Filarial infections in 447 cats and 68 dogs from six endemic areas of human filariasis in Peninsular Malaysia were studied as part of the study on the zoonotic transmission of subperiodic Brugia malayi infection. 20.6% of cats and 57.4% of dogs had filarial infections. Cats were infected with subperiodic B. malayi, B. pahangi, Dirofilaria repens and D. immitis. Dogs were infected with B. pahangi and D. immitis. 6.9% of the cats had subperiodic B. malayi infection. The zoonotic implications of these infections and their impact on the filariasis control programme in Peninsular Malaysia were discussed.