Abstract:The abortions in sheep are important at various aspects, i.e. economical, animal healthcare or zoonotic. Abortions in sheep may occur sporadically or as enzootic outbreaks. The causative agent of the abortion is investigated if more than 2% of abortions in pregnant animals are registered within the herd. The amount of suspect material to be delivered for examination ranges from 12% to 21% of all registered abortions.Our research was carried out at the territory of AP of Vojvodina. Over a three-year-period we investigated 367 serum samples obtained from sheep that have aborted. Serum samples were examined for brucellosis, leptospirosis, listeriosis, toxoplasmosis, enzootic abortion (chlamydiosis), Qfever, salmonellosis.All examined sera were negative to brucellosis. Leptospirosis was diagnosed in 3.2% cases. Specific antibodies were detected for L.hardjo and L. grippotyphosa . Serotype L.hardjo was first identified in cattle at the territory of Vojvodina, and in the recent years it has been also registered in sheep. T.gondii was detected in 7.1% abortions in sheep. Presence of specific antibodies against C.burnetii was established in 19.6% of investigated serum samples. Vojvodina is considered endemic region for Q-fever, and sheep are the primary reservoir of C.burnetii that was confirmed in this research.

Lyme disease, or Lyme borreliosis can occur in domestic animals and in people, with no characteristic symptoms. That is why Lyme disease is often diagnosed and treated as some other disease. Clinical symptoms of this disease are not specific and they can look like a number of different diseases, which is why the disease is called -the great imitator. The reservoirs of the disease are ticks Ixodes ricinus. During the research from 2005 to 2007 it was established that the prevalence with Lyme borreliosis exists within the tick population.The objective of this paper is a survey of the presence of Lyme disease in different populations of different animal species (horses, cattle, sheep and dogs) in the region where the infection of ticks with Borrelia burgdorferi was established in the percentage of 25-28%.The methods used were the ones for the determination of Borrelia burgdorferi in ticks, with a dark field microscopy, and also the presence of antibodies against Borrelia burgdorferi was determinated with a complement fixation reaction, in the blood sera of horses, sheep, cattle and dogs.As the result it was found that the cause of Lyme disease, Borrelia burgdorferi is constantly present within the tick population. In examined horses and cattle the presence of antibodies against B. burgdorferi was not found, while in sheep and dogs, the presence of antibodies was found.Any seropositive animal, and also an infected tick, represents a danger for the human population and also for other animals, which are in the surrounding. Lyme disease is usually not mortal, but it can create a lot of problems leading to the decrease of production in domestic animals or an illness with clinical symptoms in humans, horses and dogs.