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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
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
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
Comparative study of the immunopathological response in ochrathoxin A, cadmium and mercury toxicities in ducks (Anas platyrrhynchos domesticus)
(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1996) Vyas Madhavrao Shingatgeri; KAU; Rajan, A
The present investigation was undertaken for the first time to assess the level of contamination of mercury (Hg) and Cadmium (Cd) in the soil, water, plants and biosamples in localities where there is significant duck population and to study the pathological effects of these chemicals and ochratoxin A (OA) with special reference to immune response in the ducks and duck embroys. The residues of these chemicals in various tissues of the ducks were also assessed. Hg and Cd were detected in all the samples from all the localities surveyed and its presence especially in the soil, vegetation, fish, liver and kidney of the ducks from these areas indicated its public health significance. After the administration of OA, HgCl2 and CdCl2, there was dose dependent embryo mortality and reduction in hatchability rate. The mortality percentage in the highest dose group of embryos inoculated with HgCl2, Cdcl2 and OA was 55%, 51.6% and 48.3% respectively while the hatchbility rate was 29.92%, 35% and 47.83% respectively. This clearly indicated the embryotoxic action of these chemicals. The body weight, weight of the thymus, and the bursa of Fabricius was found lowered in the embryos inoculated with these chemicals. The variations noticed in the weights at different periods of observation between the chemicals were also dose dependant. The weight of the spleen of the embryos inoculated with OA and HgCl2 was comparable to the normal embryo but with CdCl2, it was found significantly lowered in the highest dose group at the 28th day of incubation. These observations, therefore indicated that Cd has an adverse significant biological effect on the lymphoid organs of the developing embryo. Similar effect was observed with Hg and OA but was relatively low. Histologically, depletion of the lymphoid elements consequent to degeneration, necrosis and cytolysis was the characteristic feature in the bursa of Fabricius and thymus, however, it was comparatively less in the spleen. Ultrastructural changes in the lymphoid cells in all these organs showed membrane alterations, mild to severe mitochondrial changes, ribosomal detachment and fragmentation of RER and nucleolar and nuclear changes indicative of cell damage, and marked reduction in differentiation into plasma cells. Epithelial cells were also found affected. The toxic effects of these chemicals were more or less similar in the bursa of fabricius, intensity and severity being more with CdCl2 followed by HgCl2 and OA in that order. In the thymus, also, CdCl2 caused severe pathological effects while with HgCl2 intensity was least. In the spleen there was increased erythrophagocytosis in addition to these changes and was more severe with HgCl2. In the liver, severe necrobiotic changes were found in the hepatic cells associated with ultrastructural picture of organellar damage and lytic changes in the nucleus. Intensity of these changes was more severe in CdCl2 treated embryos followed by those treated with OA and with HgCl2. In the kidney, the cellular alterations were more in the proximal convoluted tubules and the intensity of these alterations was less in OA and CdCl2 treated embryos compared to those treated with HgCl2. The embryos inoculated with OA, HgCl2 and CdCl2, revealed degenerative changes in the lymphoid and other organs. The adverse immunobiological effects of OA, Hg and Cd on the developing embryo were established by histological and ultrastructural studies. In the ducks, OA, HgCl2 and CdCl2 were fed orally (at the rate of 300 ug, 10mg and 15 mg/kg body weight respectively) for 90 days. Clinically ducks showed dullness, restlessness and unusual hyperresponsiveness and inco – ordination of movement, in OA, HgCl2 and CdCl2 fed ducks respectively at the later stage of the experiment. Progressive reduction in the gain of the body weight, of the bursa of Fabricius was noticed in all the groups (OA, HgCl2 and CdCl2 treated) while that of the thymus was noticed mainly in CdCl2 and OA treated ducks. There was highly significant reduction in the total erythrocyte count (TEC), Haemoglobin (Hb) concentration and Packed Cell Volume (PCV) in the groups fed OA, HgCl2 and CdCl2. Highly significant leucopaenia with relative heterophilia and lymphocytopenia was observed in OA and HgCl2 fed ducks, while highly significant leucocytosis with heterophilia and lymphocytopenia was seen with CdCl2 fed ducks. These alterations revealed the toxic action of these chemicals on the haemopoietic cells and the formed elements of the blood. Estimation of the haemagglutination inhibition (HI) antibody titre, total serum protein (TSP), serum globulin (SG) and serum IgG and IgM levels clarified the adverse effect of OA, Hg and Cd on the humoral immune system, which was evident at an early stage in Cd and Hg treated ducks while at a later stage in OA fed ducks. There was marked reduction in the serum IgM and IgG level in response to New Castle disease Virus (NDV) in ducks fed HgCl2 and CdCl2 respectively. The highly significant reduction in the T – lymphocyte count in the peripheral blood, increase in the migration indices in response to NDV in leucocyte migration inhibition test (LMIT), reduction in cutaneous response to phytohaemagglutinin – M (PHA – M), 2, 4 – dinitrochlorobenzene (DNCB) and the decreased spleen indices in Graft versus host reaction (GVHR) indicated the toxicity of OA and Cd on the cell – mediated immunity, which was more pronounced and evident at an early stage in Cd treated ducks than compared to OA treated ducks. However, the results of the migration indices, PHA – M cutaneous response and GVHR demonstrated that the CMI response escape the toxic insult of the Hg and is dependant on the duration of exposure, which was clarified by T – cell dependant lymphocytopaenia and reduction in cutaneous response to DNCB at the last week of the experiment. Significant reduction in the phagocytic ability in all the ducks treated either with OA, HgCl2 or CdCl2 was observed by carbon clearance assay. There was reduction in the weight of the bursa of Fabricius and spleen. The thymus showed focal areas of congestion and petechiae in Cd induced toxicity, and was found appreciably reduced and atrophied with Cd and at later stages with OA. Degenerative and retrograde changes indicative of necrobiosis were observed histologically. Ultrastructural changes were more severe with CdCl2 followed by HgCl2 and OA in that order. In the spleen of ducks fed CdCl2 there were proliferative changes initially followed by degenerative changes at later stages. In the thymus, effect of the Cd was more severe on the lymphocytes followed by OA and was least with HgCl2. Histological and ultrastructural studies revealed degenerative nephropathic changes in the kidney associated with Hg, OA and Cd toxicity. Intensity of alterations was more with Cd. The hepatic lesions characterised by moderate to severe hepatosis were more pronounced in the case of Hg and Cd in an increasing order. Histological and electron microscopic studies elucidated the neuropathological changes associated with Hg, Cd and OA toxicity. Estimation of OA, Hg and Cd residues indicated a steady increase in the accumulation of these substances in the various tissues depending on the dose and duration of exposure. Highest concentration of OA, Hg and Cd was detected in the kidney, followed by liver. Residues of these substances at varying concentrations were also detected in the muscles, brain, spleen, bursa of Fabricius and thymus. This study brought to light the immunosuppressive effect of OA, Hg and Cd which would compromise the dichotomous defence mechanism of the ducks. Also adverse effects on hepatic, haemopoietic, reneal and nervous system were documented. It was clarified by this investigation that immunotoxic effect of these chemicals could lead to breakdown of immunity and outbreak of diseases when the ducks are maintained in a polluted environment. The need for the systematic monitoring of the environment and taking appropriate steps to prevent environmental pollution were stressed. The public health importance of residues of these chemicals was brought to light.
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.
Open Access
Assessment of the role of aflatoxin in the aetiology of carcinoma of the mucosa of the ethmoid
(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1995) Surinder K, Chaudhary; KAU; Rajan, A
The present investigations were planned to assess the role of aflatoxin B1 (AFB1) and /or virus in the aetiology of ethmoid carcinoma using pig as a model in vivo and bovine ethmoid mucosa culture in vitro. Thirty – two, large white Yorkshire piglings of two – three months age were procured from the University pig Breeding Farm, Mannuthy and divided at random into four groups of eight each. The pigs in group I and group II were administered aflatoxin B1 (0.070 mg/kg b.wt/inoculums by intravenous route at weekly interval for six months) and /or ethmoid tumour extract (2 ml/pig/inoculums, intranasally, at fortnight interval for three months). The pigs in group III were administered ethmoid tumour extract alone, while the pigs in group IV were kept as negative controls. During the period of observations of 18 months all the pigs of different groups given AFB1 and /or ethmoid tumour extract appeared healthy and no clinical manifestation of the carcinoma of the mucosa of ethmoid was observed. However, there was appreciable reduction in the weight and mild degree of depression. In the AFB1 treated pigs, sacrificed at 9, 12, 15 and 18 months of investigation, the ethmoid mucosa had