1. Section of Parasitology, Department of Pharmacology, Microbiology and Food Hygiene
2. †Division of Parasitic Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA
3. *Department of Morphology, Genetics and Aquatic Biology, Norwegian College of Veterinary Medicine, PO Box 8146 Dep., 0033 Oslo, Norway
4. ‡Borre‐Horten Small Animal Clinic, Kiellandsgate 12, 3183 Horten, Norway
5. §Animal Health Diagnostic Laboratory, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824‐1314, USA