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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, T
An 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.
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 Varghese
The 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.
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, A
A 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 stressed
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 B
An 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 AFB
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.
Open Access
Pathological effects of aflatoxicosis in ducks
(Department of Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1999) Latha, K; KAU; Mammen, J Abraham
In 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.
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 M
Homologous 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.
Open Access
Pathology of bacterial mastitis in bovines
(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1998) Nandakumar, S; KAU; Sreekumaran, T
The pathology of bacterial mastitis in bovines was studied considering the following aspects such as bacterial isolation; changes in milk, antibiotic sensitivity pattern, haematology, whey protein pattern and histopathological examination of the mammary gland and supramammary Iymphnodes. Two hundred and sixty two samples were found to be subclinically positive based on California Mastitis Test. The organisms isolated from clinical and subclinical cases were Staphylococcus, E. Coli, Gram negative bacilli, mixed infections, Streptococcus, Yeast and Gram positive bacilli in the decreasing order of prevalence. All the major pathogens were sensitive to pefloxacin, gentamycin and chloramphenicol and resistant to penicillin. Leucopenia could be noticed in clinical and subclinical cases of mastitis. Relative neutrophilia could be observed in mastitic animals. Total plasma protein was also increased. There was an increase in T-Iymphocyte count in mastitis affected animals. ~omatic cell count was increased in clinical and subclinical cases, but was not indicative of infection, unless confirmed by bacteriological examination. SOS-PAGE on whey proteins revealed an increase in protein content in mastitic milk as a result of the plasma proteins, cellular proteins, bacterial proteins. There was marked increase in immunoglobulins in mastitic milk, when compared to normal. Histopathology of mammary glands revealed the presence of inflammatory cells in the acini and interstitium of mammary glands as the main lesion. Varying degrees of inflammatory reaction could be noticed in almost all the quarters. Supra mammary lymph nodes revealed distension of subcapsular sinuses, active secondary follicles in the cortex, sinus catarrh and medullary hyperplasia in mastitis affected animals.
Open Access
Pathology of ascites syndrome in broiler chicken
(Department of Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1996) Jacob Alexander; KAU
The post mortem reports maintained at the Department of Pathology during the period 1985 – 95 revealed that the prevalence of ascites syndrome (AS) was gradually on the increase. Investigations carried out on field cases showed that AS occurred in better managed farms and also in farms where the feed did not contain aflatoxin. The bacteriological study and screening of ascetic fluid in electron microscope for virus did not indicate a microbial etiology. Two separate experiments were conducted with vencob strain of broiler chicken. In each of the experiments the feed additives were mixed in the feed and fed ad libitum from the second week onwards. The body weight was recorded weekly. The PCV, haemoglobin, serum protein, albumin, globulin, albumin – globulin ratio, sodium and potassium were estimated at fortnightly intervals. At the eighth week the live birds were slaughtered and the gross and histopathological lesions were evaluated. The organ weight, relative organ weight and RV : TV were also evaluated. In the first experiment 50 chicks of two weeks of age were randomly divided into three treatment groups of 12 each. The control group consisted remaining 14 chicks. The treatment groups were given monensin sodium, pure sodium chloride (99.99%) and furazolidone in the feed at the rate of 360, 25, 000 and 800 ppm respectively. The birds in the monensin group were stunted due to less feed and water intake. The serum biochemistry, lesions, organ weight and a lesser RV : TV indicated that monensin might not cause AS. The sodium chloride group initially exhibited excessive thirst, diarrhoea, hyperaemic skin and distended abdomen but by the end of the eighth week none had ascites on post mortem examination. The PCV, haemoglobin, serum Na++ and RV : TV were higher than the control. The furazolidone group exhibited nervous symptoms and one bird died of ascites syndrome at the 45th day of treatment. The body weight, PCV, haemoglobin, serum protein, albumin, globulin, potassium and organ weight were lesser than the control group. Congestion, hydropericardium and nephrosis were noticed in the birds. Ectopic cartilaginous nodules, pulmonary congestion and oedema, loss of striation and separation of myocardial fibers and severe diffuse granular degeneration of hepatocytes were also noticed. The second experiment consisted of 80 chicks of two weeks age randomly divided into 8 groups of 10 each. Furazolidone was administered at a higher dose (1000 ppm) and common salt was given instead of sodium chloride at the same dose rate (25,000 ppm). Cephalexin was also administered to another group at the rate of 800 ppm. Two salts of cobalt namely chloride and nitrite were given to two separate groups at 600 ppm each to elucidate its aetiological role. In addition, two groups were utilized for transmission studies using the ascetic fluid and liver suspension collected aseptically from field cases. The birds in the furazolidone group showed nervous symptoms, and was stunted. One bird died of ascites on the 53rd day of the treatment. The PCV, haemoglobin, serum protein, albumin, globulin, Na++ , K+ and organ weight were lesser while the relative organ weight and RV : TV were higher than the control group. These observations suggested that furazolidone was a potential agent which could cause AS. In the common salt group three birds died of AS on the 5th, 11th and 24th days of treatment. They showed sequential progressive lesions. Increased feed and water intake, respiratory distress, and distended abdomen were noticed. Their body weight, PCV, haemoglobin, serum Na++ and K+ content were higher than the control. Congestion, oedema, haemorrhage and ectopic cartilaginous nodules were noticed in the lungs. Severe congestion of the central and portal veins and thickening of the Glisson’s capsule were seen in the liver. Mesangial cell proliferation, and thickening of the basement membrane of the glomerular tuft were evident. The weight and relative weight of the heart, RV and LV were the highest among all the groups. The RV : LV was higher when compared to the control. The weight of the spleen, lungs, liver and intestine was greater than the control. These results indicated that common salt was more potent than sodium chloride in precipitating AS. In the cobalt chloride and nitrite groups, the birds showed a reddened skin and had a lesser body weight than the control. The PCV, haemoglobin and serum Na++ were higher while the serum K+ and absolute organ weight were lesser than the control. The RV : TV ratio was higher than the control in both the groups. These suggested that excess amounts of cobalt in chicken feed might cause ascites. When cephalexin was given to the birds no noticeable symptoms were observed. The serum Na++ , K+ , organ weight, relative organ weight and RV : TV were lesser than the control and it did not cause AS. Transmission studies using liver suspension and ascetic fluid injection intraperitoneally did not cause ascites. A microbial etiology therefore couldnot be elucidated.

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