Veterinarians recommend that all dogs receive preventative health care measures, such as core vaccinations, heartworm and tick-borne disease testing, and deworming for intestinal parasites. There are considerations for these diseases and their prevention strategies that are specific breeding dogs, as we strive to keep them safe through pregnancy and produce healthy puppies.
Core vaccinations
Distemper and parvovirus are serious, potentially fatal, infections that primarily affect puppies. Antibodies from their dam can protect puppies until they are old enough to be vaccinated. Unlike human babies, puppies receive very little antibody transfer across the placenta; the majority is transferred by nursing colostrum in the first 18 hours after birth. The dam must have adequate immunity herself in order to pass it on to her puppies. She gets this immunity from her own vaccinations. Most dogs develop long-lasting immunity from their vaccinations as puppies and young adults, but some dogs do not respond as strongly especially if “minimal” vaccine protocols are used, or their immunity may wane over time, making booster vaccinations necessary.
Breeders are advised to keep their bitches up to date on distemper & parvovirus vaccinations or to check titers for these two diseases prior to breeding. It may be advisable to check titers even in bitches that have current vaccinations to ensure they have developed and maintained appropriate immunity. If monitoring with titers instead of repeating vaccination, the titers should be performed annually, as immunity may decline at any time.
DHPP (distemper-hepatitis-parvovirus-parainfluenza), also known as DAPP (distemper-adenovirus-parvovirus-parainfluenza), is the most common vaccine used to protect dogs from these diseases. A distemper-parvovirus only vaccine is also available and may be applicable in certain situations. These are modified-live vaccines, which means that they contain an attenuated, or weakened, version of the virus. There is some risk that the attenuated virus could actually infect puppies if the dam is vaccinated during pregnancy. For this reason, it is recommended to avoid vaccinating bitches within 30 days prior to breeding or during pregnancy. If a bitch is found to have low distemper or parvovirus titers during breeding or pregnancy, one option for protecting the puppies is to give them an injection shortly after birth of serum from a vaccinated dog. This can provide them with protective immunity until they are old enough for their own vaccinations.
The incidence of rabies in dogs is lower in the United States and Canada than in some parts of the world thanks to widespread vaccination, however it does still occur and is always fatal to dog. Rabies is also generally fatal to humans, though there are rare cases of survival. Depending on the area, wildlife such as raccoons, skunks, foxes, and bats can transmit rabies to dogs and humans. Despite the best precautions and husbandry practices, exposures can occur due to wildlife in the yard or bats gaining access into the house. Bitches can spread rabies to their puppies across the placenta during pregnancy, during whelping, or after whelping through normal licking and mothering care. It is untreatable at this point and both dam and puppies will be lost.
Rabies vaccination is required by most states and regulated by local ordinances in others. A current list of state regulations is available here. In all states, rabies vaccines may only be given by a veterinarian or other authorized professional.
Vector-Borne diseases
Diseases transmitted by mosquitoes and ticks can cause significant complications during pregnancy. Heartworm disease is easily preventable with monthly medications that are FDA approved as safe to use during pregnancy. Untreated heartworm disease can be fatal, especially during pregnancy, which produces extra strain on the cardio-respiratory system, and during anesthesia in cases where cesarean section is needed.
Lyme disease has the potential to cause infertility and pregnancy loss, as well as systemic disease in the bitch. It is spread by ticks, but may also be transmitted through natural breeding or artificial insemination. Doxycycline, the primary antibiotic used to treat Lyme disease, is not recommended for use during pregnancy due to potential harmful effects on the puppies.
It is recommended that all bitches be screened for heartworm and tick-borne diseases prior to breeding and maintained on monthly preventatives through pregnancy. It is also recommended to test stud dogs for Lyme disease at least once a year, and more frequently in areas that are at high risk of exposure. The commonly used “4DX” test screens for heartworm and Lyme, as well as two additional tick-borne diseases, Ehrlichia and Anaplasmosis, which can also cause illness but typically do not have reproductive complications.
There are a wide variety of tick preventative medications currently available. Many of them are not tested or FDA approved for safety during pregnancy, and medication efficacy and risk of tick exposure vary based on geographic location and dog lifestyle. Breeders should consult with their veterinarian to determine the best tick preventative strategy for their situation.
Intestinal Parasites
Roundworms and hookworms are very common intestinal parasites of dogs. Once exposed, a dog will carry the worms, typically dormant, in their body forever. The hormones of pregnancy cause the worms in a bitch to recrudesce and spread across the placenta (roundworms) and through the milk (roundworms and hookworms) to puppies. Transmission across the placenta is responsible for many puppies that are small or weak at birth, and transmission through milk often results in puppies that are unthrifty and have diarrhea or vomiting in the first few months of life. Without proper deworming, puppies can develop heavy worm burdens that affect their development and overall health. Based on the development pattern of the worms, fecal exams on puppies will not show the presence of worms until at least 4-5 weeks of age, even though they are present and can cause illness prior to that time. The current deworming strategy that is most widely recommended by reproductive veterinarians is to treat the bitch with fenbendazole (Brand names: Panacur, Safegard) once daily for three days starting at 42 days post-ovulation, and to treat the dam and puppies with pyrantel pamoate (Brand names: Strongid, Nemex-2) at 2-, 4-, 6-, and 8-weeks post-whelping. Puppies should be checked individually for the continued presence of worms at approximately 12 weeks of age.
Coccidia is a protozoal parasite that can also cause diarrhea, lethargy, and inappetence in puppies, and may lead to dehydration and death if not treated promptly. Many adult dogs shed coccidia asymptomatically, and oocysts shed in feces spread easily through the environment; this is the most common source of infection in puppies. Puppies can show signs of illness due to coccidia as early as 3 weeks of age. Oocysts are shed intermittently so multiple fecal exams may be necessary to identify them. Sulfadimethoxine (Brand name: Albon) is the only drug FDA approved to treat coccidia in dogs, however other off-label treatments may be more effective. Breeders should consult with their veterinarian to determine the best course of treatment for coccidia and develop a preventative strategy in kennels that may be persistently infected.
The first step in planning a successful breeding is to ensure the health of the dam and sire, both for their own sake and for the health of the puppies they will produce. Bitch owners should review their dog’s health records and plan to have any needed tests or vaccinations completed at least 2 months before the bitch is expected to come in heat. If she is going to be due for anything during the expected time of pregnancy, consider updating it early. In consideration of stud dog health that could affect the bitch or puppies, owners should have a heartworm & Lyme disease test performed at least once a year and maintain current rabies vaccination status (most veterinarians will not see a dog for semen collection or artificial insemination without current rabies vaccination).
Timely attention to preventative health care will lessen stress at the time of breeding and allow you to focus on the best part – healthy dogs & puppies!