Mastitis is a bacterial infection of the mammary glands, almost exclusively seen in females. It may occur in one or multiple glands and usually occurs in lactating animals. It is a fairly uncommon condition, but occurs more frequently in bitches (female dogs) than in queens (female cats).
Mastitis is most commonly caused by an ascending infection from the teat opening. Other potential causes or contributing factors include trauma (from nursing kittens) and hematogenous spread (spread via the blood). It is more common in older cats. Poor hygiene can also be a contributing factor.
Mastitis can be a painful condition that usually is fairly localized, although some animals may become systemically ill or even septic (bacterial infection in the blood). What to Watch For Swellings in one or more mammary glands
Purulent or discolored milk or discharge from glands
Painful mammary glands
Glands may abscess
Loss of appetite
Sick or dying newborns
Fever in some pets
A good history and complete physical exam are very important in establishing the appropriate order of diagnostics. The diagnosis is sometimes made on this basis alone. Additional tests may include:
Fluid analysis with microscopic evaluation of the milk or any discharge
Aspirate (inserting a needle and syringe to remove a sample of material) and cytology of solitary masses
Bacterial culture and sensitivity of the fluid
Complete blood count (CBC)
In cases of significant systemic illness the following may be recommended:
A biochemical profile
Chest and abdominal radiographs (X-rays)
Systemic antibiotic therapy
Topical warm water compresses
Affected glands should be emptied
Glands may need to be surgically lanced or drained.
Severely or chronically affected glands may need to be removed (mastectomy)
If systemically ill or septic, intravenous fluids would be necessary
Home Care and Prevention
If glands are still draining, additional warm water compresses will be required. Nursing puppies may, or may not, need to be weaned but they often require additional nutritional supplementation.
Since mastitis is most often associated with nursing, not allowing your pet to breed is a good preventative measure. The best preventative measure is to have your pet spayed before her first heat.
If you are breeding your pet, make sure that the bedding and surroundings are routinely kept clean. If your pet is lactating, observe the teats daily for any signs of redness, pain or abnormal swellings and discharge.