Lymphatic filariasis caused by filarial nematodes, Brugia malayi and Wuchereria bancrofti is a major vector borne disease prevalent in human beings in the tropics. This study was carried out in the Department of Clinical Veterinary Medicine, College of Veterinary and Animal Sciences, Mannuthy to estimate the seroprevalence of lymphatic filariasis, if any in domesticated pets in Kerala, India using filarial antibody detection spot/immunodot test. Of the 100 clinically suspected cases of filariasis, 80% dogs were found to be positive for microfilaria on wet blood film examination. Staining of blood smear with Giemsa stain demonstrated that 16 (20%) out of 80 dogs were positive for sheathed microfilaria and remaining were nonsheathed. The staining characteristics of sheathed microfilaria were in agreement with the microfilaria of the zoonotic human lymphatic filariae, Brugia malayi. Sera from 16 dogs with sheathed microfilariae, 6 dogs with non sheathed microfilariae and 6 non microfilaraemic healthy controls were utilized for immunological test using Signal MF Reagent (filarial antibody detection spot/immunodot test kit). Out of 16 cases with sheathed microfilariae subjected to immunospot test, 8 samples showed clear positive reaction, 4 samples showed faint reaction and the other 4 samples showed negative result. Twelve cases, six each of nonsheathed microfilariae and control animals exhibited negative reaction . Immunological test was done using Signal MF Reagent which is a a rapid flow-through immune filtration test using recombinant filarial antigen WbSXP-1 for detecting IgG antibodies of brugian and bancroftian filariasis in human beings in an endemic area and the sensitivity of the test was found to be 90.8% with brugian and 91.4% with bancroftian filariasis. Failure of detection of antibody in four cases with sheathed microfilariae subjected to immunospot test might be due to varying degrees of chronicity of the disease in these patients. All the animals with nonsheathed microfilariae subjected to immunospot test showed negative reaction indicating the absence of cross reactivity. This high seroprevalence of human lymphatic filarial parasite in pet animals is a matter of immediate concern and necessary control programme is urgently required to check the transmission of this zoonotic filariasis. This may also be applicable to other countries where human lymphatic filariasis is endemic.