1. Caesar Kleberg Wildlife Research Institute, Texas A&M University–Kingsville, Kingsville, Texas 78363, USA, and Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, Texas 77843, USA
2. Caesar Kleberg Wildlife Research Institute, Texas A&M University–Kingsville, Kingsville, Texas 78363, USA
3. Department of Pathology, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA