Dogs are known to host several tick-borne pathogens with zoonotic potential; however, scant information is available on the epidemiology of these pathogens in low-income tropical countries and in particular in sub-Saharan Africa. With the aim of investigating a wide range of tick-borne pathogens (i.e., Rickettsia spp., Anaplasma spp., Erhlichia spp., Borrelia spp., Hepatozoon spp. and Babesia spp.), 273 blood samples were collected from dogs in selected districts of Ethiopia and analyzed by real-time and/or end-point PCR. The results of the study showed that Hepatozoon canis was the most prevalent pathogen (53.8%), followed by Anaplasma phagocythophilum (7.0%), Babesia canis rossi (3.3%), Ehrlichia canis (2.6%) and Anaplasma platys (2.2%). Furthermore, five samples tested positive for Borrelia spp., identified as Borrelia afzelii (n = 3) and Borrelia burgdorferi (n = 2), and two samples for Rickettsia spp., identified as Rickettsia conorii (n = 1) and Rickettsia monacensis (n = 1). The finding of Anaplasma phagocythophilum and different species of the genera Borrelia and Rickettsia with zoonotic potential was unexpected and alarming, and calls for further investigation on the roles of dogs and on the tick, species acting as vector in this specific context. Other pathogens (Hepatozoon canis, Babaesia canis rossi, Anaplasma platys, Ehrlichia canis) are already known to have an important impact on the dogs’ health but have minor zoonotic potential as they were rarely or never reported in humans. Dogs from rural areas were found to be at higher risk for different pathogens, probably due to the presence of other wild canids in the same environment. The findings of the present study contribute to a better knowledge of the epidemiology of tick-borne pathogens, which is relevant to human and animal health.

An experimental study was conducted on day-old chicks to evaluate the safety and efficacy of combined Newcastle diseases (ND), fowl pox (FP) and fowl typhoid (FT) vaccine. The vaccine was prepared using the Lasota strain of Newcastle disease virus (NDV), the FP strain of fowl pox virus (FPV) and the 9R strain of FT. The vaccine was found safe, as no clinical signs or mortalities were observed. Post vaccination Haemaglutination Inhibition (HI) titre for ND was above the required protection level (≥1:16) and its geometric means (GM) were 0.0098, 0.0063 and 0.0059 for group one, two and three respectively, who received conventional and combined vaccine. The difference in GM between the three vaccinated groups were not significant (p=0.544). The trivalent combined vaccine did not show significant difference in the HI titre result among the groups that were given conventional vaccines and the other two experimental groups which received trivalent vaccine (p=0.257). From 75 samples, 73 (97.3%) were positive for FT through rapid slide agglutination test (RSAT). The chicks were challenged separately for the three diseases using the specific pathogens. Both combined and conventional vaccine conferred protection upon challenge. For ND challenge, 93.3% (n=14/15) of the control groups died. From FT and FP control groups 86.6% (n=13/15) and 20% (n=3/15) respectively died up on challenge. Both combined and conventional vaccine type conferred a similar and good level of protection. However, the use of combined vaccine has considerable advantage particularly in terms of convenience and cost effectiveness to control multiple diseases through simple immunization schedule. Further studies were recommended on the development of combined avian vaccines in Ethiopia.

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