Experimental toxoplasmosis in red-legged partridges (Alectoris rufa) fed Toxoplasma gondii oocysts C. Martı ´nez-Carrasco a, * , A. Bernabe ´ b , J.M. Ortiz a , F.D.Alonso a a Departamento de Sanidad Animal, Facultad de Veterinaria, Campus Universitario de Espinardo, 30100 Murcia, Spain b Departamento de Anatomı ´ a y Anatomı ´ a Patolo ´ gica Comparadas, Facultad de Veterinaria, Campus Universitario de Espinardo, 30100 Murcia, Spain Received 25 November 2004; received in revised form 22 February 2005; accepted 9 March 2005 Abstract Thirty red-legged partridges (Alectoris rufa), 5-month-old, were orally inoculated with oocysts of the OV-51/9 Toxoplasma gondii. Birds were distributed into five groups and received, respectively, 10 (group A, 4 birds), 50 birds), 10 2 (group C, 4 birds), 10 3 (group D, 4 birds) and 10 4 (group E, 4 birds) oocysts. One partridge from group B and one group E died suddenly of acute toxoplasmosis at 7 day after inoculation (DAI) with demonstrable T. gondii in se rest of birds remained clinically normal until killed at 44, 58, 65, 72, 79 or 100 DAI. Brain, heart, liver and skele these partridges were bioassayed individually in mice; T. gondii was demonstrated in all these tissues, except i birds inoculated, respectively, with 10, 50 and 10 2 oocysts. Lesions were not seen in histologic sections of tissues from sur partridges. These results suggest that red-legged partridges are resistant to clinical toxoplasmosis. # 2005 Elsevier B.V. All rights reserved. Keywords: Red-legged partridges; Alectoris rufa; Toxoplasma gondii; Toxoplasmosis; Oocyst 1. Introduction Toxoplasma gondii is a protozoan that has been reported in many species of warm-blooded animals, including avian species. Felids are the only hosts that can spread oocysts in the environment (Dubey and Beattie, 1988). Birds can act as intermediate hosts of T. gondii.Natural toxoplasmosis has been described in domestic and wild birds, butclinicalcases and outbreaks are not frequent, because infection often occurs subclinically or without specific symptoms in birds (Dubey,2002).In wild gallinaceous birds, spontaneous fatal toxoplasmosis has been described partridges (Perdix perdix) by Pokorny ´ (1955), in wild turkeys(Meleagridisgallopavo)by Howerth and Rodenroth (1985) and Quistet al. (1995),and in Erckel’sfrancolin (Francolinus erckelii)by Work et al. (2002).However, there are several reports of isolation of viable T. gondii from tissues of partridges pheasants (Phasianus colchicus) and turkeys (Litera ´k et al., 1992; Lindsay et al., 1994) captured in the wild without clinical signs.Experimental T. gondii infec- www.elsevier.com/locate/vetpar Veterinary Parasitology 130 (2005) 55–60 * Corresponding author. Tel.: +34 968 367842; fax: +34 968 364147. E-mail address: cmcpleit@um.es (C. Martı ´nez-Carrasco). 0304-4017/$ – see front matter # 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.vetpar.2005.03.003