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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 Utero-ovarian and endocrine pathology in goats(Centre for Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2008) Thomas, K Thomas; KAU; Vijayan, NThe present study was aimed at finding out the various utero ovarian disorders affecting goats and correlating with the lesions of pituitary, thyroid and adrenal glands. A total number of 1000 genital tracts were examined for utero-ovarian disorders. Out of which 84 genitalia showed one or more lesions in the ovary, oviduct and uterus. A total of 54 cases out of 84 showed lesions in the ovaries. The follicular cysts were the most common condition and were recorded in 14 cases (1.4%). The other conditions encountered were ovarian hypoplasia (0.6%), luteal cyst (0.3 %), embedded corpus luteum (0.3 %), persistent corpus luteum (0.2 %), ovarian haematoma (0.2 %), ovarian sclerosis(0.4 %), senile atrophy (0.3 %), follicular atresia (0.4 %), epoophoron (0.2 %), serous inclusion cyst (0.2 %), parovarian cyst (0.6 %) and perioophoritis (0.3 %). Seven cases showed lesions in the oviduct. The conditions encountered were hydrosalpinx (0.2 %), hyperplasia of the salpingeal epithelium (0.2 %) and ovario-bursal adhesion (0.3%).Uterine disorders were recorded in 36 cases. The conditions encountered were cystic endometrial hyperplasia (0.6%), adenomyosis (0.4 %), mucometra (0.4 %), perimetrial cyst (0.6%), endometritis (1.4 %) and metritis (0.2%). The histopathological changes of all these conditions have been studied in detail and the possible pathogenesis described. The various pathological changes associated with reproductive disorders are suggestive of endocrine imbalances, multiple nutritional deficiencies, infectious nature, managemental factors and developmental defects. The results of the study highlighted the need to monitor the hormonal levels in the blood, micronutrients and managemental factors. Lesions of varying frequency in pituitary, thyroid and adrenal glands were recorded in 23 out of 84 cases with utero-ovarian lesions examined. Lesions observed in the pituitary glands were pituitary abscess (1), Pituitary cyst (6) and pituitary apoplexy (2). In the thyroid gland, lesions recorded were hypoplasia (7), colloid goitre (5) and nodular goitre (2). Lesions observed in the adrenal glands were cortical hypoplasia (2), cortical hyperplasia (5) and medullary hyperplasia (8). Correlation study has highlighted that in many of the utero-ovarian disorders there were concurrent affections of the endocrine glands particularly pituitary, adrenal and thyroid glands which is of major significance.ThesisItem Open Access Pathology of pneumo-enteric lesions in goats(Centre for Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2007) Hamza, Palekkodan; KAU; Vijayan, NThe present study was undertaken to assess the mortality pattern, prevalence and pathology of pulmonary and intestinal tract disorders in goat. The result of the present investigation and evaluation of data from the records revealed a high incidence of pulmonary and intestinal tract disorders in goat. A total of 111 cases were subjected to detailed investigation which included 80 kids, 11 young ones and 20 adults. The samples collected were subjected to detailed gross and histopathological examination. The lesions observed were classified and recorded and the lesions were explicated giving possible etiopathogenesis. The study revealed eighty percentage incidence of pulmonary lesion. The pulmonary lesions observed were congestion, oedema, atelectasis, emphysema, pneumonia and pulmonary haemorrhage. The pneumonic lesions encountered were classified as suppurative pneumonia, fibrinous pneumonia, interstitial pneumonia, haemorrhagic pneumonia and aspiration pneumonia. The gross and histopathological features of each type of pneumonia have been described and possible etiological factors had been indicated. Escherichia coli, klebsiella sp. and Corynebacterium sp. were isolated from the pneumonic lungs. The lesions observed in bronchial lymph nodes were congestion, oedema, depletion of lymphocytes and necrotic changes in the cortical area. Bronchi and bronchioles revealed proliferative and inflammatory lesions suggesting a viral etiology with secondary bacterial infection or exposure to chronic air pollutant which act as irritant. Seventy two per cent of cases showed various pathological lesions in intestinal tract. The major lesions encountered in small intestine were congestion, degeneration and necrosis, catarrhal enteritis, subacute enteritis, haemorrhagic enteritis and ulceration. The parasitic lesions observed in intestinal tract were coccidiosis, pimply gut and cestodiasis. Lesions in the large intestine were congestion, degeneration and necrosis, catarrhal colitis and necrotic colitis. Mesenteric lymph node changes included oedema, congestion, degenerative and necrotic changes. Escherichia coli and Klebsiella sp. could be isolated from intestinal contents and the possible role of these organisms in the causation of enteritis had been discussed. An attempt was made to correlate the lesions in respiratory and intestinal tract. Even though there were no typical gross lesions suggesting PPR, the possibility cannot be ruled out