Breasts and Nipples on a Dog: What Do They Do, and What Could Go Wrong? - Simply For Dogs
Breasts Nipples Dog

Breasts and Nipples on a Dog: What Do They Do, and What Could Go Wrong?


With Janice being at the mid-point in her pregnancy, my thoughts have been turning, as they invariably do at this time, to breasts and nipples.

Now, let me get something out of the way before I go any further. I love getting comments on my posts. I know that I’ve probably just set myself up for comments like “I’m a red-blooded American male, and my thoughts are always on breasts and nipples, LOL!” Please, restrain yourselves! We’re talking about breasts and nipples on a dog, okay?

Moving right along, this is the point in the pregnancy where the breasts on a dog become fuller, and the nipples on a dog start to appear more distended. Right now, Janice’s body is beginning to prepare for the arrival of the puppies, which she’ll begin to nurse very soon after the delivery so that they can benefit from the colostrum, or “first milk.”

Colostrum is thicker than the milk that will come later, and yellowish. It contains valuable antibodies that ensure good health and resistance to disease. Puppies that don’t get the colostrum often fail to thrive, and could even die. I’ve never had a problem with any of my litters in this regard, but if I did, I’d make a speedy trip to the animal hospital to get colostrum replacer. It’s not as good as the genuine article produced by the mother, but it can be a lifesaver.

What’s the Big Deal Here?

So, you’re wondering, “Why is Ash, dog blogger extraordinaire, so focused on breasts and nipples now, having been down this road before?”

It’s something I always focus on, starting right around this time, and continuing until the puppies are weaned. It’s because I’m a compulsive worrier when it comes to my dogs, and even though I’ve never had any problems with the breasts or nipples on a dog I’ve had bred, I know that they can occur. For that matter, some disorders can occur even in the absence of pregnancy, and some can even occur in male dogs.

I’m not trying to alarm you; most dogs make it through life without problems in the breasts or nipples. My goal with my posts is simply to offer you as much information as I can about a variety of topics. You might never have a use for the information I’m providing here, but I want you to have it just in case you do need it. So, let’s talk about some of the more common mammary problems.

Breasts Nipples Dog


Mastitis is an inflammation that results from an infection. It can happen at any time that the bitch is producing milk, and is usually caused by streptococcus, staphylococcus or coliform bacteria. Normally, these bacteria are found on your dog’s skin, or in the intestines. So, as you might expect, mastitis is most commonly found in bitches that are housed in dirty kennels, or whose skin is in poor condition. Sometimes, too, puppies can transfer bacteria from their nails to the breasts and nipples on a dog that is nursing.

With mastitis, the dog’s mammary glands will appear reddened and will feel unusually firm. The milk may have a yellowish or greenish tinge, and if the condition is more severe it could appear brownish, reddish, or even contain blood clots.

In very severe cases, gangrene can occur, and abscesses could also develop. At this stage, the mammary glands may appear dark, or even black. This is an emergency, and you must get your dog to the vet immediately. If you wait, she could develop sepsis, go into shock, and die.

To treat mastitis, your vet will prescribe broad-spectrum antibiotics. If the puppies are not nursing, you will need to express the milk from the mammary glands twice a day (and, of course, provide milk replacer to the puppies). You can also make your dog more comfortable by packing the mammary glands in warm, wet towels.

If the condition has progressed to the point of abscessation or gangrene, the vet will surgically remove the dead tissue. If the condition has progressed rapidly, it may be necessary to remove the entire mammary gland.

I know that this all sounds pretty scary, and it is, but the good news is that mastitis is very preventable. Make sure to keep the whelping area clean. Replace the bedding a couple of times daily, and disinfect the crate or whelping box once a day. Keeping the puppies’ toenails trimmed will go a long way toward preventing bacteria from getting under the skin of the breasts and nipples on a dog that’s nursing. Make sure, too, to check the breasts daily; it’s a lot easier to treat mastitis in the early stages than it is once it’s taken hold.

False Pregnancy

This condition is also called pseudocyesis or false lactation. You’ve probably heard of it occurring, rarely, in humans. It can actually be a fairly common condition in bitches. It happens when the progesterone levels fall following a heat (usually about two months after the heat ends), and it can also occur if the bitch is spayed during this time. If she is taking progesterone drugs, and they’re withdrawn, this can be another cause.

Signs of the disorder can include “nesting” behavior (gathering up stuffed animals and taking them to a specific location, for instance), and milk production. The disorder can also develop in the absence of any noticeable signs.

