Q: I have a question which several veterinarians could not answer for me. My cat Sylvester seems to have lost his voice. What would be the cause of this? Could an illness be involved? 

A: Loss or change of voice is one of those vague problems that drive vets crazy.  In most cases that I’ve encountered, I could not attribute the voice change to any particular cause.  In some instances, however, the cause is readily apparent. The most common cause I’ve seen is a viral upper respiratory infection, with the herpes virus and/or the feline calicivirus being the main culprit. Most viral upper respitory infections result in runny eyes, snotty nose and lots of sneezing. Occasionally they’re result in laryngitis — a “sore throat” — and a hoarse or lost voice.

I’ve seen cats with oral tumors involving the throat or the vocal cords that resulted in a voice change or loss. Finally, there is a condition called laryngeal paralysis, in which the nerve that controls the vocal folds becomes damaged, causing the larynx not to open properly, resulting in a change of voice. This is much more common in dogs than cats. Interestingly, I diagnosed my first case of this about four days ago.

Even though most cases are due to upper respiratory infections, which are fairly benign, a change in voice should be evaluated by your veterinarian. He or she might want to sedate the cat and perform a thorough oral exam, looking at the back of the throat, and even trying to pass an endotracheal tube down the trachea to see if there is a mass or other obstruction. X-rays may be necessary to look for masses that are in the trachea or in the neck that cannot be detected simply by feel.