Mastitis is a bacterial or fungal infection of the mammary glands. These glands are found in the breast and run the highest risk of infection when a new litter of puppies is being nursed.

Mastitis is much more common in other animal species, but it can lead to life-threatening complications for both the mother and the pups if left untreated. [1]

Mastitis Symptoms

  • Loss of appetite
  • Lethargy
  • Vomiting
  • Fever

In early stages, one of the indicators might be that the puppies are not gaining weight fast enough while nursing. In a case such as this, the breast area should be very carefully checked for redness and swelling.

There may not be too many obvious signs in the early stages of infection, but keep an eye out for general discomfort and irritation. As things progress, the mammary glands will become quite swollen, and the skin surrounding the breast area may become discolored (purple and red).

Milk from the mother will at times show traces of blood or pus, and will be thicker than usual. When infection has reached a critical stage both the mother and pups can start showing obvious sings of illness.

In the very late stages of mastitis, parts of the breast area skin can take on a dark purple color, or even black.

Did you Know?

Mastitis most commonly occurs during the first few weeks after giving birth

Minimizing The Risks

There is no foolproof way to prevent mastitis, but you can decrease the chances of infection. Maintaining a clean nursing area for the mother and pups is extremely important.

Catching the problem early on can mean the difference between life or death. It is advised that the mammary glands be checked daily to ensure that there is no abnormal swelling or sensitivity.

The mothers’ temperature can also be checked from time to time. The average temperature for a dog is 101.0 to 102.5°F (38.3 to 39.2°C)

Inspecting the color and consistency of the milk is also a good way of checking for irregularities. [2] [3]

Can Mastitis Kill Puppies?

During the first phase of galactosis, the mother will start producing something known as ‘first milk’ a few days before giving birth, and continues doing so for seven to eight weeks afterwards. Unlike regular milk, this particular type contains vital nutrients, vitamins and antibodies that strengthen the immune system of the puppies. [4]

With severe cases of mastitis feeding will cause the mother so much pain and discomfort that she will refuse to continue. In pushing them away, she deprives her pups of what they need to survive. In this instance mastitis is indirectly responsible for the death of the puppies

Galactosis and Galactostasis

While these two words sound incredibly similar, they have different meanings.

Galactosis is a term that describes the secretion of milk, while Galactostasis is an irregular collection or build up of milk in the mammary glands.

Galactostasis (also known as caked breasts) is very likely to occur during a phantom pregnancy, as there are no puppies to remove the milk. A small litter of puppies can also cause this condition, since the milk will possibly not be removed quickly enough. [5]

Phantom Pregnancy

While mastitis is most commonly found in dogs that have recently given birth, it can also affect dogs that are not pregnant. Certain female dogs who have not been spayed have the potential to go through what is known as a phantom pregnancy.

In these cases, the dog displays all the signs of pregnancy, without actually expecting. The body and reproductive system goes through all the motions of preparing for the birth and nursing process. These dogs are just as vulnerable to mastitis as pregnant dogs. [6]

Did you Know?

Manually extracting milk from the breast can offer relief and reduce the chances of bacterial buildup


A visit to the vet is the only sure way to determine if your dog has mastitis.

The diagnosis may be achieved by merely performing a physical examination.

If further testing is required, some or all of the following procedures may be performed:

  • Complete blood cell count
  • Milk cytology
  • Bacterial Culture

Complete Blood Cell Count

This is a blood test used to observe the red blood cells, white blood cells and platelets. This helps to determine how serious the infection is.

Milk Cytology

With this procedure, a milk sample is carefully extracted from the mammary gland into a sterile vile. From there the sample is inspected under a microscope for traces of bacteria and fungus.

Bacterial Culture

This is where a milk sample is sent away to the laboratory for further examination. Various antibiotics will be tested against the bacteria in order to determine which one will prove most effective in treatment. [7]


If mastitis is diagnosed and verified, your vet will likely prescribe a course of antibiotics to combat the infection. Two of the most commonly known antibiotics used in the treatment of mastitis are clindamycin and doxycycline. [8] [9]

Both of these are available in tablet form, but can also be administered via injection.

If the mastitis is not too severe, the mother may return home to her pups.

Relief at Home

There are various things that can be done to ease the pain and discomfort of the nursing mother after retuning home from the vet.

Some or all of the following may prove useful:

  • Warm water compresses
  • Cabbage leaves
  • Hand milking
  • Salves and ointments

Warm Water Compresses

A cloth can be soaked in warm water, rung out and placed gently on the breast area. This process can be repeated multiple times, but remember to keep the cloth clean.

Cabbage Leaves

Cabbage leaf compresses have also been known to aid in the relief of pain and inflammation. The leaves can be held in place on the mammary glands with a loosely fitted bandage. These should stay on for around two to four hours to gain the full potential benefits.

Hand Milking

Your vet may also recommend manually removing any access milk. This can help with relieving pressure and promoting blood flow.

Salves and Ointments

Various salves and ointments are available for over the counter purchase. These can help to both prevent and relieve irritation from dry, chapped skin on the mother’s journey to recovery. [10]

Future Solutions

Evidently plant essential oils are being tested and considered as a possible future treatment option in the fight against mastitis.

Research has shown that various plant essential oils contain antibacterial and anti-inflammatory properties. It is still a very young initiative, but current results look promising. [11]

Final Thoughts

While we might often feel like we know what’s best for our dogs, it’s always safer to get a veterinary opinion. Follow their instructions carefully and do not hesitate to book follow up consultations if the situation does not improve.