I started breeding dogs in the late 1980’s and I have shown dogs in AKC conformation and performance since 1974. I did not get real interested in breeding dogs until I had learned a lot more about my breed at the time, which was Rottweilers. At that time, I was feeding a basic commercial kibble diet and added a few supplements such as vitamin C, B complex and vitamin E.
My girls didn’t seem to have trouble conceiving, but I had experienced some infant mortality, hypoglycemia in young puppies, and some reabsorption of neonates. Furthermore, I had seen some heat cycles that were generally around every 6 months, but in some bitches, as frequent at 4 to 5 months between cycles. It was obvious that those bitches with the more frequent cycles were more likely to produce fewer puppies, or come up empty. At that time, in the 80’s and 90s, there was some anecdotal remedies to try, but none of them included tips on diet other than hearing about a breeder’s particular fondness of one brand of food or another.
As with most things, favorite brands of dog foods waxed and waned over those years, with people being drawn to ‘natural’ brands, large or small dog formulas, adult, or puppy foods, or even more recently, ‘grain free’ or ‘organic’. During the time I was feeding a dry commercial food, I also experienced cancer in my dogs, most commonly lymphosarcoma and osteosarcoma. It was because of the cancer incidences in my dogs that I began to research nutrition and canines and made the decision to begin feeding my dogs a natural raw diet.
Studies had shown that high sugar diets (carbohydrates, which are sugars) were the fuel to feed cancer cells, and high quality protein (not processed as in dog food, but raw or lightly cooked) helped with the dog’s immune system and were the building blocks of the organs, skin, coat and overall good health.
Dogs must get iron, vitamin D, vitamin A, and the amino acids l-carnitine and l-taurine from animal based sources. The high heat used during the heavy processing of commercial kibbles can destroy these amino acids. While most of these nutrients come from red meat and organ meat, I do use raw chicken for the bones (soft, easy to consume and digest) for the needed calcium and minerals they contain.

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Besides seeing a reduced incidence of cancer in my dogs, I began to see some other positive benefits from feeding a raw, natural diet. Some of these included not smelling ‘doggy odor’ anymore, seeing my dog’s teeth remain clean and their stools turn white and blow away. I also realized that my older dogs who were dealing with joint pain and arthritis issues were more mobile as they experienced far less inflammation in their joints. An additional and unexpected benefit that I saw, was the change in fertility in my girls!
Because I had not changed my dog’s diet to a raw diet for breeding reasons, I was not quick to see the changes, nor did I immediately attribute the diet change to the breeding benefits. After just a few years on a raw diet, my girls went from cycling every 5 to 7 months to every 7 to 9 months and their heat cycles were less ‘dramatic’ in discharge and mood swings.
Another true benefit was that my girls were no longer having false pregnancies! Additionally, my girls seemed to never miss ‘catching’ (getting pregnant) whether from a natural breeding or a surgical artificial insemination using fresh chilled or frozen semen.
While litters weren’t ‘enormous’, they generally had at least 8 puppies. Last fall, I bred my toy dog, a Brussels Griffon, using fresh chilled semen and she had 6 puppies – all naturally born – in two hours. They were all healthy and they are all doing well today.
As a result, my curiosity increased, which is why I decided to do some additional research on diet and fertility. I wanted to know how feeding a raw diet could make such positive fertility changes in the bitches. So below is some of the information I found. While most of the information is based on human studies, I believe the information on the adrenals and hormones also applies to canines.
Sugar and Insulin
When a diet is high in carbohydrates, which convert to sugar (grains, starches such as potatoes, peas, carrots, and sweet potatoes, and simple sugars like honey, fruit, and fructose), the food causes the sugar levels in the body to increase. This, in turn, causes insulin to be released to lower the sugar levels.
Then, when the sugar level drops, cortisol is released to help raise the sugar level. This reaction boomerangs back and forth which can cause insulin exhaustion. This cycle affects estrogen, progesterone and testosterone levels.
Additionally, when cortisol is repeatedly released in response to a high sugar diet, it competes with progesterone for the same receptors and cortisol wins this race every time. And progesterone is essential for fertility.
Commercial kibble diets typically contain 40% or more carbohydrates. Dogs that eat this type of diet have sugar spikes and drops daily. As a result, the body can become confused. The girls may start to ovulate and then stop (as with bitches whose cycles are too close together). Or, they may get pregnant, but due to the hormone fluctuations, reabsorb the litter.
The sugar causes insulin and cortisol spikes to try and balance the rise and fall of sugar levels and affects ovulation, maturing of the egg, and proper implanting. Additionally, dogs that eat diets high in carbohydrates will produce more testosterone because of the continued amount of insulin released to lower the sugar levels from the spikes caused by the carbohydrates. This can prevent good heat cycles and pregnancy.
Sugar causes inflammation and as a result can affect the uterine lining. The eggs may get fertilized, however, if the bitch’s uterus does not have a healthy lining, the eggs will not properly implant. Constant inflammation of the uterine lining will eventually cause scarring, which is not only another obstacle for egg implanting, but it can cause permanent infertility. Less inflammation means less chance of a uterine infection and a better immune system during pregnancy.
