A Dog Breeding Roundtable with Veterinary Theriogenology Residents
Breeding dogs can be complicated. To help increase the number of theriogenologists, veterinary specialists trained to help breeders with the reproductive health of their dogs, provide advice on breeding decisions and care for new litters of puppies, a newly funded Theriogenology Residency Program was introduced last fall.
The program, a collaboration among the Theriogenology Foundation, American Kennel Club and AKC Canine Health Foundation, provides funding of $100,000 for each theriogenology residency. The recipients are: Karen Von Dollen, DVM, of North Carolina State University; Carla Barstow, DVM, of Auburn University; Victor Stora, DVM, of the University of Pennsylvania; and Tessa Fiamengo, DVM, of The Ohio State University.
Today’s Breeder is pleased to share this roundtable Q&A with these promising veterinary theriogenologists who will help shape the future of canine health and reproduction.
Q: How much of your work involves helping breeders understand breeding coefficients and pedigree analysis?
Dr. Barstow: We do a lot of genetic counseling with our clients, which involves the use of breeding coefficients and understanding pedigrees. Breeding coefficients look at the percentage of inbreeding. While linebreeding can be desirable to double up on good traits, it also can double up on bad traits. The higher the inbreeding coefficient, the higher the chance the dam and sire may pass on a genetic defect and the higher the possibility of reduced fertility.
We look at the results of genetic tests and then use those results to choose the best combination of parents to minimize the chances that future offspring will have or carry these diseases. Sometimes we knowingly breed a carrier animal because he or she is a desirable breeding prospect for other reasons, but we analyze the pedigree of potential mates to ensure they are genetically clear to prevent the disease or defect from spreading further in the population. This allows us to use great dogs from a particular breed for future matings and not to limit the available gene pool.
For example, exercise-induced collapse (EIC) that occurs in Labrador Retrievers and some other breeds is a recessive disease, meaning that an affected dog needs two copies of the bad gene in order to display signs of this disease. Because there is a DNA test for EIC, we can test both the sire and dam. If they are both carriers of EIC, then it would be advisable not to breed that pair as 25 percent of the puppies will likely be affected by the disease. However, if the dam is an EIC carrier and the potential sire is EIC clear, then we can safely breed that pair, knowing that 50 percent of the puppies will be carriers for EIC, but none will be affected with the disease. A female puppy that is EIC clear can then be selected from that litter to replace her dam and carry the genetics of her mother without carrying on the disease.
When examining hip dysplasia, there is not a great genetic test available that determines whether dogs will get this disease or pass it on to their future offspring. This is because there are many different genes responsible for hip dysplasia rather than a single gene that can easily be tested. This is where pedigree analysis is very important. It is not just the depth of pedigree with the parents and grandparents that matters, but also the breadth of the pedigree with littermates. It is possible that the male you are wanting to breed is “OFA (Orthopedic Foundation for Animals) Excellent” and his parents are “OFA Good.” What might not be known without pedigree analysis is that this male’s littermate was severely dysplastic by 6 months of age. Although your desired male is OFA Excellent, this sire is not a good choice for breeding if you want to minimize hip dysplasia in your breed.
Dr. Von Dollen: When I am discussing breeding plans and potential genetic pairings, I strive not to interfere with the carefully laid plans of a dedicated breeder. My goal is to balance respect for the considerable effort that goes into generating and developing a breeding kennel for the overall health of a breed. If an animal with an identifiable problem that would compromise the health of the offspring is presented for breeding management, I advocate for the breeder to consider the health, comfort and quality of life for all dogs involved in the breeding.
Q: What are the pros and cons of breeding older bitches and older stud dogs?
Dr. Fiamengo: Many times owners hope to breed older animals. This may be because they were actively campaigning the dog when it was younger, or they want to continue to breed a dog that is producing high-quality offspring. Unfortunately, using older breeding animals of either gender can pose difficulties secondary to a reduction in fertility.
In aging bitches, for example, we see increased interestrous intervals, the length of time between heat cycles, decreased conception rates and decreased litter size. For males, some studies have shown a significant decrease in sperm quality as early as 6 years of age. This reduced fertility does not mean that these animals can no longer be used for breeding, but it often means that it will be more challenging. With males, some of these problems can be alleviated by collecting and freezing semen between the ages of 2 and 5 years old, when semen quality is higher and freezing success rate is greater, for use at a later point.
Dr. Stora: The pros for using older bitches and older stud dogs is that it helps to keep these individuals in the genetic pool and thus helps with genetic diversity. The cons are they are subject to more illnesses, especially infertility, because of their age. The ability to reproduce an older dog is sometimes a luxury. In a world where some dog breeds are essentially endangered species due to their limited genetic diversity, keeping the most genetic diversity is key. Eliminating older reproducing animals eliminates those genetics. Keeping them allows for more genes to flow in an already limited population.
