Evidence of a Limited Schizogonous Cycle for Cytauxzoon felis in Bobcats Following Exposure to Infected Ticks

Abstract

Schizogonous tissue stages of Cytauxzoon felis (Apicomplexa: Theileridae) were not observed by microscopic evaluation of impression smears of liver, spleen, lung and lymph nodes in 10 bobcats (Lynx rufus) from Oklahoma with naturally occurring piroplasm infections. Schizogonous stages were observed in similar tissues from experimentally-infected bobcats at 11 days postexposure to infected Dermacentor variabilis, but not at 30 days following tick feeding. The schizogonous cycle of this parasite appears to be short, although the bobcat appears to be a long-term carrier.

Fatal Cytauxzoonosis in a Free-ranging Bobcat (Lynx rufus)

“…Even though most infected bobcats remain healthy, it is possible for them to develop fatal infection. One of two bobcats died after parental inoculation of tissue homogenates from a domestic cat that died of cytauxzoonosis (Kier et al, 1982), and one of two bobcats developed fatal cytauxzoonosis after researchers allowed C. felis infected ticks (Dermacentor variabilis) to feed on the bobcats (Blouin et al, 1987). However, we found no reports of fatal infection in naturally infected freeranging bobcats.…”

“…In contrast, C. felis infection of healthy, free-ranging bobcats (Lynx rufus) has been found by several investigators (Glenn et al, 1982(Glenn et al, , 1983Kocan and Blouin, 1985;Blouin et al, 1987). In some areas, infection is quite common.…”

“…When infected with the schizogonous tissue phase of C. felis, domestic cats developed both the intraerythrocytic and tissue phases, and infection was fatal. Only the intraerythrocytic form has been found in naturally infected free-ranging bobcats (Glenn et al, 1983;Blouin et al, 1987). However, bobcats can develop the tissue phase.…”

“…However, based on work in domestic cats, it probably did develop and recover from the tissue phase. In a second experiment, two bobcats were experimentally infected by allowing C. felis infected D. variabilis to feed on them (Blouin et al, 1987). Schizogonous forms of C. felis were found in both bobcats 11 days after tick-attachment.…”

Prevalence of infection and 18S rRNA gene sequences ofCytauxzoonspecies in Iberian lynx (Lynx pardinus) in Spain

“…The infected lynx reported by Luaces et al (2005) did not show any sign of disease and haematological and biochemical values were normal. However, although bobcats can develop the tissue phase of the pathogen and may die of experimental cytauxzoonosis (Kier et al 1982 ;Blouin et al 1987), it was considered that C. felis could not cause the death of wild bobcats. This view changed when Nietfeld and Pollock (2002) reported a free-living bobcat cub that died of acute cytauxzoonosis.…”