Dog mammary glands swollen: what to know

Mammary tissue may enlarge during or after a heat cycle, pregnancy, or a false pregnancy. One gland or several may become firm, warm, tender, or enlarged with mastitis, particularly after nursing. A discrete lump, changes in skin, or discharge from a nipple needs examination because appearance and touch cannot reliably identify its cause.

Tell the veterinarian whether your dog is female or male, neutered, nursing, recently in heat, or taking hormones. Note whether swelling is on one side, how quickly it appeared, and whether appetite or energy has changed.

Do not squeeze, massage, puncture, or apply creams to the glands. Prevent licking with a suitable barrier if needed, keep the area clean and dry, and record changes with dated photographs. Arrange a veterinary appointment rather than waiting for swelling to settle on its own.

A veterinarian may examine all glands and nearby lymph nodes, then discuss sampling or imaging if a lump is present. Do not give antibiotics or anti-inflammatory medicines unless prescribed for this dog.

Seek urgent veterinary care if the gland is very painful, hot, red, purple, ulcerated, or rapidly enlarging; if pus or blood is coming from a nipple; or if your dog has fever, vomiting, marked tiredness, refuses food, or seems unwell. Nursing puppies that are weak or not feeding also raise the urgency.

Ask whether the pattern fits hormonal swelling, mastitis, or a mass; whether testing is needed; how to protect the skin; and whether neutering or another treatment would reduce future episodes. Ask how soon a change should be rechecked.