Is there a difference between food intolerance and food allergy?

Food allergy is a genuine allergic response where the immune system becomes overly sensitive to ingredients a pet has previously eaten. For food allergy to occur, the pet must have been exposed to the problematic allergen or a similar one with cross-reactivity. On the other hand, food intolerance doesn’t need prior sensitization and can happen on the first exposure. In dogs and cats, food intolerance reactions typically manifest as gastrointestinal issues like diarrhea or vomiting.