Research Communications of the 27(th) ECVIM-CA Congress: Intercontinental, Saint Julian's, Malta, 14th to 16th September 2017

Disclosures: No disclosures to report. Canine babesiosis is a tick-borne protozoal disease, affecting dogs worldwide. According to previous studies, B. canis is considered as the main species involved in canine babesiosis, but in recent years more studies show the existence of Babesia gibsoni infected dogs both in Europe and Romania. B. gibsoni infection in dogs is mainly described in American Pit Bull Terriers, although the significance of this breed predisposition is not yet fully understood, however the possibility of both blood-to-blood transfer and transplacental infection has been considered as a possible modality of host contamination. A 3 year old female, American Staffordshire Terrier was referred to our clinic, previously diagnosed with Babesia canis infection and treated with one dose of imidocarb dipropionate three days prior. The dog presented fever, pale mucous membranes and hemoglobinuria. Complete blood count revealed severe anemia (HCT 13%, Hg 4 g/dL, RBC 1.56 9 10 12 / L), thrombocytopenia (PLT 32 9 10 9 /L) and mild leukocytosis with neutrophilia. Coomb's test (Alvedia) and rapid test for Dirofilaria immitis antigen, Ehlichia canis antigen, Borrelia burgdoferi antigen, Anaplasma phogocytophilum/Anaplasma platys antibody (Rapid CaniV-4 Test Kit, Bionote) showed negative results. Giemsa-stained blood films were positive for small (1-2.7 µm) pleomorphic inclusions. Babesia spp. DNA was detected by polymerase chain reaction (PCR) assay, further molecular characterization of the sample showed the involvement of Babesia gibsoni (Macrogen Europe, Amsterdam). Following molecular identification of Babesia gibsoni, combination therapy was initiated with Clindamycin (25 mg/kg PO BID), Doxycycline (15 mg/kg PO BID), and Metronidazole (5 mg/kg PO BID). Fourteen days after therapy Hb, HCT, RBC and PLT values increased, but the blood sample tested positive for B. gibsoni by PCR. Therapy was ceased after 6 weeks, when HCT reached 40% and PCR showed complete B.gibsoni infection sterilization of the patient. Blood samples tested three and six months after the initiation of the treatment remained negative for B. gibsoni. Since the female was 5 weeks post-partum at the time of babesiosis diagnostic was established, four samples from two different litter pups were tested and found negative for B.gibsoni, although transplancetal transmission is possible in B.gibsoni infection. Accurate diagnosis is important in dogs presenting hemolythic anemia, because B.gibsoni is resistant to traditional anti-babesial therapy, but combination therapies may be efficient in order to reduce and eliminate parasitemia. Disclosures: No disclosures to report. Cytauxzoon felis is an emerging tick-transmitted protozoan parasite of domestic and wild felids. Cytauxzoonosis is typically fatal in clinical cases without aggressive treatment. Combination treatment with atovaquone and azithromycin (A&A) along with supportive care has improved survival rates to over 60%; in contrast, survival rates with imidocarb dipropionate are 26%. Parasite resistance to atovaquone via a cytochrome b parasite gene (cytb) mutation has been identified in other protozoans and is a concern for C. felis. Specifically, mutations at the M128 amino acid position of the putative atovaquone binding site on CYTB have been associated with resistance. We aimed to characterize the atovaquone binding region of cytb in samples from a C. felis-infected domestic cat that remained parasitemic despite t