Health and Ecological Aspects of Stray Cats in Old San Juan, Puerto Rico: Baseline Information to Develop an Effective Control Program

Jessica Castro-Prieto, Maria José Andrade-Núñez


The overpopulation of stray cats in urban areas represents a potential risk for humans, as stray cats may carry diseases, such as toxoplasmosis, and virus such as rabies, the feline immunodeficiency, and the feline leukemia. In Old San Juan, a historic neighborhood and one of the most touristic places in Puerto Rico, there is an overpopulation of stray cats. In this study, we generated baseline information fundamental to developing a successful control program by estimating the stray cat population size, density, and spatial distribution. Furthermore, we quantified the number of neutered cats and developed a spatial database to include information about the external physical condition of each individual. We estimated a population of 178 (±21) cats, with a density of 3.6 cats/ha. Overall, we observed 209 cats, from which 149 (71%) were identified as new and 60 (29%) were recaptured. We found stray cats had a significant non-random and clustered spatial distribution (z-score = -19.39 SD; ratio = 0.29; p<0.0001), with an observable larger abundance in residential zones where food was provided. A total of 105 (70%) cats were neutered, and 32 (21%) individuals exhibited very poor physical conditions, including skin problems, scars, underweight, and blindness. We concluded that the ecological and descriptive data generated in this study are essential for an effective control of stray cats and their potential impacts on humans living in this neighborhood.


stray cats; population size; public perception; Puerto Rico; spatial distribution

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