Elimination diet: Colitis can be caused by food intolerance, either to a specific food or to preservatives, dyes, fillers, contaminants or even the natural proteins in the food. Your dog could also have an allergy to a certain food, such as wheat or corn. The best way to pinpoint these allergies is by feeding a pure diet, one that contains no food product in your dog’s current diet. You can make your own home cooked food or you can buy one of the many allergy specific diets available today, such as duck, rabbit, or sweet potato to name a few. During the eight to ten week test period, the dog can only eat the special food, with no treats or goodies allowed. This is an easy way to determine a food allergy in your dog, and less expensive than the standard skin testing.
Methotrexate is given weekly as an intramuscular injection of 15 to 25 mg. Side effects are rare and include leukopenia and hypersensitivity interstitial pneumonitis. Hepatic fibrosis is the most severe potential sequela of long-term therapy. Patients with concomitant alcohol abuse and/or morbid obesity are more likely to develop hepatic fibrosis and therefore should not be treated with methotrexate. It is prudent to obtain a baseline chest radiograph and to monitor complete blood count, liver function and renal function every two weeks until the patient is receiving oral therapy, and every one to three months thereafter. Before methotrexate therapy is initiated, the risks of treatment and the possible need for a liver biopsy should be discussed with the patient.