The con to using these older animals is that there is a greater chance of disease. One caveat to consider is that having an otherwise healthy older bitch pregnant is better than allowing her to cycle without an intention to breed her. As the bitch cycles, the effects of a nonpregnant uterus are additive. They form cysts, and this predisposes them to pyometra, a life-threatening uterine infection. The pregnant uterus is much healthier. Lastly, spaying a bitch after her breeding career is a healthy solution to this problem.
Q: What are some examples of puppy emergencies, and how do you advise breeders to handle them?
Dr. Von Dollen: When puppies are born not breathing or otherwise compromised, I advise breeders to keep them calm, keep rubbing them and keep them warm. The neonate is astoundingly resilient to the insults of oxygen deprivation. It is remarkable to see what warmth and tactile stimulation from vigorous rubbing can achieve.
Early identification of a jeopardized puppy is crucial for minimizing emergency and life-threatening situations. Breeders should use all their senses — except taste — in monitoring a litter. They should listen for distressed whimpers or suspicious quiet, smell for the products of gastrointestinal upset or unsanitary housing, feel for appropriate temperatures of puppies and environment, and observe interactions among littermates and the dam. Breeders should weigh puppies at least once daily to provide an objective result to alert whether a puppy may need intervention.
Dr. Barstow: If a puppy is not breathing after being born, it is no longer recommended to “swing” puppies to help clear fluid from the airway as that could lead to possible brain damage or the puppy being dropped, which could cause further injury. Instead, a puppy should be held with its head down at a 45-degree angle while rubbing along its back. The puppy should be rubbed very vigorously, starting from the tail and working toward the head. This helps the fluid drain without having to swing the puppy. A bulb syringe can be used to gently suck fluid from the mouth and nose. You also can gently blow a couple of breaths into a puppy’s nose and mouth to help expand the lungs.
If a puppy is not gaining weight, it could be due to some puppies being weaker than their littermates and needing supplementation for the first couple of days. This puppy will need to be either tube- or bottle-fed every couple of hours around the clock. Eye droppers and sponges have been used but are not recommended as they have a higher risk of causing pneumonia from the milk being accidentally inhaled.
Puppies do not have the extra fat stores that adults have so it is very important that puppies eat often and that they are gaining weight. Weight gain during the first few days is the single most important factor of puppy well-being. If they are not gaining weight, then they should be supplemented with a high-quality puppy milk replacer. Many people prefer to use goat or cow milk; however, cow milk doesn’t have enough fat or protein, and goat milk doesn’t have enough carbohydrates or milk solids, which contain lactose and minerals.
If a puppy is cold and not gaining weight or thriving, breeders should check the temperature of the whelping box. Cold puppies don’t nurse and then they lose weight, and it becomes a vicious cycle. It is important to ensure that a puppy is warm before it is fed. Otherwise, the milk will curdle in the stomach, as puppies’ digestive systems do not work appropriately when they are cold. The temperature of the room should be about 75 degrees Fahrenheit. A warming lamp or heating pad set on low can be placed in one corner of the box. Puppies need to be able to crawl away from it in case they get too warm. Determine how puppies are gathered when resting to gauge how they are doing. Puppies piled on top of one another are likely cold, and those spread all over the box are probably comfortable.
Q: What are the most common problems dog breeders face and for which they seek specialists?
Dr. Stora: I would have to say ovulation timing. There are a lot of myths about when the most fertile period is in the female. Commonly, female dogs are labeled infertile when, in fact, they are not. They are just improperly timed. Female dogs can have cycles that differ from one another, with some being longer than others. Going by the old paradigm of “breeding after 13 days of spotting or vaginal bleeding” will commonly get it right if the female is average, but this will always miss the outliers that have a different cycle.
For example, suppose a dog is in proestrus, the period of time before ovulation or the first nine days of bleeding. Estrus is the period of ovulation and the fertile period, with the middle being the most fertile. Estrus is nine days on average, therefore 13 days after bleeding would be excellent timing to breed the average female. If a female is slightly different and in proestrus for a longer period, the fertile period would not be just 13 days after bleeding. Ovulation timing and the ability to time the female’s heat cycle more accurately in order to catch female dogs that are different than the norm are the most common problems breeders face.
Dr. Fiamengo: One of the most common concerns we address outside of routine breeding management or semen collection appointments is breeding soundness on animals that are experiencing subfertility issues. Breeders also often call us for consults on concerns about a pregnancy, whelping and the weaning process and options for mismatings, or accidental breedings, which may include allowing the bitch to carry the litter to term or terminating the pregnancy.
This article was originally published in Purina's Today's Breeder and is reprinted with permission.
- Understanding the Role of E. coli Biofilm in Canine Pyometra (09/19/2018)
- New Research in Canine Semen Evaluation and Fertility Outcomes (11/30/2017)
- Canine Brucellosis Update (06/21/2017)
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