Veterinary medicine (Auckland, N.Z.)最新文献

Background: Bovine trypanosomosis remains a vital livestock disease and constraint which is intimidating livestock health and production, regardless of ongoing tsetse and trypanosomosis control struggles in Jimma Arjo district, East Wollega zone, Ethiopia.

Methods: A cross-sectional study was carried out with the objective of determining prevalence of cattle trypanosomiasis and apparent tsetse fly density in six randomly selected peasant associations of Jimma Arjo District from April 2018 to January 2019.

Results: From overall 819 arbitrarily selected cattle (n= 36; 4.39%), infection rate was recorded. Selected animals were invariably infested with different trypanosome species among which Tryapanosoma congolense (80.55%) was the most common, followed by T. vivax (11.11%), T. brucei (5.55%) respectively. Co-infection of T. vivax and T. congolense accounted for 2.77% of total infection rate. This finding indicates a statistically significant difference (p<0.05) among good, medium, and poor body condition animals with respect to Tryapanosomosis infection rate. Poor body condition animals were highly infected with trypanosome parasite as compared to medium and good body condition score animals. This study shows statistically significant association was obtained between mean packed cell volume (PCV) and trypanosomiasis infection rate (P<0.05). The lower mean PCV value (21.14%) were highly affected as compared with high mean PCV value animals (25.26%). The result of entomological survey, by using mono pyramidal traps deployed near animal grazing field and rivers of selected peasant association (PA), showed presence of four Glossina species namely Glossina morsitans, G. pallidipes, G. tachinoides, and G. fuscipes with high fly density per trap in Meta PA. Higher catches of G. fuscipes were registered as compared to other vectors.

Conclusion: Generally, this study indicated the disease is still a main problem for livestock health and production in the study area and it necessitates disease and tsetse fly control.

Background: In the global dairy industry, mastitis is the main economic significant disease of cattle. Milk and other dairy outputs are scarce in developed countries, including Ethiopia.

Methods: In this cross-sectional investigation in the Modjo district, milk samples were collected aseptically from 384 randomly selected lactating cattle to investigate the prevalence of clinical and sub-clinical mastitis and determine the possible risk factors and isolate bacterial pathogens causing mastitis. Besides, clinical mastitis cases have been reported by veterinarians based on milk, udder, or systemic cow anomalies, whereas the presence of subclinical mastitis was determined using California Mastitis Test (CMT).

Results: The research revealed that subclinical mastitis (71.02%) is more prevalent in dairy farms of the study area than in the clinical type (28.9%). The quarter-level frequency was 36.9%; from which, 34.9% and 3.4% were from subclinical form and blind teat, respectively. There was a significant correlation between the frequency of mastitis in lactating cows (p < 0.05) and factors, such as breed, age, body condition score, herd size, milking mastitic cow at the end, and previous mastitis history. The dominant mastitis-causing agents isolated in this study were Staphylococcus aureus (40.3%), Streptococcus species (24.3%), Coagulase-negative Staphylococcus (12.5%), E. coli (8.3%), Staphylococcus hyicus (3.5%), and Staphylococcus intermedius (1.4%). The high occurrence of mastitis, particularly sub-clinical mastitis, revealed significant economic potential losses in dairy farms in the research district.

Conclusion: Therefore, appropriate measures aimed at increasing the understanding and hygiene milking methods of dairy farmers, routine monitoring for subclinical mastitis, dry cow therapy, and culling of chronically contaminated cows to reduce bovine mastitis and its impact on milk production and food security.

Introduction: Infectious bursal disease virus (IBDV) is an avian viral pathogen that causes infectious bursal disease (IBD) of chickens. The disease has been endemic in Ethiopia since 2002, and vaccination has been practiced as the major means of disease prevention and control. An IBD vaccine is produced in Ethiopia using primary chicken embryo fibroblast (CEF) cell, which is time-consuming, laborious, and uneconomical. The present study was carried out to develop cell-based IBDV LC-75 vaccine using Vero cells and to evaluate the safety, immunogenicity and protection level.

Methods: Identity of the vaccine seed was confirmed with gene-specific primers using reverse transcription polymerase chain reaction (RT-PCR). Confluent monolayer of Vero cells was infected with vaccine virus and serial passage continued till passage 10. A characteristic virus-induced cytopathic effect (CPE) was observed starting from passage 2 on the third day post-infection. The infectious titer of adapted virus showed a linear increment along the passage level. The virus-induced specific antibody was determined using indirect ELISA after vaccination of chicks through ocular route.

Results: The antibody titer measured from Vero cells vaccinated chicks revealed similar level with the currently available CEF cell-based vaccine, hence no significant difference. Chicks vaccinated with Vero cell adapted virus showed complete protection against very virulent IBDV, while unvaccinated group had 60% morbidity and 25% mortality.

