Thumbnail Image

Thesis

Browse

1998 - 19995
Reset filters
Subject: Veterinary Pathology × End date: 1999 × Start date: 1998 ×
Reset filters

Search Results

Now showing 1 - 5 of 5
  • Thumbnail Image
    ThesisItemOpen Access
    PREVALENCE AND PATHOLOGY OF POLIOENCEPHALOMALACIA IN GOATS
    (COLLEGE OF VETERINARY AND ANIMAL SCIENCES-MANNUTHY,THRISSUR, 1999) N. DIVAKARAN NAIR; A. Rajan
    Polioencephalomalacia is a significant emerging disease problem in goats Although, PEM in goats was disease problem m goats. recognized and reported as early as 1956, its etiology is poorly understood and symptomatolgy, pathological features and therapeutic approach have not been well defined and documented. Hence an investigation was undertaken to assess the prevalence of the disease based on the data available from i -F i-hw citate for a period from 1991 76 Veterinary hospitals of to 1994. This data documented revealed an increasing trend to the occurrence of the disease and significantly high o n 4 Pt +-hP first five months of which incidence was recorded m the first a. amVhcprvpd in the month of April, the peak incidence was observe spontaneous cases of the disease were studied m detail and experiments were conducted taking goat as a model using selected incriminating agents such as Amprolium ;350 mg/kg body weight), Amprolium and rice gruel (350 mo/kg, and ad libitum rice gruel), nee gruel (ad libitum), sodium sulphate (150 mg/kg body weight followed by 500 mg/kg body weight on the 10th day) BHC (2.5 mg/kg followed py 5 mg/kg body weight on the 10th day) and Ficus tsiela mOXb. The experiment was for a period of 45 days. 5V ii /-mptomatology, weight of the animals at fortnightly intervals, weight of the brain, CSF protein concentration. Drain autofluorescence, gross and histopathological alterations of the brain and ultrastructural pathology were the markers utilized for evaluating the disease processes. The sodium sulphate, BHC and Amprolium and rice gruel created group showed symptoms and lesions more or less similar to the spontaneous cases. Only few animals in each group developed the disease such as two in amprolium and rice gruel treated group, four in BHC treated group and chree in sodium sulphate group. This showed that individual idiosyncracy plays an important role in the manifestation of the disease. The symptoms developed at different latent periods were not progressive as compared to the spontaneous cases where Che symptoms were progressive. The symptoms included lethargy, depression, knuckling at the fetlock, frequent cremors, opisthotonos and loss of eye preservation reflex. Blindness was seen in one of the, natural cases. The histological lesions of the brain in all the cases were comparable in different segments of the brain. Mostly ic was characterized by diffuse laminar cortical aeaeneration and necrosis, occasional neuronal swelling, ii i giial cell reaction and white matter vacuolation. Vascular changes predominated in the sodium sulphate group and also in the natural cases. There was glial cell response in the form of nodules in sodium sulphate group and natural cases. A predominant perivascular and neuropil accumulation of lymphocytes, gitter cells and monocytes were .seen in the natural cases. These were considered as secondary deposition following a toxic degenerative neuropathy. The necrotic focicould well be delineated in few of these cases by the bluish or creamy autofluroscence of the affected brain, but was not found to be of any primary diagnostic value as all the affected brain did not show fluorescence. Ultrastructural investigation revealed the basic reaction of the brain tissue to be similar in both the experimental and natural cases except for their intensity. Ultrastructural lesions were characterized by neuronal swelling, membrane lysis, segregation of the filamentous and granular component of nucleolus, cytoplasmic organellar aamage such as fragmentation of RER, partial degranulation of ribosomes, mitochondrial swelling, cristolysis and lornplete disappearance of organelle. Neuropil spongiosis and splitting of myelin at the intraperiod line and firmation of multiple vacuolations of the white matter were • onaracteristic. From this observations it was clearly iv deiineated that the primary insult was a biochemical one which caused much damage to the volume control mechanism of the cell and subsequent cellular damage. The CSF protein evaluation revealed high protein level in the spontaneous cases whereas in the experimental cases, the concentration remained within the normal range indicating that it has no diagnostic value. In this investigation it has not been possible to induce PEM with Amprolium even at a dose rate of 350 mg/kg body weight and it was proved that amprolium is not a cause for PEM. Rice gruel ad libitum was found to be tolerated by the animal except one which showed dullness and abdominal distension towards the end of the experiment. Diffuse neuronal degeneration was observed in the brain of this animal. Based on this observation it was concluded that rice gruel consumption every day as a component of the concentrate feed in goats might not cause any detrimental effects and the problem comes only when it is fed in large quantities on a single day. B'^icus tsiela Roxb. though produced vascular damage and aiifuse neuronal degeneration in one of the experimental animals, goats were found to be highly resistant to Ficus r-iela Roxb. toxicity and the variation in the susceptibility of different species to this toxicity was brought to light. From this investigation it was also clarified that sodium sulphate, BHC, rice ^ and amprolium could be initiating agents of PEM under certain circumstances and no single cause seems to be responsible for PEM.
