Canine tick-borne parasites have emerged in recent years, showing a wider geographic distribution and increased global prevalence. In addition to their veterinary importance, domestic dogs play an important role in the transmission cycles of some agents by acting as reservoirs and sentinels. This study investigated Babesia, Theileria, Anaplasma, and Ehrlichia species in asymptomatic dogs in ten provinces of Turkey. DNA obtained from blood samples collected from 757 domestic dogs (243 stray, 351 shelter, 163 pet) of both sexes and various ages were evaluated using PCR and reverse line blotting (RLB) assays. Of the 757 dogs tested, 41 (5.4%) were found to be infected with one or more parasites. Ehrlichia canis (37/757, 4.9%) was the most common canine tick-borne pathogen, followed by Anaplasma platys (4/757, 0.5%). Babesia canis and Theileria annulata were each detected in 1 (0.13%) sample. Combined infection of E. canis and A. platys was detected in 2 (0.3%) samples. The prevalence of tick-borne pathogens was higher in adult dogs (6.8%) than in those under one year old (3.1%). Difference in infection rate of male and female dogs was not significant. Pet dogs had a lower prevalence of infection (1.2%) compared to stray (7.4%) and shelter dogs (6%) although the difference between stray and shelter dogs was not significant. Babesia canis, T. annulata, A. platys, and E. canis species were identified at the molecular level in dogs in several provinces of Turkey, with E. canis being the most common species among tick-borne pathogens. Detailed studies should be conducted regarding the existence and prevalence of B. canis and Dermacentor reticulatus in eastern Turkey.

Blood and tick samples were collected from 333 apparently healthy sheep and 257 goats as well as 10 sheep exhibiting clinical signs of babesiosis in Adana, Gaziantep, and Adiyaman Provinces in southern Turkey. Fully engorged female ticks were selected and maintained in an incubator until they oviposited. The tick carcasses and their egg masses were examined. Piroplasms compatible with Babesia spp. and Theileria spp. were observed in both symptomatic and asymptomatic small ruminants. Genomic DNA isolates from blood of ovine, tick samples, and egg masses were screened for piroplasms by utilizing 18S rRNA polymerase chain reaction and reverse line blotting (RLB) assays. Parasitemia ranged from 0.01% to 5.6% of erythrocytes in clinical cases. RLB showed positivity in 239 (40.5%) of the sampled apparently healthy sheep and goats and revealed the presence of three Theileria and one Babesia species. Theileria ovis was the most prevalent (35.4%), followed by Babesia ovis (5.4%), Theileria annulata (3.9%), and Theileria sp. MK (0.3%). Thirty-two small ruminants infected with T. ovis were also infected with B. ovis One animal infected with T. ovis was also infected with Theileria sp. MK. Ticks were identified as Rhipicephalus bursa, Rhipicephalus turanicus, Hyalomma excavatum, Haemaphysalis parva, and Hyalomma anatolicum Egg masses of two female R. bursa carcasses were infected with B. ovis This is the first report of theileriosis caused by T. annulata in sheep and goats in Turkey.

Babesia ovis, transmitted by Rhipicephalus bursa ticks, is the causative agent of ovine babesiosis, a disease characterized by fever, anemia, hemoglobinuria, and high mortality in sheep. This study investigates whether sheep that survived babesiosis without treatment can serve as a source of infection for B. ovis-free host-seeking R. bursa larvae in a later season. Three donor sheep were experimentally infected with B. ovis, and after six months, persistence of B. ovis was assessed through blood and tick transmission experiments. Blood from donor sheep was intravenously injected into three recipient sheep, while donor sheep were also infested with B. ovis-free R. bursa larvae. Engorged nymphs molted to adults, and new recipient sheep were infested with these ticks. All recipient sheep were monitored for B. ovis for 100 days using microscopic, serological, and molecular approaches. The presence of B. ovis was confirmed in the recipient sheep that received blood, leading to clinical infection in two. However, no B. ovis was detected in recipient sheep infested with ticks. These results suggest that sheep recovering from B. ovis infection do not serve as a source of infection for R. bursa larvae in subsequent seasons.

Anaplasma phagocytophilum causes tick-borne fever in small ruminants. Recently, novel Anaplasma variants related to A. phagocytophilum have been reported in ruminants from Tunisia, Italy, South Korea, Japan, and China. Based on 16S rRNA and groEL genes and sequencing, we screened the frequency of A. phagocytophilum and related variants in 433 apparently healthy small ruminants in Turkey. Anaplasma spp. overall infection rates were 27.9% (121/433 analyzed samples). The frequency of A. phagocytophilum and A. phagocytophilum-like 1 infections was 1.4% and 26.5%, respectively. No A. phagocytophilum-like 2 was detected in the tested animals. The prevalence of Anaplasma spp. was comparable in species, and no significant difference was detected between sheep and goats, whereas the prevalence significantly increased with tick infestation. Sequencing confirmed PCR-RFLP data and showed the presence of A. phagocytophilum and A. phagocytophilum-like-1 variant in the sampled animals. Phylogeny-based on 16S rRNA gene revealed the A. phagocytophilum-like 1 in a separate clade together with the previous isolates detected in small ruminants and ticks. In this work, A. phagocytophilum-like 1 has been detected for the first time in sheep and goats from Turkey. This finding revealed that the variant should be considered in the diagnosis of caprine and ovine anaplasmosis.

A novel Babesia sp. infecting goats was discovered based on the molecular findings obtained in the current study, which was conducted in the Mediterranean region of Türkiye. The goal of this study was to isolate this species of Babesia (Babesia sp.) infecting goats in vivo and to assess the genetic and morphological characterization of the parasite. To identify the animal naturally infected with Babesia sp. and isolate the parasite from this animal, field studies were conducted first, and genomic DNA were extracted from blood samples taken from goats (n = 50). The Theileria, Babesia, and Anaplasma species were identified using a nested PCR-based reverse line blotting (RLB) method. The study included one goat that was determined to be infected with Babesia sp. (single infection) in RLB for in vivo isolation. A blood smear was prepared to examine the parasite’s morphology, but it was found to be negative microscopically. Following that, a splenectomy operation (to suppress the immune system) was performed to make the parasites visible microscopically in this animal. Parasitemia began after splenectomy, and the maximum parasitemia was determined to be 1.9%. The goat displayed no significant symptoms other than fever, loss of appetite, and depression. During a period when parasitemia was high, blood from this goat was inoculated into another splenectomized goat (Theileria-Babesia-Anaplasma-Mycoplasma spp. free). On the third day of inoculation, 10% parasitemia with high fever was detected in the goat, and on the fourth day, the goat was humanely euthanized due to severe acute babesiosis symptoms. Except for mild subcutaneous jaundice, no lesions were discovered during the necropsy. According to the microscopic measurement results, ring, double pyriform, spectacle-frame-like, and line forms were observed, and it was observed to be between 1.0–2.5 µm (1.38 ± 0.17 to 0.7 ± 0.21-all forms). A phylogenetic analysis and sequence comparison using the 18S rRNA and cox1 genes revealed that this species is distinct from the small ruminant Babesia species (18S rRNA 92–94%, cox1 79–80%) and has the highest similarity to Babesia sp. deer, which has been reported in deer. Furthermore, it was determined to resemble B. venatorum, B. divergens, Babesia sp. FR1 and Babesia sp. MO1 species, all of which are zoonotic. Additional research is needed to clarify the clinical status of this parasite in goats and other hosts (mountain goat, sheep, calf).