Mastitis occurs  in lactating females and is a septic inflammation involving one or more of the mammary glands.

Clinical signs of mastitis include mammary discomfort, discolored milk, fever, and/or purulent discharge from the mammary glands.

Treatment involves antibiotic therapy, warm compresses and milking the affected glands. If infection is detected puppies or kittens should not be allowed to nurse on the infected teats.

Prognosis is good, but mastitis can recur in subsequent lactations.