Currently, the best diagnostic procedure to identify adverse food reaction remains an elimination diet in small animals:
Novel or hydrolyzed protein.
Fed exclusively.
For at least 8 weeks.
Approximately 50% of food-allergic cats may respond to strict prescription diet trials in 30 days; however, 8 weeks may be needed to capture a diagnosis in more than 90% of cases.
Prescription source.
Antipruritic medication can be needed to provide relief at the beginning of the diet trial. Glucocorticoids or cyclosporine can be used.
Consider a topical or long-lasting isoxazoline at the beginning of the trial to avoid oral flea and tick medication.