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ThesisItem Open Access Pathology of hypothyroidism in pigs(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences,Mannuthy, 1995) Prasanna, K S; KAU; Sreekumaran, TAn experimental model of hypothyroid state was induced in piglets, using thiourea with the objectives of studying the sequence of clinico pathological changes and its influence on the animal health and growth. Tweleve Large White Yorkshire male piglets of 2 – 3 months age were selected for the study. The animals were divided into control group of six animals and experimental group of six animals. Experimental hypothyroidism was induced by feeding thiourea daily for a period of three months at the dose level of 50 mg per kg body weight. Haemogram, body weight, plasma proteins, serum cholesterol and serum thyroxine values were estimated at periodic intervals. The piglets were subjected to detailed autopsy after sacrifice. Gross lesions were recorded and detailed histopathological examination of tissues was carried out. During the course of experiment all the experimental animals recorded stunted growth and appreciable reduction in feed intake and alopecia of neck and shoulder regions. There was significant increase in blood cholesterol values and plasma protein level in thiourea fed group. A significant reduction in serum thyroxine level was also recorded. There was significant increase in the relative weight of thyroid, adrenal and pituitary glands of experimental animals. Gelatinisation of subcutaneous fat and dilatation of right ventricles were common findings at autopsy. Histologically the thyroid glands exhibited varying degree of hyperplastic changes and depletion of colloid in the follicles. Hyperplasia and hypertrophy of the lining epithelium was also observed. Predominant histological changes in the pituitary was hyperplasia and hypertrophy of the basophil cells and degranulation of the acidophil cells. Adrenal glands showed diffuse hyperplasia of zonafasiculata and accessory cortical nodule formation. Skin revealed acanthosis, hyperkeratosis and keratinisation of harifollicles. In all the hypothyroid animals testis showed varying degree of tubular degeneration. A random survey study was conducted to assess the thyroid status of pigs from different parts of Kerala using serum thyroxine as the marker. This concluded that most of the animals had the normal range of serum thyroxine levels.ThesisItem Open Access Determination Of Permissible Level Of Aflatoxin In Broiler Chicken Feed(Department of Pathology, College of Veterinary and Animal Sciences,Mannuthy, 1999) Arulmozhi A; KAU; Koshy VargheseThe study was undertaken to assess the effect of various levels of aflatoxin on the performance of broilers and to establish the permissible level of aflatoxin in the broiler feed. One hundred and eighty day old broiler chicks were divided into six groups of 30 birds each and were given feed containing graded levels of aflatoxin at 0, 20, 40, 60, 80 and 100 ppb for a period of 45 days. Feed intake, weekly body weight gain, feed efficiency, haemogram, serum profile, organ weight, residual aflatoxin in tissues and pathological changes in liver, kidney, bursa and spleen were studied at fortnightly intervals to evaluate its dose related effects. A dose dependent decrease in the daily feed intake and mean body weights were noticed in all the groups. The cumulative FeR was extremely poor at 80 and 100 ppb levels at sixth week of age. The toxicopathological changes in the birds varied in its intensity in relation with the level of aflatoxin in the feed, with most severe changes being at higher dose levels. The values of haemoglobin, PCV, total leucocyte count, Iymphocytes, total serum protein and albumin showed a decrease whereas the ESR, heterophil and serum enzyme were increased. The aflatoxin, even at 20 ppb levels caused degenerative and necrotic changes in liver and kidneys and the intensity of the lesions increased with higher levels of toxin. Attempt for regeneration and repair processes were well pronounced by the 30th and 45th day. Lymphoid depletion was a characteristic feature in bursa and spleen. Degeneration and lysis of lymphocytes with cys; formation was also seen in bursal follicles. Residual aflatoxin was detected in the liver and muscle in all groups by the 45th day. The net returns from the toxin treated birds showed a dose related decline compared to control and the loss in profit at 20 ppb level was marginal About 24 per cent of the poultry feed samples tested during the period from January to July 1999 were contaminated with aflatoxin quantitatively ranging from 20 to 200 ppb. The results of the present study shows that even at 20 ppb aflatoxin causes cellular and subcellular damage to the tissues. However, the economic loss at this level was marginal when compared to higher dose levels. Hence 20 ppb can be considered as permissible level in broiler chicken