  • Thumbnail Image
    ThesisItemOpen Access
    IMMUNOPATHOLOGICAL RESPONSE OF THE JAPANESE QUAIL (Coturnix coturnix japonica) IN EXPERIMENTAL AFLATOXICOSIS
    (COLLEGE OF VETERINARY AND ANIMAL SCIENCES Mannuthy - Thrissur, 1999) SURESHKVMAR, M.; Divakaran Nair, N.; SURESHKVMAR, M.
    One month old Japanese quails vaccinated with Ranikhet disease vaccine (Lasota strain) on 7th day, v.'ere divided into three groups viz.. A, B and C of 35 birds each for assessing the inununopathological responses in experimental aflatoxicosis. Birds of group B and C were administered aflatoxin B^ by oral intubation at the rate of 0.5 ppm twice weekly for two months and group A were vaccinated with R^B strain vaccine at the age of 46 days. Seven birds from each group were sacrificed at fortnightly intervals for the evaluation of various organ weights, haematological, biochemical and haemagglutination inhibition titre values. Liver weights and spleen weights were significantly increased in the toxin treated birds while bursal weights were significantly depressed from that of controls. Packed cell volume, erythrocyte count and leucocyte counts wervB significantly increased in the toxin treated birds at the end of the experiment with a significant increase i,n erythrocyte sedimentation rate at the 45th and 60th day of the experiment. A relative heterophilia and lymphopenia were observed in the toxin treated birds. Serum total protein, albumin and globulin ievels were significantly depressed in the toxin treated birds but the albumin-globulin ratio was unaltered. A relative decrease in the haemagglutination inhibition titre values of the toxin treated birds was recorded. The gross and histopathological lesions in the liver of the toxin treated birds were suggestive of progressive hepatic degeneration, necrosis and fatty changes. There was lymphoid depletion and vascular sclerosis in the spleen while the bursae of the treated birds showed lymphoid depletion, necrosis of lymphocytes, intra and interfollicular cyst formation in increasing intensities in a time dependant manner. The pathomorphological alterations and a relative depression of HI titres in the aflatoxin treated quajIs indicates a moderate depression of the immune status by aflatoxin at such a low dose level.
  • Thumbnail Image
    ThesisItemOpen Access
    DETERMINATION OF PERMISSIBLE LEVEL OF AFLATOXIN IN BROILER CHICKEN FEED
    (COLLEGE OF VETERINARY AND ANIMAL SCIENCE,MANNUTHY, 1999) ARULMOZHl, A; 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 FCR 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, lymphocytes, 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 charactenstic feature in bursa and spleen. Degeneration and lysis of lymphocytes with cyst formation was also seen m 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.
  • Thumbnail Image
    ThesisItemOpen Access
    IMMUNOPATHOLOGICAL RESPONSE OF THE DUCK /ylaas platyrrhyncos domesticusi TO SUBLETHAL DOSE OF SELECTED AGRO - CHEMICALS
    (COLLEGE OF VETERINARY AND ANIMAL SCIENCES Mannuthy - Thrissur, 1998) VUAYAN., N.; Valsala, K.V.; VUAYAN., N.
    The study was conducted with the objective of assessing the teratologic, embryotoxic and iramunopathologic 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 Che above chemicals caused moderate deleterious effects on Che lymphoid system, though no teratologic effects could be Observed. The histological and ultrastructural changes also confirmied the deleterious effects at the tissue and cellular 1evel. The immune system of the ducks exposed to the above reals 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.
  • Thumbnail Image
    ThesisItemOpen Access
    PATHOLOGY OF THE HARDERIAN GLAND IN CHICKEN AND DUCK
    (COLLEGE OF VETERINARY AND ANIMAL SCIENCES Mannuthy - Thrissur, 1998-02) MOHAN, S; Valsala, K. V.
    The lymphoid tissue of the upper respiratory tract includes paraocular and paranasal lymphoid structures as well as some lymphoid accumulations In the pharynx and larynx. However, of all these paraocular lymphoid tissue, the Harderlan gland Is highly Immunopotent. The role of the Harderlan gland In the Immunopathologlcal response was evaluated taking chicken and duck as models and RD, IBD and Duck plague vaccines as antigens. The sequential cellular response following ocular antlgenic stimulation was clarified. Significant Increase In the plasma cell number, enlargement of the lymphoid foci and Russell body formation following ocular antlgenic stimulation were the hall marlcs of the Immune response of the Harderlan gland of the chicken but this was not so much significant In the case of ducks. Harderlan gland was highly reactive especially In the chicken but not so much In the case of ducl