Veterinary Pathology

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Browsing Veterinary Pathology by Author "Bersissa Kumsa"

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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; 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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    Gross and Histopathological Study on Pneumonic Lungs of Small Ruminants Slaughtered at Different Restaurants and Modjo Export Abattoirs, Ethiopia
    (2020-06) Tsegaye Wolde; 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.