Canine Mastitis

Kelly Roper
Trio of pups nursing from a healthy mom

Canine mastitis is typically associated with dogs who are nursing puppies, but this isn't always the case. Learn more about this condition, its causes and treatment.

About Canine Mastitis

Mastitis is essentially a bacterial infection of the milk ducts in a dog's mammary glands. When a dog becomes pregnant, her body gears up to support the litter, and this includes producing milk for the pups to nurse.

After the pups are born and begin nursing, sores, cracks and scratches sometimes form as the nipples become tender from the activity. This opens a pathway for bacteria to enter one or more ducts. Under normal circumstances, the immune system is able to combat the invading bacteria, but sometimes the immune system is overwhelmed and the bacteria get a foothold in the tissue and a mastitis infection develops. Chances of contracting an infection are higher if the female is rearing her litter in unsanitary conditions. Left untreated, the infection can lead to septic shock and death.

All of that said, any female can contract a mastitis infection. This includes non-pregnant females and older females. In cases such as this, cancer of the mammary glands is another possible cause for the condition, and it's one that should be checked for immediately.

Symptoms

Spotting the signs of a mastitis infection is crucial to providing early treatment that will not only save your female a great deal of discomfort, it could save her from a more serious blood infection.

Symptoms to watch for include:

  • Sudden loss of appetite
  • Fever and lethargy
  • Aggressive behavior (Caused by pain)
  • Tenderness of one or more breasts
  • An abscess or infected-looking scratch near the nipple
  • Redness, heat, swelling and hardness of the affected breast(s)
  • Dark discoloration of the affected breast(s)
  • Discolored milk
  • Foul-smelling pus discharge from the nipple

Puppies themselves will show signs of drinking infected milk. Symptoms include:

  • Distressed behavior (Crying, restlessness)
  • Dehydration
  • Weight loss
  • Eventual lethargy followed by death

Diagnosis

Diagnosing a case of canine mastitis is relatively straightforward. The vet will gently examine the dog's breasts to determine if one or more teats are infected. In addition to looking for the signs listed above, the vet may try to carefully express the breast to check for the presence of pus if it isn't already visible due to leakage.

Treatment

If you suspect your dog may have a mastitis infection, call your vet immediately to report what you've observed. Treatment for a canine mastitis infection largely depends on how far the infection has progressed. If it's caught in the early stages, repeated expressions may be enough to remove the contamination, but it's best to let your vet decide what your dog needs.

Common treatments include one or more of the following:

  • Applying warm, moist compresses to the affected breast - This increases circulation and may make it easier to express the nipple and get the milk flowing. This in turn relieves pressure and reduces pain.
  • Soaking up the infected milk and any pus discharge with a paper towel and throwing it away - This is an important sanitary measure.
  • Administering antibiotics - This helps remove any remaining traces of infection.
  • Performing a mastectomy - This is a last resort to remove severely infected tissue and bring an end to chronic mastitis infections.

Hospitalization and supportive care measures may be necessary in conjunction with any of these treatment methods.

Caring for the Litter

Feeding

Since the infected milk makes the puppies sick, it is necessary to wean the pups off mom and begin bottle-feeding them with puppy milk replacement formula unless they are old enough to be weaned on to puppy food. Nearly all pet supply stores sell this formula as well as nursing kits that come with a bottle, nipple and nipple brush. The formula label provides mixing directions as well as information about how much you should feed each pup, according to its weight, and how far apart to space those feedings.

Cleaning

Additionally, you may also have to take over cleaning the pups if their mother loses interest in them. This means you'll need to help them relieve themselves until their bodies are developed enough to eliminate waste on their own. You can easily do this by wiping their genitals and anus with a baby wipe to stimulate elimination. This is only necessary for the first few weeks of life until you observe the pups begin to eliminate without your help.

Prognosis

With proper treatment, it is possible for a female to recover and go on to rear other litters. However, a dog is more susceptible to future mastitis infections once she has had one, and spaying may become necessary at some point.


A bout of canine mastitis can have devastating affects on a dog and her litter if it isn't spotted in time. Now that you know the telltale signs to watch for, you'll be better prepared to deal with the situation if it ever arises.

Canine Mastitis