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Health & Wellness

Parents of nursing dogs should know about mastitis

Red and swollen mammary glands can be a sign of an infection.

Some pups’ first order of business in the morning is to flip on their backs for their daily belly rub. Not only do these petting sessions make your dog happy (cue the leg kicks and pleasant sighs), but they also help you to feel for any abnormal changes in that area. 

If you feel a bump around your pup’s mammary-gland area (especially if they’re nursing puppies), they could struggle with mastitis, which is when one or more mammary glands become inflamed.

What’s mastitis in dogs?

Mastitis happens when bacterial or fungal infections cause dogs’ mammary glands to become inflamed, Dr. Emily Singler, VMD, Fetch’s on-staff veterinarian, explains. 

“Bacteria usually get into the mammary gland through the nipple from the environment, especially if the skin isn’t kept clean,” Dr. Singler says. 

Dogs with bodies that are low to the ground are more likely to have their mammary glands rub against surfaces that have the potential to infect the area. However, that’s not the only way dogs can contract mastitis. 

If you’re a parent to a mama dog, congratulations! Watch your dog to see if they shy away while their puppies are nursing. 

“Older puppies that have some teeth can sometimes cause trauma to the mammary glands while nursing and introduce bacteria this way,” Dr. Singler adds. 

In rare cases, fungal infections from another part of the body can spread through the bloodstream into mammary glands and cause mastitis.

Symptoms of mastitis

Mastitis commonly affects nursing dogs, so if you notice your dog has become reluctant to nurse or their mammary-gland area is red or swollen, these are signs of an infection. Your pup might even shy away if you touch the firm area, as it can cause them pain

When a mother pup is sick, she might stop eating and become lethargic. In turn, her puppies might cry more because they’re not receiving enough milk. 

“It’s also possible to notice pus and a strong, foul odor coming from the nipples,” Dr. Singler adds. “In some cases, an abscess will form, and it may burst and start draining.”

Extreme mastitis cases can lead to dead tissue and can become a black or purple color.

RELATED: What’s the difference between a sebaceous cyst and a bump?

Treatment of mastitis in dogs

Treating mastitis depends on how severe your dog's case is and whether or not they're still nursing, Dr. Singler says. Usually, antibiotics (in pill or liquid form) are the main treatment option depending on your pup's size and preference.

Warm compresses applied to the affected area can help reduce inflammation and encourage drainage — pain medication is usually needed as well.

If the infected momma pup has dead tissue, the puppies should stop nursing so that the dead tissue can be treated with surgery, antibiotics or pain medication. Once the mom is healthy, the pups can often start feeding again. Your veterinarian will let you know if it's safe for puppies to keep nursing.

In extreme cases, mastitis can cause sepsis, where bacteria enters the dog's bloodstream and circulates throughout the body. This condition can cause severe sickness in dogs and can be fatal, so pups at this level might be hospitalized to receive IV fluids and medication until they're better.

When will my dog get better?

With treatment, mastitis will likely improve significantly within 1 to 2 weeks. However, if left unchecked, the condition will continue to get worse.

“Although this isn’t common, mastitis can be chronic in some dogs, where it doesn't completely go away with medication,” Dr. Singler says. If they don't heal, the affected mammary glands will be removed, and the pup will be spayed.

How to prevent mastitis in dogs

Ensuring a mom’s skin and bedding are always clean is one way to prevent mastitis. Keeping the puppy's nails short so they don't scratch the mother’s mammary glands while nursing can help, too.

With your vet's permission, you can start offering food to the puppies at around 4 or 5 weeks old. “This is important because it allows the puppies to get some of their calories from the puppy food and spend less time nursing,” Dr. Singler adds.

Once puppies reach 4 or 5 weeks of age, Dr. Singler recommends having an area where the mother can get away from the puppies to take a break from nursing. It’s also a good idea to check her mammary glands for any bites or scratches to prevent any mastitis development. 

Spaying the mama dog is always a great way to avoid unplanned pregnancies and prevent mastitis in the future.

The Dig, Fetch's expert-backed editorial, answers all of the questions you forget to ask your vet or are too embarrassed to ask at the dog park. We help make sure you and your best friend have more good days, but we’re there on bad days, too.

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