A recent blog from a veterinarian on PetMD, a pet health website, cautions pet owners about following a new petfood trend of feeding petfoods that contain "novel" ingredients.

Dr. Jennifer Coates says petfood manufacturers have started to include "whacky ingredients" in their over-the-counter petfoods, such as buffalo or kangaroo. These novel ingredients in petfood may be helpful to pet owners looking to switch their pet's diet to address a special condition such as allergies.

Previously, she says, a lamb and rice formula was popular for managing these special conditions, but became a less-effective treatment option after becoming widely available. Petfood companies saw the opportunity in this to bring petfoods with new ingredients to the market, making these novel ingredients available over the counter for the first time, Coates says.

However, she cautions pet owners that feeding a limited or novel ingredient food for no reason may lead to problems in the future for pets that would develop a tolerance to these ingredients. She also says that pet owners should realize that if they try a novel ingredient food at home, but do not eliminate other potential causes for the pet's symptoms, the condition still may not improve and the will not know what ingredients to blame.

"Don’t feed a novel ingredient food to your pet without a very good reason to do so," Coates says. "You should think of these products almost like you would an antibiotic. If we misuse them now, they may not be effective in the future."