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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 Studies on the pathological effects of fipronil and their amelioration by curcumin in rats(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2010) Senthilkumar, T; KAU; Divakaran Nair, NThe present study entitled ‘Pathological effects of Fipronil and their amelioration by curcumin in rats’ was undertaken by administering with fipronil in group I animals and both fipronil and curcumin in group II animals for 28 days. Group III administered with honey served as control. The weekly body weights, clinical signs, haematology, biochemical parameters, mortality pattern, gross pathology and histopathology of various organs were analysed to study the effect. The oxidative damage of the liver was assessed by the estimation of lipid peroxides, reduced glutathione and superoxide dismutase. A significant decrease in the mean body weights was observed in group I and II. ALT, AST, cholesterol and creatinine levels showed a significant increase in the group I and significantly lower levels in group II. Total protein, albumin, globulin, PCV and Hb levels were significantly lower in group I but significantly higher in group II. TLC, ESR and DLC revealed no variation. Group I showed significantly higher lipid peroxides and lower glutathione and superoxide dismutase levels in the liver. Group II showed significantly lower lipid peroxides and higher glutathione and superoxide dismutase levels in the liver. The animals showed dullness and inappetance in the treatment groups. Mortalities were observed in both groups. Hepatomegaly and focal necrotic spots in the liver, enlargement of thyroid were the major gross lesions in group I. Gross lesions were less in group II. Smaller and cystic dilatation of acini, hyperplasia and fibrosis of thyroid, necrosis, hypertrophy and individualization of hepatocytes, tubular and glomerular degeneration and necrosis of the kidney, alveolar septal thickening, peribronchial lymphoid cell hyperplasia and bronchostenosis of the lung, predominance red pulp of spleen, desquamation and fusion of villi and goblet cell hyperplasia in the intestine, hyalinization of cardiac muscle fibers were observed in group I animal. Uniform sized follicular acini of thyroid, prominent kupffer cell reaction of hepatocytes,mild degeneration of tubules of kidney, predominance of white pulp of spleen, glial cell response in the brain, glandular hyperplasia of intestine were the major findings in group II animals. The study revealed that fipronil is thyrotoxic, hepatotoxic and nephrotoxic to rats and curcumin has good ameliorating effect against fipronil toxicity.ThesisItem Open Access Studies on sequential post-mortem changes of isolated chicken eye(Centre for Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 2010) Arya Aravind; KAU; Vijayan, NThe present investigation was undertaken to study the sequential postmortem changes of different components of chicken eye and to choose an ideal fixative. Six eyes each were fixed at zero hour, half hour, one hour, one and a half hours, two hours, four hours and twelve hours in ten per cent neutral buffered formalin and gluteraldehyde fixative. Eyes were fixed for a minimum of three weeks. A clean cut was made near to the midline of the fixed eye slightly to one side of it, so that the origin of the optic nerve and pupil were included in the sections. The eye consisted of three tunics; tunica fibrosa consisting of cornea and sclera, tunica vasculosa with choroid, ciliary body and iris and tunica interna consisted of retina. The postmortem changes were mostly appreciated in the cornea, which included condensation of the nucleus of the epithelium of cornea, interepithelial detachment and exfoliation of epithelium. The cytoplasm revealed vacuolar and degenerative changes and there was separation of collagen fibres of corneal stroma. The corneal endothelium showed swelling, lysis and detachment. The presence of lysed erythrocytes was prominent after two hours in the choroid. As the time interval advanced, there were varying degrees of dispersion of melanin pigment. The swelling of the cytoplasm of the ciliary body was more evident in the non- pigmented epithelial layer. The epithelium of the iris showed detachment and fragmentation. Retinal detachment was noticed from zero hour of fixation in GF fixative and ten per cent NBF fixative. The changes were prominent in the ganglion cells which showed condensation of the nuclei along with vacuolar and lytic changes of the cytoplasm. Postmortem changes of pecten were appreciated by the lysed erythrocytes in the capillaries along with the vacuolar degeneration and lytic changes affecting melanocytes and hyalocytes. PAS positive areas were detected in the Descemet’s membrane and Bowman’s membrane of cornea, lens capsule, pecten and layer of rods and cones of retina. Masson’s trichrome staining proved to be useful to appreciate the changes in the collagen fibres, muscles and epithelium. The histometry of the eyeball showed a significant decrease in thickness of cornea at 120 minutes when compared with zero hour in neutral buffered formalin fixative. From the study it can be concluded that GF fixative is a better fixative for eye than 10 per cent NBF fixative.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 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.