Browsing by Author "Devada, K"

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Anthelmintic resistance in gastrointestinal nematodes of goats
(Department of Veterinary Parasitology, College of Veterinary and Animal Sciences, Mannuthy, 2005) Deepa, C K; Devada, K
Investigation on the prevalence of gastrointestinal nematodes of goats in Thrissur Corporation area was carried out by detecting faecal eggs and larvae after coprological examination and coproculture respectively. The faecal samples for coprological examination were collected from animals brought to the University Veterinary hospitals, Kokkalai and Mannuthy, University Goat and Sheep farm and from nearby houses around Mannuthy. Screening of faecal samples of 320 goats during the period of study from June 2004 to May 2005 revealed 114 as positive (35.63 per cent). The type of positive infection noted were Strongyle (95.61 per cent) and Strongyloides (4.38 per cent) infection. Monthwise prevalence of gastrointestinal nematodes showed maximum infection in May (48 per cent) while a lower prevalence in August (28 per cent). Seasonwise, the prevalence of gastrointestinal nematodes was found to be 30.7 per cent, 33.33 per cent and 39.13 per cent during cold wet South West monsoon (heavy rainfall), warm wet North East monsoon (low rainfall) and dry season respectively. The prevalence of gastrointestinal nematodes was observed to be higher in young goats below one year (42.10 per cent) and in females (85.96 per cent ) than males (14.03 per cent). There was no significant variation between breeds and management . The species of nematodes encountered were Haemonchus contortus (55.26 per cent), Oesophagostomum columbianum (13.15per cent), Trichostrongylus colubriformis (21.05 per cent), Bunostomum trigonocephalum (6.14 per cent) and Strongyloides papillosus (4.38 per cent). The comparative biometry of various infective larvae of the commonly found nematodes were noted. Resistance to various anthelmintics by the nematodes in goats of the University Goat and Sheep farm, Mannuthy were detected by the methods namely Faecal Egg Count Reduction Test (FECRT) and Egg Hatch Test (EHT). Forty kids aged between three to six months were used for this purpose. Faecal Egg Count Reduction Test revealed resistance to albendazole, ivermectin and morantel citrate by the gastrointestinal nematodes. The drugs namely albendazole, ivermectin and morantel citrate showed a per cent worm reductions of 30, 53, 45 with 52, 34 and 62 as lower 95 per cent confidence limits. Specific resistance to benzimidazole group by EHT showed the ED50 value of albendazole (µg per ml) in EHT to be 0.211556 which further established resistance to albendazole by the gastrointestinal nematodes of goats. Anthelmintic resistance is best controlled in the ground level by the use of correct type of anthelmintics at the correct dose against nematodes in goats. Breeding for disease resistance, development and use of vaccines and biological control using nematophagous fungi are the prospective methods for the control of anthelmintic resistance.
Biology, pathogenesis and control of syngamus trachea infection in chicken
(Department of Parasitology, College of Veterinary and Animal Sciences, Mannuthy, 1987) Devada, K; Sathianesan, V
In a study conducted for a period of one year on the biology, pathogenesis and control of Syngamus trachea infection in chicken, it has been found that the infection was more in very young birds below 1 to 2 months of age, reared under the free range system and during the monsoons. The egg cultures became infective on the seventh day of culturing. A dose of 3,000 infective eggs or larvae was found to be suitable for a successful establishment of infection in chicks. Experimental infection could be set up by the direct feeding of the infective eggs or larvae without the necessity of the intervention of any transport hosts like earthworms. A detailed study on the stage to stage development of the parasite was carried out. They established in the trachea by the eighth day and attained patency 18 to 22 days following infection. Gaping movements, nodular growths on the tracheal mucous membrane, haemorrhage and production of mucus in the trachea, consolidation and ecchymosis of the lungs were the chief clinicopathological symptoms observed. Anthelmintic efficacy of mebendazole, thiabendazole, albendazole and ivermectin was assessed on the basis of the reduction of ova in the droppings, disappearance of worms from the trachea and gain in body weight of the treated birds. Mebendazole administered at 40 mg per kg body weight was found to be the most effective among the drugs tried closely followed by albendazole given at 15 mg per kg body weight and then thiabendazole at 500 mg per kg body weight. Ivermectin dosed at 200 micrograms per kg body weight subcutaneously was found to be the least effective. Assessment of the effect of irradiation at 5 KR on the development of S. trachea in chicken was attempted twice with no conclusive results.
