By Carol Beuchat PhD
Breeders with lots of experience in the whelping know how to prepare for whelping and manage the newborn puppies.
But there are things you should know about whelping that you can't learn in the whelping box because they have to do with physiology and developmental biology - things that are happening in the puppies while they transition from one environment in the uterus to one in the real world where the conditions could not be more different.
Newborn puppies are like premature infants. Not only are they helpless, but many of their organs are not fully developed. The kidney, brain, lungs, GI tract, and nervous system all undergo significant development in the weeks after birth, and during this time it is critical that there are no events that will affect development because any damage done to developing organs or DNA will affect the puppy for life.
Uterine inertia (dystocia) is very common during whelping in dogs. This increases the time it takes a puppy to be born, during which it can become hypoxic because of inadequate oxygen. We know a lot about the serious consequences of perinatal hypoxia in animals and humans, and we can map the list of health disorders in adult dogs to many of the same conditions found in animals or humans that experienced a period of hypoxia during birth. Because many of these problems don't appear until later in life, we don't make the connection with oxygen deprivation during birth.
| Kidney Renal dysplasia occurs when development of the kidney is disrupted at birth, causing the cortical glomeruli to fail to develop. This leaves the animal with kidneys that are inadequate to support an older, larger animal, and the ultimate result is kidney failure (Hemker et al. 2016). Gastrointestinal Tract Necrotizing enterocolitis (NEC) is a very serious gastrointestinal disorder that occurs in premature infants, in which intestinal tissue becomes inflamed and dies. It is linked to hypoxic-ischemic injury (inadequate oxygen and blood flow) in both humans and animals (Sha et al 2025). In newborn puppies (3 days old), exposure to hypoxia (PaO2 = 15-25 torr) resulted in significant intestinal pathology in 10/12 puppies fed formula since birth, but in none of the colostrum-fed puppies (Hansbrough et al. 1985). The damage to the intestinal tract during infancy affects GI function for life. Cancer Rates of cancer in dogs are much higher than expected when compared to other mammals. Scientists have been trying for years to figure out why this is with no success, and much time and money have been invested in research looking for causal genes. But a critical thing to know about canine cancer is that the mutations found in tumor tissues are somatic, not germ line. That is, they are not inherited, but created after sperm and egg join. To address the issue of cancer in dogs, we need to be looking for what causes these spontaneous mutations. Many of the canine cancers can afflict young animals, so the mutations must have occurred earlier in life instead of as a consequene of old age. If we acknolwdge that cancer is widespread across many breeds, then we should probably look for a mutation-causing event that is likely to be common to dogs of many breeds, instead of pointing to a long list of "potential" factors that are unlikely to be common across dog breeds (e.g., flea and tick treatments, yard pesticides, environmental toxins, kibble, etc.). Perinatal hypoxia is common in purebred litters whelped by breeders (Gill 2001; Tonnessen et al. 2011) and can result in the formation of "reactive oxygen species" like free radicals. These can damage tissue as well as cause mutations in DNA. Damage to DNA is perpetuated at every cell division, resulting in a clone of cells in an organ or tissue that all carry the same genetic defect. This can happen in different tissues in different animals and breeds, and it is likely that there are regions of DNA that are predisposed to mutations. This could explain why we don't find causal mutations for most cancers, and why high rates of cancer afflict many breeds. The "cure" for these cancers is not in finding an inherited mutation; it's to prevent the mutation from occurring. If the somatic mutations that cause cancer in dogs are a product of oxidative stress at the time of birth, then to prevent these cancers, we must prevent the uterine inertia that results in perinatal hypoxia. The key to this will be to prevent the exposure to light that blocks secretion of melatonin that results in uterine contractions that are inadequate to expel the puppy. I have been calling the conditions necessary to avoid uterine inertia "dark whelping". Other Disorders There are more health problems in dogs that could be a consequence of hypoxia during whelping such as cardiovascular and lung disease, epilepsy, neurologial deficits, immune system disorders, and behavioral issues. |
It should not come as a surprise that there should be serious health consequences to the hypoxia experienced by many puppies during birth The problems are familar and well-documented in humans and other animals, and dogs were even used as the experimental animal for some of these studies.
