Do Male Dogs Have Nipples?
You might be surprised during a tummy rub of your dog, to find nipples there. But male dogs have nipples too, and this is normal. Most male mammals have nipples - except male mice, rats, and platypuses.
Why Do Male Dogs Have Nipples?
It is easy to understand why female dogs have nipples - they are used to feed their young. So why do male dogs have nipples?
While they do not suckle pups, male dogs have nipples due to the way they develop in the womb. Nipples are part of the “rudimentary state” of development. Dogs begin as an embryo, and some body parts are formed first, including nipples. This is when the dog’s sex has not yet been determined. Later on, in the developmental process, hormones determine the sex of the dog. The nipples remain on the male dog even when its sex is established. The process of natural selection has not found it necessary to remove them as they do no harm, and nipple-less male dogs have no natural advantage over dogs with nipples.
A similar example is that whales still have pelvic bones, even though they do not have legs. These bones cause no issue or disadvantage for whales, and so are retained during embryonic development.
What Do Nipples On Male Dogs Look Like?
Nipples look similar on male and female dogs, although if a female dog is feeding her young, her nipples will be more pronounced.
Nipples are usually small round bumps formed in two lines from the groin running up your dog’s stomach. This pattern is the same in both sexes.
If your dog is short-haired, the nipples will be easy to spot. If your dog has long or very thick hair, they may be harder to see - but you can usually feel them if you pat your dog’s stomach.
Nipples usually range in color from pink to black, depending on your dog.
Your pet’s nipples will be approximately the same size. However, if a nipple seems much bigger than others, or seems unusual, or is producing fluid, take your dog to the vet.
How Many Nipples Does A Male Dog Have?
This depends on your dog’s size and does vary. As a rule of thumb, a large male dog can have ten nipples - five rows of two nipples. A smaller dog typically will have eight nipples, arranged in pairs. Average numbers do not tend to vary between male and female dogs.
While most dogs have a symmetrical number of nipples, occasionally, there is an odd number of nipples.
Dog nipples (both male and female) have names, which relate to their position on the dog’s abdomen.
A ten-nippled dog would have nipples named as follows, depending on their location on the dog’s body. From top to bottom:
- Two cranial thoracic nipples (the first set of nipples nearest to the front paws)
- Two caudal thoracic nipples
- Two cranial abdominal nipples
- Two caudal abdominal nipples
- Two pair of inguinal nipples ( the last set of nipples nearest the dog’s groin)
Dogs have a large number of nipples because they tend to produce a large number of puppies. Contrast this with horses and humans, who tend to have only two nipples, because they do not usually produce more than two offspring at a time.
While nipples of male dogs are not required for suckling, they still develop in the same number as for a female.
Could It Be A Tick, Not A Nipple?
Some lumps on your dog’s underside look like nipples but might be ticks. There are various ways to tell the difference but if you still cannot be sure, ask your vet for advice:
- Look where the “nipple” is. Nipples occur more or less straight on your dog’s underside. If the “nipple” is not in line or is too close to an actual nipple, it could be a tick.
- Look for legs. You might initially confuse a large tick with a nipple, but you will never find legs on a nipple. A tick’s legs are usually short and black.
- Look at the bottom of the lump, and if it looks like it is buried or stuck, chances are it is a tick. If the bottom is aligned to the skin, it is likely to be a nipple. It could also be a mole or a scab.
- Compare the lump to the other dog nipples. If it looks the same, it is likely to be a nipple.
It is not a good idea to pull on a lump when you are checking for ticks. This could hurt your pet and might cause bleeding. If it is not a tick or a nipple, it could be a growth. If you are not sure, consult your vet. If you discover a tick, remove it carefully to avoid hurting your dog.
It is wise to treat your dog for fleas and ticks.
When Should I Be Concerned about Nipples On Male Dogs
You should check your dog’s nipples from time to time. There are some signs to look out for which might mean something is not quite right:
- If your dog’s nipples are enlarged, this could be a sign of testicular cancer. This is more common in non-neutered dogs but does still occur in neutered males. Larger than usual, nipples might be accompanied by other symptoms, such as a swollen stomach, stomach pain, anemia, and uneven hair loss. Sometimes other male dogs will be attracted to your dog during this condition. Take your dog to the vet. If the diagnosis is testicular cancer, the process of neutering will remove cancer. If your pet is neutered, chemotherapy may be required. Usually, the prognosis for testicular cancer in dogs is good because it is not aggressive and rarely spreads to other areas.
- Swollen nipples could also be a sign of mastitis. They could also be producing a discharge, and your pet may be lethargic. Mastitis is not common in male dogs, but if it is not treated, it can be fatal. Consult a vet as soon as possible. If caught early and treated, your dog will recover. Antibiotics will usually be prescribed. Occasionally, in serious cases, your dog may need intravenous fluids.
- If there seems to be a lump under your male dog’s nipple, discharge or blood, take your dog to the vet. While rare, occasionally, male dogs get mammary gland or other tumors. Some are benign, but others could be cancerous.
Changes in nipple color over a period of time are not usually a cause for concern. This happens naturally as your dog ages.
Can Nipples Occur In Different Places On Male Dogs?
Usually, male dogs have nipples in lines extending from their paws to their legs, but sometimes dogs might have something looking like a nipple on the inside of their legs. If you see this on your pet, look at the other leg to see if there is a similar feature. If there is, these are likely nipples. If not, consult your vet.