without using modern techniques such as immuno histochemical studies.ThesisItem Open Access Effect of a composite mixture of Emblica officinalis, Terminalia chebula and Terminalia bellirica on aflatoxicosis in rabbits(Centre for Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2009) Indu, K; KAU; Lalithakunjamma, C RAmong the various mycotoxins, aflatoxins have been the subject of most intensive research because of the extremely potent cytotoxic and carcinogenic effects. Mycotoxicosis and its counteraction have received greater attention by researchers in the last few decades. In this context an evaluation study on the protective effect of a herbal composite mixture triphala (containing Emblica officinalis, Terminalia chebula and Terminalia bellirica) on aflatoxicosis in rabbits was carried out. The study was conducted for a period of two months with twenty four rabbits divided into three groups of eight each. Rice culture containing 27 ppm of aflatoxin was added appropriately to the ration to get a final concentration of 0.5 ppm. Group I was given 0.5 ppm aflatoxin contaminated feed and group II was given combination of triphala (four per cent) and aflatoxin (0.5 ppm ) contaminated diet. Group III was provided with control diet. There were reduction in body weight gain, Hb, PCV, TLC, lymphocyte count while heterophil count, AST, ALT and ALP levels showed an increase in the toxin fed animals. Addition of triphala at four percent level in the aflatoxin contaminated feed effectively counteracted these changes. The gross and histopathological changes due to aflatoxin were reduced in triphala group. There was widespread vascular changes, extensive necrotic changes, bile duct proliferation, biliary hyperplasia and cholangiocellular carcinoma in the liver and necrotic changes in the kidney of toxin group. These changes were reduced in intensity in triphala group and there was no development of tumors in liver. Regenerative process were well pronounced in the liver and kidney of triphala group. Hence the present study revealed that supplementation of composite mixture of Emblica officinalis, Terminalia chebula and Terminalia bellirica at four per cent level could counteract the toxic effects of aflatoxicosis in rabbits.ThesisItem Open Access Pathology of experimental pasteurellosis in ducks(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2009) Pramod, S; KAU; Divakaran NairThe present study was undertaken to evaluate the pathological aspects of pasteurellosis in ducks following experimental inoculation by different routes – subcutaneous and intranasal. The haematobiochemical changes associated with the infection were also studied. Body weight changes at weekly intervals, mortality pattern, haematological and biochemical parameters such as total erythrocyte count, total leucocyte count, haemoglobin concentration, differential leucocyte count, total protein, albumin and globulin values estimated at weekly intervals were the parameters used, to study the changes caused by the infection. Gross pathological changes and histopathological changes of heart, liver, lung, kidney, brain, intestine, spleen, caecal tonsils and bursa were also studied. Statistically significant alteration was not observed in body weight. Mean Hb, TEC, PCV, albumin, heterophil and eosinophil percentage values were markedly increased after infection. Correspondingly, the lymphocyte and monocyte counts and the total protein values showed a significant decrease. Acute onset of the disease with sudden mortality was noticed in subcutaneously inoculated birds. Peracute death without any symptoms and lesions was shown by two birds in this group. The peracute pattern of mortality seen in this group was not observed in intranasally inoculated group. But the severity of clinical signs and lesions were more in intranasally inoculated birds. After the first two peracute deaths, symptoms of acute toxaemia such as pyrexia, dullness, depression, inappetence, reluctancy to move, paralysis of limbs and neck and incordination were expressed by the birds before death. The birds died from second day after inoculation onwards revealed an acute haemorrhagic septicaemic picture on all visceral organs. Haemorrhages on epicardium and scattered pin point necrotic foci in the liver, the prominent lesions of fowl cholera, were clearly evident. These lesions were more pronounced in the birds inoculated intranasally with P. multocida, which died on 23rd, 24th and 25th day post- inoculation. The lung and brain lesions were more severe in these birds. Reisolation of P. multocida was carried out from the liver, heart and spleen of all the dead birds except control and survived birds. The present study proved that the route of entry of organism played a significant role in the progression of infection, onset of mortality, number of deaths and symptoms and lesions in fowl cholera outbreaks. The immune suppression due to lymphoid organ damage in fowl cholera make the birds more susceptible to other infections.ThesisItem Open Access Pathology of deltamethrin toxicity in chick embryo(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2007) Abhijith Thampan; KAU; Divakaran Nair, NThe present study was taken up to investigate the embryotoxic and teratogenic effects of deltamethrin along with