Bacterial Breast Infection in Cats

Mastitis is a breast bacterial infection that affects the mammary glands of cats that have just given birth. It can cause ailments for both the mother and her kittens. The condition is painful for new moms and life-threatening for their kittens, and this is why it is important to take your cat to the veterinarian as soon as symptoms develop.

Mastitis is a breast infection that affects a single mammary gland or multiple mammary glands in lactating cats. The infection can come on without any warning and lead to pain, swelling and loss of appetite.

Acute septic mastitis causes the milk to look clear or lumpy. This breast bacterial infection is usually localized in cats, but the condition can lead to an infection in the blood that causes the cat to become ill or septic.

Cats suffering from mastitis will show the following symptoms:

• Heat, swelling and pain of the infected glands
• Depression, dehydration and loss of appetite
• Yellow, thick or bloody milk
• Fever
• Lethargy
• Refusal to let kittens nurse from the infected gland
• Ill or dying kittens

Taking your cat to the veterinarian at the first sign of mastitis can lead to early detection and treatment.

Mastitis is caused by ailments such as bacteria and abrasions. The bacteria involved usually includes Staphylococci, Streptococci and E. Coli. 

The following ailments are causes of mastitis:

• Damage to the nipples due to the kittens constantly nursing
• Bacteria entering the mammary gland due to the abrasions from the paws and teeth of the kittens
• Infected mammary glands becoming gangrenous or developing an abscess
• Bacteria growth after blockages occur in the milk duct
• Another infection spreading through the bloodstream and into the mammary glands
• Caked Breast: a build up of milk inside the breast that causes heat and pain. This condition can lead to mastitis.

You should take your cat to the veterinarian as soon as you notice any symptoms of a breast infection such as mastitis. Your veterinarian will give your cat a complete physical exam and ask questions about the symptoms. 

Your veterinarian may need to perform the following tests on your cat:

• Bacterial culture and sensitivity of the infected liquid
• Fluid analysis and microscopic examination of the milk or discharge
• Aspirate and cytology of solitary masses-- The veterinarian will insert a needle to remove a sample of material.
• Complete blood count

There is always a possibility that your cat is displaying symptoms of a systemic illness from the infection. If this happens, you veterinarian will need to perform the following additional tests:

• X-Rays of the chest and abdominal area
• Blood cultures
• Urinalysis
• A biochemical profile

There is a possibility your veterinarian will be able to diagnose the infection after a physical examination. Your veterinarian will order additional tests if your cat is not displaying enough clinical signs to make a diagnosis.

The treatment depends on the severity of the infections, but may include the following:

Antibiotics Therapy

Your veterinarian may prescribe broad spectrum antibiotics to your cat until they have received the bacterial culture results. They will prescribe a more appropriate antibiotic once receive the results. Your cat may also be given medication to help manage the pain, and there is a possibility the kittens may need to be given antibiotics.

Emptying The Glands

The veterinarian empties the infected mammary glands by manually expressing them to remove the infected milk. The mammary glands need to be lanced and drained, and there is a chance the veterinarian will need to lance and drain the glands surgically.

Treating Gangrenous Tissue

The necrotic material is removed from the gangrenous tissue.

Possible Additional Treatments

If your cat is systemically ill or septic, your veterinarian may need to administer intravenous fluids for several days. The veterinarian will also treat dehydration if necessary. Glands that are severely or chronically infected may need to be removed altogether.

Be sure you always administer antibiotics as directed by your veterinarian. You should also schedule a follow-up appointment to ensure the infection is healing. Your veterinarian may suggest applying a warm compress and expressing the gland several times a day. You may also need to reduce food intake to stop the milk production temporarily or permanently. Kittens that are still nursing will need to be given an appropriate replacement using a bottle. If your cat has suffered from mastitis in the past, then she should be prescribed an antibiotic before giving birth to future litters. This is done to prevent the infection from returning.