Seroepidemiology revealed neosporosis as an under-realised entity in dairy cattle reared in South India.

From the dairy herds (n = 16) reared in few localities of South India with the history of reproductive inefficiency and incidental abortion, 176 sera samples from Jersey (n = 108) and Holstein Friesian (n = 68) crossbred cows were collected to detect prevalence of bovine neosporosis antibodies induced by Neospora caninum (N. caninum) through competitive enzyme linked immuno-sorbent assay (cELISA). The overall true prevalence was found as 23.5% whereas 7.7, 19.1, 25.7 and 40.5% was observed in cows of less than 1 year, 1 to 3 years, 3 to 6 years and above 6 years of age, respectively, denoting that increase in prevalence of N. caninum antibody correlated directly with the age. Among the cattle with and without abortion, 41.1 and 20.6% of true prevalence was found, respectively. The breed-wise true prevalence was 24.3 and 22.2% in Jersey and Holstein Friesians crossbred cows, respectively, indicating that crossbred cows of both breeds are equally susceptible to neosporosis. The prevalence of N. caninum antibody might be attributed to coexistence of dogs resulting in contamination of feed with dog faeces. The presence of dogs with the cattle herd predisposed the herd 3.59 times more to acquire neosporosis than the herd without dogs. The annual estimated economic loss in an aborted herd of having 11 animals was 0.23 million INR due to loss of both calf and milk yield.

Herd-level risk factors for bovine viral diarrhea infection in cattle of Tamil Nadu.

A cross-sectional study was carried out to identify risk factors for bovine viral diarrhea virus (BVDV) infection in 62 randomly selected dairy herds which were tested for BVD serum antibodies by using an indirect ELISA kit (IDEXX). Results from the chi-square test analysis were interpreted by analyzing by chi-square test. A sum of 500 sera samples were screened and 66 animals (13.20%) showed positive for BVDV antibody. Within herd, BVD seroprevalence was 12-65%. This study concluded that epidemiological risk factors like location, herd size, housing patterns like, tail to tail system, roofing pattern, distance between the manure pit and farm, and distance between farms were significantly associated with BVDV serological status (P < 0.05).

Development of indirect enzyme-linked immunosorbent assay for diagnosis of canine leptospirosis.

AIM: This study was taken up to develop an indirect enzyme-linked immunosorbent assay (i-ELISA) for screening antibodies against Leptospira spp. in canines. MATERIALS AND METHODS: An i-ELISA was developed using outer membrane protein extracted from Leptospira interrogans serovar canicola used for coating the well with concentration of 0.5 µg/µl. A total of 250 serum samples from clinically affected and apparently healthy dogs were collected along with relevant epidemiological data at Teaching Veterinary Clinical Complex, Veterinary College and Research Institute, Namakkal, and subjected to i-ELISA. RESULTS: Out of 250 sera samples, 140 (56.00%) were found to be positive by i-ELISA. All the sera samples were subjected to microagglutination test (MAT) with panel of 12 different serovars. A total of 71 (28.40%) sera samples were positivity to MAT excluding the sera samples positive to L. interrogans serovars canicola and icterohaemorrhagiae in vaccinated dogs. Sensitivity and specificity of i-ELISA were higher in compared with MAT was 91.54% and 58.10%, respectively. CONCLUSION: An indirect ELISA developed for the detection of canine antileptospiral antibodies proved to be highly sensitive, rapid and easy to perform and overcome the drawbacks of MAT.

Seroprevalence of Leptospiral Antibodies in Canine Population in and around Namakkal.

Leptospirosis is a reemerging and a complex zoonotic bacterial disease, caused by pathogenic serovars of Leptospira interrogans. A total of 124 sera samples of dogs belonging to different categories like vaccinated, unvaccinated-semiowned, and stray dogs were subjected to sampling. Microscopic agglutination test (MAT) was conducted by using Leptospira culture. Out of 42 vaccinated dogs, 24 (57%) were positive to one or more serovars. Of the 24, 22 (52.3%), 11 (26.19%), 4 (9.5%), 1 (3%), and 2 (4.7%) were positive to icterohaemorrhagiae, canicola, pomona, grippotyphosa, and autumnalis, respectively. Of the 48 unvaccinated semiowned dogs, 10 (28.8%) showed positive agglutination to one or more serovars. Of the 10 samples, 7 (14.5%), 2 (4.1%), 3 (6.2%), 3 (6.2%), and 5 (10.2%) were positive to icterohaemorrhagiae, canicola, pomona, grippotyphosa, and autumnalis, respectively. Among the 34 stray dogs, 12 showed positive agglutination to one or more leptospiral antibodies. Of the 12 samples, 6 (17.6%) showed positive agglutination to icterohaemorrhagiae, 2 (5.8%) to canicola, 5 (14.7%) to pomona, 7 (20.5%) to grippotyphosa, and 5 (4.7%) to autumnalis. This study emphasized the changing trends in the epidemiology of leptospirosis with higher prevalence of serovar L. grippotyphosa in street dogs.