Mapping and measuring disparities in welfare for cats across neighborhoods in a large US city

Abstract

Objective: To determine whether disparities in health and welfare among cats are present within neighborhoods and across census tracts in a large US city, and to compare results with area-level human data.

Sample population: 17,587 cat intake records from 2 animal sheltering organizations serving Boston, and summary data from city animal control authorities for a 5-year period (2004 through 2008).

Procedures: Geocoded addresses (n = 15,285) were spatially joined to neighborhood and census tract polygons. Cat intakes and deaths were calculated per capita and compared with human demographic and death data. Poisson mixed-effects models were used to smooth mortality rates and calculate relative risks.

Results: Data from geocoded records indicated that annual rates of cat intakes and deaths ranged widely (0.85 to 10.3 cats/1,000 persons and 0.27 to 3.9 cats/1,000 persons, respectively) within 16 neighborhoods of Boston. The disparity across 156 census tracts that comprised these neighborhoods was even greater (0.10 to 22.1 cats/1,000 persons and 0.15 to 6.47 cats/1,000 persons for intakes and deaths, respectively). Cat deaths were significantly correlated with human premature deaths at the neighborhood level (R2 = 0.77). Overall, annual per capita city-wide shelter-associated mortality rate for cats (estimated at approx 2.6 cats/1,000 persons) was similar to rates in other progressive communities.

Conclusions and clinical relevance: By use of geospatial techniques, 14- to 40-fold gradients in cat deaths were detected across Boston neighborhoods and census tracts. Cat deaths were associated with human premature deaths and socioeconomic indicators reflecting deprivation. Targeted interventions may be effective in resolving these disparities.