Conclusion: It is concluded that the IBDV vaccine strain well adapted on Vero cells and found to be immunogenic induces antibody development and successfully protects chicks against challenge with the circulating field IBDV isolate. Hence, it is recommended to produce IBD vaccine using Vero cell culture at the industrial scale to conquer the limitations caused by using CEF cells and thus to vaccinate chicks population to protect against the circulating IBDV infection.

Purpose: Newcastle disease causes considerable loss in the poultry industry worldwide and its outbreaks are regularly reported from all continents of the world, including Ethiopia. The investigation was conducted from October 2020 to June 2021 to determine the prevalence of Newcastle disease (ND) in districts selected from Buno Bedele zone, Western Oromia.

Methods: The study design used was a cross-sectional type. For this study, a total of 480 serum samples were collected as per sample collection guideline from randomly selected chickens that were apparently healthy and had no history of vaccination against Newcastle disease. Indirect ELISA was performed and all data were analyzed using SPSS statistical software.

Results: From serological investigation, overall seroprevalence of Newcastle disease was 30%. Seroprevalence of Newcastle disease was 34.94%, 22.22%, and 31.76% in Didessa, Chora, and Gachi districts, respectively. Among computed risk factors, breed showed statistically significant difference and the odds of infection were lower in adult than in young chickens. Similarly, the odds of infection with Newcastle disease virus were significantly higher in crossbred than in locally bred backyard chickens.

Conclusion: This study revealed Newcastle disease was prevalent in the study areas; therefore, regular investigation of Newcastle disease should be conducted along with detailed studies on molecular characterization of circulating field strains in the area.

Background: Staphylococcus aureus (S. aureus) has been reported as the most commonly isolated highly contagious pathogen from human, animals and animal products. Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a significant pathogen with zoonotic potential that could have devastating consequence for the health and well-being of animals and human.

Methods: A cross-sectional study was conducted from July 2020 to January 2021. A total of 233 samples from cow milk, udder swabs and milkers' hand swabs were collected for culture and identification based on the standard protocol. Antimicrobial susceptibility tests were performed for all isolates by using Kirby Bauer's disk diffusion test. MRSA was detected by cefoxitin disk diffusion test.

Results: S. aureus was isolated from 50 (21.46%) of 233 samples and the prevalence of MRSA was 4%. The highest prevalence was found in cow milk 36 (25.53%) followed by hand swabs 10 (19.23%) and udder swabs 4 (10%). S. aureus prevalence was 58.33%, 30.0%, 21.43%, 17.92%, 15.79% in farm D, C, E, A, B respectively. A large percentage (58.33% and 30%) were from farm D and C. S. aureus isolation rate showed statistically significant association with farm types (p = 0.011) and with previous mastitis exposure (p = 0.001). High level of resistance was observed to penicillin (94%) and ampicillin (92%), but low level resistance to gentamicin (0%), amikacin (0%), ceftriaxone (0%), chloramphenicol (4%), ciprofloxacin and cefoxitin (4%). The overall prevalence of multidrug resistance (MDR) was 10.42%.

Conclusion: Prevalence of S. aureus in milk showed statistically significant association with respect to previous mastitis exposure and farm types (p = 0.011). High level of resistant to penicillin and ampicillin was observed. Therefore, effective mastitis control programs, best veterinary practice among all farms and use of antibiotics in the farm should be strictly controlled.

Purpose: Although helminthiasis have been recognized as health constraints of small ruminants, there was no study conducted to reveal their types and burden in goats and sheep slaughtered at Bishoftu, Ethiopia. Hence, this study is aimed to evaluate the current status of helminth parasites and estimate its burden in study animals.

Methods: The study was carried out from November 2016 to April 2017 to identify the species and also to estimate the burden of small intestinal parasitic helminth in goats and sheep using a standard worm recovery procedure. The study animals were 230 goats and sheep slaughtered at Bishoftu Elfora export abattoir during the study period.

Results: The study revealed that the overall infection rate was 83.5%. Among 105 samples taken from sheep, 87.6% were positive, whereas 100 (80%) of 125 examined samples from goats were positive for helminth parasites. There was no statistically significant difference (p>0.05) between the species. However, age and animal origin considered as a risk factor indicated statistically significant differences (p<0.05). In sheep, the prevalence of Trichostrongylus colubriformis, Bunostomum trigonocephalum, and Moniezia expansa was 69 (46.9%), 34 (43.6%), and 51 (52.6%), respectively, while the prevalence of Trichostrongylus colubriformis, Bunostomum trigonocephalum, and Moniezia expansa in goats was 78 (53.1%), 44 (56.4%), and 46 (47.4%), respectively.

Conclusion: This study revealed a high infection with parasitic helminths. Thus, effective control and prevention methods are necessary to minimize their effects on animals as well as the economy.

Introduction: Ticks are major health problems of goats that contribute to a significant economic loss in Ethiopia.

Methods: A cross-sectional study using a systematic random sampling technique was conducted to determine the prevalence, potential risk factors of hard ticks (Acarina: Ixodidae) of goats, and the acaricide utilization practice of herd owners in the Benatsemay district.

