Veterinary Pathology

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    BOVINE TRYPANOSOMOSIS: PARASITOLOGICAL PREVALENCE, VECTORIAL DENSITY AND TRYPANOCIDAL DRUG UTILIZATION PRACTICE IN TSETSE SUPPRESSION AND NON-SUPPRESSION AREAS OF SOUTH OMO ZONE, ETHIOPIA
    (2019-06) Tegegn, Tesfaye; Hagos Ashenafi (Prof)
    Questionnaire survey to assess knowledge and attitude of trypanocidal drug utilization practices, entomological survey to know apparent cyclical vector density and other mechanical vectors responsible for trypanosome infection transmission and parasitological study to elucidate the prevalence of bovine trypanosome was conducted in tsetse suppression areas and tsetse non-suppression areas of South Omo Zone, Southern Ethiopia from November 2018- May 2019. SPSS version 20 and R- software packages were used to analyze collected field data. For questionnaire survey, 124 cattle owners from tsetse suppression areas and 60 cattle owners from tsetse non-suppression areas were interviewed about their knowledge, attitude and practice (KAP) of trypanocidal drug utilization and constraints of trypanosome infection in the area. Blood samples from 1284 local breed cattle; 642 samples during dry season (344 from tsetse suppression areas and 298 from tsetse non-suppression areas) and 642 during wet season (344 from tsetse suppression areas and 298 from tsetse non-suppression areas) were parasitologically examined by using buffy coat technique and thin blood smear method. For entomological survey, 96 NGU traps were deployed (64 traps in tsetse suppression areas, 32 traps in tsetse non-suppression areas) in suspected Glossina multiplication habitats. The overall prevalence of bovine trypanosome infection in South Omo zone was found to be 11.05% (142/1284). The overall seasonal prevalence of bovine trypanosome infection in South Omo zone was 14.33% (92/642) and 7.78% (50/642) for dry and wet seasons, respectively. There was a statistically significant difference (P <0.05) in disease prevalence between the two seasons. During dry season, only sex and the grazing system were significantly associated with trypanosome infection occurrence but in wet season none of the risk factors were statistically significant. Multiple logistic regression analysis of trypanosome infection prevalence indicated that sex, body condition score (BCS), grazing system and season were significantly associated (P<0.05) with the prevalence of the disease in tsetse suppression areas. However, only sex and season for tsetse non-suppression areas were significantly associated with the prevalence of trypanosome infection. Trypanosoma congolense (T. congolense) was the dominant trypanosome species; 80% and 71.64% respectively from tsetse suppression areas and for tsetse non-suppression areas followed by Trypanosoma vivax (T. vivax). Overall pooled mean packed cell volume (PCV) indicated parasitaemic animals (23.57±3.13) had significantly lower PCV than aparasitaemic animals (27.80±4.95) and animals examined during dry season (26.22±4.37) had lower mean PCV than animals examined during wet season with significant association. Similarly, parasitaemic animals from tsetse suppression areas (PCV= 23.76± 3.07) and tsetse non-suppression areas (PCV= 23.37±3.21) had significantly lower mean PCV than their aparasitaemic counterpart (tsetse suppression areas, PCV= 27.73±5.07 and tsetse non-suppression areas, PCV= 27.88±4.82). However, mean PCV of animals infected with T. congolense (23.59±3.22) was not statistically different (P > 0.05) from those animals infected with T. vivax (23.26±3.31). It was also indicated that the probability of anaemic animals to be parasitaemic was significantly higher (P < 0.05) than non-anaemic animals in both tsetse suppression areas and tsetse non-suppression areas. Entomological survey result revealed that 2.64 F/T/D and 2.03 F/T/D respectively from tsetse suppression areas and tsetse non-suppression areas during dry season and 0.42 F/T/D and 0.56 F/T/D during the wet season. Glossina pallidipes (G. pallidipes) was the only cyclical vector identified from the area along with numerous mechanical vectors of genus Tabanus, Stomoxys and Haematopota. Higher dependency of cattle owners on trypanocidal drugs to treat their sick animals and limited trypanocidal drug availability in the veterinary pharmaceutical market in conjunction with unsustainable and less participatory vector control activities may intensify the threat of the disease in the area. Furthermore, upsetting current prevalence report of the disease in such area with frequent trypanocidal drug usage and drug injection by unskilled herdsmen and owners report on trypanocidal drug treatment failure may point out the issue of trypanocidal drug resistance in the area. Therefore integrated and safe control and prevention effort should be engaged to uphold cattle production and productivity in the area.
