2017 ACVIM Forum Research Abstract Program

By Week 10 after I. scapularis infestation, 21 of 23 dogs had developed serological evidence of B. burgdorferi infection. Of the 3 dogs with OspC antibodies alone that were administered doxycycline for 28 days, 2 dogs never developed antibodies against the other peptides and were negative for OspC antibodies by Week 2 or Week 6 after starting doxycycline administration. The other treated dog became positive to the C6 peptide alone during week 1 of doxycycline administration, was positive for 2 of the next This model induced serological evidence of B. burgdorferi infection of 21 dogs with 17 of 18 untreated dogs developing serological evidence of chronic infection characterized by antibodies against OspF and C6 peptide. While only 1 dog may have spontaneously limited antibody production against all 4 peptides, all 3 dogs administered doxycycline during the acute phase limited antibody production. These results should be confirmed in larger numbers of dogs, but may suggest that treatment when OspC antibodies are first detected may block development antibody responses associated with chronic B. burgdorferi infection. A natural resistance of cats to leishmaniosis, primarily due to a cellular immune response, is widely suggested. Leishmanin skin test (LST) has been successfully used in humans and dogs and a positive LST result indicates exposure to Leishmania and a state of cell mediated immunity. A total of 96 cats, seronegative for FeLV and FIV, presenting to a Veterinary Teaching Hospital in an endemic area in Brazil, were evaluated by LST. Leishmania infection was confirmed in 56 cats by bone marrow qPCR, and 40 non-infected cats composed the control group. Among infected cats, 23/56 presented clinical signs and 33/56 were asymptomatic. Each cat was intradermally injected with a suspension of 4 9 10 7 L. chagasi promastigotes (inactivated in thimerosal solution), in the inner surface of the right thigh, and thimerosal solution was injected in the opposite limb. All control and infected cats tested negative to LST at any time reading (24, 48 and 72 h after inoculation). We expected that at least part of the 26 asymptomatic (and seronegative) cats presented a positive LST. In canine leishmaniosis (CanL) LST can detect a high proportion of asymptomatic dogs, although some of them have negative LST even in the presence of a cellular immune response. The method employed was previously used for CanL, and its potential immunogenicity was confirmed by promoting positive LST in five naturally infected and asymptomatic dogs from the same endemic area. However, the LST tested do not seem to be an adequate tool for the diagnosis of feline leishmaniosis. Transportation of blood from remote areas can be problematic. While DNA is generally stable and a number of studies have evaluated DNA extracted from dried blood of mammals, there is minimal information determining the sensitivity of different techniques using dog blood. The objective of this study was to determine the optimal technique for extracting DNA from filter paper dried blood spots using Ehrlichia canis DNA as the target.