What does the abbreviation 'OU' indicate in a treatment plan for a pet's ears?

The abbreviation 'OU' stands for "both ears." It originates from the Latin phrase "oculus uterque," which translates to "each eye," but in veterinary medicine, it is often adapted to refer to both ears in the context of ear treatments. In a treatment plan, this indicates that a particular medication or procedure is intended for application in both ears of the pet. This is particularly important in ensuring that the treatment is comprehensive and addresses potential issues in both ears, whether related to infection, ear mites, or other conditions.

In contrast, the abbreviation that would refer to only one ear is typically 'AS' for the left ear or 'AD' for the right ear. Options indicating "outer usage" or "observation unit" are not relevant terms concerning ear treatment in pets. Understanding these abbreviations is crucial for effective communication and treatment in veterinary practice.