Loading...
![Thumbnail Image](assets/images/Collection.png)
Theses
Browse
19 results
Search Results
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 Immunopathological response of the duck (Anas platyrrhyncos domesticus) to sublethal dose of selected agro-chemicals(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1998) Vijayan, N; KAU; Valsala, K VThe study was conducted with the objective of assessing the teratologic, embryotoxic and immunopathologic effects of two agro-chemicals carbofuran and 2,4-D used in agricultural operations, on duck embryos and ducklings. The embryological studies included the observation on the embryonic defects and weight of the lymphoid organs along with the histopathologic and ultrastructural studies of the lymphoid organs like the bursa, spleen and thymus. The results showed that the contamination of the eggs with the above chemicals caused moderate deleterious effects on the lymphoid system, though no teratologic effects could be observed. The histological and ultrastructural changes also confirmed the deleterious effects at the tissue and cellular level. The immune system of the ducks exposed to the above chemicals for two different durations were assessed using a battery of tests. The humoral immune system was assessed based on the body weight, lymphoid organ weight, haematological evaluation, serum biochemical evaluation and the evaluation of HI titre against NDV. The cell-mediated immune system was assessed by the skin reactivity tests to DNCB and PHA. LMIT and GVHR were also employed to assess the cell-mediated immune system. The histological and ultrastructural studies were also conducted after six weeks and ten weeks of the experiment. The assessment of the immunological profile employing these elegant tests revealed that these agro-chemicals caused mild but significant suppression of the cell-mediated and humoral immune response. By this investigation it was clarified that these agro-chemicals have mild to moderate degree of immunotoxic effect when exposed for a short duration, but the changes were severe when exposed for longer duration. From the .studies, it was demonstrated that the immunotoxic effect of carbofuran is more compared to 2,4-D (herbicide) and the changes were dose and time dependent.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 Ochratoxicosis in quails (Coturnix coturnix japonica) with special reference to Inununopathological response(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1992) Amir Abbas, Farshid; KAU; Rajan, AIn this investigation the pathological effects of OA in quail embryo and adult quail were studied with special reference to the immune system. Ochratoxin A (OA) was inoculated into the quail embryos, at the dose rate of 0.02 ^g per embryo. There was 68.66 per cent mortality which clearly indicated the direct action of OA. The embryos which were sacrificed on the 13th and 16th day of incubation showed significant reduction in the body weight, weight of bursa of Fabricius, spleen and thymus. Histological changes in these lymphoid organs were, atrophy, necrosis and depletion of lymphoid elements. Ultrastructurally the changes were time dependent. There were changes in the shape of the nucleus with condensation of granular and fibrillar components of the nucleoli. The adverse immunobiological effect of OA on the developing lymphoid organs was established by histological and ultra structural studies. OA at the dose rate of 50 /ag/bird/day for a period of 60 days was administered through oesophageal intubation. Pathological changes were sequentially documented with special reference to the immune system. In the OA fed quails, the clinical signs included emaciation and hyperexcitation at the later part of the experiment. There was highly significant reduction in the body weight, weight of bursa of Fabricius, spleen and thymus. The reduction in the weight of lymphoid organs gave evidence to the adverse effects of OA on the immune system. There was reduction in the total erythrocyte count (TEC), haemoglobin (Hb) concentration and packed cell volume in OA fed birds indicating the significant damaging effect on the haemopoietic sytem. Estimation of total serum protein (TSP), serum globulin (SGI) and serum immunoglobulin fractions clarified the biological adverse effect of OA on the humoral immune system. Highly significant reduction in total leukocyte count (TLC) and T cell dependent lymphopenia proved the immunosuppressive effect of OA. There was reduction in T cells, increase migration indices in response to Fowl pox antigen in leukocyte migration inhibition test (LMIT), the reduction in the cutaneous response to 2,4-dinitrochlorobenzene (DNCB) and phytohaemagglutinin-M (PHA-M) and spleen indices in the graft versus host reaction (GVHR), clarified the immunotoxicity of OA on the cell-mediated immune system.ThesisItem 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.ThesisItem Open Access Pathological effects of aflatoxicosis in ducks(Department of Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1999) Latha, K; KAU; Mammen, J AbrahamIn this investigation the pathological effects of aflatoxicosis and permissible levels of aflatoxin were studied at different dose levels viz. 5ppb, 10ppb, 20ppb and 40ppb. In the aflatoxin fed ducks, reduced feed intake and diarrhoea were noticed. There was a significant