feed.ThesisItem Open Access Immunopathologic and toxic effects of endosulfan in chick embryo(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2004) Kalai Selvan, P; KAU; Divakaran Nair, NThe present study was undertaken to investigate the immunopathologic and toxic effects of endosulfan in chick embryo. The embryos were exposed to endosulfan at various dose levels through different routes. The weight of the embryo, bursa, thymus and spleen, histopathology of the lymphoid organs, liver, kidney and brain and quantification of the preformed maternal IgY level in the egg yolk were the parameters analysed to study the effects. Endosulfan was found to be teratogenic at the grven dose levels. The abnormalities observed were agenesis of beak, crossed beak, short lower beak, eventration of viscera and curled toe. Endosulfan did not cause any significant gross changes in the developing embryos except mild haemorrhages. Endosulfan treatment did not produce any significant reduction in the weight of the embryos as well as the weight of the lymphoid organs. On histopathological examinations endosulfan was found to be nephrotoxic and hepatotoxic to the embryos. Varying degrees of degeneration and necrosis was evident in kidney and liver. Effect on the bursa, thymus and spleen were mild to moderate where in the degenerative changes predominated. Dose dependent increase in the involution process of the thymus as evidenced by increase in the Hassal's zone was observed. The lesions in the developing lymphoid organs reflected that endosulfan is toxic to the system and going to affect the immunocompetency by way of immunosuppression and thereby rendering the chicks susceptible to various diseases. The study indicated that the endosulfan treatment did not have any effect on the preformed maternal immunoglobulin level in the egg yolk.ThesisItem Open Access Pathology of cardio-pulmonary disorders in canines(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2003) Pradeep, M; KAU; Vijayan, NThe present study was undertaken to assess the prevalence and pathology of various cardiac and pulmonary disorders in dogs. The data collected from the autopsy records maintained at the Centre of Excellence in Pathology, Mannuthy and seventy eight samples of heart and lungs from necropsy cases formed the basis of the study. Ninety nine per cent cases showed varying types of cardiac and pulmonary lesions. The highest incidence in the heart was dilated (75.32 per cent) and hypertrophic (15.58 per cent) cardiomyopathies. The other lesions found were hydropericardium, cardiac tamponade, haemorrhage, myocarditis, endocarditis, endocardial fibroelastosis, valvular blood cyst coronary arteriosclerosis and mural. thrombus. Myocardial infarction was found to be confined to the left ventricles and interventricular septum in all the encountered cases (5.19 per cent). Pulmonary congestion (70.51 per cent), haemorrhage (32.47 per cent) and edema (31.17 per cent) were observed with higher incidence rate. The other lesions found in the lungs were bronchitis, emphysema, pneumonia, collapse, infarction, mineralization, ossification, anthracosis and endarteritis obliterans. Metastatic osteosarcoma in the lungs, metastatic lymphosarcoma in the heart and lungs were also observed. The incidence of cardio-pulmonary disorders encountered was relatively high. The need and scope for investigation into the pathological disorders of the heart and lungs of canines were highlighted.ThesisItem Open Access Gastrointestinal and neurotoxic effects of cypermethrin in rats(Centre For Excellence In Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2008) Remya Nair, R; KAUThe present study entitled ‘Gastrointestinal and neurotoxic effects of cypermethrin in rats’ was undertaken to investigate the potential toxic effects of cypermethrin in rats with particular emphasis on its effect on the nervous and digestive system.The clinical signs, gross pathology, histopathology, haematology and biochemical parameters were analysed to study the effects. Cypermethrin was found to be neurotoxic and gastroenterotoxic at the given dose levels. Oral administration of cypermethrin in medium and high doses produced nervous signs in animals. However cypermethrin did not cause any significant variation in the body weight of animals. All haematological parameters evaluated showed a dose dependent reduction in its value. Biochemical parameters assessed revealed hepatotoxic and multisystemic effects of cypermethrin. Gross lesions observed in the intoxicated groups were bloat, congestion of lungs, heart, brain, pulmonary haemorrhage and degenerative changes in liver and kidneys. On histopathological examination, cypermethrin was found to be neurotoxic, hepatotoxic, enterotoxic, pneumotoxic, cardiotoxic and nephrotoxic as evidenced by varying degrees of degeneration and necrosis in various organs examined. Effects on all organs were mild to moderate degenerative changes at the low