Anorexia or inappetence, especially if sudden, is rarely a sequela of oral and dental diseases in dogs and cats. Inapettence is more commonly associated with systemic diseases (commonly, for example, kidney diseases in cats) or infections. It may also be related to changes in the environment and/or food. Therefore, a visit to a veterinarinarian specialized in internal medicine, is the first step.
Anorexia may be associated with stomatitis in cats, as the condition is extremely painful. However, dogs and cats will more commonly express oral and dental pain as behavioural changes associated with the use of oral cavity (eating and playing). Affected animals may comprehend food differently – they become slower, messier or chew the food differently. Commonly they will show preference to soft foods and may avoid playing with harder toys.
The three most common reasons for oral/dental pain in dogs and cats are periodontal diseases, dental fractures and tooth resorption. Some signs of these diseases may be seen on awake animals (such as mobile teeth, gingival recession, gingival and oral inflammation, dental fractures and/or discoloration, swelling, discharge). However, proper diagnosis can always only be made with complete oral and dental examination including (at least) full-mouth dental radiographs with the animals under general anaesthesia.
If you have noted any problems with your animal, please consult your veterinarian.