Diseases of Puppyhood
BY FRED LANTING AND LELAND CARMICHAEL, DVM, PhD, Prof. at Cornell
(as published in PureBred Dogs/American
Kennel Club Gazette, August 1988, pp. 88-93
reprinted with permission from Fred Lanting)
Breeders’ responses to
early puppy deaths vary. Some expend a great deal of effort, while others “let
nature take its course” and stoically hope the next breeding will be more
successful. Many have discovered that neonatal puppy mortality is preventable
or call be reduced through scrupulous attention to prenatal and postnatal care.
These breeders, who in the past may have accepted 20 to 25 percent mortality
before weaning, have learned that such losses can be reduced dramatically by
simple changes in management, including veterinary checkups.
Culling, or removal
from participation of poor breeding stock, is an important factor in reducing
puppy losses. Both the bitch and the stud should be free of disease, which
would include hereditary problems as well as acquired communicable disease. Of
course, the bitch should be in good condition and free of parasites so she can
easily handle the stresses of gestation, whelping, and care of her pups.
Another factor is an appropriate environment for birth and development of the
whelps. Relative quiet is recommended, at least until the puppies’ senses are
fairly well developed. Cleanliness is essential, for disease obviously can be
spread by cockroaches, rodents, and other vermin. Another part of good
environmental management is regulation of temperature and humidity, especially
in the first week after birth.
Despite remarkable
progress during the past two decades in the areas of knowledge about infectious
diseases of dogs and in strategies to control them (See the Sidebar, “Causes of
Puppy Deaths”), there has been relatively little improvement in our
understanding of the various causes of neonatal deaths. However, it has become
clear that infectious diseases constitute only a small proportion of puppy
death causes up to the time of weaning. Contagious diseases generally assume a
prominent role only after that time when maternal antibody protection wanes. In
this article, we will categorize puppy deaths into two broad areas:
non-infectious and infectious causes, which roughly coincide with two time
periods divided approximately by weaning at three to five weeks. Remember that
there is some overlap in some of those given in the sidebar on the causes of
puppy deaths, and that these percentages may arise partly from reports by
people who had to make assumptions about the causes of death.
Non infectious Causes
The scientific
Community has well established that there are significant physiological
differences between neonatal and older pups or adults. Blood sugar,
ability to regulate body temperature, and immunity or resistance to infection
are among the differences to be appreciated when comparing puppies only
three or four weeks apart in age. An understanding of these will lead to
breeder management practices that will favor reduced
death rates.
Causes of Puppy Deaths
It has been well
established that there are significant physiological differences between very
young pups and older dogs Differences such as immaturity in the regulation of
body temperature, blood sugar and resistance to infection should be considered.
Appreciation of these important differences between neonatal pups and puppies
only 3 to 4 weeks old helps to explain why certain management practices lead to
higher death rates while others greatly reduce mortality. —LEC & FLL
Cause Percentage
·
Chilling 16
·
Stillbirth 15
·
Trauma by bitch 13
·
Dystocia 11
·
“Disease” (sic) 10
·
“Undetermined” 9
·
Accidents 6
·
“Weak pups” 5
·
Cannibalism 3
·
Other (lactation failure, parasites, deformities…) 12
Source: J.F. Moiser, cited in Current Vet. Therapy VII, Kirk.
ed. p.80 Saunders, Phila, 1977
The first three weeks of
life are most critical. Approximately 75 percent of puppy deaths occur then,
and the vast majority of these during the first week. Although the definitive
cause of neonatal death is rarely determined, most seem to have a genetic,
physiologic, or behavioral basis. In many cases the
environment or the bitch’s psyche (temperament, mainly) is flawed. The
principal causes include difficulties at time of whelping. There may be
prolonged labor after which the bitch “gives up”;
sometimes this is keyed to her lack of exercise prior to breeding and whelping,
sometimes to too small a birth canal or pelvic opening often to not having been
kept in good condition through vigorous exercise. Many breeds are selected for
large heads and arrow hips because of fashion, but breeders of these usually
are prepared for Cesarean section. Some brachycephalic breeds have individual pups with enlarged
heads; many bitches in a breed where it is common to bear
Congenital (at time of
birth) anomalies including stillbirth, runting, and
other physical abnormalities may account for up to 40 percent of early pup
deaths. Most of these defects are inherited, but some may result from prenatal
infection such as in the case of the heart defect called myocarditis,
which can result from parvovirus. Some of the more dramatic are isolated
examples of congenital problems. One dog food manufacturer inadvertently added
toxic doses of vitamin D, and the suspected cause of death initially was
distemper; in another case, a mercury fungicide used to treat grain was
responsible.