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    Bovine Tuberculosis Lesion Description with Molecular Characterization of Mycobacterium Species from Cattle Slaughtered at Abattoirs Bishoftu, Ethiopia
    (Addis Ababauniversity, 2016-06) wagari, Akinaw; Demissie, Tilaye (Prof)
    A cross-sectional study was conducted at ELFORA and Bishoftu Municipality Abattoir from November 2015 to April 2016 to describe the gross and microscopic lesion of bovine tuberculosis and characterize its causative agents. Post-mortem examination, pathological scoring, bacteriological culturing, Zeihl Neelson staining, histopathology and multiplex polymerase chain reaction (PCR) were used for investigation. Six hundred twenty six (626) Cattle were recruited for the study and the prevalence was found to be 2.9% (18/626) on the basis of gross lesion. There was statistical significant (X2=24.01 and P=0.000) difference between age of the animal and tuberculosis lesion. Eighty eight percent (88%) of the gross lesion was detected in the thoracic cavity while 12% of the lesion was found in the abdominal cavity and head region. Only twenty eight percent (28%=5/18) of the suspicious lesions yielded colonies of which one were acid-fast positive. Severe depletion of lymphocytes, calcification, cellular debris and aggregation of macrophage were observed microscopically. Further identification of the isolates using multiplex PCR revealed that the isolates belong to the Genus Mycobacterium. Of the isolates that showed signal to the Genus Mycobacterium, it was the members of the non-tuberculosis Mycobacterium complex. In conclusion, TB lesions were caused by the non-tuberculosis Mycobacterium complex. Hence, as the isolates were the non-tuberculosis Mycobacterium complex members, the pathogenecity and public health importance of these members in cattle needs further study. Key words: Bishoftu, Bovine tuberculosis, Calcifications, Cattle, Non-tuberculosis Mycobacterium, PCR
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    Characterization of infectious bursal disease lesion and molecular detection of the virus from outbreak cases in poultry farms in selected towns in Central Ethiopia
    (Addis Ababa University, 2023) Meron Teshome; Dr. Tilaye Demissie; Hika Waktole (Assoc. Prof.); Dr. Debebe Ashenafi
    In Ethiopia, chicken production is challenged by infectious diseases among which infectious bursal disease frequently occurs as outbreaks and causes significant number of deaths. It causes mortality to chickens aged between 3 to 6 weeks old. This cross sectional study was conducted in Bishoftu, Gelan, Mojo and Dukem poultry farms that had infectious bursal disease outbreak between December 2022 and April 2023. Purposive sampling method was employed in which samples were collected from 100 chickens showing clinical signs and indicative gross pathological lesions during postmortem. Based on questionnaire, 74% of the respondents said they regularly vaccinate their chickens for infectious bursal disease properly whereas 26% didn’t have proper follow up and gave vaccines repeatedly. Based on occurrence of diseases, 52% of respondents said, they had gumboro like disease in their poultry farm previously. And 74% of owners burn or buried dead birds but 26% used to throw the dead chickens out. Vascular disorder mainly hemorrhage and organ swelling were the most frequent gross lesions observed in many organs. The depletion of the lymphoid follicles and formation of cystic structure both in the cortical and medullary regions of bursa with accumulation of necrotic debris in the cystic structures was frequently examined microscopic lesion in bursa. Hyperplasias of the bursal inter-follicular epithelial and formation false glandular structure were also observed. In spleen, lymphocytic depletion in both white pulp and red pulp and hemorrhages in the trabecular sinuses were the common microscopic lesions. Severe hemorrhages in the interstitial space and necrosis of renal tubular epithelium were the repeatedly observed lesion of kidneys. The common microscopic lesions of the proventriculus were hemorrhage into the inter-glandular connective tissue, necrosis and slough off of the proventricular epithelium. Liver showed multifocal hepatocellular necrosis. Based on lesions and molecular detection result, it could be concluded that infectious bursal disease is still the real challenge to poultry producers by causing mortality and reduced growth in young and reduced production in adult chickens. Scheduled vaccination and strict biosecurity should be practiced to reduce the occurrence of the infectious bursal disease in poultry farms.
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    CHARACTERIZATION OF LESIONS AND EVALUATION OF HAEMATOLOGICAL AND SERUM BIOCHEMICAL CHANGES IN SCAVENGING CHICKEN NATURALLY INFECTED BY GASTROINTESTINAL HELMINTHS IN AND AROUND BISHOFTU
    (2017-06) Debella, Taweya; Dr. Tilaye Demissie, Yacob Hailu (Prof)
    A study was conducted from November 2016 - May 2017 on eighty free range chickens purchased from Bishoftu local markets, to determine the prevalence of gastro-intestinal helminths,for characterizetion of lesions of lesions in parasite positive chicken, and to evaluate change in haemathological and serum biochemical parameters. The gastrointestinal helminths were isolated and characterized. Blood sample was collected from brachial vein in vacutainer tube with anticoagulant for hematological examination and also in plain vacutainers for serum biochemical analysis. After gross lesion characterization tissues were collected into sample bottles containing buffer neutral 10% formalin for microscopic lesion characterization. From a total of 80 chicken examined by postmortem 76 (95%) were infested with one or more types of helminth parasites. Seven nematode parasites namely, Aucaria hamulosa, Ascaridia galli, Hetrakis.dispar, Hetrakis gallinarum, Hetrakis isolenchae, Subulura brumpti, Allodapa sucturia and 6 cestode species namely, Raillietina tetragona, Raillietina cesticillus, Raillietina echinobothrida, Hymenolepis Carioca, Hymenolepis continana and Choenetenia infun were identified. The diference in isolation rate was not significant between male and female (x2=0.278, P>0.05) and among age group (x2=0.268, P> 0.05). The frequent gross lesions include necrosis and haemorrhages in gizard,very soft feces containing much mucous exudate in the small intestine, tickened mucosal wall with petechial haemorrhage and thick white pesty mucous in the lumen. Microscopic lesions revealed degeneration and necrosis of epithelium and intestinal glands, infiltration of inflammatory cells arround the parasite attachments in intestines, excessive tissue damage, hemorrhage, and necrosis in the affected gizzard.The mean haemoglobin, total erythrocyte count, total leukocyte count and packed cell volume were 11g/dl, 2.67x106/ul, 3.04 x103/ul, 30.3% respectively in naturally infected chickens and 12g/dl, 3.5 x106/ul, 2.4 x103/ul, 36.3%, respectively in negative chicken.The mean difference was statistically significant for total erythrocyte count, total leukocyte count, and packed cell volume (P<0.05). Chickens with mixed parasites showed decreased levels of glucose and increased in total protein and aspartate aminotransferase. Means diference for the single and mixed infection was statistically significant for aspartate aminotransferase, total protein and glucose. It can be concluded that gastrointestinal helminthes are one of major problems of local backyard chicken.
