Summary & Analysis: Food-related aggression in shelter dogs: a comparison of behavior identified by a behavior evaluation in the shelter and owner reports after adoption

To best understand this article in the context of the behavior evaluation literature, please see National Canine Research Council’s complete analysis here.

Article citation:

Marder, A. R., Shabelansky, A., Patronek, G. J., Dowling-Guyer, S., D’Arpino, S. S. (2013). Food-related aggression in shelter dogs: a comparison of behavior identified by a behavior evaluation in the shelter and owner reports after adoption. Applied Animal Behaviour Science 148(1-2), 150–156. doi:

National Canine Research Council Summary and Analysis:

This article is included as the most comprehensive of only 3 we are aware of (the others are Van der Borg, Netto, & Planta, 1991 and Mohan-Gibbons, Weiss, & Slater, 2012) that contains data on dogs who failed a behavior evaluation but were nonetheless adopted. And even at that, only dogs who tested as mildly expressing the behaviors of interest (growling, snarling, snapping, and biting a fake hand) were made eligible for adoption and therefore for inclusion in this prospective study. The results not only suggest validity issues, but call into question whether the behaviors tested for are actually of interest to pet owners.

The purpose of Marder, Shabelansky, Patronek, Dowling-Guyer, and D’Arpino’s 2013 study was to assess the relationship between the presence or absence of food aggression (FA) as diagnosed by a behavior evaluation in the shelter and presence or absence of the same behaviors in the adoptive home, as well as owners’ perceptions of these behaviors. The authors explain that it is imperative to better understand these questions because dogs who are labeled as food aggressive in shelters have grim outlooks for adoption. They point to a 2012 online survey by Mohan-Gibbons et al. which found that the most common reason for deeming a dog unadoptable was signs of aggression over food or non-food items, and that slightly more than half of shelters surveyed made no attempts to adopt out these dogs. These statistics are concerning because it is not clear whether FA+ in the shelter setting and/or during behavior evaluations predict FA+ in the adoptive home. Moreover, they found little evidence to suggest FA+ is a serious concern for adopters. Marder et al. (2013) sought to clarify these points by following up with owners who had adopted dogs deemed FA+ (food aggressive) and FA- (not food aggressive) at the shelter.

Behavior evaluation data was collected from two subtests of the Match-Up II Shelter Dog Rehoming Program and involved using a rubber hand on a stick to interfere with the dog and her food items while eating. The authors were aware of the questionable construct validity of the rubber hand devise (see discussion in the overview literature review for an analogous question of the value of testing responses to fake dogs in predicting reactions to real dogs) but this commonly used method for testing FA  was not the subject of this study. Behaviors that constituted failing the test included snarling, snapping, growling, lunging, and biting behavior in response to the rubber hand circling the food dish, pulling it away while the dog ate, resting inside the food dish, and separately touching a treat that the dog had been chewing for 30 seconds .

Both dogs who passed and dogs who failed the FA test were adopted into homes and their owners were subsequently surveyed regarding their in-home behavior, although those judged as exhibiting “severe” behaviors were excluded. Ninety-seven dogs were included in the final sample. Overall the response rate was low (43%), but there was no statistical difference in response rate between owners who had adopted FA+ dogs and those who had adopted FA- dogs. The follow-up surveys asked participants if they considered their dog to be FA+, and if so, how big of a challenge it presented. If respondents reported that their dog was not FA+, they were asked to estimate how challenging it would be if their dog was FA+. All participants were then asked if given the chance, how likely they would be to adopt the same dog again. Data showed that the behavior evaluation’s negative predictive value was much stronger (78%) than its positive predictive value (55%). In other word, dogs who failed the test had little more than a 50/50 chance of exhibiting the behavior in a home, but those who passed were indeed unlikely to express FA once adopted. Twenty of the ninety-seven dogs (21%) were deemed FA+ on the behavior evaluation. In the home, 28 of the 97 (29%) showed FA+ behavior, but the majority of these dogs (82%) exhibited the mildest forms (growling and showing teeth) and 93% presented the behavior only rarely.

Also interesting to note is the adopters’ perceptions of their dogs’ behavior and attitudes towards potential FA+. None of the adopters considered their dogs to be FA+; 93 participants said they did not consider their dog to be FA+ (including 26 of the 28 who had observed FA+ behavior in the home) and the remaining 4 were unsure. Moreover, when asked if having a FA+ dog would be challenging, only 5% of owners said it would be “a great challenge” and 28% said it would be “not a challenge at all.” Finally, and perhaps most telling, most adopters said that if given the chance, they would be very likely to adopt the same dog again. This apparent attachment was true for dogs who had exhibited FA+ behavior and those who had not.

There is a potential confound regarding the owner perception data: owners who adopted FA+ dogs were informed of that categorization and were counseled on how to interact with the dog, so one might assert that this population is more forgiving of FA+ behavior or that the information they received helped mitigate problems at home. Of course, this only highlights the fact that there is a population willing and able to adopt these dogs, thus it is a moot point.

This study revealed three important concepts regarding shelter dogs and FA; 1) nearly half of dogs who show FA+ behavior on a behavior evaluation will not exhibit the same behavior in the adoptive home, 2) even owners who occasionally observe FA+ behavior do not consider their dog to be food aggressive, and 3) owners do not find FA+ behavior to be particularly challenging.

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