Neospora caninum infection in captive Axis Deer (Axis axis).

BASSO W.; MORÉ G.; QUIROGA M.A.; PARDINI L.; BACIGALUPE D.; VENTURINI M.C.; LARSEN A.; VALENZUELA M.C.; MAKSIMOV P.; SCHARES G.; VENTURINI L.

University of Hamburg, Bernhard-Nocht Institute for Tropical Medicine. Alemania

Congreso; XXIII Anual Meeting of the German Society for Parasitology; 2008

 Neospora caninum infection is an important cause of abortion, stillbirth and perinatal death in cattle and of neuromuscular disease in dogs and was also reported in other domestic and wild mammal species. Axis deer (Axis axis) inhabit wooden regions of India and Nepal and are bred in captivity in zoos and recreational hunting units worldwide. N. caninum infection was diagnosed in one 14-day-old Axis deer at the zoo from La Plata, Argentina by serological, histopathological and molecular techniques and N. caninum was isolated in gerbils (Meriones unguiculatus) from brain tissues. The fawn presented dilatation of the anal sphincter at birth and incontinence, developed weakness and ataxie during the first week, and died at 14 days of age. At necropsy, dilatation of the last portion of the gut was observed. Microscopically, the main lesions consisted in non-suppurative encephalitis, suppurative bronchopneumonia, fibrin necrotic enteritis and degenerative changes in the liver. Thick-walled N. caninum-like cysts were observed in fresh brain samples. The fawn was serologically positive for N. caninum (IgG IFAT titer 6400) and negative for T. gondii (IgG IFAT titer <25). Brain homogenate was inoculated into 5 gerbils. Gerbils 1 and 2 developed ataxia and bent head at 22 and 26 days post inoculation respectively. Gerbil 2 recovered after 2 weeks. Histopathology of Gerbil 1 revealed non-suppurative encephalitis. N. caninum DNA was demonstrated in brain samples of the fawn and of Gerbil 1 with Np6+-Np21+ specific primers. Four of 5 inoculated gerbils had antibodies to N. caninum (IFAT titer  800) at 75 days post infection. Serologic examination for N. caninum was also performed to 4 neonates (1-2 days-old) that died in the same enclosure and to 13 asymptomatic adult deer. All neonates and 12/13 adults had IFAT antibody titers between 25 and 6400. PCR on brain samples from 1/4 neonates was positive for N. caninum. To our knowledge this is the first confirmed diagnosis of N. caninum infection in Axis deer.