Summary of Tufts University study on the effect of dietary
protein on dog behavior
In this study, four groups of
dogs were fed diets containing three different protein levels and the behavior
over time recorded by the dogs’ owners and the supervising veterinarians.
Only one sub-group was reported to show any effect of changes in protein
intake; in the rest, no differences in behavior were noted.
The dogs were each classed into one of four behavior groups: those who
showed Dominance aggression, those who showed Territorial aggression, those
considered to be Hyperactive, and those whose owners reported no behavioral
problems. Each group was fed a low (17%), medium (25%) and high (32%) protein
diet for a two week period and owners were instructed to score their dogs’
behavior on a daily basis.
All dogs in the study were neutered adults, in good health as determined
by examination and blood tests. Owners were instructed not to do any behavior
modification (training) during the testing period. Each dog’s behavioral
diagnosis was confirmed by an interview between the dog’s owner and a veterinary
behaviorist. All dogs in the aggressive groups displayed a minimum of 2 episodes
per week in the three months prior to the study. The hyperactive dogs were
referred by their own veterinarians.
During the first two weeks of the study, all the dogs were fed their regular
diets and their behavior scored by their owners. Areas scored were territorial
aggression (aggressive toward strangers at home), dominance aggression (aggression
toward owners), excitability, and fearfulness. Then each group was fed each
of the test diets for two-week periods and their behavior scored during
that time. Caloric intake was kept uniform by keeping the amount of carbohydrate
stable and adjusting the fat content to compensate for the differing protein
levels.
Within the Territorially aggressive group, two sub-groups were identified:
those who had pronounced dominant tendencies and those who had pronounced
fearful tendencies. While the scores for fearfulness did not vary for any
of the dogs in any of the groups during the tests, the scores for Territorial
aggression changed significantly for the Territorially aggressive/Fearful
group when fed the low and medium protein diets. For the rest of the groups,
behavior did not vary significantly with the changes in diets.
The study concluded that a reduction in dietary protein is not generally
useful in the treatment of behavior problems, with the possible exception
of those with territorial aggression that is the result of fear.
Summarized from an article in the February 1996 issue of the Journal of
the American Veterinary Association (JAVMA)
Original article co-authored by: Nicholas H. Dodman, BVMS; Ilana Reisner,
DVM; Louis Shuster, PhD; William Rand, Ph.D; U. Andrew Luescher, DVM; Ian
Robinson, PhD; Katherine A Houpt, VMD, PhD.