Diet trial monitoring
One can find variable recommendations regarding the length of time necessary to see improvement once a patient is placed on
the hypoallergenic diet, with some recommending a 12-week diet trial. In my experience, it is rare for a food-allergic patient
to not show measurable improvement within four to six weeks, so six weeks is our normal recommended length. Requiring clients
and patients to struggle on for 12 weeks without seeing improvement in clinical signs can cause many owners to lose faith
with the entire process, leading the owners to abandon the food trial and possibly seek out a different opinion. It may require
more than six weeks for the maximum improvement to be seen, but at least the patient is improving during the process, which provides encouragement to continue
During the food trial, it is important to minimize the other causes of pruritus that will interfere with the ability of the
client and veterinarian to determine the success or failure of the food trial. Zealous flea control in flea endemic areas
is necessary. Monitoring for and treating secondary infections (pyoderma and Malassezia dermatitis) is also necessary. These infections are often the reason a food trial is being performed in the first place,
so it is not uncommon to treat the patient with appropriate antimicrobial therapy potentially for the first half of the food
trial. Further counseling is then needed to ensure the medications are not administered in a treat.
In Part 3 of this series, I will discuss common pitfalls to avoid when performing diet trials.
Dr. Lewis sees dermatology patients in California, Arizona, Nebraska, New Mexico and Washington. In 1991, he established Dermatology
for Animals, PC.
1. Mueller R, Tsohalis J. Evaluation of serum allergen-specific IgE for the diagnosis of food adverse reactions in the dog. Vet Dermatol 1998;9:167-171.
2. Olivry T, Bizikova P. A systematic review of the evidence of reduced allergenicity and clinical benefit of food hydrolysates
in dogs with cutaneous adverse food reactions. Vet Dermatol 2010;21(1):32-41.