Recent studies by Dr. Jeffrey Russell have proved some interesting outcomes for human fertility. 120 women who were undergoing fertility treatments were studied. They kept a log of the food they consumed daily. The women who ate the highest amount of protein and lowest amount of carbohydrates were the most successful in producing healthy, well-developed eggs and having a healthy uterine environment for conception. Dr. Russell thinks protein is essential for good quality embryos and better egg quality.
Another study that was done at Harvard University on 18,000 women over 8 years of age, showed that diets high in potatoes, grains, white bread and sugar resulted in poor fertility.
http://www.newsweek.com/how-diet-affects-fertility-94591
While these are human studies, the effects of insulin, cortisol, and hormones would be the same for canines. Dogs are carnivores and have no nutritional need for carbohydrates. Therefore, one might infer that carbohydrates in the diet for dogs would affect their fertility even more than humans.
Fats
While healthy fats such as omega-3 fatty acids and fats from quality proteins (beef, chicken and lamb) are essential for canine health and a dog’s fertility, you want to avoid trans fats as they have been proven to cause infertility in people. Trans fats are fats ‘hardened’ to use be used in cooking, such as Crisco and margarine. It is likely trans fats are used in commercial dog foods. It is also important to remember that fats in commercial dog food can be rancid. Manufacturers can use the term ‘animal fat’ on dog food labels which does not tell you anything about the quality of the fat used. ‘Animal fat’ can include any fat – even generic by-products, diseased farm animals and road kill.
http://www.dogfoodadvisor.com/choosing-dog-food/dog-food-fats/
Further, it is important to avoid flax seed oil, soybean oil or soybean meal, and lentils and beans, as these all contain phytoestrogens, which can block estrogen and cause infertility.
Male Fertility
Studies have shown giving Vitamin E to male dogs, also with a small amount of selenium helps with sperm production.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6598180/
This article also concludes vitamin E is helpful for sperm production and also their studies have shown omega 3 fatty acids and vitamin C can help as well.
http://www.cbra.org.br/pages/publicacoes/rbra/v39n1/pag141-145%20(RB538).pdf
Avoid using ketoconazole (a medication giving orally to kill yeast) as it can cause infertility in males.
https://actavetscand.biomedcentral.com/articles/10.1186/s13028-021-00616-9
This article suggest glycosaminoglycans. These can be found in many arthritis supplements. My own repro vet recommended Bayers Synovi 4. The main ingredient is green lipped mussels.
“Glycosaminoglycans. This is the most common nutraceutical category used for improving sperm quantity and quality. It is found in many formulations by many manufacturers. Many, like International Canine Semen Bank’s CF- PlusR, contain perna (green-lipped) mussels as the primary active ingredient. Anecdotal reports suggest improve semen quality in bulls, horses, and dogs. The theory of the mechanism, according to Dr. Roger Kendall is enhanced cellular reactions and amino acid uptake. There is no documentation to support the use of this product in the dog. The dosage for this application has not been determined; there are dosage regimens for the use of these products for other purposes such as improving joint mobility. Unless there is an allergic response, it is unlikely this product would cause any harmful side effects.”
Conclusion
My conclusion is if you remove most, or all, carbohydrates from your bitch’s diet, her fertility will vastly improve as long as uterine scaring hasn’t become too advanced or other physical problems are not present. Giving her animal proteins in her diet, which have high bioavailability (raw or lightly cooked meats) may well result in healthier eggs, embryos and more viable puppies at birth. The diet would include a good amount of red meat (beef, pork, lamb, wild game) and about 10% organ meat (kidney, liver).
It would seem logical to assume litters would be of good size and that the mother would have good milk production with these changes. In the case of my own dogs, it certainly was true. I am talking about at least 8 bitches, not one or two. The results don’t happen overnight as it takes a few months for hormones to; however, I think that breeders who make this change will be delighted with the results. I have helped numerous people in the past with this issue with almost all of them having positive results!
Male dogs benefit from supplements as well, to help with sperm motility and amounts. I recommend a raw diet for both females and males and the supplements recommended in this article, and below.
Supplements
Supplements that are helpful with regulating hormones include vitamin E and EPA Fish oil capsules. Vitamin E and omega 3 fish oil work together to help achieve better fertility. I also recommend the Berte’s Immune Blend which contains the needed vitamin E, B vitamins including folic acid (helpful for preventing birth defects), vitamin D3 (for uptake of calcium), and digestive enzymes and probiotics which help with the uptake of nutrients and provide the good flora and fauna bacteria needed before and during pregnancy. Omega-3 fish should be added at one fish oil capsule daily for 10 to 20 pounds of body weight.
While this article is written primarily with the female in mind, feeding a quality diet and adding the recommended supplements are also suggested to help fertility in males. It is just as important to provide quality bioavailable animal proteins and proper supplementation to stud dogs. The Bertes Immune Blend, alongwith fish oil capsules, is also important for males. Add a green lipped mussel supplement for males as well.