Warmth is vital to
newborn puppies. Rectal temperatures do not reach ‘‘normal’’ (about 101 degrees
F.) until puppies are about one month old when they more efficiently metabolize
food. An ambient whelping box temperature of 85 90 degrees, with a relative
humidity of 55 to 65 percent is desirable during the first week, though it can
be lower if the dam is present to provide body heat and warm milk. Newborn pups
generally do not recover from a few hours of chilling, so the mother’s
instinctive reluctance to leave the nest for any substantial time or distance
is naturally understandable. In the second and third weeks the temperature can
be adjusted to 80 degrees in her absence, with further reduction to 75 degrees
by the fourth week Chilling can occur at higher temperatures than you would
find comfortable.
What are the best ways
to supplement or take the place of the dam’s body heat to prevent chilling?
Many breeders use a heat lamp for the few minutes that the bitch is outside
relieving herself, but extended use of a lamp can bring about dehydration,
especially in winter in a house that is not humidified. A puppy, which is about
80 percent water, can dehydrate rapidly; signs include rosy pink nose and feet
pads and dry skin that does not “unfold” when pinched. Preferable is a heating
pad on a low Setting and covered with a dish towel, or a hot water bottle that
is renewed each time you remove the dam’s warmth. Keep the room fairly close to
the ideal whelping box temperature for safety’s sake, especially for orphaned
puppies.
Why is temperature so
important that chilling ranks as the leading cause of early death? For one
thing, there are biochemical regulatory processes that may not be efficient at
lower temperatures, and pups are not able to reach a healthy 100 degrees
minimum on their own until they are over three weeks old. More importantly,
several studies indicate that the canine immune system does not function
optimally until this body temperature is reached. Thus, infections which mature
dogs are able to localize and withstand may become generalized in very young
pups, affecting most of the body systems. The extent to which the immune system
in neonatal pups is functionally immature is still unclear, and much has yet to
be learned. It appears that proper immune function is related to the
development of certain types of cells called lymphocytes, which are produced in
the thymus gland and elsewhere, and circulate in the blood and lymph systems.
There they do battle with foreign invaders such as microbes and other agents. A
low body temperature inhibits cell division and proliferation of these
infection fighters, and thus a chilled puppy may have inadequate defenses at the time they are most needed.
Practical implications
of such research have not been fully explored, but we have already recognized
that pups less than three or four weeks old may respond abnormally to modified live vaccines. Certain vaccines that are perfectly
safe in older dogs may cause illness in very young, pups. For example,
distemper virus vaccine may cause encephalitis in puppies under age four weeks.
This has been seen most commonly in pups that were given combined vaccines of
distemper and hepatitis (adenovirus type 1). In contrast, the type 2 (CAV 2 or
simply A 2), which fully protects against hepatitis or the parvovirus (CPV)
vaccines appear safe. Research at the
Bacterial, Protozoan,
and Viral
Microbial infections
are generally thought of as being caused by bacteria, one celled “plants”, but
don’t forget the one celled animals (motile) called protozoa. The plant/animal
distinction is of minor practical import to the breeder except as it may
influence treatment or prevention. The more common early bacterial problems
include umbilical infections, generalized skin disease, and “puppy septicemia.” this latter term, as well as “acid milk” or
“toxic milk” have obscure meanings, though they
provide the breeder or clinician with convenient categories for illnesses whose
exact cause has not been established.
