[1] Purdue Univ, Sch Vet Med, Dept Vet Clin Sci, W Lafayette, IN 47907 USA
[2] Purdue Univ, Sch Vet Med, Dept Comparat Pathobiol, W Lafayette, IN 47907 USA
[3] Ohio State Univ, Dept Vet Clin Sci, Columbus, OH 43210 USA
[4] Univ Penn, Sch Vet Med, Dept Clin Studies, Philadelphia, PA 19104 USA
[5] Univ Tennessee, Coll Vet Med, Dept Small Anim Clin Sci, Knoxville, TN USA
[6] N Carolina State Univ, Coll Vet Med, Dept Clin Sci, Raleigh, NC USA
[7] Univ Illinois, Coll Vet Med, Dept Vet Clin Med, Urbana, IL 61801 USA
[8] Virginia Tech, Dept Small Anim Clin Sci, Virginia Maryland Reg Coll Vet Med, Blacksburg, VA USA
[9] Kansas State Univ, Coll Vet Med, Dept Clin Sci, Manhattan, KS 66506 USA