Dr. Callan is a professor at Colorado State University in the Department of Clinical Sciences, head of the Livestock Medicine and Surgery Service, and Chief of Staff for the Large Animal Hospital at the CSU James L. Voss Veterinary Teaching Hospital. He obtained his DVM degree at Oregon State University in 1986 and then obtained a MS in reproductive physiology at Utah State University in 1988. Dr. Callan completed a residency in large animal internal medicine at the University of Wisconsin–Madison where he also obtained a PhD in virology in 1996. He has been a faculty member at CSU since 1996 and provides clinical care for ruminant and camelid livestock at the CSU Veterinary Teaching Hospital. Dr. Callan is a member of the American College of Veterinary Internal Medicine.
Clinical interest - in livestock medicine and surgery with an emphasis on infectious diseases and immunology.
Research interest - in livestock infectious diseases, and nutritional and metabolic disease.
PhD, University of Wisconsin - Madison (Veterinary Science, Virology), 1996MS, Utah State University (Bioveterinary Science, Reporductive Physiology), 1988DVM, Oregon State University, 1986BS, Washington State University (Veterinary Science), 1984BS, University of California, Davis (Biochemistry), 1982
Diplomate, American College of Veterinary Internal Medicine, Large Animal, 1996
Wilsterman S, Soboll-Hussey G, Lunn DP, Ashton LV, Callan RJ, Hussey SB, Rao S and Goehring LS (2011). Equine herpesvirus-1 infected peripheral blood mononuclear cell subpopulations during viremia. Vet Microbiol 149(1-2): 40-7. PubMed # 21093993Ashton LV, Callan RL, Rao S and Landolt GA (2010). In Vitro Susceptibility of Canine Influenza A (H3N8) Virus to Nitazoxanide and Tizoxanide. Vet Med Int 2010.Bragg R, Hackett ES, Callan RJ, Holt TN and Hackett TB (2010). Inadvertent transvaginal administration of sodium phosphate enemas in 2 alpaca crias. J Vet Emerg Crit Care (San Antonio) 20(6): 623-7.Walz PH, Grooms DL, Passler T, Ridpath JF, Tremblay R, Step DL, Callan RJ and Givens MD (2010). Control of bovine viral diarrhea virus in ruminants. J Vet Intern Med 24(3): 476-86.McCoy AM, Hackett ES, Callan RJ and Powers BE (2009). Alimentary-associated carcinomas in five Vietnamese potbellied pigs. J Am Vet Med Assoc 235(11): 1336-41.Davidson A, Traub-Dargatz JL, Magnuson R, Hill A, Irwin V, Newton R, Waller A, Smith K, Callan RJ, Meehan M, Owen P, and Salman M (2008). Lack of correlation between antibody titers to fibrinogen-binding protein of Streptococcus equi and persistent carriers of strangles. J Vet Diagn Invest 20(4), 457-62.Powers JG, VanMetre DC, Collins JK, Dinsmore RP, Carman J, Patterson G, Brahmbhatt D and Callan RJ (2005). Evaluation of ovine herpesvirus type 2 infections, as detected by competitive inhibition ELISA and polymerase chain reaction assay, in dairy cattle without clinical signs of malignant catarrhal fever. J Am Vet Med Assoc 227(4):606-611.Sullivan EK, Callan RJ, Holt TN, Van Metre DC (2005). Trichophytobezoar Duodenal Obstruction in New World Camelids. Vet Surg 34(5):534-529.Powers JG, VanMetre DC, Collins JK, Dinsmore RP, Carman J, Patterson G, Brahmbhatt D and Callan RJ (2005). Evaluation of ovine herpesvirus type 2 infections, as detected by competitive inhibition ELISA and polymerase chain reaction assay, in dairy cattle without clinical signs of malignant catarrhal fever. J Am Vet Med Assoc 227(4):606-611.Callan RJ and Van Metre DC (2004). Viral diseases of the ruminant nervous system. Vet Clin North Am Food Anim Pract 20(2):327-62, vii.
Food Animal Exclusive/Predominant