dose level. Medium and high dose intoxicated groups revealed necrotic changes, extensive haemorrhages, congestion in organs like liver, kidney and lungs apart from the changes observed in low dose group animals. Haemodynamic disturbances were manifested in the forms of congestion and haemorhages in lungs, heart, liver and kidneys. The histopathological evaluation revealed no cypermethrin induced toxic effects on the oesophagus. Spinal cord lesions were observed only in the lowest dose group. Brain lesions were only degenerative changes. These findings suggested that biochemical effects rather than structural changes were involved in toxicity.ThesisItem Open Access Hepato-renal pathology in canines(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2001) Lakshmi, R; KAU; Koshy VargheseThe present investigation was undertaken to assess the prevalence and pathology of the liver and kidney disorders in canines. The results of the present investigation and the evaluation of data from the records revealed a high incidence of liver (76 percent) and kidney (85 per cent) disorders. A detailed systematic examination of one.hundred cases of canine carcasses brought for autopsy during the period of investigation was conducted and the gross and histopathological lesions were studied in detail and were classified based on age, sex and breed. Vascular and degenerative changes were the predominant lesions in these organs. The other lesions recorded in the liver were necrosis (15 cases), hepatitis (19 cases), fibrosis (9 cases) and cirrhosis (2 cases). One case each of cholangiocarcinoma, hepatic cyst and adhesion of diaphragm and the liver was encountered in the present study. Among kidney disorders, glomerular lesions were predominant next to vascular and degenerative changes. A total of 59 cases had some lesions in the glomeruli of which, 32 hadglomerulonephritis. PGN was the predominant type of glomerulonephritis. Males had a higher predilection for PGN and it was common in animals less than three years of age. MN and MPGN were common in animals more than three years of age. The high incidence of glomerular lesions and their possible causes were discussed. Tubulo-interstitial nephritis was observed in 16 cases. Interstitial nephritis was common in males while both cases of pyelonephritis were seen in females. Acute interstitial nephritis was seen in animals less than five years of age while all cases of chronic interstitial nephritis was seen in animals more than five years of age. Bacterial isolations were obtained in the liver or kidney or both in only 14 cases. Viral etiology was suspected in two cases where intranuclear inclusions were seen in the hepatocytes and the glomerular epithelium. The high incidence of vascular lesions without any evidence for infectious etiology in rest of the animals suggested the involvement of some toxic factors. The importance of identifying the specific etiology in these suspected cases of toxic conditions and the need and scope for further studies in these lines were highlighted.ThesisItem Open Access Prevalence and pathology of dermatological disorders in cattle(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1996) Anilkumar, R; KAU; Rajan, AA study was undertaken to assess the prevalence and pathology of dermatological disorders encountered m cattle m Kerala To study the prevalence of various types of skin disorders data were collected from the Disease Surveillence Report published by the Directorate of Animal Husbandry during the period 1989 1993 The various skin disorders encountered according to this data were tail necrosis (1 44 per cent) cutaneous mycosis (10 58 per cent) Eczematosis (6 09 per cent) pox (4 75 per cent) tick infestation (37 22 per cent) lice infestation (25 72 per cent) mangy dermatitis (13 82 per cent) wart (0 36 per cent) In this study tick infestation was found to be highly prevalent. Dunng the course of this investigation skin biopsies collected from 97 cattle were subjected to detailed gross and histopathological examination They were classified as Cutaneous ulceration (22 68 per cent) Fly bite dermatitis (15 46 per cent) Decubitus ulcers (12 47 per cent) Hyperkeratosis (9 3 percent) Papillomatosis (9 27 per cent) Hypertrichosis (8 25 per cent) Ectoparasitic mjuiy (6 19 per cent) Teat lesions (6 19 per cent) Fibroma (2 07 per cent) Dermatophilosis (1 03 per cent) Squamous cell carcinoma (1 03 per cent) and Fibrosarcoma (1 03 per cent) Cutaneous ulceration was the most common disorder encountered and Biopsies revealed epidermal lysis In fifteen animals fly bite dermatitis was noticed with greyish white necrotic papules and wheals on the neck shoulder ears and around eyes Perivascular changes were seen microscopically Nine cases of hyperkeratosis were studied which may be associated with hypovitammosis A Udder and teat papillomatosis was encountered m nine animals with ballooning degeneration and clumping of keratohyahn granules