Penicillin is a drug belonging to the beta-lactam class of antibiotics that has been extensively used to treat various bacterial infections in dogs. Since its discovery, the drug has played a crucial role in veterinary medicine — much like it has in human medicine — combating bacterial diseases that were once considered untreatable. Here’s what you should know about penicillin’s uses, dosage, and side effects for dogs.

Penicillin for dogs is primarily used to treat bacterial infections. It is derived from the Penicillium fungi and works by inhibiting bacterial cell wall synthesis, leading to the destruction of the bacteria. It is particularly effective against infections caused by gram-positive bacteria, such as Staphylococcus, Streptococcus, and Clostridium species, and some gram-negative bacteria. Some of the common conditions for which vets might prescribe penicillin include:

It’s also used in cases of septicemia and meningitis, among other conditions caused by penicillin-sensitive microorganisms. Moreover, vets may prescribe the medication after surgeries to prevent potential infections.