Mammary Inflammation (Mastitis) in Cats

Key Takeaways

Mastitis in cats is inflammation of the mammary gland(s).

• Mastitis can be caused by a bacterial infection or during weaning if there is a buildup of milk in the gland(s)

• Symptoms include hot mammary glands that are painful to the touch, secretion of pus from the teat(s), lethargy, and failure of kittens to gain weight

• Diagnosis is made by thorough physical exam, blood work, and bacterial culture

• Depending on the cause, treatments include systemic antibiotics, warm or cold compresses, manual draining of the gland(s), or surgery

• The prognosis is good with treatment

• If left untreated, mastitis can progress into a systemic issue and become life-threatening

A Closer Look: What is Mastitis in Cats?

Although mastitis is uncommon in cats, prompt veterinary attention is warranted whenever symptoms of mastitis are evident. Mastitis occurs almost exclusively in lactating mother cats (queens), but can also be seen in false pregnancy. Most cats will respond quickly to treatment, especially if caught early. If left untreated, infections can spread into the bloodstream, causing sepsis.

Risk Factors

Mastitis can vary in severity in multiple ways. Mastitis may only affect one gland, or the entire mammary chain. Untreated mastitis will usually increase in severity. Vomiting, kitten aggression, and teat and tissue discoloration indicate worsening mastitis.

Possible Causes

Septic causes

• Ascending infection via teat canals

• Unsanitary conditions

• Systemic infection originating elsewhere in the body

Non-septic causes

• Constant nursing in queens with large litters 

• Secondary galactostasis (build up of milk) in queens nursing small litters

• Trauma inflicted on the mammary glands by kittens’ nails or teeth

• Forced or abrupt weaning

Main Symptoms

• Restless, crying kittens that are not gaining weight

• Inflammation of mammary gland (swollen,  hot, painful, and/or discolored mammary gland(s))

• Ulcerated skin around gland

• Abnormal milk color/consistency



• Loss of appetite

Testing and Diagnosis

Diagnosis of a case of possible mastitis begins with a full physical examination. Diagnosis may involve blood work, cytological examination of the affected gland or fluid from affected teat(s), x-rays, and ultrasound.

Steps to Recovery

Treatment varies with the type and severity of the mastitis, and usually includes systemic antibiotics and pain relief. In severe cases where infection has advanced, hospitalization with IV fluids and other supportive care may be necessary. Surgery to debride and flush the affected gland(s) or to remove the gland(s) are also possibilities. Non-septic mastitis may be treated with warm or cold compresses and/or manual draining of the gland(s).

With appropriate treatment, prognosis is good, with most cats recovering within 2-3 weeks. In cases where infection has entered the bloodstream, prognosis is guarded.


Prevention of mastitis can be done through a number of actions;

• Maintain a clean & dry queening area

• Ongoing attention to the condition of the mother, especially when weaning

• Trim kittens’ nails

• Encourage kittens to suckle from all teats - move them around if needed

Mastitis is not contagious, but infectious pathogens can spread from a mother to a kitten while the kittens are nursing.

Is Mastitis Common in Cats?

Mastitis is uncommon in cats, occurring almost exclusively in nursing mothers.

Typical Treatment

• Antibiotics

• Pain medication

• Warm or cold compresses

• Encourage kittens to suckle from affected teat(s)

• Hand milking if kittens not available

• Hospitalization

• IV fluids

• Surgery

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