the effects on antioxidant mechanisms and on haematological parameters. The weight of the embryo, bursa and spleen, histopathology of liver, kidney, brain, heart, spleen, bursa and thymus, antioxidant assay which includes estimation of super oxide dismutase, lipid peroxidation , reduced glutathione, and haematological parameters such as total erythrocyte count, total leukocyte count, haemoglobin concentration, , heterophil percentage, lymphocyte percentage and heterophil lymphocyte ratio along with blood glucose level were the parameters analysed to study the effects. The study revealed a dose related increase in the embryo mortality in the treatment groups with a maximum of 18 percent in group VI inoculated with 1600ppm of deltamethrin. Deltamethrin was found to be teratogenic at the given dose levels. The anomalies observed were shorter lower beak (prognathism), curled toe, stumpy toes, syndactylism, shortened left limb, edema of the head and crossed beak and live sticky chicks. Deltamethrin did not cause any significant gross lesions in the developing embryos except mild haemorrhages. Deltamethrin did not result in any significant reduction in the weight of the embryos or the weight of lymphoid organs. On histopathological examination deltamethrin was found to be hepatotoxic and nephrotoxic which was evident by varying degrees of degeneration and necrosis in liver and kidney. Effect on lymphoid organs like spleen, thymus and bursa were mild to moderate with predominance of degenerative changes. Dose related changes were also observed in the heart which included vacuolar degeneration, thinning of fibres , myolysis and inter muscular haemorrhage. At the highest dose levels, deltamethrin caused significant brain lesions like gliosis, dark neurons, spongiform changes, neovascularisation and neuronal necrosis. Antioxidant assay on liver tissue at 200 and 400ppm dose levels revealed the potent hepatotoxic effects of deltamethrin mediated through free radicals as indicated by an increase in the lipid peroxidase and decrease in reduced glutathione and super oxide dismutase. Deltamethrin also resulted in significant increase in blood glucose level and reduction in haemoglobin concentration of exposed chicks maintatined for four weeks.ThesisItem Open Access Pathology of gastrointestinal disorders of rabbits(Centre for Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2007) Devi, S S; KAU; Lalithakunjamma, C RThe present study was undertaken to assess the prevalence and pathology of gastrointestinal disorders in rabbits. The results of the study revealed a high incidence of gastrointestinal disorders in rabbits. The study was based on a detailed postmortem examination of fifty rabbit carcasses. The gross and histopathological lesions were closely observed and classified based on age and nature of changes. Vascular lesions were predominant in the stomach whereas inflammatory conditions outnumbered vascular and degenerative changes in the intestine. In the stomach the most conspicuous vascular change was congestion while catarrhal gastritis was the prominent inflammatory lesion. Catarrhal enteritis was the commonly observed pathology in the intestine. Parasitic as well as bacterial agents were found to be associated with the lesions. The most important bacterial pathogens isolated were E. coli and Salmonella. Intestinal coccidiosis was also observed in a considerable number of cases. Various developing forms of Eimeria spps were identified in the sections of duodenum and jejunum in affected cases. Verminous enteritis was observed in one case where the larvae of pinworm was seen penetrating the submucosa of the jejunum. Mesenteric lymph nodes of fifteen cases revealed vascular, degenerative and necrotic changes of varying degrees. Depletion of lymphocytes associated with degeneration and necrosis of germinal centers in lymphoid follicles of mesenteric lymph nodes were all indicative of immune suppression. Lymphoid depletion was also evident in the Peyer’s Patches of ileum. Liver samples of thirty animals showed pathological changes, some in combination with gastrointestinal lesions. Pasteurella was isolated from the liver in two cases with hemorrhagic tracheitis. Hepatic coccidiosis was observed in certain cases, which were histologically characterized by bile duct hyperplasia, fatty degeneration and vascular changes. The higher incidence of gastrointestinal disorders, the role of immune suppression and isolation of different pathogens indicated the necessity for an indepth study on the multi factorial etiology associated with gastrointestinal disorders in rabbits.ThesisItem Open Access Pathological studies on the ameliorative effect of Curcuma longa on experimental Pasteurellosis in rabbits(Centre for Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2008) Manjula V, James; KAU; Lalithakunjamma, C RAn experiment was conducted to evaluate the symptoms and lesions of experimental pasteurellosis and to study the beneficial effects of Curcuma longa (turmeric) in managing pasteurellosis. Thirty two New Zealand white rabbits were divided into four groups each having eight replicates. Group I served as control. Group II were given feed mixed with turmeric at the rate of 2 g/kg body weight for the whole period of experiment and on the