Experimental infection of cattle with invasive larvae of Elaphostrongylus cervi

In order to examine the susceptibility of cattle for elaphostrongylosis four 4-month old calves were infected per os with doses of 10 000-50 000 invasive larvae of E. <LF>cervi. One 1 calf was the control. Clinical symptoms such as decreased appetite, weakness, cough, mucus outflow from nostrils and rales in the bronchia, were observed from the 6th day post infection only in calves infected with the <LF>highest doses. The calf infected with 30 000 of larvae in 20(th) day of invasion had a strong cough and purulent outflow from its nostrils. The calf infected with 50 000 larvae from 19(th) day post infection also indicated disorders of <LF>gastrointestinal motility and meteorism. Two calves with clinical symptoms were necropsied on the 30(th) and 60(th) day post infection. Inflammatory changes were found in their lungs, hyperemia in the gastrointestinal tract as well as hyperemia, blood extravasations and submeningeal hematomes in the nervous system. Despite these changes, no nervous disorders were observed in the calves. A few dead larvae of E. cervi were isolated from the cranial cavity and vertebral canal. Calves infected with the smaller doses were observed for 300 days and did not show any clinical symptoms of invasion. No eggs of this parasite were found in coproscopic examinations of faecal samples from the infected calves. This study showed that cattle are less susceptible to elaphostrongylosis than small ruminants.