Methicillin-Resisant Staphylococcus aureus (also called "MRSA") is a human bacterium that can be transmitted to animals who can in turn re-transfer the bacteria to back to humans. Pets are not generally infected with MRSA and do not get disease from MRSA but instead act as carriers. Animals can certainly get infected with Methicillin-Resistant Staphylococci but not with the same Staph species that infects people. Methicillin-Resistant Staphylococcus pseudointermedius (often called "MRSI" or "MRSP") is the species of Staph which infects pets. These mutant forms of Staph make antibiotic selection more difficult and culture/sensitivity testing may be needed to select an effective anti-Staph antibiotic. In the past, simply knowing an infection was caused by Staphylococci was enough to determine an effective antibiotic regimen. Those days are gone.