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    Characterization of Lesions in Diseased Fishes; Isolation and Identification of Edwardsiella Tarda from Selected Lakes and Ponds Of Central Ethiopia
    (Addis Ababa University, 2021) Rediet Wolde; Dr. Jirata Shiferaw
    Fish is a nutritious animal rich in protein and consumed by many peoples throughout the world. A cross-sectional study with purposive sampling was conducted from December 2020 to May 2021 with the objectives of lesion characterization in diseased fishes, isolation, and identification of Edwardsiella tarda. From Batu, Langano, and Babogaya lakes and ponds in Bishoftu, a total of sixty fishes were examined for gross lesions. Skin, muscle, gill, liver, kidney, spleen, and heart were collected for microscopic lesion characterization and Edwardsiella tarda isolation. Grossly, few lesions were observed. Out of 60 samples, 25% (n=15) were positive for Edwardsiella tarda by conventional PCR. A statistically significant difference (P<0.05) was observed in the frequency of identifying E.tarda between the three study areas and four fish species. After the histopathological process and staining, tissues were divided into two based on E. tarda confirmation. Gills from Edwardsiella tarda positive fishes revealed hyperplasia, focal necrosis, and swelling of the lamellar epithelium. Microscopic lesions in the liver include nuclear condensation, cytoplasmic vacuolation, and swelling of hepatocytes. Lesions in the hepatic blood vessels comprise severe hyperplasia of the endothelium, hyperemia, and elastic fibers in the intima of hepatic artery. Kidneys of Edwardsiella tarda positive fishes had suppurative interstitial nephritis, melano-macrophage deposition in interstitium, and interstitial hemosiderin deposition. Examination showed infiltration of inflammatory cells and focal area necrosis of the epidermis, lymphocyte infiltration in muscle, and accumulation of hemosiderin pigments in spleen. Microscopic lesions in Edwardsiella tarda negative fishes indicated significant changes like lamellar epithelial degeneration with vacuolation, and total necrosis of structure in gill, periportal hepatitis, and hepato-necrosis with vacuolation of liver, glomerulitis, multifocal tubulointerstitial nephritis, epithelial cells degeneration and cloudy swelling in kidney, dermal edema in skin and myocarditis with fibrosis of heart. Based on the study several lesions were identified from diseased fishes. Thus, further studies on lesion characterization in diseased fishes of different species with large sample sizes and study area should be conducted.
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    Characterization of Pathological Lesions on the Nervous system of Horses naturally Affected by Dourine In and around Dodola Wereda, Arsi-Bale Highlands of Oromia, Ethiopia
    (Addis Ababauniversity, 2015-10) Meseret, Melke; Dr. Hailu, Yakob
    A cross sectional study was undertaken in three purposively selected horse-breeding districts of the Arsi–Bale highlands of Ethiopia, namely Dodola, Assassa and Adaba from March 2015 to the end of June 2015. The aim of this study was to describe the neurologic signs and the pathologic findings in the nervous system of horses naturally affected by dourine; and to reveal the presence of the parasite in the nervous tissue or cerebrospinal fluid or in both. For this purpose, a total of 20 local breed of horses with naturally occurring neurologic signs of dourine were considered as study animals. Out of the 20 animals, 12 horses were clinically positive and then selected. From jugular vein of each animal, 7.5 ml and 10 ml of blood using heparinised and plain vacutainer tubes were collected for parasitological (Woo) test and serological (CATT) tests, respectively. The most common signs in the horses were notable weight loss, depigmentation on the vulva and perineal region, and hind legs paralysis. Out of the 12 horses, 2 mares revealed strong seropositive result in CATT test and were subjected for post mortem examination and followed by histopathological analysis. There were no clear gross pathological lesions in the brain, spinal cord and sciatic nerves of the two mares. None of the animals examined showed trypanosomes in Giemsa-stain as well as in blood samples by Woo test. Histopathological examinations of nervous tissue (cerebral cortex, cerebellum, spinal cord and sciatic nerve) showed lesions primarily on the lumbar and sacral regions of the spinal cord and the left sciatic nerve. The primary lesions were degenerative changes and neuronal necrosis of the spinal cord, as well as cellular infiltration and degeneration of the sciatic nerves. Therefore, the present study disclosed that clinically sick horses being seropositive without parasites in the blood as well as nervous tissues revealed moderate degree of pathological lesions. Further sensitive and specific diagnostic techniques need to be applied in order to detect parasitaemia. On the other hand immunological methods seem vital to determine the exact cause of the lesion. Key words: Arsi–Bale highlands, CATT, Dourine, Ethiopia, Histopathology, Horses, Woo test
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    CHARACTERIZATION OF SHEEP AND GOAT SKIN LESIONS CAUSED BY DIFFERENT AGENTS AND IMPACT ON THE RESPECTIVE LEATHERS AT TANNERIES
    (2014-06) NIGUSSU, FASIL; Dr. Tilaye Demissie, Dr. Getachew Terefe
    The objectives of this study were to determine the type and extent of damage and to characterize gross and microscopic lesions as well as quality grading of processed skin to crust stage. In this study 500 animals (350 sheep and sheep and 150 goats) were examined for any skin problem from both ectoparasites controlled and non controlled areas. Nine goats and 11 sheep with skin diseases were conveniently selected for characterization of pathological lesions and evaluation of defect in the tannery and quality grading. Ten goats and 10 sheep skins which apparently look normal were also taken to tannery as controls. Out of the 500 animals examined for skin abnormalities 42 % were infested by lice, 15.7% by fleas, 18.57% by sheep ked, 2.5% ticks, 2% mange, and 25% were infected by pox virus. Generally, the predominant gross pathologic lesions were crusts, scabs, pit depression, alopecia nodules, lichenification, fissuring and erythema. In pox infection lesions were macules, papules with central depression which finally became gray (necrotic) lesion and developed to scabs. Histopathologically pox lesions include acanthosis, parakeratosis and hyperkeratosis in the epidermis and the dermis showed vasculitis, infiltration of inflammatory cells such as macrophages, fibroblasts and histiocytes. Generally microscopic lesions induced by ectoparasites were similar with little variation and includes parakeratotic, hyperkeratosis, and infiltration with eosinophils. Perivascular with eosinophils, plasma cells, and lymphocytes infiltrations. Different downgrades to leather quality due to various agents were observed at tannery and this includes aesthetic appeal, poor grading and rejection of which 50% were rejected, 15.4% categorized as grade 6, 19.2% as grade 5, and 11.5% as grades 1-4 category (annex.2). Ectoparasites were the major causes of down grading and rejection followed by sheep and goat pox.
