DISEASES OF NEONATAL PUPPIES.
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,
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 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 sugars, 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 six to
twelve smaller pups may have one or two abnormally large pups. Poor mothering
is another principal cause of high mortality, so such bitches probably should
not be bred again.
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 which only heats up to body temperature and covered
with the blanket, and using a neonatal puppy bag (available from this site) to
keep the puppies warm when the dam is removed is best. 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. In Toy breeds in
particular, puppies over eight weeks may still have an adverse reaction to
vaccination.
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 University of Wisconsin suggests the combination of
distemper and hepatitis (A 1) vaccines suppress the immune system
more than when either virus is given alone. There is a need to more fully
evaluate the safety and efficacy of combined vaccines, and the strains of
viruses used, in young pups. This was demonstrated in a most unfortunate and
dramatic manner when it was shown that a commercial live canine coronavirus
vaccine caused encephalitis in most cases when it was used in combination with
distemper virus vaccine. The offending vaccine was quickly withdrawn from the
market.
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" has 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 needed. 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 unsuppressed 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.
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.