While female dogs naturally produce milk after giving birth to nourish their puppies, male dogs generally do not lactate. However, in some rare cases, male dogs can produce milk. This seemingly unusual occurrence raises questions around how it happens, what the milk contains, and whether it requires medical intervention.
In this article, we will explore the key questions around male dog lactation:
- Do male dogs have mammary glands that can produce milk?
- What causes male dogs to start lactating?
- What hormones influence milk production in males?
- Can medical conditions lead to lactation in males?
- What is the composition of male dog milk?
- Is it possible for a male to display maternal nursing behaviors?
- When is veterinary care needed for lactating male dogs?
- How can lactation in males be managed?
By examining these key questions, we will gain a fuller understanding of this rare but noteworthy phenomenon.
Mammary Glands in Male Dogs
Although less developed than in female dogs, male dogs do have mammary glands. As explained on PetCarrierVerdict, both male and female dogs have mammary glands located along two parallel rows on the underside of their belly. The mammary glands in male dogs are normally small and undeveloped since they lack the hormones that promote mammary development.
According to Paws Up, the mammary glands in male dogs serve no functional purpose. They do not produce milk and are simply vestigial remnants from embryonic development. Even though the mammary glands are present, they remain dormant in male dogs under normal circumstances.
Hormonal Changes Can Induce Lactation
Although uncommon, male dogs can sometimes produce milk. This occurs when there is an imbalance of hormones, especially progesterone and prolactin. Progesterone is responsible for stimulating mammary gland growth and development, while prolactin controls the actual milk production.
When a male dog is neutered, the testosterone levels drastically decrease while progesterone levels remain constant or even rise. This hormonal imbalance can cause enlargement of mammary glands and milk secretion. According to veterinarians, anywhere from 2 to 10% of neutered male dogs experience lactation at some point in their lives (Source).
The rise in progesterone coupled with the loss of testosterone feedback often triggers a condition called benign prostatic hyperplasia (BPH). This causes enlargement of mammary glands, making them capable of producing milk. Prolactin levels may also increase after neutering, further contributing to lactation.
Lactation usually occurs within 2-3 months after neutering. However, some male dogs may not show signs until years later. The hormonal changes related to neutering can make male lactation possible in both young pups and senior dogs alike (Source).
Medical Conditions Causing Lactation
There are certain medical conditions that may cause lactation in male dogs. These conditions lead to hormonal imbalances that can stimulate milk production in mammary glands.
One potential cause is the growth of a tumor on the testicles. Testicular tumors may produce hormones like progesterone and prolactin that induce lactation. According to veterinarians, “Testicular tumors are the most common tumor type in intact male dogs” (source). Therefore, any abnormal milk production in an intact male dog warrants an examination for testicular cancer.
Another condition is hyperadrenocorticism, in which the adrenal glands overproduce cortisol. High cortisol levels can mimic the hormonal changes of pregnancy and lead to lactation. Hyperadrenocorticism tends to affect older dogs and causes increased thirst, urination, and appetite (source).
Hypothyroidism is also associated with hormonal changes that may stimulate lactation in male dogs. The thyroid gland produces too little of the hormone thyroxine, which disrupts the hormonal balance. Symptoms include lethargy, obesity, and hair loss (source).
Any male dog experiencing abnormal lactation should be evaluated by a veterinarian to diagnose and treat potential underlying conditions.
The Composition of Male Dog Milk
Studies that have analyzed the composition of male dog milk find that it can have a similar nutritional profile to milk produced by female dogs.
According to research, male dog milk contains high levels of protein, fat, and minerals like calcium. One study found male dog milk to have a protein content ranging from 6.62-17.34%, a fat content ranging from 8.92-14.31%, and an ash (mineral) content ranging from 1.11-1.81%. The lactose content was lower, ranging from 1.56-3.80%.
The nutrient composition appears comparable to female dog milk, which contains around 8.1% protein, 10.0% fat, and 1.1% ash. However, levels can vary depending on factors like the dog’s diet and genetics.
Compared to commercial puppy milk replacers, studies indicate that male dog milk contains higher protein and fat levels as well as beneficial fatty acids like DHA that are absent from artificial formulas.
Pseudopregnancy
Pseudopregnancy, also known as a phantom pregnancy, is a condition that can occur in intact female dogs after an estrus or heat cycle. During this time, the female dog shows signs of pregnancy, including enlarged mammary glands and milk production, but she is not actually pregnant.
