Does My Dog Have Mastitis? How to identify, treat, and prevent mastitis in nursing mothers

Signs of Mastitis

• Depression or lethargy
• Decreased appetite
• Fever (temperature over 102.5°F)
• Dehydration
• Not wanting to nurse the puppies or seeming uncomfortable when nursing
• Failure of the puppies to thrive
• Hot, firm, swollen and painful breast tissue (mammary glands)
• Thin cream-colored, watery, or blood-tinged fluid can be expressed from the affected gland(s)
• Signs of septic shock (shaking, weakness, panting, fever, low blood pressure)
• Abscess or gangrene of the affected gland(s) if left untreated

Causes of Mastitis

Mastitis is caused by several well-known bacteria: Escherichia coli (E. coli), Staphylococci, and β-hemolytic Streptococci are most commonly cultured.

Bacteria gain access to the mammary gland by several possible routes:

• Ascending infection, up the teat canal from the skin
• Infection caused by trauma to the nipple, teat canal, or mammary glands from the puppies’ teeth or nails
• Poor environmental hygiene
• The spread of a systemic infection going on elsewhere in the body
• Prolonged periods of milk accumulation in the gland without milk removal - many cases of mastitis result from sudden weaning of the puppies.

What Can You Do to Help Your Dog?

In most cases, mastitis can be prevented!

• Always keep the environment and whelping box as clean as possible.
• Ensure that all the mammary glands are used for nursing.
• Regularly trim the puppies’ nails to prevent scratching and trauma to the mother’s skin.
• Keep the mother’s skin clean: excessive hair can be carefully trimmed, and the skin rinsed with warm water or saline twice a day (1 teaspoon of salt in 2 cups of cooled boiled water). The skin should be patted dry afterward.
• A warm or cold gel compress wrapped in a cloth can be used to reduce inflammation. Apply the compress for no more than 20 minutes at a time.

Treatment of Mastitis

When caught early, the prognosis for mastitis is good. Your vet will likely recommend culturing blood or milk samples. This will help determine the type of bacteria causing the infection so proper treatment can be provided. The mother will likely require antibiotic medication, specific to the bacteria involved.

If the infection is mild, the puppies will typically be allowed to continue nursing. Your vet may also advise you to express milk from the infected gland(s) several times a day to help clear the infection. This makes the mother more comfortable, encourages blood flow, and promotes healing. It’s important to monitor the puppies closely for any side effects of the medication, which may be present in the milk at low levels. Your vet will let you know if this is a concern.

If the mother is very ill or in septic shock, she will need to be hospitalized. Intravenous fluids, pain relief, and specific antibiotics for the infection will be essential. The prognosis for these cases is guarded, even with aggressive treatment. Unfortunately, abscessed or gangrenous glands will require surgical removal under general anesthesia.

When is it Time to Visit a Vet?

• If you notice that your dog has any signs of mastitis
• She is not comfortable nursing her puppies
• She has a fever

Still worried?

Book a video appointment to speak with one of our vets.