Like humans and other mammals, dogs who are nursing their young can develop mastitis, a painful and potentially dangerous bacterial infection of the mammary glands.
What puts a dog at risk?
Fortunately, mastitis isn’t a common problem in dogs — although they’re more likely than some animals, like cats, to contract it. It typically only occurs in lactating females. It can be caused by an infection at the teat opening, an infection spread through the blood (a process known as hematogenous spread), poor hygiene or trauma to the mammary gland.
Because trauma is sometimes a factor, dogs with short legs, such as Dachshunds and Corgis, may be more prone to mastitis because their teats are more likely to collide with surfaces. However, trauma to the mammary gland of any dog can occur from nursing.
In addition to these risk factors, it’s believed that mastitis is also more common in older lactating females.