Upper respiratory infections (URIs) are relatively common in turtles. Clinical signs include swollen or weepy eyes, foamy discharge from the nares and/or mouth, and gurgling sounds from the respiratory tract.
Lack of Vitamin A in the diet predisposes turtles to URIs. Vitamin A is important in maintaining the integrity of all epithelial cells. In turtles, epithelial cells of the respiratory tract are especially sensitive. Without Vitamin A, the cells lining the ear and respiratory tract undergo a process called metaplasia. During metaplasia, the normal rectangular or columnar cells of the ear and respiratory tract are replaced with flat or squamous cells. The change in cell shape makes it more difficult to remove inhaled particulates like dust or bacteria, and lead to respiratory infections. Turtles with URIs will be fed cod liver oil which is a good source of Vitamin A.
It is not uncommon to see URIs accompanied by an aural abscess.
URIs can be passed from turtle to turtle fairly easily. Thus, we take precautionary measures when treating these cases, including isolating URI turtles, doing their treatments last, and wearing gloves while handling.