Development of a precocious strain of Eimeria tenella
(Department of Veterinary Parasitology, College of Veterinary and Animal Sciences, Mannuthy, 2001) Sangeetha, R; Devada, K
Studies on the prevalence of caecal coccidiosis in • chicken, by referring to the postmortem registers maintained at the centre of Excellence in Pathology, College of Veterinary and Animal Sciences~ Mannuthy revealed that 48.4 per cent of 550 coccidia positive viscera was due to Eimeria tenella. A pure line of E. tenella was established in the laboratory by single oocyst isolation technique from a virulent field case of caecal coccidiosis in chicken. A stabilised strain of E. tenella was developed by administering a dose of 1.5x103 sporulated pure line E. tenella oocysts per bird orally to six three to five day old coccidia free White Leghorn chicks and harvesting the caecal contents at 168 hr pi for 15 cyclic~l passages. For the development of a precocious strain of E. tenella a dose of 1.5x103 sporulated E. tenella oocysts per bird was administered orally to six, three to five day old White Leghorn chicks. The caecal contents were harvested at 136 hr pi and the oocysts were allowed to sporulate and subsequently repassaged by applying selection pressure in increments of one hour reduction at each passage. At the end of 18 cyclical passages, oocysts obtained at 125 hr pi were designated E. tenella. as the precocious strain of A comparative study between the precocious and stabilised strain of E. tenella revealed the following observations~ The prepatent period of the precocious strain was 125 hr while that of the stabilised strain was 135 hr. The oocyst morphology did not reveal any significant difference between the two strains. The precocious strain was less pathogenic and produced milder clinical signs than the stabilised strain. The gross lesions of caeca were less morbid in the precocious strain infected group. Weight gain was more in the precocious strain infected group than in the stabilised strain infected group. The precocious strain produced less mortality and showed a drop in oocyst production. Endogenous study revealed an accelerated growth in the early stages of the asexual life cycle in the precocious strain infected group
Immunodiagnosis of bovine gastrothylacosis using coproantigens
(Department of parasitology, College of Veterinary and Animal Sciences, Mannuthy, 2000) Kandasamy, A; Devada, K
A study was conducted on the prevalence of paramphistomatidosis in Thrissur from June 1999 to May 2000, feasibility of coproantigen detection by ELlSA and comparison of sensitivity of ELlSA using coproantigens and ELlSA using serum antibodies in diagnosis of gastrothylacosis, caused by Gastrothy/ax crumenifer, in cattle. It was noted from the registers maintained at the University Veterinary Hospitals at Kokkalai and Mannuthy and that at the Department of Veterinary Parasitology, College of Veterinary and Animal Sciences, Mannuthy, that out of a total number of 1534 faecal samples from bovines examined, 253 (16.5 per cent) animals were found to be positive for amphistome eggs with the maximum prevalence (23 per cent) in June and July. Generally the infection was prevalent throughout the year. An indirect ELlSA using rabbit hyperimmune serum against somatic antigens of G. crumenifer was performed to detect coproantigens in faecal samples collected from 100 known G. crumenifer infected cattle. Seventy four samples were found to contain detectable levels of coproantigen indicating a sensitivity of 74 per cent. Serum samples collected from the same infected cattle were tested for antibodies to G. crumenifer by an indirect ELlSA using somatic antigens. Fifty one samples were found positive for antibodies indicating a sensitivity of 51 per cent. It was seen that when 43 cattle were positive for both coproantigens and serum antibodies, 18 cattle were negative for both of them. Although 31 cattle which were negative for serum antibodies were found positive for coproantigens, eight cattle negative for coproantigens were found positive for serum antibodies. The results showed that coproantigen detection, which revealed a higher sensitivity than the detection of serum antibodies by ELlSA, is feasible for the diagnosis of gastrothylacosis in bovines.
Immunodiagnosis of toxoplasmosis in goats
(Department of Parasitology, College of Veterinary and Animal Sciences, Mannuthy, 1997) Syamala, K; Devada, K
A serological survey was carried out on the prevalence of caprine toxoplasmosis in Kerala, by two simple and sensitive serological tests-modified agglutination test (MAT) and carbon immuno assay (CIA). A total of 152 goat sera were collected from the Government Goat Farms, Attappady and Kommeri, Kerala Agricultural University Goat Farm, Mannuthy and from the slaughter houses at Trichur and Ernakulam. The MAT carried out for Toxoplasma gondii antibodies revealed 53.29 per cent as seropositive while CIA revealed 44.07 per cent. A higher prevalence was detected among does than in bucks. A remarkable age-wise prevalence was not observed in this study. Eventhough a higher prevalence was noticed in Malabari breeds, as the number of goats in each breed was too uneven, a breed-wise prevalence could not be ascertained. Area-wise, a higher prevalence was noticed in goats that belonged to Kannur district, both by MAT and CIA. Modified agglutination test was a sensitive and specific test for the serological surveys on caprine toxoplasmosis, while CIA was a cost effective and simple test which could be made use of under our field conditions. The methods of maintenance and propagation of T. gondii RH strain in mice in the laboratory were standardised and it was found that a dose of 0.30 ml of '+++' infective fluid given intraperitoneally was sufficient for propagation of the strain in mice in the laboratory. White mice experimentally inoculated subcutaneously and intraperitoneally, exhibited similar symptoms like huddling in one corner, anorexia, rough hair coat, respiratory distress and ascites. The intracerebrally inoculated mice showed epileptic symptoms and blindness. Haemorrhage and congestion of lungs, catarrhal inflammation of stomach and intestine and necrosis of liver were the main gross lesions noticed in the acutely infected mice. Alveolar and interstitial pneumonia coagulative necrosis of liver, destruction of tubular and glomerular epithelium of kidney, necrosis of spleen and destruction of cardiac musculature were the prominent microscopic changes observed. Infection in mice by bioassay with acid pepsin digested visceral organs of acutely infected mice was successful. This indicated that T. gondii tachyzoites could survive acid pepsin for 75 min, as the tissues utilised for bioassay carried only Toxoplasma tachyzoites. Studies on the sensitivity of T. gondii tachyzoites to heat revealed that they could be killed by incubating at 56°C for 30 min or boiling at 100°C for five minutes. The method of cultivation of T. gondii tachyzoites in duck embryos by the chorioallantoic membrane route was successful resulting in yellowish white pock lesions on CAM, with congestion and haemorrhage on embryos and brain. A successful cryopreservation of T. gondii using tris-glycerol as cryoprotectant for 145 days at -20°C and for 250 days at -56°C was achieved.
