ETIOPATHOLOGY OF LAMB MORTALITY IN RAYALASEEMA REGION OF ANDHRA PRADESH
Loading...
Date
2016-12
Authors
VENKATA RAGHAVENDRA, SANGUBOTLA
Journal Title
Journal ISSN
Volume Title
Publisher
SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA
Abstract
ABSTRACT:
Present study was undertaken to study the etiopathology of lamb mortality in Rayalaseema region of Andhra Pradesh state to find out the prevalence and probable causes for lamb mortality. In an epidemiological survey, a total of 1798 lambs were recorded as dead in four districts of Rayalaseema region, of them the mortalty rate was in descending order Anatapur, Chittoor, Kadapa and Kurnool. The mortality was higher in females than males. Maximum mortality was observed in winter season and at 1-3 months age group. The mortality was majorly due to infectious origin 1533 (85.26%) followed by non-infectious origin 223 (12.4%) and miscellaneous causes 42 (2.34%). Majority of deaths were due to respiratory system affections followed by digestive system affections, multiple system involvement, combined digestive & respiratory systems, non specific affections, circulatory system, urinary system and combined respiratory & urinary system in descending order. Out of 100 faecal samples of ailing lambs examined, 68 samples were positive for different parasitic ova and oocysts. In the age group of 4-6 months it was maximum. The positive cases of parasitic ova in ailing lambs were more in females than in males. Various parasitic ova identified were eggs of Strongyle, Moniezia sp, Schistosoma sp, Haemonchus sp, Paramphistome sp, Trichuris sp and oocysts of Coccidia sp. The samples collected during the postmortem examination revealed ova of Trichuris sp, Moniezia sp, Strongyle and cysts of Balantidium sp. Out of 102 blood samples collected from ailing lambs the blood picture was decreased PCV, Hb, TEC, MCHC, neutrophils, monocytes, eosinophils and increased TLC, MCV, MCH, lymphocytes were observed when compared with apparently healthy group (n=10). Males showed increased PCV, neutrophils, eosinophils, MCV and in females increased TLC, lymphocytes, monocytes and MCHC, where as almost similar Mean±SE values of Hb, TEC were noted in both males and females. Out of 50 serum samples from ailing lambs screened, increased TP, albumin, globulin, A/G ratio, creatinine and decreased calcium, ALT were observed when compared with apparently healthy group (n=10). Increased TP, albumin, globulin, AST were reported in males whereas increased A/G ratio, calcium, ALT in females and similar values of creatinine in both sexes were noted. A total of 53 different samples collected from ailing lambs and affected organs were subjected for culture isolation of microorganisms and molecular characterization by using PCR assay. E.coli, Salmonella sp and S.aureus isolates were obtained by culture method. E.coli isolate was positive for stx2 gene, isolates of Salmonella sp for invA gene and isolates of S.aureus for nuc gene. The prevalence of gross and histopathological changes was noted from 179 dead lambs in Rayalaseema region of Andhra Pradesh during the period of study from December, 2015 to June, 2016. Lambs from Chittoor, Kadapa, Anantapur and Kurnool districts were died in descending order. The mortality was more in females than males. The highest mortality was noted in summer followed by winter. Lambs died at 4-6 months age followed by 1-3 months age, 7-9 months, 10-12 months age and <1 month age in descending order. The mortality of lambs in this region more due to multiple system affections and due to inflammatory origin majorly followed by non inflammatory origin i.e. 179 dead lambs. Inflammatory origin conditions included inflammation of multiple organs involvement was recorded to be highest. Gross lesions in respiratory system observed were tracheitis, congestion, consolidation, suppuration, aspiration, nodular growths and haemorrhages of lungs. In circulatory system, haemorrhages, congestion of coronary blood vessels, gelatinization and necrosis of epicardial fat, small pin point to streaks of pale areas on epicardium and hydro pericardium were observed in heart where as in spleen petechial haemorrhages and congestion were noted. Mild to severe enlargement, edema and hemorrhagic mesenteric lymph nodes and enlarged supra scapular lymphnode in one case were recorded. Congested cerebral blood vessels were noted. In the digestive system, rumen and reticulum filled with plenty of food material (phytobezoars), that was hard and dry, Haemonchus sp worms in abomasum, empty stomach and intestines, duodenal haemorrhages, enteritis (catarrhal and haemorrhagic), thickened intestinal mucosa, congested mesenteric blood vessels, volvulus and tape worms in intestinal portions were observed. The liver showed the lesions including congestion, necrotic areas, haemorrhages, calcification, enlarged and infarcted, cirrhotic changes, icteric patches on surface, larva migrans, abscesses and distended gall bladder. In renal system, softened (pulpy) kidneys, congestion, haemorrhages, cysts in medulla, dilatation of renal pelvis of kidneys, urinary bladder distention and urethral stricture were recorded. Three cases of Anthrax suspected lambs (confirmed by blood smear examination), One dog bite case and three abortion cases reported were not subjected to post mortem. A total of 453 tissue samples of different affected organs included lungs, liver, kidney, heart, intestine, lymphnode, spleen and brain were collected from 179 lambs that were died and subjected to histopathology. In respiratory system, pneumonia was major condition encountered and included different types, non specific pneumonia, suppurative pneumonia, bronchopneumonia, Jaagsiekte, interstitial pneumonia, fibrinous pneumonia, verminous pneumonia, aspiration pneumonia and Suppurative pneumonia combined with Jaagsiekte. In circulatory system, the lesions of heart included myocarditis, presence of Sarcocysts and parasites in myocardium. In spleen, congestion, presence of hemosiderin pigment, thickened trabeculae, degeneration and hyperplasia of splenic corpuscle and lymphoid aggregation around splenic corpuscle were recorded. In mesenteric lymphnodes the lesions included congestion, depletion of lymphoid cells, edema, haemorrhages, fibrous tissue proliferation, reactive hyperplasia, section of parasite, cyst in the vessel and abscess. A case of lymphosarcoma was also observed. Brain lesions like neuronal degeneration, vacuolation, apoptosis, neuronophagia, satellitosis and focal to diffused mono nuclear cell infiltration were observed. In kidney samples, congestion, degeneration of tubules, presence of casts, necrosis of tubules, shrunken glomeruli, fibrous tissue proliferation, cystic spaces, tubular edema, fatty change in glomeruli as well as in tubules, cloudy swelling, presence of hemosiderin pigment, infarction were noted. Accordingly the conditions classified as nonspecific nephritis, glomerular nephritis, haemorrhagic glomerular nephritis, haemorrhagic nephritis, parasitic ova and parasite in cystic fluid were recorded. In intestines congestion, haemorrhages, ulcers, fibrous tissue proliferation, degeneration of glands, various villous abnormalities were observed. The conditions were classified as catarrhal enteritis with parasitic load, nonspecific enteritis, haemorrhagic enteritis, diptheritic enteritis, necrotic enteritis. In liver sinusoidal congestion, fibrous tissue proliferation, focal to diffused necrosis, mild to moderate fatty change, degeneration of hepatocytes, bileduct epithelial hyperplasia and proliferation, calcification, presence of hemosiderin pigment were noted. Further the conditions classified as hepatitis, presence of parasitic ova, granuloma formation, abscess, haemorrhages and fibrotic nodule and bacterial colonies in portal triad.
Description
THESES
Keywords
null