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    A Clinic-Pathological Study, Lesion Characterization and Financial Loss Due to Fasciolosis and Hepatic Necrobacillosis in Cattle Slaugthered at Three Municipal Abbatoirs of Central Ethiopia
    (2020-06) Wondimu, Hika; Dr. Bulto Giro, Dr Jirata Shiferaw
    The study was conducted from October, 2019 to May, 2020 by using cross-sectional study design to assess a clinic-pathological, lesion characterization, and financial loss due to fasciolosis and hepatic necrobacillosis in cattle slaughtered at three municipal abattoirs of central Ethiopia. Sixty cattle were selected using systematic random sampling for this study, from which blood samples and liver tissue of the same animals were collected before and after slaughter, respectively. Tissue sampling for bacterial culture and histopathology were collected from the infected liver. Post-mortem inspection results, 41.6% (25/60) gross pathologic lesions, of these, 20% (12/60) were mixed infection of liverfluke and Fusobacterium necrophorum while 8% (5/60) and 13.3% (8/60) of the infections were due to Fusobacterium necrophorum and liverflukes alone, respectively. The histopathologic examination of the affected livers indicated heavy infiltration of inflammatory cells, biliary cirrhosis and extensive fibrous of connective tissue proliferation in the hepatic capsule. The hematological assay results indicated that PCV, Hb, and RBC’s were lower in the infected cattle while, the WBC’s (Eosinophilia, Neutrophilia, Monocyte, and Lymphocyte) were higher. The biochemical analysis of blood samples from the infected cattle showed that the liver enzymes AST, ALT, and ALP were significantly higher in animals with hepatocyte degeneration. The estimated financial losses due to liver condemnation by fascioliasis and hepatic necrobascillosis were 1,747,200 ETB/ ($56361.3) annually. Therefore, the study concluded that the liverflukes and infections due to Fusobacterium necrophorum are the major problems of cattle slaughtered at the selected abattoirs of the study areas. Thus, corrective measures and further investigations are recommended to lessen economic loss from fasciollosis caused liver condemnation.
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    Clinical Signs, Serum Biochemical Profiles and Reproductive Pathological Lesions in Horses Naturally Infected With Dourine in Western Arsi Zone, Ethiopia
    (Addis Ababauniversity, 2015-10) Gizaw, Yonas; Dr. Ashenafi, Hagos
    Dourine a venereal transmitted trypanosomosis is endemic in Ethiopia and is the major health problem threatening equines. Until recently, pathologic tissue changes associated with the disease are poorly described. The present study was conducted from November 2014 to June 2015 with an objective of investigating clinical signs; isolate T. equiperdum from blood, serum biochemical change and reproductive pathological lesions in dourine infected horses. A cross-sectional study design and purposive sampling were used to identify and select dourine infected horses. Twelve mares with typical signs of dourine and serologically positive with CATT/T. evansi were identified. The genital and nervous signs were most commonly observed in infected mares while the cutaneous signs were less prominent in the present study. Despite attempts made to isolate the parasite using woo test, no trypanosomes were detected in all of examined blood samples. There were no significant variation (p>0.05) in the mean values of total protein, albumin, AST, ALT and ALP between the infected and healthy groups but a relative increase were observed in all biochemicals analyzed except mean level of albumin which showed a relative decrease in infected group compared to healthy one. Gross lesions observed in the two euthanized infected mares includes, swollen vulva with visible areas of depigementation, congestion of the mucosa of vagina, thickened and congested mucosa of uterus, ovarian follicular cysts, slightly enlarged and congested spleen, enlarged and swollen liver with multiple necrotic foci. Microscopically, mononuclear cell infiltration mainly of lymphocytes and plasma cells and periglandular inflammation were observed in the vulva, vagina, cervix and uterus. In addition, interstitial mastitis, haemosidrine deposition in the spleen and liver and lymphcocyte depletion in the spleen were observed. The results of these gross and histological findings indicate the presence of various organs involvement with severe degree of lesions. Thus, dourine imposes further pathological studies in naturally and experimentally infected mare and stallions by increasing the sample size. Key words: Ethiopia, Infiltration, Mare, Mononuclear cells, Serum biochemical, Trypanosoma equiperdum
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    Comparative Evaluation of Pathological Lesions in Fish Collected from Different Effluent Sites in Lake Batu and Lake Hawassa, Ethiopia
    (Addis Abeba University, 2023) Assaye Desta; Tilaye Demissie (Asst Prof)
    A cross sectional study was conducted from November 2022 to May 2023 with the objective of comparatively evaluating gross and microscopicl lesions in fish collected from different effluent sites that were identified based on water chemical analysis in lake batu and lake hawassa. Water and fish samples were collected from effluent and reference sites. Mean (±SD) of water quality parameters were statistical different for a mmonia, nitrate, nitrite, silica, total dissolved solute (TDS) and alkalinity by sampling sites (P < 0.05). Mean for ammonia, nitrite, silica and alkalinity were found significantly higher (P<0.05) in Lake Batu water samples compared to Lake Hawassa. Means of all analysed water quality parameters were found significantly higher (P < 0.05) in effluent site of Lake Batu compared to reference sites. Similarly, except nitrite the mean water quality parameters were found significantly higher (P < 0.05) in effulent site compared to reference site for Lake Hawassa. Based on logistic regression analysis (OR) fish collected from lake Batu were 2.46 times more likely to develop gross gill lesions (P<0.05) ; and 1.8 times likely to develop gross skin lesions (P<0.05) than fish collected from lake Hawassa. Regarding sites of fish collection, fishes collected from effulent sites were 2.95 times mor likely to develop gross gill lesions (P<0.05); 4.67 times more likely to develop gross liver lesions (P<0.05) and 2.98 times more likely to develop gross skin lesions (P<0.05) compared to reference site in lakee Batu. For Lake Hawassa; fish collected from effulent site were 2.9 times more likely to develop gross gill lesions and 2.98 times more likely to develop gross skin lesions (P<0.05) in effulent sites compared to reference site. Based on microscopic lesions grading; la mellar necrosis for gill, multifocal hepatocelular necrosis and biliary epithelium necro sis for liver, and epidermal cell necrosis for skin were stage III lesions. Stage III lesions were identified more frequent for lake batu effulent site than lake hawassa effulent site and stage III lesions were nor identified for reference sites of both lakes. Based on microscopic lesions, haemorrhage, aneurysm and lamellar fusion in gill; aneurysm and hydropic degeneration in liver; haemorrhage, aneurism and separation of layers in skin, were stage II lesions. Stage II lesions were frequently identified in fish collected from effulent sites of both lakes and less frequent in reference sites of both lakes. Stage I lesions were lymphocytic infiltration, hyperplastic primary and secondary lamellae and goblet cell hyperplasia in gill; lymphocytic infiltration in liver; lymphocytic infiltration in skin. Stage I lesions were found in both reference and effluent sites of both lakes. It could be summarized that severe necrotic lesions (stage III) and degenerative and hemorrhagic lesion (stage II) swere more ferquent in fish collected from effulenet site than refrence site and this was also in parelell to chemical parameters of water quality. It could be concluded that the majority of stage III & stage II lesions were probably induced by contamination of lake waters by town sewerage, agricultural and industrial wastes. It also looks that lake Batu is more contaminated than lake Hawassa (based on lesion stages & water quality parameters), however, this need further detailed study. We think the result can be basics for further study and we recommend more detailed study.