Results: Out of 285 examined goats, 85.26% of goats were found infested by Rhipicephalus and Amblyomma tick genera. The body condition score of goats was the only factor that was significantly (p < 0.05) associated with tick infestations. The frequently identified tick species were Rhipicephalus pulchellus (14.38%), Rh. decoloratus (11.22%), A. cohaerens (5.26%) and A. variegatum (4.21%), and mixed infestation (38.59%). Herd owner's questionnaire survey revealed that 100% of interviewees responded that tick infestations were frequently encountered throughout the year and prevailed on aged goats (90%) and dry season (60%). Concurrent usage of ethnomedicinal plants and conventional acaricides were dominant practices to control tick infestation as responded by 60% of interviewees. Among the conventional acaricides, Diazinon and Ivermectin were the most practiced acaricides as replied by 90% of the respondents. Moreover, community animal health workers (CAHWs) (43.33%) and owners themselves (33.33%) were primarily responsible for acaricide application to tick-infested animals. About 66.67% of the livestock owner's responses also disclosed that diazinon was the most effective acaricide followed by ivermectin (16.67%) and amitraz (6.67%). Finally, 56.57% of the respondents replied that acaricidal drugs from private veterinary drug shops were overpriced than the same acaricides from government veterinary clinics.

Conclusion: In this study, there was a high prevalence of hard ticks in goats, and irrational application of acaricides was noted in the Benatsemay district; thus, appropriate tick control measures should be taken to minimize tick burden through using acaricides.

Introduction: Chicken nematodes are found all over the world. Ascaris and Heterakis are among the cosmopolitan chicken nematodes. In different parts of Ethiopia, these parasites have long been thought to be the leading cause of illness and loss of productivity. However, there has been little research on their burden in Gondar city; hence, this study was carried out to establish a realistic estimate of the prevalence of Ascariasis and Heterakiasis in chickens.

Methodology: A cross-sectional study was undertaken in Gondar city, North West Ethiopia, from November 2019 to May 2020 to evaluate the prevalence and different related risk factors of chicken Ascaris and Heterakis infections. A total of 384 hens were tested utilizing the faecal flotation technique, with 170 native and 214 alien varieties. During the collection of faecal samples, the breed, age, production system, and feces consistency of chickens were all taken into account.

Results: One hundred seventy-one (44.5%) of the total (384) investigated feces tested positive for at least one of these parasite illnesses. The parasite's prevalence was influenced by age, breed, and the type of production technique used. A higher infection rate was observed in the younger (68.9%) indigenous (67.1%) chickens reared under the extensive production system (46.9%).

Discussion and conclusion: The prevalence of ascariasis and heterakiasis was nearly half percent in this study, even though the study was conducted in dry season, which is relatively unfavorable to parasites living in the environment and it specified only on the two common chicken ascaris nematodes. This study strongly suggested that Ascaris and Heterakis parasites were serious problems for chickens in Gondar city, and appropriate control strategies needed to be advised.

Foot and mouth disease (FMD) is an extremely contagious viral disease of livestock caused by foot and mouse disease virus genus: Aphthovirus, which causes a serious economic impact on both individual farmers and the national economy. Many attempts to advance a vaccine for FMD have failed to induce sterile immunity. The classical methods of vaccine production were due to selective accumulation of mutations around antigenic and binding sites. Reversion of the agent by positive selection and quasi-species swarm, use of this method is inapplicable for use in non-endemic areas. Chemical attenuation using binary ethyleneimine (BEI) protected the capsid integrity and produced a pronounced immunity against the challenge strain. Viral antigens which have been chemically synthesized or expressed in viruses, plasmid, or plants were tried in the vaccination of animals. DNA vaccines expressing either structural or nonstructural protein antigens have been tried to immunize animals. Using interleukins as a genetic adjuvant for DNA vaccines have a promising effect. While the challenges of inducing sterile immunity lies on non-structural (NS) proteins of FMDV which are responsible for apoptosis of dendritic cells and have negative effects on lympho-proliferative responses which lead to transient immunosuppression. Furthermore, destruction of host protein trafficking by nonstructural proteins suppressed CD₈ ⁺ T-cell proliferation. In this review, it tried to address multiple approaches for vaccine development trials and bottle necks of producing sterile immunity.

Background: The study was performed from January 2016 to May 2017 with the aim of identifying the impact of sheep and goat pox in skin quality in selected localities of central Ethiopia.

Materials and methods: A total of 1360 fresh, salted and dried skins were examined and graded. Pox lesion positive skins were examined by PCR to identify the agent.

Results: The prevalence of sheep and goat in the study areas was 4.022%. From a total of 86 rejected skins, a large number of skins were in the rejected category (2.78%). There were highly statistically significant associations (p < 0.05) between sheep and goat pox and species and study areas. However, there were no statically significant associations (p > 0.05) between skin size and sheep and pox. Molecular diagnosis of the case revealed that goat pox virus was responsible for the lesion.

Conclusion: Goat pox virus is the main cause of skin rejection and the factor that causes downgrading of skin.