According to VCA Hospitals, the exact cause of pseudopregnancy is unknown, but it is likely related to hormonal fluctuations after estrus [1]. The increased levels of progesterone can cause physical and behavioral changes similar to those seen in pregnant dogs.
Interestingly, the hormonal changes of pseudopregnancy can also induce lactation in male dogs. The abnormally high progesterone levels can stimulate the development of the mammary glands and milk production in males [2]. So even though the male dog did not actually mate or sire a litter of puppies, the hormonal environment mimics pregnancy and facilitates lactation.
Therefore, unusual enlargement of the nipples and secretion of milk in male dogs should not automatically be assumed as a sign of disease. If the male lives with an intact female that recently underwent an estrus cycle, pseudopregnancy is a likely explanation for the lactation.
Nursing Behavior
Some male dogs may exhibit maternal nursing behaviors towards puppies. Male dogs have mammary glands just like female dogs, and their mammary glands are capable of producing milk under certain circumstances (source). While female dogs have high levels of the hormone prolactin during pregnancy and after giving birth, which enables them to produce milk, male dogs generally do not have high prolactin levels. However, in rare cases hormonal changes or medical conditions can cause prolactin levels to rise in males and induce lactation.
If a male dog’s mammary glands become enlarged and start producing milk, the dog may display maternal behaviors like allowing puppies to nurse. Some male dogs have even been known to demonstrate nesting behaviors before their mammary glands begin secreting milk. The underlying cause of these maternal behaviors in male dogs is likely hormonal changes, combined with potential parental instincts.
When to See a Vet
Most cases of lactation in male dogs are harmless and will resolve on their own. However, there are some instances where veterinary examination is recommended:
If the mammary glands become hot, swollen, or painful, this could indicate an infection called mastitis. Mastitis requires prompt veterinary treatment with antibiotics and anti-inflammatories (https://wagwalking.com/condition/mastitis).
If milk production lasts longer than 3-4 days or the mammary glands become excessively engorged, this is abnormal and warrants a veterinary visit. It could signal an underlying condition causing persistent lactation (https://www.petmd.com/dog/conditions/reproductive/dog-pregnancy-birth-and-puppy-care-complete-guide).
If there are any lumps, lesions, or abnormalities of the mammary tissue, this requires investigation to check for potential mammary tumors. Male dogs can develop mammary tumors even without mammary gland development.
If your male dog starts spontaneously producing milk, it’s a good idea to call your veterinarian, even if there are no other symptoms. They can help determine the underlying cause and rule out any medical conditions.
Managing Lactation
If your male dog begins lactating, there are some steps you can take to manage it:
- Gently wrap the nipples with self-adherent bandage to discourage nursing and protect the skin. Change the bandages frequently to keep the area clean and dry. Be careful not to wrap the bandages too tightly. [1]
- Wash the nipple area with warm water after each bandage change to remove any dried secretions. Apply an antibacterial ointment if needed to prevent skin infections.
- Limit access to objects or spaces your dog may try to “nest” in. Provide safe chew toys to discourage sucking behaviors.
- Make sure your dog gets plenty of exercise and playtime for stress relief. Extra walks and play sessions can help distract from the urge to nurse.
- Consider supplements like rutin or sage tablets, which may help naturally decrease milk production.[2]
- Consult your vet about medication options if the lactation persists more than a week or causes significant discomfort.
With some simple management techniques, male dog lactation is usually temporary. But if it becomes problematic for your pet’s health or behavior, be sure to consult your veterinarian.
[1] https://www.marvistavet.com/false-pregnancy-canine.pml
[2] https://pawsclawstails.com.au/how-to-keep-your-male-dog-calm-when-a-nearby-female-dog-is-in-heat/
Conclusion
In summary, male dogs can sometimes produce milk, but it is relatively rare. This can occur due to hormonal changes from medical conditions like testicular cancer or hormone therapy. Pseudopregnancy, where male dogs exhibit maternal behaviors like lactation, can also cause male lactation. While male dog milk contains nutrients, it hasn’t been studied extensively, so the composition is not fully known. If a male dog starts spontaneous lactation, it’s a good idea to have them checked by a vet to rule out any underlying medical causes. Usually lactation goes away on its own, but steps can be taken to manage it if needed. So while uncommon, some male dogs are capable of lactation in certain circumstances.