microscopically Eight crossbred cattle recovered from the foot and mouth disease had hypertrichosis Hair coat was shaggy and wavy Ectoparasztic injury was encountered m cattle mainly due Boophilus infestation Teat lesions encountered were mamly due to traumatic injury and chapping Two cases of fibroma and one case of fibrosarcoma were encountered on the teat of cattle A growth on the vulval region was diagnosed as squamous cell carcinoma An expenmental study on the cutaneous hypersensitivity reaction m cattle to PHA, 2 4 DNCB and BCG was earned out Mast cell response to these mitogens was also studied Effect of Agropesticides Furadan and BHC on local application on the skin of calves were studied Dermatosis was the charactenstic response The need for taking care to avoid pesticide contamination on the skin of animals was stressedThesisItem Open Access Aflatoxin induced cytological alterations in ducks(Department of Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1996) Vigil Anbiah, S; KAU; Manomohan, C BAn experimental study was conducted in desi ducks to assess the cytological alterations induced by aflatoxin Bl (AFB1) and 4 dimethyl amino azo benzene (4 DAB) One hundred and eight desi ducks of one month age were selected for the study The birds were divided into two treatment groups which were given A1 Bl (l0ug/kg body weight and l5ug/ kg body weight) and 4 DAB (5 mg and 10 mg/kg body weight) and a control group each group consisted of thirty six birds Body weight haemogram clotting time total serum protein serum albumin serum globulin albumin-globulin ratio serum aspartate amino transferase serum alanine amino transferase serum bilirubin and cytogenetic assay were estimated at periodic intervals The ducks were subjected to detailed autopsy and histopathology Clinically the exprimental birds were healthy Anaemia leucocytosis and increased blood clotting time were noticed in birds which received 15 ug/kg body weight o f AFB1 and both the dose levels of 4 DAB Total serum protein was reduced in all the treated birds In the aflatoxin group serum albumin and globulin levels were decreased Albumin globulin ratio was increased in 4 DAB tieated buds Serum aspartate ammo transferase level was elevated in buds winch moved 10ug/kg body weight of A1 Bl and 10 mg/kg body weight of 4 DAB Birds which received ATB1 as well as 10 ing/kg body weight of 4 DAB showed an elevation in serum alanine amino transferase level Serum bilirubin was incieased in all the treated birds Those ducks which were fed with AFB1 at 1 5ug/kg body weight showed tendency of hepatoma formation during the experiment The ducks which received 5 mg/kg body weight of 4 DAB exhibited gross and histopathological lesions suggestive of hepatosis and mild curhosis 1 he birds given 10 mg/kg body weight of 4 DAB tevealed gross as well as histopathological lesions of hepatic degeneiutiou and necrosis and indications of neoplatic changes Trend towaids polyploidy was the major chromosomal aberration observed in ducks which received 15g/kg body weight of AFBThesisItem Open Access Neuropathology and diagnosis of rabies in domestic animals(Department of Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1996) Silamban, S; KAU; Ramachandran, K M (Guide)An investigation was made to study the epidemiology, clinical signs, pathologic lesions and diagnosis of rabies in domestic animals in the state of Kerala. Epidemiology of rabies for the last 12 year period from July 1983 to June 1995 was assessed from the post – mortem records maintained at the department of Pathology. Regional distribution, Prevalence in each species and year – wise occurrence were studied. Canine rabies was found preponderant. Rabies was recorded in wild animals also. Detailed clinical signs and gross pathological changes in the rabies positive cases were studied. One hundred and six rabies suspected carcasses of different species of animals were examined for the disease employing Sellers’ impression smear staining, histopathology, fluorescent antibody test (FA test) and immunoperoxidase test (IP test). Twenty – two of them were confirmed positive for rabies. Negribodies were demonstrated with Sellers’ staining and histopathological staining. Sellers’ staining was identified to be the simple and rapid staining method that could be employed in the field laboratories. In addition to H & E, Mann’s stain and Sellers’ stain were applied for staining histological sections. H & E was found to be satisfactory for routine staining. Histological changes in the brain (cerebrum, cerebellum and hippocampus), salivary gland (parotid and submaxillary) and trigeminal nerve of rabies positive animals were studied. The efficacy of the diagnostic techniques used for rabies diagnosis was compared. FA test confirmed maximum number of rabies positive cases. The results of the rabies diagnosis was cross – checked by Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Oregon State University, USA.
