How to Prevent Mastitis in Dogs
To prevent your lactating dog from getting mastitis, let her puppies nurse as much as possible, which will help flush out bacteria. You should also make sure you're feeding your dog high-quality, nutritious dog food, since it will help boost her immune system so she's less vulnerable to a bacterial infection. Once a day, clean your dog's mammary glands with a warm compress so bacteria doesn't build up there. If your dog has long fur, shave it around the mammary glands, since long fur can pick up more bacteria.
Encourage the use of all the mammary glands. The dog's teats will naturally flush out bacteria as the milk is pushed out of it. This means it is very important that the puppies use all the teats as they nurse. This helps keep the teats healthy and the bacteria flushed from them. If the teats are not being used, try to manually get the puppies to use them. If this doesn't work, you may need to squeeze milk from the teats. This helps release any milk contaminated by bacteria, and helps expel the bacteria so it doesn't end up in the bloodstream. Provide your dog with proper nutrition. Malnutrition may lead to a lowered immune system that can't fight off bacteria. This may make the dog vulnerable to mastitis. Feed your dog the proper foods to get the best nutrition. Feed the dog multiple meals throughout the day. Slowly increase how much food you give the dog each day. The dog will need more food because of the increased milk production needed to feed the puppies. You may consider giving the dog puppy food, which has a higher calorific value than regular dog food. Spay your dog. The only way to guarantee your dog won't get mastitis is to spay the dog. Mastitis only occurs in female dogs that have given birth and have lactating mammary glands. Spaying keeps the dog from getting into the situations that leads to the condition. This may be a good idea if you have a dog who has previously had mastitis. Dogs who have had the condition before are at a higher risk of getting it again. Keep the living area clean. Mastitis is a bacterial infection. One of the main ways dogs come in contact with the bacteria is from unclean living areas. To help prevent the bacteria from infecting your dog, change the bedding where the dog and puppies lay often. Make sure to clean the area as well. Many cases of mastitis start from the opening of the teat, so helping keep the environment clean can help prevent this. Clean the mammary glands regularly. Since bacteria gets into the mammary glands to cause mastitis, you should clean the dog's mammary gland are regularly. Use a warm compress to clean around the area every day. You should make sure to clean any wounds around the mammary glands that may be caused by a puppy's claws. Clean the underside of your dog after they go outside. Remove dirt and debris from around the teats. You should also clean them to make sure no urine has accidentally splashed onto the mammary glands. Groom the dogs. Another way to help prevent infection is to keep the dogs groomed. This includes the mother and the puppies. Start by shaving the hair around the mammary glands on the mother. This is important for longhaired dogs, since the hair can pick up bacteria and infect the glands. Keep the nails on the puppies trimmed. This helps reduce the risk of the puppies scratching the mother. Recognize the symptoms. When you have a dog who has just given birth, you should watch for the symptoms of mastitis. Mastitis can be a mild condition you can treat at home, but it can also turn into a severe condition that can lead to death. Common symptoms of mastitis include: Pus or bloody discharge from the teats Red, swollen, warm, hard, or painful mammary glands Lethargy or depression Loss of appetite or dehydration Fever Reluctance to nurse or neglect of the puppies Aggressive behavior Failure of puppies to thrive or grow Crying or whining from puppies Take your dog to the vet. If you believe your dog has mastitis, you should take them to the vet. This is important because mastitis can move quickly and turn severe, which may lead to death. The vet can properly diagnose mastitis by performing a physical exam and running tests. The vet may be able to diagnose mastitis from only a physical exam. They may also take a bacterial culture, milk sample, or do a needle aspiration of the mammary tissue to analyze. Treat mastitis. Mastitis has a good prognosis, especially if it is caught early. The most common treatment for mastitis is antibiotics to eliminate the bacteria. If the mastitis is severe, the dog may need to have the mammary glands surgically lanced and drained, or they may have to have them removed. Applying a warm compress to the mammary glands can help reduce swelling and help the milk flow normally. 
Encourage the use of all the mammary glands. Provide your dog with proper nutrition. Spay your dog. Keep the living area clean. Clean the mammary glands regularly. Groom the dogs. Recognize the symptoms. Take your dog to the vet. Treat mastitis. 