Mastitis is a bacterial infection of the mammary glands that sometimes occurs in lactating bitches. This infection may lead to swelling, inflammation, or abscess. Milk production is often compromised in the affected nipple.
A common cause of mastitis is a scratch from a nursing puppy’s toenail, which becomes infected. Poor sanitary conditions or a whelping room that is too warm may also lead to mastitis.
Mastitis typically first presents as a hard, warm swelling of one or more mammary glands. Milk from affected nipples may be normal, or laced with pus or blood. With severe mastitis the bitch may develop a fever or lethargy, or neglect her puppies.
For mild or isolated cases of mastitis, hot compresses may be enough to stimulate milk flow and ease the discomfort. Antibiotics are given to address the underlying infection. Abscessed breasts need to be lanced and drained.
If mastitis only occurs in one or two glands, the puppies can still nurse from the unaffected nipples. If all of the glands are affected, the puppies must be removed from the bitch and bottle-fed. In extreme cases, the infection may become systemic and abscesses may burst.
Most bitches will recover well from mastitis with antibiotic therapy. If mastitis occurs during weaning, reducing the bitch’s food intake will help dry up the milk and reduce swelling and discomfort.