Prevalence and treatment of bovine coccidiosis
(Department of Parasitology, College of Veterinary and Animal Sciences, Mannuthy, 2000) Sreevidya Nambiar, K; Devada, K
A detailed study on the prevalence, clinical pathology and treatment of coccidial infections in cattle belonging to all age groups was undertaken at the Veterinary Hospitals, University Livestock Farm, Buffalo Breeding Station, Cattle Farm, Pattambi, KeralaAgricultural University and other localities in Thrissur during the period from June 1999 to May 2000. The prevalence of the infection was found to be 2.2 per cent. On the whole, the incidence of coccidiosis was found to be high in animals below one year, and female animals, during the rainy and humid months. Clinical signs; predominantly blood tinged or foul smelling diarrhoea and the microscopical examination of the faecal samples from suspected cases were made use of for diagnosis. Eight Eimerian species causing coccidial infections in cattle were identified and they were Eimeria bovis (35 per cent), E. zuernii (55 per cent), E. subspherica (10 per cent), E. ellipsoidalis(60 per cent), E. cylindri ca (fi ve per cent), E. bareillyi (five per cent), E. brasiliensis (five per cent) and E. wyomingensis (10 per cent). The most commonly encountered species were E. ellipsoidalis, E. bovi s, and E. zuernii. Haematological studies of clinically infected animals revealed reduction in the values of haemoglobin, packed cell volume, total leukocyte and lymphocyte counts. A reduction in serum total protein and globulin fractions was also observed during the assay of serum protein fractions in these animals. Treatment trials against bovine coccidiosis using drugs, Sulphadimidine sodium (125 mg per kg body weight for three days), Amprolium hydrochloride (20 mg per kg body weight for five days) and Salinomycin (2 mg per kg body weight for 21 days) orally resulted in nearly cent per cent efficacy in the clinically affected animals. All the three drugs were found to be equally effective.
Prevalence, pathology and treatment of coccidiosis in rabbits
(Department of Veterinary Parasitology, College of Veterinary and Animal Sciences, Mannuthy, 2002) Shameem, H; Devada, K
A detailed study on the prevalence, pathology and treatment of coccidial infections in rabbits belonging to all age groups, breeds and sex was undertaken at the Rabbit Research Station, Mannuthy and at six local rabbi tries in and around Thrissur during the period from October 2001 to September 2002. The overall prevalence was observed as 18.54 per cent. The prevalence of , coccidiosis was found to be high in young rabbits below three months and in female rabbits ofNew Zealand Whiteduring the months of heavy rainfall. The infection was diagnosed by the microscopical examination of faecal samples and clinical signs which included diarrhoea, soiled fur, anorexia and loss of condition. Subclinically affected rabbits showed no apparent signs except growth retardation and reduced feed intake. Six eimerian species causing coccidial infections in rabbits were I identified. Mixed infections were common and the commonly encountered species were E. magna, E. perforans and E. media. They were found as Eimeria media (80 per cent), E. magna (86 per cent), E. perforans (86 per cent), E. coecicola (50 per cent), E. jlavescens (15 per cent) and E. piriformis (8 per cent). Gross lesions found in the dead rabbits brought for postmortem at the Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy comprised of oedematous, thickened intestine with circumscribed greyish white foci on the mucosa. Histopathological examination of the intestine revealed characteristic lesions of intestinal coccidiosis with schizonts and gametogonic stages in the / epithelium of the intestine. Active inflammatory reaction with mononuclear infiltration was noted. The tips of villi showed necrotic changes and desquamation of epithelial cells resulted in villous atrophy. Haematological studies of infected animals revealed reduction in the values of PCV, Hb and erythrocyte count and a slight increase in leucocyte count when compared to the apparently healthy animals. Therapeutic trials against rabbit coccidiosis usmg drugs like sulphadimidine sodium (200 mg per kg body weight for three days), furazolidone (10 mg per kg body weight for five days) and metronidazole (40 mg per kg body weight for three days) orally, showed sulphadimidine sodium as the drug of choice. The other two drugs did not give satisfactory results. The mean clearance values of the three drugs were 99.68 per cent, 85.48 per cent and 69.92 per cent respectively.