How to Prevent Mastitis in Your Whelping Dog

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Mastitis is an extremely painful inflammation of the mammary glands that can occur when a dog with puppies is nursing or just before whelping. Inflammation can be caused by a blockage in a milk duct supplying the teats, which is often accompanied by bacterial infection when milk “backs up”, and bacteria present proliferate, or when bacterial infection is introduced into the teat, such as can occur from a small wound or from unsanitary conditions around the teat.

Continued nursing and expressing the milk to clear blockage and infection usually resolves mastitis if caught at an early stage, however, if it does not resolve and is left untreated, it can be life-threatening to your dog and her puppies. An untreated bacterial infection can become systemic and bacteria-infected milk can make puppies sick.

Your dog could be affected by mastitis if she is experiencing pain or swelling or redness of her teats, her milk may be discolored, or there may be a discharge from the nipples. An affected dog may refuse to nurse and experience lethargy and fever. Ensuring that your whelping dog gets help to resolve mastitis as soon as possible is important so mastitis does not advance to a serious condition in the mother dog and adversely affect the puppies as well.

Causes and Prevention of Mastitis in Dogs

Mastitis, which is inflammation of the mammary tissues in a whelping dog, can be caused or contributed to by several factors.

Bacterial Infection

Bacteria introduced through a wound near or on the teat, or from bacterial contamination near the opening of the teat, can travel up the milk duct and result in bacterial infection. This can be more common in short dogs that are low to the ground, such as Dachshunds or Corgis. Also, when puppies develop teeth they can cause such wounds, or wounds from the puppy's nails can occur. Trimming puppies’ nails will reduce the incidence of injury to the mother dog.

Examine your dog frequently to see if there are any wounds present and treat appropriately. Keeping the dog well groomed, and removing excess hair from the mammary area will help prevent contamination and make any wounds visible. Help the mother dog with cleaning the area if she needs assistance keeping the area sanitary. Ensure bedding is cleaned frequently so the whelping dog and puppies have a clean environment, free from bacteria, when nursing occurs. Ensure the mother dog has a complete diet so that her immune system is able to combat exposure to bacteria. If bacterial infection is suspected, antibiotic medication from your veterinarian will be required.


Clogged Ducts
Plugged milk ducts are the most common cause of mastitis. The ducts that supply the teats with milk are subject to inflammation and blockages from a variety of conditions. If a blockage occurs, bacterial infection can develop from the proliferation of bacteria that is naturally present in the area, resulting in a bacterial infection in association with the blocked duct.

If there is an overproduction of milk, and puppies do not drain it in a timely manner, engorgement can occur, resulting in milk becoming thickened and plugging up ducts. A tumor, scar tissue, lesion, or growth in the mammary area can also result in blockage. Examine your female dog a few times daily to see if signs of mastitis from a blocked duct are beginning to occur. If signs of inflammation are present:

  • Ensure puppies use all teats equally to drain milk from ducts and flush out bacteria naturally

  • Express milk from teats manually if puppies are not draining them adequately

  • Apply warm compresses to the mammary glands to aid in milk flow

  • If blockage does not resolve, or if signs of bacterial infection are present, seek veterinary attention

Accumulation of Milk

Another form of mastitis, galactostasis, also referred to as caked breasts, can occur at the end of pregnancy, during a false pregnancy, if there is a small litter, or at the later stages of lactation where milk accumulates at the teat site. The mammary glands and ducts are not affected, but teats can be painful, warm and swollen. Keep an eye on your dog's teats from late pregnancy through to weaning to catch signs of inflammation. Gradual weaning prevents galactostasis from occurring, as does a reduction in diet, and fluid intake, in the lactating female to reduce milk production.


Chronic Issues

If your dog is chronically experiencing mastitis she may not be a good candidate for a breeding program, and spaying her may be an option that should be considered to prevent future cases of mastitis.

Importance of Prevention

Having a sick whelping female is not just a problem for the dog owner in caring for the mother dog, but also becomes a problem if puppies are affected because they cannot nurse due to contaminated milk or because the mother will not allow it. A serious case of mastitis can result in a very ill mother dog and ill newborn pupies who are malnourished or dehydrated, which can result in the loss of puppies. Preventing mastitis and ensuring that lactation occurs will prevent a host of other problems to both mother and puppies.

Good Health for Mom and Pups

The last thing a mother dog needs to contend with is an inability to nurse and illness. Motherhood is hard enough! As a pet owner, you can help your dog avoid mastitis or inflammation and infection of mammary tissues by observing your dog's teats and mammary tissues regularly, at the end of pregnancy, and throughout the lactation process. If wounds, injury, or contamination occur, treatment of wounds and cleaning the area will help prevent mastitis conditions from developing. At the first sign of inflammation, applying warm compresses and ensuring milk is adequately expressed will usually prevent the condition from developing further. However, if your dogs show signs of illness and mastitis progresses, get your dog veterinarian attention as soon as possible to obtain antibiotics appropriate for treating mastitis.