Puppies are born blind and deaf, but this delay in development is not only limited to the sensory organs. It also affects thermal regulation, immunity, hydration and metabolism, in addition to which, there is a lack of hepatic and fatty reserves. All these handicaps make the puppy susceptible to numerous disorders of origins as diverse as trauma, infections, dehydration, hypoglycemia or low body temperature.
Neonatal mortality and morbidity rate increase as the litter size of the bitch increases. This phenomenon is most likely linked to the frequency of anoxia aftereffects (lack of oxygen, which leads to lack of blood flow to the brain). These occur as a result of primary uterine inversion, which is often seen in older breeding bitches.
An increase in the incidence of birth defects (cleft palate, megaesophagus, heart defects) within a litter can likely be traced to excessive inbreeding among the ascendants. In fact, since most of these defects are recessive traits, their occurrence necessarily means that two carrier genes of the disease were expressed simultaneously, one from the mother and one from the father. Excessive consanguinity (often more than four generations), therefore, increases the risks of recessive genes being expressed. At the same time, the degree of prolificacy decreases.
The mother's diet during pregnancy is discussed in the chapter on nutrition. It should simply be noted that overeating during this period results in the deposit of fat in the pelvic region and thereby increases the risk of dystocia (abnormal birth). The risk is greatest during an episode of constipation in the final stages of gestation. Indeed, since the rectum is anatomically located above the vagina in dogs, a state of repletion reduces the size of the birth canal. This is why it is important to verify that the rectum is emptied the day before whelping and to give the breeding bitch an oral or rectal laxative if she is constipated.
Dystocia is a factor that obviously can cause neonatal mortality. Therefore, it is preferable to refrain from breeding a bitch that has experienced dystocia again, unless the cause of dystocia was clearly exceptional (temporary obesity, underdeveloped pelvic region, etc.).
Medication Given during Pregnancy
The most critical period for teratogenous action of certain medicines (which produces defects) is naturally during the embryonic phase when tissue is being differentiated (seventeen to twenty-one days). However, the fetus can also be exposed to risks later on that may cause defects in the late-forming organs such as the palate, cerebellum or the urinary tract.
Veterinarians are now familiar with the list of teratogenous products, their doses and period of maximal susceptibility for most species.
If possible, the simplest precaution is to refrain from administering drugs, anesthetics, hormones, external parasite treatments or even vaccinations during gestation, unless the health of the bitch depends on it and the veterinarian is completely sure that the treatment is innocuous.
Problems with Lactation
While gestation and whelping are the most difficult hurdles to overcome for small breeds, it is lactation that can sap large breeding bitches and consequently, can impede the rapid growth of the litter.
In the canine species, mastitis is often caused by a trauma inflicted by the puppies'nails or an ascending infection transmitted through licking of the litter or resulting from a skin infection (pyoderma).
In addition to pathogenic germs in the milk that cause "toxic milk syndrome" (usually colibacillus, hemolytic streptococcus or staphylococcus), this form of mastitis frequently involves dilution of the milk, which alters the nutritional value of the milk. This is especially serious as this disorder generally occurs at the onset of lactation.
Prevention is simple in theory. It consists in identifying the germ that is causing the mastitis in order to eliminate the source. Although hygiene is usually easy to control during pregnancy, such is not the case with cutaneous staphylococci, which requires lengthy antibiotic treatment.
Observation and thorough palpation of the breasts will sometimes reveal malformations of the teats that contribute to ascending infections. These anatomical predispositions can sometimes warrant removing the mother from the litter, artificial nursing or giving the puppies to a foster mother.
While the ability to lactate is a trait that is largely considered to be predominantly heredity, hypogalactia (lack of milk), agalactia (absence of milk) or delays in the onset of lactation are generally difficult to predict, especially in primpara. Frequently these disorders are accompanied by maternal instinct problems, which are often associated with poor socialization or discomfort.
Since the passive immunization (immunoglobulin-G) of puppies is made possible almost exclusively through early ingestion of the colostrum, some breeders, as a precaution, either keep the colostrum of a donor bitch frozen or the mother's serum that they feed to the puppies to offset the absence of colostrum.
In the following days, the immunoglobulin A in the mother's milk serves to protect the puppy's intestinal epithelium and thereby naturally limits the occurrence of infectious diarrhea.
The onset of lactation can be stimulated through different treatments, including:
- Massaging the breasts or injecting oxytocin, which only stimulates ejection of the milk without producing any real action in terms of secretion (recommended only in cases of "lacteal retention");
- Herbal treatments (galega, malt, fennel, cumin, etc.) are often used in an empirical manner even though they have not yet been shown to produce any specific action!
- Certain anti-vomiting pills are used because they have a stimulating effect on prolactin secretion.
It should also be noted that, conversely, overproduction of milk may lead to excess consumption and saturation of the puppies'ability to digest lactose and consequently, cause osmotic diarrhea. This generally occurs at the onset of lactation, but is rarely a contributing factor to mortality if care is taken to separate the gluttonous puppies from their mother's breast several times a day. This act is preferable to drying up the mother through medical means, unless the health of the mother so requires.
Viral infections Transmitted by the Mother
Canine herpes virus (CHV) is a cause of puppy mortality during the first week of life that is currently becoming an alarming problem among dogs.
In France, in fact, nearly 50% of breeders who are seeing a decline in the fertility rate of bitches and an increase in neonatal mortality are unknowingly harboring breeding bitches infected with canine herpes virus.
A herpes virus infection is often very discrete in adults. The virus grows in mucous membranes that are normally colder than the body temperature (genital, ocular and respiratory mucous membranes) owing to stress, secondary infection, immunodepression or a period of sexual activity.
In both males and females, this virus sometimes causes papules on the genital mucous membrane that are difficult to see without careful examination (total externalization of the bulbus penis in males and vaginal speculum in females) and are sometimes responsible for a refusal to cover.
The virus is essentially venereal. It is spread by infected external studs when they naturally mate while the virus is in an active stage.
The germs involved in most cases of neonatal septicemia or in toxic milk syndrome are generally found in the vaginal flora of all healthy bitches.
Simple, prepartum vaginal antisepsis is advised.
The most frequently observed parasites in puppies are helminths (Ascarids, Trichuris, Ankylostoma, Tenia) and protozoan (Giardia and Coccidia). The period of sexual activity of bitches is a factor that aggravates the risk of helminthic parasitism in puppies because the bitch provides a favorable environment for the breeding and not just the survival of parasites such as Toxocara canis, Uncinaria stenocephala and to a lesser degree, Ankylostoma caninum. Modifications of the bitch's hormone balance (and in particular, changes in progesterone levels) cause the larvae in hypobiosis (type of hibernation) to come out of hibernation and migrate towards the uterus and breasts. During this period, the fetus and then the puppies generally cannot escape infestation no matter what efforts are made to de-worm. The objective therefore is to attempt to reduce the parasitic pressure by working on the mothers, puppies and the environment at the same time.
The mother's incisor teeth are rarely monitored before whelping whereas their importance should not be neglected given the role they play in cutting off the umbilical cord when the puppies are born. The quality of the joining edges of the dental arches is just as important as the presence of tartar or gingivitis. Brachycephalic or prognathic mothers will naturally encounter more problems in accomplishing this task and thereby expose their puppies to hemorrhaging of the cord (internal or external) and to umbilical infections that may be complicated by an umbilical hernia, abscess of the lining, peritonitis, even neonatal septicemia. In order to limit these risks of infection, it is possible to apply bio-adhesive chlorhexidine patches to the mother in the peripartum phase. This procedure seems to be successful in limiting infection.