Density estimates of rural dog populations and an assessment of marking methods during a rabies vaccination campaign in the Philippines.
We estimated the population density of dogs by distance sampling and assessed the potential utility of two marking methods for capture-mark-recapture applications following a mass canine rabies-vaccination campaign in Sorsogon Province, the Republic of the Philippines. Thirty villages selected to assess vaccine coverage and for dog surveys were visited 1 to 11 days after the vaccinating team. Measurements of the distance of dogs or groups of dogs from transect lines were obtained in 1088 instances (N = 1278 dogs; mean group size = 1.2). Various functions modelling the probability of detection were fitted to a truncated distribution of distances of dogs from transect lines. A hazard rate model provided the best fit and an overall estimate of dog-population density of 468/km2 (95% confidence interval, 359 to 611). At vaccination, most dogs were marked with either a paint stick or a black plastic collar. Overall, 34.8% of 2167 and 28.5% of 2115 dogs could be accurately identified as wearing a collar or showing a paint mark; 49.1% of the dogs had either mark. Increasing time interval between vaccination-team visit and dog survey and increasing distance from transect line were inversely associated with the probability of observing a paint mark. Probability of observing a collar was positively associated with increasing estimated density of the dog population in a given village and with animals not associated with a house. The data indicate that distance sampling is a relatively simple and adaptable method for estimating dog-population density and is not prone to problems associated with meeting some model assumptions inherent to mark-recapture estimators.
Childs
J E
JE
Division of Viral and Rickettsial Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA. jfc5@ciddvd1.em.cdc.gov
Robinson
L E
LE
Sadek
R
R
Madden
A
A
Miranda
M E
ME
Miranda
N L
NL
D000823:Animal Identification Systems; D000818:Animals; D003625:Data Collection; D004283:Dog Diseases / Q000517:prevention & control*; D004285:Dogs; D016015:Logistic Models; D010679:Philippines; D011156:Population Density; D011818:Rabies / Q000517:prevention & control / Q000662:veterinary*; D011819:Rabies Vaccines; D012424:Rural Population; D012494:Sampling Studies
D011819:Rabies Vaccines