dose has been reported
by some to be effective when the 3-day regime was not.
I would also recommend
that you ask your vet about Albon™ (sulfamethoxine) which is much more
effective, although for a different reason, and should be given for 15 to
21 days. The sulfa drugs do nothing to the Giardia organism itself, but
they do combat the secondary bacterial infections that are probably the
real killers of puppies. Such an approach allows the pup to regain enough
health to withstand the protozoan, even though it may be retained in the
body for a while. It is more readily available, probably lower in cost,
and in widespread use. A disadvantage in any sulfa drug is a number of
adverse side-effects, but I have not had any problems, probably because I
do not keep dogs on the medication longer than recommended, and have
genetically strong breeding stock.
There are a few
less-often used: Valbazen (albendazole) is about 90% effective in removing
cysts but has been implicated in birth defects, suppression of the immune
system, and destruction of red blood cells. .Atabrine (quinacrine) also
has unpleasant side effects. Some have recommended a Giardia Lamblia
vaccine for dogs with persistent or repeated cases.
Toxic gut syndrome (TGS)
— This disorder has been identified as a specific syndrome, with some
similarities to other disorders such as intestinal volvulus, which may
have been blamed for death when TGS was the real villain. The German
Shepherd Dog has a higher packed cell volume (number of blood cells per
unit of blood) than do most other breeds, with 50 to 60 percent “solids”
compared with 40 to 45 percent. When such a dog becomes dehydrated,
thickened and/or lessened blood supply to the small intestine increases
growth of bacteria that are always present there. These Clostridium and E.
cold bacteria produce such quantities of toxins that the dog is unable to
get rid of them fast enough, and death by poisoning occurs. By the time
owners see symptoms such as discomfort when the abdomen is touched,
attempts to vomit, and excessive salivation, it is probably too late.
Prevention may be accomplished through dietary means (feeding
Lactobacillus acidophilus, yogurt, or cultured buttermilk), or by the same
toxoid vaccine that is given to lambs to prevent Clostridium perfringens
types C and D. As research is done on this recently defined syndrome, more
will become known as to the best treatment.
Other problems — Ulcers
have been diagnosed too frequently in German Shepherds and may be related
to pancreatic problems or other causes: it’s difficult to tell, when
several conditions exist at once, whether one is the cause or effect of
another. Necrotic bowel syndrome, a disorder of unknown cause, is
diagnosed usually on autopsy, when part of the intestine is found to be
dead and rotting away. This condition may be synonymous with or overlap
intussusception or other diseases. It takes a small toll, mostly among
heavily linebred German Shepherd Dogs.
Eosinophilic ulcerative
colitis — This syndrome is most common in Cocker Spaniels and German
Shepherd Dogs. If your pup or adult has intermittent to constant diarrhea,
with or without blood, and does not respond to treatments for the more
common disorders, this disease may be the cause. Initial treatment may
include corticosteroids, antibiotics, and antispasmodics to see if the
symptoms can be halted.
Irritable colon — Also
known as spastic colon, this disorder with mucus in or on the surface of
soft or frequent stools may be the result of stress. The best cure is
prevention — breed stable temperaments and build confidence in puppies.
Polyps — Rectal polyps
are little round or teardrop shaped red to purplish balls. Sometimes they
are clustered like tiny grapes, and are found very close to the anal
opening or further inside the rectum. They should be surgically removed,
since they rupture easily and are a potential site for infection. A drop
of bright red blood recurring on the end of stools is a sign that you
should have the dog examined for polyps.
****************************************************
The author is a breeder since 1945, a teacher and lecturer in canine
topics, and dog show judge. His book, The Total German Shepherd Dog, is
available from http://www.Hoflin.com
and he can be contacted at Mr.GSD@Juno.com