Medical Library
REP

Mastitis

Overview

Mastitis is a painful bacterial infection of the mammary glands that most commonly affects nursing female dogs and cats. It occurs when bacteria ascend into the teat canal, causing the glands to become swollen, hot, and hard. Without treatment, the infection can spread to the bloodstream, leading to life-threatening sepsis.

Key / Hallmark Signs

  • Pain
  • Swollen mammary glands
  • Fever
  • Vocalization (pain)
  • Dehydration
  • Redness
  • Lethargy

Common / Supporting Signs

  • Loss of appetite
  • Milk leakage

What to do?

This condition requires veterinary attention.

If your animal shows the Key or Common signs listed, please visit a clinic immediately.

Report Case / Get Help

Medical Details

Transmission

Mastitis is not contagious in the traditional sense, but the bacteria (often E. coli or Staph) can be introduced via the nursing puppies' mouths or unsanitary bedding. It is not zoonotic to humans.

Progression & Stages

Early stages present as mild swelling and refusal to nurse. The condition progresses to severe inflammation where glands become hard and painful. In advanced stages, the gland may turn purple (gangrenous) or rupture, leading to systemic shock.

Diagnosis

Diagnosis is based on a physical examination revealing hot, firm, and painful mammary glands. A sample of the milk may be cultured to identify the specific bacteria causing the infection.

Treatment Protocols

Treatment aggressively targets the infection with systemic antibiotics and pain management. Warm compresses and hand-milking are used to relieve pressure. Puppies may need to be weaned immediately. Severe necrotic cases may require surgical removal of the affected gland.

Prevention

Hygiene is critical; the whelping area must be kept clean and dry. Keeping the puppies' nails trimmed prevents trauma to the teats. Daily checks of the mammary glands allow for early detection.

Prognosis

The prognosis is good if the infection is caught early and treated aggressively. However, it becomes poor if the gland becomes gangrenous or if the animal develops septic shock.

Medical References

  • Merck Veterinary Manual, VCA Hospitals

Medical DisclaimerThis information is for education only and does not replace examination, diagnosis, or treatment by a qualified veterinarian.