Troubleshooting Heat Cycles in DogsThere are a lot of factors that can influence heat cycles. Here our Director of Veterinary Services, Dr. Bramlage, answers some common heat cycle questions.
What if Mom is Sick?I often get the hypothetical question of do we breed a sick mom? When sick, rarely will a female cycle successfully if at all. Even if they do come in heat, few will get pregnant. If mom is sick, we don't breed.
What are Split Heats?Split heats happen when a female starts her heat, does not ovulate, and then eventually finishes her heat cycle with another set of follicles. Females do interrupt the cycle after standing, do not ovulate, and bring up another set of follicles standing a second round to be bred. When this happens, her second standing heat is fertile. This is the result of a vitamin B deficiency. Using Doc Roy's® B Strong will correct this issue for next time.
She Bred But It Did Not Take?There can be different factors at play when you have a female that cycled, stood to breed but did not take. Assuming you're Brucellosis negative, there are three main causes:
- Inconsistency of breeding and failing to get ovulated eggs fertilized often results in false pregnancies. The female did ovulate and the ovary functions like they are pregnant. These females usually produce milk at 70 days post breeding.
- Breeding too early. It's important to remember females ovulate at the end of heat. If we need to limit our male use for multiple females in heat, we skip the first breeding when they stand not the most important last breeding.
- Not ovulating. This usually happens when they are three to four years old. They have come out of resting female or the show ring and it is time to breed but they do not get pregnant. We often pick up with progesterone that does not rise to ovulation levels or ultrasound. The follicles are mature then just regress, never ovulating the eggs. The long-term cure is to get the ovary healthier!
She Has a Healthy Heat Cycle But is Still Not Getting Pregnant?If you feel your females are coming into heat regularly and standing for the male but not getting pregnant, it might be time to have your male examined. The male's role is often overlooked until he is infertile and females come up open or with small litters. Males must be in good shape and producing high numbers of sperm for breeding success. For every one million sperm deposited in the female, only 40 make it up the fallopian tube to the egg. Only one sperm cell can make it into the egg for fertilization. There is a lot of attrition along the way so keeping the numbers high is important.
Equally important is keeping males young or some will start producing small litters, even though we have plenty of sperm, as sperm attrition increases in older males. Males reach peak fertility at five years. After five years of age we want to be proactive about managing their fertility with a supplement such as Breeders' Edge® Oxy Stud. After age eight we want to retire males or use them minimally on only our most fertile females if he is an exceptional male.
If you have any other questions about heat cycles, give our Pet Care Pros a call at 800.786.4751.
Don Bramlage, DVM, Former Director of Veterinary Services at Revival Animal Health
The materials, information and answers provided through this website are not intended to replace the medical advice or services of your personal veterinarian or other pet health care professional. Consult your own veterinarian for answers to specific medical questions, including diagnosis, treatment, therapy or medical attention.