Prevalence of antibodies to spotted fever group Rickettsia spp. and Ehrlichia spp. in coyotes (Canis latrans) in Oklahoma and Texas, USA.

Coyotes (Canis latrans) are commonly infested with ticks, including Amblyomma americanum, the predominant vector of Ehrlichia chaffeensis and Ehrlichia ewingii; Dermacentor variabilis, an important vector of Rickettsia rickettsii; and Amblyomma maculatum, a major vector of Rickettsia parkeri, a spotted fever group (SFG) Rickettsia. To determine the degree to which coyotes are infected with or exposed to tick-borne bacterial disease agents, serum samples collected from coyotes in Oklahoma and Texas were tested for antibodies reactive to R. rickettsii, Ehrlichia canis, E. chaffeensis, E. ewingii, Borrelia burgdorferi, and Anaplasma phagocytophilum by indirect fluorescent antibody (IFA) testing or enzyme-linked immunosorbent assay (ELISA). Of the coyotes tested, 60% (46/77) and 64% (47/74) had antibodies reactive to R. rickettsii and E. chaffeensis, respectively, on IFA. Additionally, 5% (4/77) had antibodies reactive to E. canis, but not B. burgdorferi or A. phagocytophilum, on SNAP(®) 4Dx(®) ELISA; subsequent serologic analysis by plate ELISA using species-specific peptides revealed antibodies to E. ewingii, E. canis, and E. chaffeensis in 46% (23/50), 18% (9/50), and 4% (2/50) of serum samples, respectively. Taken together, these data indicate that coyotes in this region are commonly exposed to SFG Rickettsia and E. ewingii and that further consideration of coyotes as a component of the maintenance cycle for these pathogens may be warranted.

Inoculation of white-tailed deer (Odocoileus virginianus) with Ap-V1 Or NY-18 strains of Anaplasma phagocytophilum and microscopic demonstration of Ap-V1 In Ixodes scapularis adults that acquired infection from deer as nymphs.

Four white-tailed deer were inoculated with either the Ap-V1 or NY-18 strain of Anaplasma phagocytophilum. Ixodes scapularis nymphs were then allowed to acquistion feed on the inoculated deer and molt to adults. Only an Ap-V1 infected deer was infected persistently and able to infect nymphal Ixodes scapularis. Molted adult ticks maintained Ap-V1 infection as demonstrated by PCR and microscopy. We report, for the first time, a morphologic description of A. phagocytophilum in I. scapularis.

Proliferative sparganosis in a dog.

CASE DESCRIPTION: A 21-month-old spayed female Border Collie was examined because of progressive right forelimb lameness, signs of pain, and subcutaneous edema. The dog lived in a fenced yard in Tampa, Fla, that contained a small area of marshy terrain. CLINICAL FINDINGS: The subcutis and intermuscular fascia contained multiple cystic cavities filled with larval cestodes (plerocercoids or spargana) and cloudy red fluid. Parasites were identified morphologically and by DNA sequence analysis as pseudophyllidean cestodes, most likely Sparganum proliferum. The dog developed a progressively worsening fever, dyspnea, mature neutrophilia, and hypoproteinemia. Septic pleuritis and peritonitis complicated the later stages of the disease. TREATMENT AND OUTCOME: Treatment with praziquantel, fenbendazole, and nitazoxanide failed to control the proliferation and dissemination of larval cestodes. The dog was euthanatized after 133 days of treatment. At necropsy, numerous parasitic tissue cysts were present in the subcutis and intermuscular fascia; these cysts were most abundant in the soft tissues of the forelimbs and cervical musculature. The pleural and peritoneal cavities contained multiple larval cestodes and were characterized by neutrophilic inflammation and secondary bacterial infection. CLINICAL RELEVANCE: Findings indicated that clinical signs associated with proliferative sparganosis in dogs may be rapidly progressive and that the condition may be refractory to antiparasitic treatment. Veterinarians should be aware of this zoonotic, water-borne agent.