How Quickly Can Mastitis Develop in Dogs?

Check daily for signs of mastitis.
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Mastitis is a bacterial infection that can affect the milk ducts of a new mama dog. While each canine is different, generally, once a pup becomes infected, mastitis spreads rapidly -- in a matter of days in some cases.

Signs of Infection

Lethargy and loss of appetite are some of the initial warning signs of mastitis. Of course, your furry friend just had a litter of puppies, so the same symptoms could just be side effects of delivery. She’ll probably also have redness, pain and swelling in her abdomen or pus leaking out of one or two teats if she has mastitis. As the infection progresses, some newborns may howl more than normal, since they’re not able to eat. Your new mama dog may avoid feeding her pups altogether.


Check your nursing mom's teats every day for abnormalities. Mastitis spreads quickly, so take your four-legged chum to the vet right away if you suspect a problem. Untreated, the infection can completely block milk ducts, cause tissues to die and ultimately force mastectomy. Plus, depending on the treatment your vet decides on, you may be left having to bottle-feed the entire furry brood yourself.