What is the primary use of an ophthalmoscope in veterinary practice?

The primary use of an ophthalmoscope in veterinary practice is to examine the interior structures of the eye. This device allows veterinarians to visualize parts of the eye such as the retina, optic nerve, and blood vessels, which are crucial for diagnosing various ocular conditions and diseases. By using an ophthalmoscope, a veterinarian can detect signs of potential health issues, such as inflammation, tumors, or retinal detachments, which can significantly affect an animal's vision and overall health.

The other choices, while important in veterinary medicine, do not pertain to the specific function of an ophthalmoscope. Measuring blood pressure involves different specialized instruments, dental cleanings are performed with dental tools, and assessing heart function typically requires a stethoscope or an electrocardiogram. Therefore, the correct answer highlights the specialized role of the ophthalmoscope in ocular examinations.