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    COMPARATIVE STUDY ON LESIONS OF REPRODUCTIVE DISORDERS OF COWS AND FEMALE DROMEDARY CAMELS SLAUGHTERED AT ADDIS ABABA, ADAMA AND AKAKI ABATTOIRS WITH BACTERIAL ISOLATION
    (2017-06) Aynalem, Mandefro; Dr. Tilaye Demissie
    A cross-sectional study was conducted from November 2016 to May 2017 on reproductive organs of cows and dromedary camels slaughtered at Akaki slaughter house, Addis Ababa and Adama municipal abattoirs to compare lesions and bacteria isolates. A total 280 reproductive organs (140 form cows and 140 from camels) were grossly inspected. Grossly visible lesions were documented and tissue samples with lesion were collected for histopathological lesion characterizations and bacteriological isolations. Various pathological lesion with different degrees of severity were observed in 36.4% (n=51) and 34.2 % (n=48) of cows and dromedary camels, respectively. Age, species and body conditions of animals were not statistically associated with most of the disorders (P>0.05). Comparatively, in cow the most frequently observed lesions were that of ovaries 16.4% while in camels it was that of uterus 21.4%. Grossly, endometritis were characterized by congestion in acute cases and congestions and thickening in chronic cases. Microscopically, endometrial glands degenerations, sloughing of epithelium, periglandular cuffing and infiltrations of inflammatory cell were some of characteristics change observed in endometritis. Grossly, the follicular cyst were large, some of them occupied the entire ovary and very thin walled. Microscopically, the follicular cysts were characterized by extremely thin granulosa layers. Most of endometritic tissues cultured for bacterial isolations were positive for either single and/or mixed bacterial infection. Staphylococcus species 28.5%, Streptococci species 19.6%, Coynebacterium species 8.9%, Escherichia coli 26.7%, Salmonella species 10.7% and Klebsiella species 5.35% were isolated from cows uteri, while in the dromedary camels, Escherichia coli 35.5%, Staphylococcus species 26.6%, Streptococcus species 13.3%, Pseudomonas species 6.6 %, Proteus species 4.4%, Salmonella species 8.8% and Klebsiella species 4.4% were isolated. It could be concluded that reproductive organ lesion were important problem in both species of animals and these disorders might be causes of infertility and appearance of these females in abattoir. The role of each identified lesion on infertility needs further investigations.
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    Comparative Study on Pathological Changes in Sheep and Goats Experimentally Infected with Haemonchus Contortus
    (2020-06) Bethlehem, Mesfin; Dr. Jirata Shiferaw, Dr. Getachew Terefe
    The experimental study was done between October, 2019 and June, 2020 in the fly-proof experimental animal facility located in the premise of the college of veterinary medicine and Agriculture at Bishoftu. A total of 14 male goat (G1 and G2) and 14 male sheep (G3 and G4) were allotted in to four equal groups. Single dose of 10,000 of infective larvae of Haemonchus contortus (L3) was orally administered to each animal in G1 and G3. Parameters such as body weight, PCV, haemoglobin, worm count, serum total protein, serum albumin, alkaline phosphatase and aspartate aminotransferase were measured. Moreover, histopathological sections were stained and examined for general changes as well as for changes in specific cells such as tissue eosinophilia and parietal cell population. The findings show that 1) All infected sheep and goats developed the infection with higher mean worm burden in goats (5590) than sheep (2887) and the difference was significant (P<0.05); 2) All infected sheep and goats exhibited a progressive anaemia; the level being more severe in goats than in sheep (P< 0.05) with mean PCVs of 13% and 18.6% respectively; 3) While body weight gain was minimal in sheep, goats have lost significant weight compared to pre-infection levels, to control animals or in relation to infected sheep (P< 0.05); 4) analysis of biochemical changes also revealed marked reduction in serum total protein and albumin but again it was much more significant in goats than in sheep (P< 0.05); 5) infected sheep and goats‟ abomasa have shown thickening, nodule development, eosinophilic infiltration and damage to parietal cells. Tissue eosinophilia was more prominent in sheep while parietal cell loss was severe in goats. In conclusion, goats under experimental infection and similar management condition with sheep develop much more severe infection and associated pathology compared to sheep and hence deserve special attention.
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    Comparative Study on Pathological Changes in the Small Intestine of Sheep and Goat Experimentally Infected with Trichostrongylus Colubriformis
    (2020-06) Arega, Tafere; Dr. Jirata Shiferaw, Dr. Getachew Terefe
    The experimental study design was conducted to determine hematological and serum biochemical parameters and pathological changes in the small intestine of sheep and goat experimentally infected with T. colubriformis in fly-proof experimental facility at College of Veterinary Medicine and Agriculture, Bishoftu, Ethiopia. During the study period, 13 sheep (6 controls, 7 infected) and 14 goats (7 controls, 7 infected) were included in the experiment. The infective larvae of T. culibriformis (L3) as a single dose of 10,000 per-animal was administered orally to infected sheep and goats (G2 and G4). From the infected group, the total recovered mean worm burden was recorded higher in infected goat (5016 larvae of T. colubriformis) (P<0.05) than infected sheep (3446 larvae) with establishment rate of 50.16% and 34.46% respectively. The total mean hematological and biochemical values recorded in infected and uninfected sheep and in infected and uninfected goat were significantly (P<0.05) lower in infected than uninfected control, except RBC and WBC count. In sheep PCV, Hb and albumin were significantly (P<0.05) lower in infected group than uninfected control group. Gross lesions found in the intestine were enteritis with petechial hemorrhages, edema, hyperemia and mucosal slough which were marked in the duodenum (62.69%) and jejunum (33.33%) in sheep and 47.05% duodenum and 45.09% jejunum in goat. The microscopic lesions developed by T. colubriformis were subtotal villus atrophy, hemorrhage, straighten and elongated dilated crypts, loss of epithelium, mucosa erosion and infiltration of inflammatory cells. In conclusion, the present experimental investigation showed that T. colubriformis infection affected hematological parameters, biochemical indices and caused pathological changes of small intestine in sheep and goat, with more severe infection in goats than sheep although they were under the same management condition.
