A survey of helminths in stray cats from Copenhagen with ecological aspects.

At autopsy of 230 adult stray cats, 120 from backyards and 110 from gardens, the intestinal tract was scrutinized for helminths. The prevalence ofToxocara cati, Taenia taeniaeformis andDipylidium caninum was found to be 79%, 11% and 14%, respectively. Comparisons were made with the results of previous Danish investigations. The prevalence ofToxocara cati was found to be independent of time of collection and the sex and habitat of the cats and identical in cats with or withoutTaenia. This indicates that paratenic hosts do not play an important epizootiological role in the transmission ofT. cati. The intensity ofToxocara per cat followed a negative binomial pattern. The high prevalence ofT. cati combined with most cats having a low wormload shows that the cat population generally possesses a high degree of resistance against superimposed infections. The intensity of maleToxocara increases with the size of the worm population. This we consider to be an expression of increasing susceptibility of the cats. The prevalence ofT. taeniaeformis was significantly higher in garden cats, due to their greater opportunity for catching mice.D. caninum, however, was significantly more frequent in backyard cats, probably owing to better living condition for the flea larvae in backyards. For bothT. taeniaeformis andD. caninum a higher frequency was found in female cats, which is thought to be associated with their care for the kittens.