Ji-Youl Jung

Meningoencephalitis caused by Halicephalobus gingivalis in a thoroughbred gelding.

ABSTRACT A 6-year-old Thoroughbred gelding was euthanized after a 2-month period of abnormal neurological signs, such as circling left in his pen and hitting his head and body against the wall. After the horse was euthanized on the farm, a half of the brain and whole blood were submitted for diagnostic tests. Histopathological examination of the brain revealed granulomatous and eosinophilic meningoencephalitis with numerous intralesional nematodes, predominantly affecting the cerebrum. Multifocal malacic foci were scattered in the brain parenchyma. The intralesional parasites were identified as Halicephalobus gingivalis by morphological features and PCR testing. To the best of our knowledge, this is the first report of meningoencephalitis caused by H. gingivalis in the horse in Korea.

Analysis of signs and pathology of H5N1-infected ducks from the 2010–2011 Korean highly pathogenic avian influenza outbreak suggests the influence of age and management practices on severity of disease

We compared the clinical signs, histopathological lesions and distribution of viral antigens among infected young (meat-type) and older (breeder) ducks that were naturally infected with the highly pathogenic avian influenza (HPAI) virus during the 2010–2011 Korean outbreak. The meat-type ducks had a high mortality rate (30%) and showed severe neurological signs such as head tremors and paresis. In contrast, HPAI-infected breeder ducks had minimal clinical signs but a decreased egg production rate. The histopathological characteristics of infected meat-type ducks included necrotic lesions of heart and brain, which may have primarily contributed to the high mortality rate. In contrast, the breeder ducks only presented necrotic splenitis, and viral antigens were only detected in the trachea, lungs and spleen. Younger ducks had a high viral titre in the organs, high levels of viral shedding and a high mortality rate after experimental HPAI virus infection. Compared to the breeder ducks, the meat-type ducks were raised in smaller farms that had poor quarantine and breeding facilities. It is therefore possible that better biosecurity in the breeder farms could have reduced the infection dose and subsequently the severity of the disease. Thus, age and management may be the influencing factors for HPAI susceptibility in ducks.