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    CYTOLOGICAL AND PATHOLOGICAL CHARACTERIZATION OF TUMORS OF DOMESTIC ANIMALS IN AND AROUND BISHOFTU, ETHIOPIA
    (2018-06) Mesfin, Mathewos; Dr. Tilaye Demissie
    Tumors are one of the disorders that affect domestic animals. The present study was conducted from October, 2017 to May 2018 with the objectives of determining the types and frequencies of tumors of domestic animals based on cytological and pathological characteristics. A cross-sectional study with purposive sampling of animals with swelling or masses was conducted for evaluation of masses by gross examination, cytology and histopathology. A total of sixty neoplastic swelling were identified. Based on cellular origin, the overall frequencies of tumors were found to be 46.7% epithelial, 36.7% unclassified, 13.3% mesenchymal and 3.3% were round cell tumors. Gross lesions observed include firm consistency, cauliflower like lesions, nodular mass, ulcerated, inflamed and haemorrhagic surfaces, pediculate, necrosis, and lobulated mass with irregular margins. Cytologically, most of the epithelial cell tumor and equine sarcoid revealed clusters of cells with different arrangements, deep nuclear chromatin, anisocytosis and anisokaryosis. Where as, all tumors of mesenchymal origin including fibropapilloma showed pleomorphic spindle cells. Mast cell tumors was characterized by its cytoplasmic granules and transmissible venereal tumors by clear punctuate intracytoplasmic vacuoles, cell shape and prominent central nucleoli. Histopathologically, equine sarcoid and papillomatosis were characterized by dermal keratinocytes proliferation, long rete pegs that extend deep into the dermis. Ocular squamous cell carcinoma was characterized by keratin tonofilaments and keratin pearls while, leiomyoma, cutaneous fibrosarcoma, basal cell carcinoma and hemangiopericytomas were characterized plump smooth muscle-like cells, herring bone pattern, cluster of neoplastic basal cells and perivascular whorls of pericyte nuclei, in the respective order. Mammary tumors were characterized by severe cellular and nuclear pleomorphism, and highly infiltrative. Sertoli cell tumor, fibrothecoma, cutaneous mast cell tumor, transmissible venereal tumor and malignant fibrous histiocytoma were chracterized by sheets of sertoli cells, spindle cells with plump thecoma cells, granulated mast cells, round cells with vesicular nuclei and pleomorphic histiocytic cells, respectively. Based on the result it could be concluded that domestic animals were widely suffering from tumors of different origin. Thus, studies involving large sample size, and wider diagnostic tools should be conducted. Key words: Cytology, Domestic animals, Ethiopia, Histopathology, Tumors
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    DETERMINATION OF ANTI-RABIES VIRUS ACTIVITIES OF CRUDE EXTRACTS FROM SOME TRADITIONALLY USED MEDICINAL PLANTS IN EAST WOLLEGA, ETHIOPIA
    (2017-06) DEMEKE, ZEWDE; Dr. Fufa Dawo, Mr. Brihanu Hurisa
    An experimental study was conducted between November, 2016 and April, 2017 at Ethiopian public health institute to evaluate the anti-rabies activities of the leaf of Justicia schimperiana, root of Phytolacca dodecandra, root bark of Croton macrostachyus and their combination at 1:1:0.75 ratio, respectively. The plants are widely used traditionally for the treatment of rabies in humans and animals in East Wollega, Ethiopia. The plant parts were dried, grinded and crude extraction was conducted as per standard of Ethiopian Public Health Institute. Crude extracts were prepared from the powders of these plants using 80% hydro-ethanol and dried by condensation process. The anti-rabies activities of these plant extracts were tested in three different doses: 300, 2000 and 5000 mg/kg in mice and compared with positive control based on the difference in mean survival time of group of mice challenged with rabies virus (CVS-11). The result showed that P.dodecandra, J. schimperiana and combination of all the three plant extracts at 300 and 2000mg/kg dose levels and C. macrostachyus at 300 and 5000mg/kg doses didn‟t significantly(P>0.05) increase the survival period of mice. However, at 5000 mg/kg dose level for P.dodecandra (P=0.002), J. schimperiana (P=0.038) and combination of all the three extracts (P=0.021) and at 2000mg/kg dose level for root bark of C. macrostachyus (P=0.011); the plant extracts were significantly (P<0.05) increased the survival time of mice. The finding illustrates the existence of promising active compounds against rabies virus in extracts of roots of P. dodecandra and root bark of C. macrostachyus at indicated doses preferably to other extracts and needs further research to elucidate its active ingredients targeted to antiviral activity. The results also suggested good correlation between the in vivo anti-rabies virus activities and traditional therapeutic uses reported by traditional healers.
