Effects of Phenotypic Characteristics on the Length of Stay of Dogs at Two No Kill Animal Shelters

In this review of dog populations at two no-kill shelters, researchers looked specifically at how physical traits of dogs, as well as their ages, might affect the length of time they stay at the shelter. Without accounting for any sort of “personality” traits, they found a strong relationship between the size of the dog and their length of stay (LOS), but found only tenuous links between the dog’s coat color and their LOS, as well as the type of breed (including “fighting breeds”) and their LOS. Researchers hope that their findings will help shelters tailor their adoption efforts to focus on getting LOS down for all dogs, concentrating first on those that might normally stay in the shelter the longest.

The factors that determine how long animals stay in a shelter before being adopted are of great concern to animal advocates who want to see adoption rates go up and shelter populations diminish. For “no kill” shelters, these numbers are especially important, as animals that don’t get adopted can languish in shelters for weeks, months, and sometimes even longer. This study, looking at two no kill shelters in New York State, attempts to shed some light on how physical characteristics and age might affect the “length of stay” (LOS) for shelter dogs in particular.

Some of the findings of their research may seem obvious: for example, younger puppies tend to have a shorter LOS, and this was not dependent on the sex or the size of the puppies in question. In other words, puppies are very adoptable all around. However, many of the other findings of the study seem to go against the grain of common sense. Giant breeds such as Saint Bernards and mastiffs stayed at the shelter only half as long as more moderately sized “guard” breeds; dogs with darker coats were just as adoptable as dogs with lighter coats; “fighting breed” dogs such as pit bulls did not show a consistently greater LOS than other breeds.

These findings are exceptional in the sense that they seem to contradict prevailing wisdom, particularly around the supposed difficulty of adopting “fighting breeds” and so called “black dog syndrome.” Though the authors of the study do not believe that this sample contradicts those phenomena directly, it is clear from the results of this study that these experiences may not be true of every shelter, and that no kill shelters in particular may be affected by their own set of phenomena based upon location and local culture: “Given the differences among reported findings, efforts should be made to understand the demographics of animals and their adopters at the local shelter level. Understanding these demographics could further improve the ability of shelters to serve animals in their care.”

Original Abstract:
Adoption records from 2 no kill shelters in New York State were examined to determine how age, sex, size, breed group, and coat color influenced the length of stay (LOS) of dogs at these shelters. Young puppies had the shortest length of stay; LOS among dogs increased linearly as age increased. Neither coat color nor sex influenced LOS. Considering only size classifications, medium-size dogs had the greatest LOS, and extra small dogs and puppies remained in shelters for the least amount of time. Considering only breed groupings, dogs in the guard group had the greatest LOS and those in the giant group had the shortest LOS. The lack of effect of coat color was not expected, nor was the shorter LOS among “fighting” breeds compared with other breed groups. Coat color and breed may have only local effects on LOS that do not generalize to all shelters, including traditional shelters. Understanding the traits of dogs in a specific shelter and the characteristics of these nonhuman animals desired by adopters are critical to improving the welfare of animals served by that shelter.