Review your notes on dysphagia. Don't forget to look at those teeth. Pain in these conditions leads to depression, which results in partial anorexia. Conditions such as severe arthritis and chronic laminitis also reduce the horse's mobility, reducing the amount of grazing in pasture raised animals. Analgesics or other more specific treatments, in certain conditions, might lead to increased food consumption and reversal of any weight loss.
Clinical signs vary and clin path data is usually nonspecific.
The erythron usually shows some degree of anemia. Chronic bacterial infections usually show a leukocytosis with a mature neutrophilia. Serum fibrinogen is usually elevated. Abdominocentesis, rectal examination, thoracocentesis, thoracic percussion, and radiographs will be useful in diagnosis. Chronic obstructive pulmonary disease in the later stages is associated with weight loss.