Mastitis in Cats

Mastitis is an infection within the mammary glands, caused by bacteria. It occurs in female cats, usually nursing mothers. Although it is seen in cats, it is a condition more common with female nursing dogs.

Symptoms of Mastitis

If you have a nursing cat, it is beneficial to keep an eye on her to ensure she doesn't have a problem with mastitis. Symptoms include:

  • Fever
  • "Fading" kittens (kittens who are sick, crying and/or dying)
  • Loss of appetite
  • Painful and swollen mammary glands
  • Enlarged teats
  • Abscesses
  • Lethargy
  • Discolored milk
  • Dehydration
  • Discharge from teats
  • Redness

Cats with basic mastitis won't appear otherwise ill and should behave almost normally. She may refuse to nurse because of the irritation to her teats and the discomfort it causes. If a cat with mastitis is displaying extreme symptoms of illness, then the bacteria has possibly gotten into their bloodstream and caused septicemia, also known as being "septic."

Causes of Mastitis

There are several forms of mastitis, all caused by different things.

  • Septic mastitis is caused by nursing kittens with forming teeth, who may be too rough while feeding. Excessive biting or chewing on the teats can cause injuries, which leave the mother open to bacterial infections which travel into the mammary gland.
  • Acute septic mastitis is a severe case of septic mastitis, where the glands begin to abscess. If not treated accordingly, these glands can turn into necrotic (dead) tissue.
  • Non-septic mastitis is caused by something other than trauma. This could be blockage in the nipple, or perhaps the mother is over-producing milk and the kittens are not drinking it quickly enough. Left in there, the milk can stagnate and breed bacteria.


After being diagnosed, mastitis is a treatable condition. Treatments your vet will recommend include antibiotics and warm compresses. The compresses can aid in draining out the gland. Glands may need to be surgically lanced, drained or removed entirely (mastectomy).

"Gangrenous" or necrotic glands are cold and darker in color. These glands have lost their blood supply and need to be surgically removed. Abscessed glands need to be drained, and sometimes will be removed depending on the severity of the abscess.

If not treated, the glands can harden and explode, leaving ulcers and craters in the abdomen. In extremely severe cases, maggots can be found in the holds, eating the dead tissue.

If the disease has taken a turn for the worst and your cat is septic, further steps - such as IV fluids - will need to be administered immediately.

When your cat comes home, warm compresses can help ease some of her discomfort, especially if her glands are still draining. If she is still nursing, you'll want to talk it over with your vet whether or not the kittens will need to be weaned.

Preventing Mastitis

Mastitis occurs most often in nursing cats, so having your cat spayed before her first heat is the best preventative measure. However, if you are purposely trying to breed your cat, make sure you check her every day. Examine her teats for signs of irritation, discharge or swelling.