Bacteria have often
been blamed for “fading puppies” because they’ve been isolated from tissues of
dead pups, but these bacteria are incidental in most cases, since microorganisms rapidly invade the blood and body tissues
from the intestinal tract after death from any cause. Bacteria are rarely found
if tissue cultures are prepared immediately after death. One other common
bacterial attack, although it more often takes place about the time of weaning
or later, is the secondary bacterial infection associated with coccidiosis, a protozoan organism.
Early infection may
gain entry via the placenta or the umbilical cord, by mouth, or during passage
through the birth canal. Lack of hygiene may contribute to umbilical infection
with ensuing generalized septicemia and early death
or polyarthritis. Much safety can be attained by
frequently checking to see that umbilical cords are drying up normally. Most
ill pups of the same age have similar clinical signs; too often they are found
dead or dying, so autopsies are not performed as often as would be desirable
for the best statistics. The most common bacteria which have been identified in
dead neonates are E. coli, staphylococci, streptococci, and pseudomonas.
Nursing from bitches
with mastitis or with teats contaminated by uterine discharge may produce a
rapidly fatal gastroenteritis characterized by foamy vomitus
and liquid feces. Such pups often exhibit severe
abdominal pain, rapidly dehydrate from the diarrhea,
and usually cry continuously. An entire litter may die. Antibiotic and fluids
treatment are often futile. Some breeders refer to “toxic milk” in such cases,
but it has not been established that the milk is abnormal, even though some
veterinarians may attribute the illness to milk toxins, metritis,
or failure of the uterus to involute properly.
Whatever the cause really is, the pup cries, becomes bloated, has greenish diarrhea, and exhibits a red, swollen anus. You need not go
so far as to “boil everything except the baby” to give it a germ-free, risk
free environment, but cleanliness and care of your bitch before, during, and
after pregnancy can help you avoid infections like these.
Infection of bitches
with Brucella canis is
associated with abortions in the last few weeks of gestation, early embryonic
death, and occasionally death of whelps, though it is not a common factor in
neonatal puppy death. Infected pups that survive often have retarded growth,
and usually remain infected for months or years. Brucellosis is not widespread
among breeders, but it is very difficult to get rid of once it gets into a
kennel.
Pups with hemolytic streptococcal infections are initially vigorous
and apparently healthy for the first day. Then they no longer suck avidly and
they become weak and rapidly lose weight. These pups become progressively
uncoordinated and develop tetanus like spasms, often showing an unnatural
extension of the spine and forelimbs shortly before death. All pups in the
litter might not be affected, and the bitch may produce healthy litters upon
subsequent pregnancies. Since the same streptococci are commonly seen both in
puppies and the dam’s vaginal swabs, antibiotic treatment of such bitches
during the next pregnancy may be an effective preventive measure. Chronic
uterine infection is insidious and clinical signs are not generally apparent to
the owner of the bitch.
Toxoplasmosis is caused
by a protozoan parasite that is spread primarily from its prime reservoir, the
cat. Oocysts (“eggs”) in cat feces
may infect rodents, man, and dogs, and you know how dogs are irresistibly drawn
to litter boxes! Most infections are subclinical;
that is, they produce no obviously identifiable signs of their presence or
activity. If, however, an affected animal is immuno
suppressed because of worms, injury, work, pregnancy, illness, or other
stresses, toxoplasmosis can be manifested, even in prenatal and neonatal pups.
Outbreaks in breeding kennels have been described wherein signs were abortions,
stillbirths, and “fading pups”. Puppies that otherwise appeared healthy
developed the symptoms and died between two weeks and three months of age. In
some cases, symptoms resembled those of distemper, with central nervous system
and ocular signs being common in chronically infected pups. Early diagnosis of
toxoplasmosis and administration of specific anti-protozoan and antibacterial
drugs can be successful, but prevention is difficult because the carriers
(infected cats) are difficult to cure.
