Verminous pneumonia in European hedgehogs (Erinaceus europaeus)

The European hedgehog (Erinaceus europaeus) is a common wildlife species in European countries. Populations are declining due to anthropogenic factors and natural diseases. Verminous pneumonia has been observed as a frequent infectious disease in hedgehogs submitted for diagnostic postmortem examination. This prompted the present in-depth investigation on the lungs of 27 necropsied hedgehogs with confirmed lungworm infections, with or without antiparasitic treatment prior to death. The histological and/or parasitic (fecal samples) examination identified Capillaria aerophila infection in most animals (82%). The parasites were found free in the airway lumen and/or within the airway epithelium, from the larynx to bronchioles. Embedded worms and eggs were associated with epithelial hyperplasia or metaplasia, and long-term inflammation. More than half of the animals (59%) carried Crenosoma striatum, and 41% had a coinfection. C striatum adults were predominantly found free in the lumen of bronchi and bronchioles, and larvae were occasionally seen in granulomas in the pulmonary interstitium, the liver, and the intestine. Independent of the parasite species, a lymphoplasmacytic peribronchitis and, less frequently, interstitial infiltration of eosinophils, neutrophils, and macrophages as well as pneumocyte type II hyperplasia was seen. Interestingly, the extent of pneumonia was not correlated with age, respiratory clinical signs, antiparasitic treatment, or single or coinfection. Verminous pneumonia appeared to be the cause of death in over 25% of the animals, indicating that these parasites not only coexist with hedgehogs but can also be a primary pathogen in this species.