grayish white, soft and oedematous appearance along with scattered small pale elevations at necropsy. Histologically, the ethmoid mucosa exhibited hyperaemia, varying degree of mononuclear cell infiltration and fatty degeneration in the initial stages. In the later stages, there was proliferation of mucous glands showing acinar, tubular or papillary arrangements. Occasionally papillary projection of the surface epithelium and focal squamous metaplasia were also observed. Ultrastructural features of the cells of the ethmoid mucosa consisted of both productive and degenerative changes. The cells had sparse cytoplasmic organelles. The poor cytoplasmic contents and irregular nucleus with nucleolar margination were the other electron microscopic features observed in the ethmoid mucosa of AFB1 treated pigs. AFB1 in the range of 43.12 – 139.43 ppb could be detected in the blood of 52.37 percent of the ethmoid tumour bearing cattle analysed in the present study. The blood samples from the AFB1 treated pigs were positive for AFB1 (40-160 ppb) upto 10 days after the withdrawal of treatment whereas AFM1 could be detected in blood sample of one pig only upto 3 days after the treatment. The ethmoid mucosa analysed after 3 months and at subsequent specified intervals was consistently negative for AFB1 and AFM1. By concerted efforts cells of the mucosa of the ethmoid were established in vitro. AFB1 treatment of long term epithelial cultures intiated from the primary culture of bovine ethmoid mucosa origin resulted in morphological transformation accompanied by increased growth in soft agar and cytochemical positivity of gamma glutamyl transpeptidase. This confirmed the tumourigenicity of AFB1. The xenotransplantation of these in vitro transformed epithelial cells in mice was not successful. Electron microscopic studies of the cells of the carcinoma of the ethmoid mucosa in spontaneous cases of cattle revealed varying ultrastructural features. The neoplastic cells were either well differentiated secretary structures or undifferentiated ones. Desmosomes and tight junctions were seen between the epithelial cells. Endoplasmic reticulum and mitochondria varied in their contents and degree of disorganization. Nucleus was highly pleomorphic and predominantly euchromatinic. The retroviral like particles were demonstrated intracellularly and occasionally in extracellular spaces in the neoplastic cells of 7 tumour bearing cattle. Similar particles were also seen in the cell free ethmoid tumour extract in three of21 tissues examined.
Open Access
Assessment of the immunopathological response in bovine mastitis
(Department of Pathology, College of Veterinary and Animal Sciences, Mannuthy, 1996) Biju, P; KAU; Lalitha Kunjamma, C R
The immunopathological response of cows suffering from clinical and sub – clinical mastitis was evaluated and compared with healthy non – mastitic cows using various immunological markers. Significant enhancement of the humoral immune response was noticed in sub – clinical cases of mastitis, whereas those suffering from clinical mastitis had only a slight difference as compared to the healthy cows. Elevated T lymphocyte count was noticed in acute (38.33 + 0.8%) and chronic (35 + 0.93%) stages of mastitis. Those suffering from sub – clinical cases had a slight reduction in the mean T cell count, (29.83%) as compared to that of the healthy non – mastitic cows (31.3 + 1.42%). Three hundred and thirty one samples (22.23%) were sub – clinically positive out of the 1489 samples examined by California Mastitis Test. Out of the 520 samples subjected for cultural examination 186 were culturally positive. Fifty per cent of the culturally positive samples contained Staphylococci, which included both coagulase positive and coagulase negative group. Other pathogenic organisms isolated included Streptococci, Corynebacterium, Pseudomonas, and gram positive bacilli. Direct correlation between the somatic cell count and California Mastitis Test score was noticed. Neutrophils were the predominant cells in the milk samples. The major pathogens were more sensitive to Gentamicin (98.21%) followed by Pefloxacine (96.42%), Chloramphenecol (91.07%), Streptomycin (82.14%), Cotrimoxazole (80.35%), Ampicillin (73.21%), Oxytetracycline (71.43%) and Penicillin (60.71%). Haematological examination of sub – clinical cases revealed leukopaenia. Slight increase in the serum total protein was noticed in sub – clinical cases. Gross changes of mastitis was noticed in 18 mammary glands tissues examined. Histologically out of the 336 glands examined, 271 were having inflammatory changes of varying degrees. Acini as well as interstitium contained inflammatory cells in 37. 68 per cent of cases. The entire parenchyma was affected in 14.49 per cent a cases. Oedematous appearance of the supramammary lymphnodes was noticed. Microscopically marked expansion of the cortex by numerous lymphoid follicles in various stages of activity was noticed.

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