Coccidiosis is another protozoan disease
but usually it only seriously affects pups immunosuppressed
by worms or other parasites or stresses. Get rid of the roundworms, hookworms,
fleas, and other adverse environment, and a healthy pup will probably not be
bothered by coccidia. If you don’t, you could lose
puppies to the combination. Secondary bacterial infection is as bad or worse than the coccidiosis
itself, so a veterinarian may prescribe one drug for the former and Albon for the coccidia, or one
drug for both, but again the value of proper management by the breeder is a
major key to avoiding serious disease.
There are several
viruses that may affect young puppies, but thanks to widespread vaccination,
infectious canine hepatitis and distemper, which can infect the pregnant dam,
have not been significant causes of neonatal mortality With
good reason, parvovirus is the most frightening to breeders. Coronavirus has been found to be of very minor
significance, and the vaccine to be not worth using. Although canine herpes
virus is a common killer of younger pups, death is simple to prevent if you are
knowledgeable and diligent. (See the category “control” in the sidebar, “Puppy
Vital Signs, A Summary”) For some reason, young bitches are more likely to
produce litters that suffer the effects of the canine herpes virus. Older
bitches are more likely to lose their whelps for a variety of other reasons.
In Conclusion
Healthy newborn puppies
are a delight to behold. They are warm, with good muscle tone, skin elasticity,
and pink mucus membranes. Their principal activity is sleeping, which may sound
like a paradox if you consider sleep to be a period of inactivity. Sleep of
newborns is marked normally by twitching, and this continues (though to a
decreasing degree) as the pup grows; you may face trouble if activated sleep is
not evident. When awakened, healthy pups suckle vigorously.
For the most part they are quiet unless separated from the dam and littermates.
Birth weight should double in about ten days. If your pups don’t fit this
pattern, turn to experienced breeders and your veterinarian for advice. If you
have properly prepared for whelping by gaining an understanding of the birth
process and the management of common emergencies with the help of these people,
you can probably keep your litters of newborn pups alive and healthy.
PUPPY VIRAL DISEASES — A SUMMARY
Parvo (CPV)
Symptoms (1st two
weeks) heart (myocarditis): stops nursing, gasps for
breath, dies.
(Later weeks)
enteritis: severe vomiting, mucoid diarrhea may become bloody; dehydration.
Most dangerous age 5 6
weeks to 4 months, depending on when maternal antibodies “wear off” and pup can
respond to vaccine.
Transmission Direct
contact with feces produced between 5th and 6th day
of infection; hands, feet, clothing, utensils (contamination can last weeks or
months). Highly contagious. Most cases occur in breeding
kennels or are carried home by dog show exhibitors, visitors to other dogs’
homes and yards.
Prognosis
Grave; very high risk. Kennel rates may be 50 percent typically, litter mortality death
risk rates up to 100 percent.
Vaccine
Immunity/Protection Good, once maternal antibodies no longer protect.
Vaccination is not immunization.
Control Annual
boosters, clean environment; change shoes and wash hands if coming home to
unprotected pups after possible exposure at shows etc.
Herpes (CHV)
Symptoms Fetal death, mummified fetus;
Neonates: general illness, dull, cease nursing, cry incessantly; all organs
affected, speckled kidneys at autopsy. (3rd week and later): mild infections of
vagina, prepuce, & upper respiratory tract.
Most dangerous age
First three four weeks—(most deaths between 9 14 days age)
Transmission At birth:
from saliva or vaginal discharge of dams infected up to 3 weeks before
whelping. Nasal, in reactivated, “dormant” carriers.
Prognosis
Very high in first couple weeks, lower in next week or two. Always and
only a risk if pups are chilled.
Vaccine
Immunity/Protection Most adults have been infected by one year; inactive virus
in nerve cells may be “awakened” during stresses. No vaccine.
Control Avoid chilling
of pups (see text)
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Copyright 2001 Fred Lanting, Canine Consulting.
Mr.GSD@juno.com. All rights reserved. Please
view his site Real GSD.
NOTE: A well-respected AKC and Schaferhund
Verein judge, Mr. Lanting
has judged in more than a dozen countries, including the prestigious FCI Asian
Show hosted by Japan Kennel Club, the Scottish Kennel Club, a Greyhound
specialty in