reduction in the body weight and carcass weight which were indicative of the toxic injury to the gastrointestinal tract. There was a significant increase in the liver weight reflecting the damage to the hepatic system. There was reduction in the haemoglobin concentration, total erythrocyte count, packed cell volume and significant increase in the erythrocyte sedimentation rate indicating the adverse effect of aflatoxin on the haemopoietic system. Leucocytosis with heterophilia and lymphopenia were observed suggesting the deleterious effect of aflatoxin on the lymphoid organs. Highly significant reduction in serum total protein, albumin values, AlG ratio and significant increase in globulin were observed indicating hepatic damage. Grossly, the aflatoxin fed birds showed pale enlarged liver, focal necrotic areas, subcapsular haemorrhage, fatty liver, greenish discolotation and surface granularity and nodularity of varying intensity depending on the dose and duration of the treatment. In the kidney and spleen, mild congestion were observed. Bursa showed atrophic changes. Histopathological alterations in the liver consisted of biliary hyperplasia, fatty changes, congestion of the hepatic sinusoids portal venous congestion, portal fibrosis, focal collection of mononuclear cells, dissociation of hepatocytes, hepatocytomegaly and fibrous tissue proliferation of varying intensity depending on the dose and duration of the treatment. In the spleen, congestion, vascular sclerosis and depletion of Iymphocytes in the cortical and paracortical areas were noticed, whereas in the kidney besides nephrosis, mild peritubular accumulation of mononuclear cell were noticed at 20ppb level of aflatoxin while tubular degeneration, swelling of the tubular epithelium, mild fibroblastic proliferation with cellular infiltration in the interstitium were noticed at 40ppb level. Generally, bursa of fabricius of the treated birds revealed lymphoid depletion in the follicles, interfollicular edema and proliferation of interfollicular connective tissue. Aflatoxin treated groups showed dose and duration dependant degrees of ultra structural changes. The ultrastructural changes noticed were intact cell nucleus with prominent nuclear pores, increased amounts of heterochromatin that appeared as clumps, dilatation and degranulation of rough endoplasmic reticulum (RER), rounded, oval or elongated mitochondria which were either normal or swollen containing swollen cristae along with the presence of electron dense material within the matrix, smooth endoplasmic reticulum (SER) that appeared as small tortuous vesiculated structures and scattered lipid droplets. Aflatoxin B1(AFB1) residues were detected in the liver, muscle pooled samples of th.e kidney and blood of birds maintained with feeds containing • aflatoxin at levels of 20 and 40 ppb during the fourth, sixth and eighth month. No residual toxin could be detected in birds treated with aflatoxin at a level of 5ppbthroughout the experiment. At dose level of 10ppb, no AFB1 residues could be detected by the second and fourth month, but during the sixth and eighth month negligible amount of residues could be detected in the liver and muscle. This study highlights the pathological effects of aflatoxicosis in ducks. Moreover, the adverse effects on the hepatic, haemopoietic and renal systems could be documented. By considering the above facts aflatoxin level of 10ppb is fixed as permissible level in ducks. However, permissible level can vary with the season, diseased conditions of the bird and storage practices of feed. Therefore, this study emphasizes the need for regular screening of feed for aflatoxin content.ThesisItem Open Access Homologous and heterologous transplantation of bovine ethmoid carcinoma cells(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1994) Ajith Jacob George; KAU; Ramachandran, K MHomologous and heterologous transplantation of bovine ethmoid carcinoma cells were attempted to assess the xenograftic efficiency of the neoplasm. Tumour tissue for the study was obtained from seven clinically affected cows. Histopathologically the tumours were classified as adenocarcinoma, papillary adenocarcinoma, undifferentiated carcinoma and squamous cell carcinoma. Tumour tissue/cell culture was successfully carried out using trypsinised single cell suspension and tumour tissue gragments. Calves were used as homologous hosts and rats, mice and rabbits were used as heterologous hosts. Cyclophosphamide, hydrocortisone and cyclosporine A were used as immunosuppressants. Transplantation was carried out subcutaneously or intraperitoneally. The inoculum consisted of trypsinised single cell suspension, tumour tissue fragments and cell suspension from tissue culture. Neoplastic cells failed to grow in immunosuppressed calves, rats and rabbits. Whereas, the tumour cells obtained by trypsinisation were successfully transplanted in mice immunosuppressed with cyclosporine A. The tumour growth was evident from the second week onwards. In immunosuppressed animals the total leucocyte count, differential leuocyte count and alphanapthyl acetate esterase positive lymphocyte count were very low compared to their controls. The results of the present study indicated that mice could be used as an experimental model for the studies on bovine ethmoid carcinoma.
- «
- 1 (current)
- 2
- 3
- »