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    Efficacy of Entomopathogenic fungi against Amblyomma Variegatum Ticks and their control practices in and around Bishoftu, Central Oromia, Ethiopia
    (Addis Abeba University, 2024) Dereje Tsegaye; Prof. Bersissa Kumsa
    Ticks impact the health of animals and humans and are associated with numerous public health and economic problems around the world. The use of chemical acaricides has been the most commonly used method for tick control on livestock in recent years. However, chemical control of ticks has several disadvantages including high expense, lead to toxic residues in meat and milk, lead to acaricidal resistance and cause environmental pollution. The present in vitro experimental study on the efficacy of entomopathogenic fungi against adult Amblyomma variegatum collected from cattle was conducted from September 2023 to April 2024 in Bishoftu town. The entomopathogenic fungi were isolated from the soil samples in different parts central of Ethiopia. Furthermore, the knowledge, attitudes and practices of the animal owners regarding ticks and tick control was assessed through a structured questionnaire survey. Of the total of 80 soil samples examined for the presence of Entomopathogenic fungi, 17 samples from Bishoftu and Burayu were positive of which Metarhizium anisopliae were detected in 10 soil samples while the rest 7 soil samples were positive for Beauveria bassiana.The working concentrations were prepared from selected positive isolations at three strength levels (1x10 6 , 1x10 7 and 1x10 8) conidia/ml was applied against Amblyomma variegatum while distilled water and Amitraz 12.5% were used as a negative and positive control, respectively. After applying different concentrations separately, and a mortality rate of 93% and 97.5% was recorded at the concentrations 1x10 7 and 1x10 8 conidia/ml respectively for metarhizium anisoplie and 93.33% and 97% for beauveria issiana after 15 days, with the lowest concentration (1x10 6) conidia/ml showing the lowest death percentage (83.25%) for metarhizium anisoplie and 80.7% for beauveria issiana whereas 76.75% mortality was recorded in the positive control Amitraz. The highest efficacy of Entomopathogenic fungi was observed for the highest concentration and time in increasing manner. The LC50 of 1 x 10 4 (% 95 CI = 1 x 10 3 - 1 x 10 8) conidia/ml for Metarhizium anisopliae and 1 x 10 4 (% 95 CL = 1 x 10 3–1 x 10 6) conidia/ml for Beauveria bassiana, and LC99 of 1x10 9 (% 95 = 1x10 8-1x10 13 conidia/ml for Metarhizium anisopliae and 1x10 9 (%95=1x10 7-1x10 11) conidia/ml for Beauveria bassiana were recorded using probit regression analysis. This suggests that the EPF have great potential as the alternative approach to chemical acaricides for the control of ticks in Ethiopia.
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    Experimental study on pathological changes and performance variations in Chickens challenged by Eimeria tenella under different genotype, age and nutrition status
    (Addis Abeba University, 2022) Misgana Tefera; Dr. Jirata Shiferaw; Prof. Getachew Terefe
    Eimeria tenella is a Protozoa which is a causative agent of avian coccidiosis. The disease cause bleeding in the cecum, diarrhea, high morbidity and mortality in chickens. The experimental study was conducted from November 2020 to January 2022 at the ILRI poultry research facility in Addis Ababa. First experiment was aimed to investigate the effect of Eimeria infection at different feeding regimes on chicken pathological changes and productivity diversity in adult Sasso T451A and Bovans brown breeds. Chickens were infected with 1 x 104 oocysts of Eimeria tenella. Three factors; feeding regimes, challenges level and breeds of chicken were seen to evaluate the effects of parasite. The results showed that Bovans brow feeds deficient infected group had significantly higher (P < 0.05) gut lesions as compared to the control group. Production performance of feed restricted groups was significantly low as compared to optimum feeding but there was no significantly difference (P < 0.05) in production performance between infected and control groups. The second experimental study investigated oocysts output, lesion scores, PCV, pathological changes and production performance following artificial intubation of 3 x 104 of Eimeria tenella oocysts. The results show that lesion scores in Sasso was significantly higher (P < 0.05) than Bovans brown on day 4 post-infection. PCV of infected chicken was significantly (P < 0.05) decreased at day 8 post-infection in both breeds, similarly oocyst count and lesion score in the infected group of chicken was higher at day 8 than day 4 post-infection, this indicate that the infection was more severe at day 8 post-infection. Histopathological examination result of infected chicken by E. tenella was observed with infiltration of inflammatory cell in the cecum tissue. Therefore, the current result showed that the effect of E. tenella on infected chicken intestine had developed pathological lesions than non-infected groups of chickens.
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    Experimental Study on Sheep Infested With Bovicola Ovis and Melophagus Ovinus of Pathological Changes, Processed Skin Defect and Effect of Treatment in Improving Skin Quality
    (Addis Ababauniversity, 2015-10) Kebebew, Getachew; Dr. Demissie, Tilaye
    Experimental study was conducted from January, 2015 to August, 2015 on sheep experimentally infested by B .ovis and M. ovinus with the objective of identifying specific pathological changes they induce, the type of defect at pickle and their effect on skin quality and effect of treatment on resumption of skin to normal state. For this purpose, thirty indigenous sheep of Arsi origin approximately 18 months age were bought from market. They were treated against infection and parasites and kept for a month to stabilize them before the commencement of the experiment. The sheep were then grouped in to five groups each with six individual sheep as non-infested control, B .ovis infested untreated, B .ovis infested treated, M. ovinus infested untreated and M. ovinus infested treated. B .ovis and M. ovinus were manually collected from donor sheep; identified, counted and then infested at 500 B .ovis and 50 M. ovinus per sheep to the respective treatment groups. All groups were managed under similar condition and followed for 95 days and Sheep within the infested treated groups were treated with diazinon and followed for additional 30 days. The total WBC count was increased in B .ovis and M. ovinus infested groups compared to non-infested control group. However, the statistically significant was only for groups infested by M. ovinus (P< 0.05). In all infested groups the differential leukocyte count was increased; nevertheless, the significant difference was only for eosinophil (P <0.05). The common gross lesions noticed were skin discoloration with excreta, crust formation, macules and erythema for M. ovinus and B .ovis with slight difference in intensity of lesion. Microscopically, hyperkeratosis and acanthosis were more severe in groups infested by M. ovinus than B .ovis. The density of inflammatory cells infiltrating dermis was severely intensive in groups infested by M. ovinus than B .ovis. In groups that were treated, the gross pathological lesions except skin discoloration were totally disappeared within 30 days; nonetheless, the microscopic lesions persisted with a decrease in number of inflammatory cells specifically that of eosinophils. At pickle stage M. ovinus was characterized by large elevated cockles and B .ovis by extensive but small cockles. All processed skins from B.ovis and M. ovinus infested groups degraded and lied toward the stages of moderate x grades (5 or 6) and less which is very poor. In treated group 50% of the processed skins from B .ovis were improved in quality and were lied to grades 1 to 4 (very good to good) but only 33% of skin from M. ovinus were improved and lied to 1 to 4 grades. It could be concluded that infestation by B .ovis and M. ovinus cause severe to mild gross pathological lesions however severe microscopic lesions to sheep skin and reduced the quality of processed skin from top grades to low grade. Definitely treatment improves skin quality but not in all affected skin, and varies between B .ovis and M. ovinus. Keywords: B.ovis, Cockle, Ethiopia, Experiment, Lesion, M. ovinus, Sheep, Skin
