There is an abnormal swelling of the breasts of the dog mostly accompanied with a lump in the mammary gland or surrounding area. Some swelling is common during heat cycles or lactation. Causes associated with abnormal swelling are accumulation of milk, Galactorrhea, tumors, Mastitis, pseudo-pregnancy. In Males it would be called Gynecomastia and the causes could be hyperplasia or hormonal disturbances.