Likewise, breeders are very familiar with the rigors of whelping a litter of puppies, and many are experienced with reviving distressed puppies and, unfortunately, with the disappointment of stillborn pups.
What is astonishing is that this seems to be accepted as a matter of course, with nobody worrying about negative consequences. While breeders work diligently to reduce the risk of genetic disorders in their puppies, the potential damage caused to tissue and DNA by exposure to hypoxia during whelping is both greater and preventable.
It is understandable that lay breeders might not generally be aware of these problems. But studies of long-term effects on health of dogs exposed to hypoxia at birth are essentially non-existant, yet the health problems of dogs are a serious issue not just in the dog community but in the general public as well. Costs for care, shorter lifespans, and the need for long-time, chronic care for the dogs in our lives are unnecessary and preventable burdens. We need both education of breeders, activation of the veterinary and reserach community, and more acute attention paid to things that have long been accepted as either routine or of no consequence.
By doing some simple, basic things, we can have healthier, longer-lived dogs. We can start collecting data on health consequences of dystocia in dogs. We need to record the timing of whelping for each puppy. We need to starting whelping in darkness (not dim light but very, very dark). We need to become more attuned to things that would matter for a human infant but are normalized for puppies.
Check out the blog posts below that I have written as my thoughts about whelping in dogs have developed. There will be more coming, as there is much more we need to learn about. Stay tuned.
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To learn more about uterine inertia in dogs, visit our Facebook group - https://www.facebook.com/groups/uterineinertiaindogs |
Can we prevent fading puppies?
Check out our new course about dark whelping!
From Breeding to Weaning: The Critical Role of Light
Starts 29 April 2026
Check out our new course about dark whelping!
From Breeding to Weaning: The Critical Role of Light
Starts 29 April 2026
REFERENCES
Gill M.A. 2001. Perinatal and late neonatal mortality in the dog. (PhD Thesis) University of Sydney.
Hansbrough, F. et al. 1983. Pathogenesis of early necrotizing engerocolitis in the hypoxic neonatal dog. American Journal of Surgery 145: 169-175.
Hemker, S.L., 2016. The role of hypoxia during nephrogenesis. Pediatric Nephrology 31: 1571-1577.
Sha, W.R., et al. 2025. Necrotizing enterocolitis: what's new and what's next? International Journal of Molecular Sciences 2025, 26, 9660.
Cornelius, A.J., R. Moxon, J. Russenberger, B. Havlena, & S.H. Cheong. 2019. Identifying risk factors for canine dystocia and stillbirths. Theriogenology 128: 201-206.
Tonnessen, R., K. Sverdrup Borge, A. Nodtvedt, & A. Indrebo. Canine perinatal mortality: A cohort study of 224 breeds. Theriogenology 77" 1788-1801.
Gill M.A. 2001. Perinatal and late neonatal mortality in the dog. (PhD Thesis) University of Sydney.
Hansbrough, F. et al. 1983. Pathogenesis of early necrotizing engerocolitis in the hypoxic neonatal dog. American Journal of Surgery 145: 169-175.
Hemker, S.L., 2016. The role of hypoxia during nephrogenesis. Pediatric Nephrology 31: 1571-1577.
Sha, W.R., et al. 2025. Necrotizing enterocolitis: what's new and what's next? International Journal of Molecular Sciences 2025, 26, 9660.
Cornelius, A.J., R. Moxon, J. Russenberger, B. Havlena, & S.H. Cheong. 2019. Identifying risk factors for canine dystocia and stillbirths. Theriogenology 128: 201-206.
Tonnessen, R., K. Sverdrup Borge, A. Nodtvedt, & A. Indrebo. Canine perinatal mortality: A cohort study of 224 breeds. Theriogenology 77" 1788-1801.
