Birth, Pediatrics, Genetics, Aging

By D. Phillip Sponenberg and Kent C. Roberts.

Problems involving birth in dogs and cats are relatively uncommon. One problem that does occur in both species is uterine inertia, or failure of the uterine muscles to contract at the proper stage of labor.

These contractions are essential during delivery because they move the newborn through the dam's birth canal. Lack of, or weak, contractions delay expulsion of the young and without prompt and effective treatment they may be stillborn. This problem is more common in overweight and poorly conditioned animals.

Difficult birth (dystocia) may result from the presence of malformed puppies or kittens in the birth canal. This problem also can result from an abnormally large puppy or kitten, or in certain breeds that have pups with large heads and shoulders.

Prompt assistance is needed in such cases to save the newborn and even to save the dam. Caesarian section to deliver the fetuses is standard procedure when manual assistance does not produce the desired results within a reasonable time.

Bitches and queens with unusually small birth canals or those with injuries to the pelvis that have narrowed the pelvic canal should not be bred, as the best means of preventing birth problems.

Infections of the female reproductive tract occur with some frequency. Acute metritis is a bacterial infection of the uterus following delivery of the young. It is more likely to occur following dystocia and may involve retained placenta.

Persistence of a dark green or reddish-brown discharge from the vulva more than 24 hours after birth of the young is an indication of trouble in the uterus which requires veterinary treatment.

Pyometra is a filling of the uterus with pus following a heat (estrus) in the bitch. Discharge from the vulva may or may not be evident but there is absorption of toxic products into the bloodstream causing depression, increased thirst, anemia and toxemia. This can be a life threatening problem and needs effective veterinary attention.

Vaginal and uterine prolapse are infrequent occurrences, particularly in the cat. They are characterized by a large mass protruding from the vulva and should be treated promptly by a veterinarian.

Pediatrics

Canine and feline pediatrics is the study of the growth, development and diseases of the young of these species. Pediatrics starts with care of the expectant bitch or queen, preparation for birth of the young and providing a clean, dry and warm environment during the first weeks of the puppies' or kittens' lives.

Nutrition plays a critical role in condition of the dam as well as the size and weight of the unborn or newborn fetuses. Proper levels of nutrition during pregnancy and nursing the young are very important to the health of both the dam and her newborn.

Loss of puppies and kittens during the first few days of life is quite high. Reasons for this mortality vary from still birth to starvation due to failure of lactation in the dam. Still birth is often the result of prolonged labor.

Exposure is a leading cause of death during the first week of life. Chilling of the newborn can occur rapidly and if not reversed in time death results. Warm, clean, dry whelping and kittening facilities are important.

The dam (bitch or queen) plays an extremely important role in the birth and care of her young. Inexperienced dams may damage the newborn accidentally to the point of death. Weak, injured or chilled puppies or kittens cannot nurse and become stronger. Swollen, infected mammary glands also make it difficult for the newborn to obtain milk.

Infectious disease can cause the loss of individual young or entire litters. Umbilical (navel) infection is common as are eye, respiratory and skin infections. Prompt diagnosis and effective treatment are important to save the very young or prevent permanent damage to the affected organs. Good sanitation is necessary to reduce the chances for these opportunistic infections to cause disease.

Fading Pup Syndrome is a disease entity of young puppies apparently normal and healthy at birth which quickly become listless, uncomfortable with distended abdomen, weak and comatose when a few days old. A number of infectious agents including canine herpesvirus are thought to cause this syndrome.

Toxic Milk Syndrome in puppies is an apparent incompatibility between the pup and the bitch's milk. Affected pups will bloat, cry and develop a greenish diarrhea. This may be due to toxins in the milk or infections in the bitch's reproductive tract. Treatment requires removing the pups from the dam, feeding them an orphan puppy formula and keeping them warm and dry.

Virus diseases that may infect the young puppy are distemper, herpesvirus, adenoviruses, coronavirus and parvovirus.

Fading Kitten Syndrome and Kitten Mortality Complex are not well understood disease problems that cause significant death loss of kittens each year. The role of virus diseases such as feline infectious peritonitis (FIP), feline leukemia, rhinotracheitis and calicivirus is not yet understood but the incidence of these diseases is widespread in the overall cat population.

Proper management, nutrition and observation of the dam and her young cannot be overstressed in successful pediatric husbandry. Prevention or the early detection of problems is particularly critical when dealing with the newborn.

Most problems are not due to infectious disease but include small size, ineffective nursing, chilling, and genetic or congenital abnormalities. Prompt attention to problems, including puppies or kittens that cry continuously, offers the best approach to solving these problems.

Genetics

The study of how characteristics are passed from one generation to the next is called genetics. Differences in hair type, body type, hair color are all under genetic control, which allow them to be accurately passed from one generation to the next. These differences are frequently used as hallmarks of certain breeds, and the fact that they are consistently passed from parent to offspring results in the various breeds being "bred true" to type.

Traits that pop up periodically in some pure breeds are most likely due to recessive genes. This allows them to be masked by the more usual form of the gene for several generations, until two of the same form combine and cannot be masked. When these concern color or hair characteristics it is usually not possible to have the offspring registered, although they are normal representatives of the breed in every other regard.

Other simple changes can result in altered metabolic pathways or severe structural changes that cause death of the affected animal. Some of these are more severe than others and usually are called "genetic diseases." Such structural abnormalities include cleft palate in pups, or kittens with brains herniated through defects in the skull. These are severe and generally cause the animal's death. Others are less severe, such as blue-eyed white cats which frequently are deaf. These can lead a fairly normal life if protected from an adverse environment.

Altered metabolism can also occur and result in disease. Included here are such things as hypertrophic neuropathy in some dogs, which causes paralysis at a young age. These and other abnormalities are sometimes studied in animals in the search for a cure for similar diseases that cause severe suffering in affected humans.

Other diseases that are genetic are not so well understood as they involve the interaction of several (up to hundreds) gene pairs. Hip dysplasia, which sometimes results in crippling arthritis in dogs, is one such disease.

The diseases are usually subject to both genetic and environmental influences, which makes their elimination from some breeds a very difficult and slow task. This is due to the environment occasionally masking the severity of the disease in some animals.

When such animals are bred they pass on the tendency for the defect, and offspring contain a high percentage of affected animals. Progress in eliminating diseases such as these can only occur slowly over a period of many generations.