False pregnancy often resolves on its own within a couple of weeks. During that time, you might need to fit your dog with a cone or an inflatable collar around her neck to keep her from licking; if the mammary glands continue to be stimulated, it will take longer for the condition to resolve.

If the bitch is still lactating within two or three weeks, medical treatment may be needed. Your vet may provide medication to adjust her hormone levels, and might also recommend that you cut her water intake by about half for 24 hours in order to help reduce the milk production. If she is uncomfortable, pain medication may also be provided.

Keep in mind that this is a condition that is likely to recur. Once it’s resolved, though, you can prevent future occurrences by having your dog spayed.

Agalactia and Hypogalactia

Agalactia is a condition in which the bitch is unable to produce milk. It sometimes occurs in bitches who are taking progesterone supplements. It’s actually a rare condition, and I’m only mentioning it here because it’s a sort of “weak cousin” to the more common hypogalactia.

Hypogalactia is inadequate milk production. It can occur in bitches that have just had their first litter, bitches that are nervous, or that have delivered their litter prematurely. Other causes can be inadequate stimulation of the breasts and nipples on a dog that has had a small litter. Parasitic infections and/or inadequate food and water can also be a factor, so as you might expect, this disorder is frequently found in puppy mill bitches.

If the cause is nervousness, the veterinarian may prescribe a tranquilizer with a short half life (so that it’s not transmitted to the nursing puppies). Other medications can also be prescribed to help with milk let-down.


This is pretty much the direct opposite of the two conditions we just covered; it’s a buildup of milk that hasn’t passed out of the mammary glands, through the nipples of a dog that’s nursing, and then, obviously, into the puppies. Sometimes, it’s a result of the puppies being normally weaned. Other times, sadly, it can be because the puppies have died and are simply not there to be nursed.

The treatment for this disorder is much the same as it is for false pregnancy. Therapies are used to reduce milk production, and discourage access to the glands by the bitch. Milking is not advised unless mastitis develops since this will simply encourage milk production.

Mammary Cancer

Mammary tumors are extremely common in female dogs. Fortunately, there’s a 50/50 chance that if your dog does develop mammary tumors, they will prove to be benign. Even better, if caught early, malignant tumors can be very treatable.

The usual sign of mammary cancer is a lump, the same as it is with human females. It’s a good idea to examine your dog’s breasts regularly. Chances are, if the lump feels loose and moves around when palpated, it’s probably a benign, fatty growth. A “fixed” lump is more likely to be cancerous. I wouldn’t go with guesswork on this, though. Any lump in your dog’s mammary glands should be checked out by a veterinarian.

Treatment involves surgically removing the masses. Then, spaying is very much recommended. Even then, there can be a likelihood of the tumors returning. With spaying, though, chances are that the cancer will not return for many years. In other words, your dog may die with mammary cancer, but will not likely die of it.

Unless you have a very valuable breeding bitch, you might want to consider having your dog spayed at a young age. As I pointed out in The Truth About Spaying and Neutering, this does not necessarily mean that you have to do it before the first heat; in fact, there is some evidence to suggest that the benefits of allowing a dog to remain intact for a year or two may outweigh the benefits from a reduced possibility of cancer. The research suggests that bitches spayed before the first heat have a 0.5% chance of developing cancer when compared with dogs that remain intact. A bitch spayed after her first heat has an 8% risk, and one spayed after two heats has a 26% risk. The numbers aren’t really known for bitches spayed after the third heat, but even in older bitches, it is believed that there can be some reduction in risk.

There is a myth that’s often put forth by people who have what they see as a vested interest in you having your dog spayed, to the effect that pregnancy will increase her risk of developing breast cancer. This is completely untrue. Pregnancy has no effect on the chances of your dog developing cancer.

Mammary Cysts

This disorder is believed to be hormonal. It’s also referred to as fibrocystic disease, or blue dome cysts. These are hard lumps that may express fluid ranging in color from clear to brown. Treatment involves surgical removal. It isn’t known whether these cysts are likely to develop into cancer, so it’s generally a good idea for the vet to have a biopsy done following the removal.

The Final Word

These are some of the more common problems that can affect breasts and nipples on a dog. As I previously stated, the chances of your dog developing any of these disorders is unlikely but not unheard of. Some are more common in pregnant bitches, while others can occur at any time and for reasons unrelated to pregnancy. Naturally, I’m keeping a close eye on Janice right now, not really expecting anything to go wrong but ready to act if it does.

While I hope you’ve found this information useful, I also hope that you will never really need it.

About the Author Ash