thirty first day of the experiment, animals were intranasally exposed to P. multocida. Group III rabbits were intranasally exposed to P. multocida on the thirty first day of the experiment and turmeric was fed at the rate of 2 g/ kg body weight after exposure until the end of the experiment. Group IV rabbits were fed on control diet alone for thirty days and then intranasally exposed to P. multocida on the thirty first day of the experiment. Body weight and haematological parameters were recorded on day zero, 14th and 28th day of the experiment and biochemical parameters on 28th day were estimated. The rabbits were challenged with 0.1 ml of 18 h broth culture of P. multocida serotype A: 1 containing approximately 3 ×108 organisms/ml by intranasal route. Blood was collected for haematological and biochemical evaluations after eighteen hours of post inoculation from all the groups. Supplementation of turmeric significantly (P<0.05) increased the body weight on 28th day of the experiment. Turmeric supplementation significantly (P<0.05) increased the haemoglobin concentration on day 28. The total leukocyte count and differential leukocyte count did not reveal significant difference between the dietary groups. The serum total protein, albumin and albumin : globulin ratio were significantly (P<0.05) higher in turmeric fed group on the 28th day. The serum creatinine values were within the normal range and no significant difference was noticed. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were comparatively lower in turmeric fed group but no significant difference were noticed on the 28th day. Results of the present study after challenge with P. multocida indicated that the haemoglobin concentration did not reveal significant difference except for numerical decrease in values noted in challenged groups compared to the control. The total leukocyte count and differential leukocyte count significantly (P<0.05) increased in challenged groups compared to the control. Also the levels of serum total protein, albumin: globulin ratio and creatinine were significantly (P<0.05) higher in challenged groups. The levels of ALT, AST and ALP were also significantly (P<0.05) higher in the challenged groups. Pathological studies on the trachea, lungs, heart, liver and kidney revealed acute lesions suggestive of septicaemia. The intensity of damage in Group II rabbits were found to be much less in these organs which were evident in the haemato-biochemical values and gross and histopathological lesions. Overall evaluation of the results of the study indicated that supplementation of turmeric was advantageous. Also the study brought to the light that apart from the beneficial effects on body weight, haematology and biochemical profile, turmeric revealed partial protective role on pasteurellosis. The results of the study prove promising and need further investigation using different levels of turmeric in diets.ThesisItem Open Access Pathological observations of Ficus tsiela (Rox b) toxicity in rats(Centre for Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2009) Litty, Mathew; KAU; Divakaran Nair, NThe present study entitled ‘Pathological Observations of Ficus tsiela (Rox b) Toxicity in rats’ was undertaken by administering the animals with different concentrations of fresh juice and alcoholic extract for a period of 21 days. The weekly body weights, clinical signs, haematology, biochemical parameters, gross pathology and histopathology of various organs were analysed to study the effect. Phytochemical evaluation of the fresh juice and extract was done and the oxidative damage of the liver was assessed by the estimation of lipid peroxides and reduced glutathione. Phytochemical evaluation of the fresh juice revealed the presence of detectable levels of tannins, glycosides, diterpenes, triterpenes, alkaloids, flavonoids and phenolic compounds whereas the ethanolic extract revealed the presence of tannins, phenolic compounds, diterpenes and triterpenes. The animals remained clinically normal throughout the experimental period and the body weight revealed a gradual increase. Hb, PCV, TLC and DLC revealed no variation whereas ALP, creatinine and CK values showed a significant increase in the higher dose groups. There was no variation in the level of blood sugar. There was an increase in the lipid peroxides and reduction in the glutathione in the liver homogenate which indicated oxidative damage. Gross lesions were not observed in the internal organs except congestion and diffuse enlargement of the kidney and liver in the highest dose group. Focal necrotic spots were present in the liver. Tubular and glomerular degeneration and necrosis of the kidney, sinusoidal congestion and multifocal necrosis of the liver, depletion of colloid and variation in the size of follicles of the thyroid gland, medullary cyst in the adrenal gland, goblet cell hyperplasia of intestine, intermuscular haemorrhage in the heart, reactive spleen with multiple cortical follicles with germinal centres, peribronchial lymphoid hyperplasia in the lungs were the lesions observed. The brain, spinal cord and pituitary did not reveal any signs of intoxication. The study revealed that the fresh juice and ethanolic extract at higher doses are nephro-hepatotoxic but not neurotoxic to rats.