Symposium for Parasitology

FATAL INFECTION IN AN ICELANDIC STALLION CAUSED BY
HALICEPHALOBUS GINGIVALIS (NEMATODA: RHABDITIDA)
26
Eydal, M. 1 , Bambir, S.H. 1 , Sigurdarson, S. 2 , Gunnarsson, E. 1 and Fridriksson, S. 3
meydal@hi.is
1
Institute for Experimental Pathology, University of Iceland, Keldur, Reykjavík, Iceland
2
Agricultural Authority of Iceland, Selfoss, Iceland
3
District veterinary officer
Infections by the soil nematode Halicephalobus gingivalis have been reported infrequently from
horses worldwide. Infections are believed to be acquired after the nematode penetrates open
wounds. The nematodes reproduce within the host tissues and the resulting infection is usually
fatal. Following an accident, an 11 year old Icelandic stallion sustained injuries to the mouth.
Several months later neurological signs were observed which gradually became more severe, the
horse lost balance, and finally had to be euthanised. Symptoms observed at autopsy were broken
front teeth and a loose palate. Histological examination of the brain (cerebellum) revealed severe
multifocal necrotic encephalitis. In necrotic areas numerous nematodes were seen. Mature
nematodes, larvae and eggs were present in the perivascular space and around blood vessels
associated with inflammatory response. Mononuclear meningitis was also present. The
nematode was confirmed as being the species Halicephalobus gingivalis based on its
morphological features. Adult worms were 250 - 300μm long and 15μm wide, eggs measured
approx. 45x15μm. Nematodes were not detected in other organs, but hemorrhages were seen in
the liver and kidneys. The worms had presumably penetrated the wounds in the mouth of the
horse as a result of the accident. In Nordic countries Halicephalobus gingivalis infections have
been reported from Norway, but this is first case reported from Iceland.
GENETIC RESISTANCE TO CYATHOSTOMES INFECTION IN PURE
BLOOD ARABIAN HORSES
Nowosad, B. 1 , Kornaś, S. 1 , Molenda, K. 2 , Skalska, M. 1 , Gawor J. 3 and Cabaret J. 4
1 Department of Zoology and Ecology, Agricultural University of Krakow, al. Mickiewicza
24/28, 30-059 Krakow, Poland, slawon@interia.pl
2 Department of Agricultural Engineering and Informatics, Agricultural University of Krakow, ul.
Balicka 104, 30-149 Kraków, Poland
3 W. Stefanski Institute of Parasitology, Polish Academy of Sciences, ul. Twarda 51/55, 00-818
Warsaw, Poland
4 Institut National de la Recherche Agronomique, IASP, 37380 Nouzilly, France
Pure Blood Arabian Horses, with complete documentation, are bred in female and male lines
originating from the ancestors imported to Poland in XVIII century. During many years of
breeding 14 female and 8 male lines were selected. The aim of the study was to determinate the
level of cythostomes infection and their possible genetic resistance on those nematodes in horses
from different lines. From 1999-2002 and 2004-2006 4835 fecal samples from Arabian horses
from southern Poland were collected during pasture seasons and examined using quantitative
McMaster method. The obtained results were analyzed by ANOVA in order to determine the
significance of differences of the level cyathostomes infection. The highest mean number of
cyathostomes eggs occurred in 2004 - 581 EPG and the smallest in 2006 – 63 EPG. The biggest
eggs output of this nematodes was found in female lines: “Mlecha” (540 EPG), “Sahara” (504),
male lines: “Latif (396)”, “Kuhailan Haifi” (363), and the smallest: “Szamrajówka” (73),
“Semrie” (187) and “Krzyżyk (127)”, “Ibrahim” (274) respectively. Most of these differences
were statistical significant. The results of these analysis lead to the proposal that there are some
susceptible and resistance genetic lines to cayahostomes infection in one breed of horses and in
the scheme of deworming origin of the horses should be taken into consideration.