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    Gross and Histopathological Study on Pneumonic Lungs of Small Ruminants Slaughtered at Different Restaurants and Modjo Export Abattoirs, Ethiopia
    (2020-06) Tsegaye, Wolde; Dr. Shiv Kumar Mishra, Dr. Bersissa Kumsa
    Cross sectional study designed to attain the objectives to characterize gross and microscopic lesions in pneumonic lung of small ruminants was conducted from October, 2019 to May, 2020. Totally 155 lungs (sheep = 86) and (goats = 69) were examined from export abattoirs and different restaurants in Modjo town during the study period. Out of which 107 (69.03%); 60 (69.8%) and 47 (68.12%) in sheep and goats, respectively, had displayed different types of pneumonia. Suppurative bronchopneumonia (45%) was the most frequent followed by interistitial pneumonia (21.5%), fibrinous bronchopneumonia (10.3%), granulomatous pneumonia (9.35%), verminous pneumonia (6.54%) aspiration pneumonia (4.67%) and embolic pneumonia (2.8%). Bronchopneumonia, both suppurative and fibrinous were grossly characterized by lungs consolidation commonly on the cranioventral area, however; fibrineous type was characterized by typical fibrin deposits while the suppurative type was characterized by suppurative exudates. The common microscopic characteristics were fibrin strands in fibrinous bronchopneumonia and massive neutrophils in suppurative bronchopneumonia. Interistitial pneumonia was typically identified grossly by prints of coastal ribs at the surface of lung and its rubbery texture on palpation and by proliferation of smooth muscle and slightly presence of edema in the alveolar interistitium microscopically. The gross appearance of verminous pneumonia was similar to interistitial pneumonia however, the cut surface reveal parasites both grossly and microscopically. The granulomatous pneumonia was recognized by the presence of nodules grossly and cellular granulomatous rim, a zone of layers consists of various inflammatory cells and few fibrosis in outer layer microscopically. Immunohistochemistry results revealed that the alveolar and peribronchiolar surface infiltrated macrophages were expressed CD45 and CD68 immunopositive reaction. Aerobic bacterias commonly Staphylococcus aureus, Streptococcus spp., Escherchia coli and Pasteurella spp. were isolated; and parasites commonly Dictyocaulus filarial, Mulleries capillaris and Protostrongylus rufescens were identified from pneumonic lung tissues. It could be concluded that pneumonia was one of the problem of small ruminants at abattoirs. Large number of aerobic bacterias and parasites were identified. Although no doubts that the parasites isolated were the causes of pneumonia from which they isolated, and xiii it was exactly while the animals were at the field for the bacterias isolated causal relationship should be done at the field.
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    Gross and Microscopic Lesions of Epizootic Lymphangitis on Carthorses in Central Oromia, Ethiopia
    (Addis Ababauniversity, 2015-10) Wakjira, Dereje; Dr. Ashenafi, Hagos
    A cross sectional study was conducted in eight towns in central Oromia, Ethiopia, from March to August of 2015 with an objective of describing the pathological findings of topical and internal organs lesion in carthorses naturally infected with Epizootic lymphangitis and revealing the presence of the fungus within the lesions of internal organs. The study animals were local breed carthorses located in the study areas that are naturally infected with Histoplasma capsulatum variety farciminosum. Among the 70 disease suspected carthorses that were found in the study area 30 were purposively screened out. Field assessment, clinical observation, microscopical examination, isolation of the agent, autopsy examination, and histopathological examination were used for this investigation. Field Survey part of this study revealed presence of a gap on knowhow of the disease. In spite of the fact that 76% (76/100) of the interviewed carthorse owners were trained by SPANA, 44% of them still believe that the disease is caused by an evil-eye or “Buda”.71% of them are accustomed to use both traditional and modern treatment methods. 37% of them believe presence of small and large nodular lesions which is found to be true that out of the 804 nodular lesions counted on this study 396 (49.3%) were small type (Female) and 408 (51.7%) large type (Male). Early and moderate stages of Epizootic lymphangitis are considered curable, however, the fate of carthorses with sever stage of the disease was euthanasia. Severely affected and abandoned carthorses were usually found staggering at the middle of highways. All the 70 disease suspected carthorses showed signs of the cutaneous forms of the disease and there were no clearly separated three forms, rather there were an extension and manifestation of the cutaneous form lesions in and around eye and respiratory organs. Giemsa stained smears of the contents of pyogranulomatous skin nodules and imprint smear of affected internal organs revealed yeast like organisms; showing that the disease. The topical body parts affected with lesion were skin and superficial lymphatics of skin of the body extremities. Nodular lesions were observed mostly in the limbs, lower trunk and head regions. Severely affected regions were the limb extremities, especially the hind limb extremities. Tick infested parts seems to be more vulnerable. The gross lesions detected on internal organs were few in number and even on few organs. Although, diverse types of lesions were detected on different organs, a mass of nodule on x mucosal part of trachea and a large nodular lesion of right lung together with diffused small granulomatous nodules of both lungs were the reportable findings of this study. Hematoxylin and Eosin stained histopathological sections reveled the characteristic pyogranulomatous lesion and many yeast-like organisms distended within macrophages. Those characteristic histopathological lesions were found both from topical and internal organ lesions. The inflammatory cells that infiltrate the tissue were macrophages, polymorphonuclear cells and plasma cells; macrophages being the predominant one. There were neither gross nor microscopic lesions detected within internal organs of some cases in this study; even in one organ. There was neither pyogranulomatous lesion nor yeast-like organisms detected from normal tissue sections of internal organs and from some non-nodular lesions of internal organs. Having such an open skin, their internal organs were found to be normal in pathologically point of view. The pathological lesions were restricted on the skin and most of the vital organs were found normal. Additionally skin has a great regeneration capacity and early and moderate stages of Epizootic lymphangitis are curable. Therefore all stages of EZL seem curable, if handled properly. The treatment may not be cost effective, however, euthanasia of carthorses in sever stage of Epizootic lymphangitis for welfare reason seems against the principle of welfare. Key words: Epizootic lymphangitis, carthorses, pyogranulomatous lesion, necropsy, biopsy, histopathology