Population Medicine & Diagnostic Sciences


Advancing the health and well-being of animals and people


Advancing the health and well-being of animals and people


Advancing the health and well-being of animals and people


Advancing the health and well-being of animals and people


Advancing the health and well-being of animals and people


Advancing the health and well-being of animals and people

Charles L Guard

Associate Professor
Production Medicine, C2 564
Dept. of Population Medicine and Diagnostic Sciences
College of Veterinary Medicine
Cornell University
Ithaca, New York 14853
Phone:  607-253-3223
e-mail: clg1@cornell.edu


  • 1970 B.S., Biomedical Engineering, Case Institute of Technology
  • 1975 Ph.D., Biology, Case Western Reserve University
  • 1980 D.V.M., Veterinary Medicine, Cornell University

Professional Societies

  • American Veterinary Medical Association
  • American Association of Bovine Practitioners
  • American Association of Veterinary Clinicians
  • American Dairy Science Association
  • National Mastitis Council
  • North American Hooftrimmers Association

Research and Professional Experience

  • 2008 - Head of Ambulatory & Production Medicine Clinic
  • 2001-2003 Honorary Scientist, Rural Development Administration, Republic of Korea, Suwon, Korea
  • 1992-1994 External examiner, Ontario Veterinary College, Post-graduate Dairy Practice Certification
  • 1992-1997 Head of Ambulatory & Production Medicine Clinic
  • 1990-1991 Visiting Professor, Department of Herd Health and Reproduction, University of Utrecht, Utrecht, The Netherlands
  • 1988-pres Associate Professor of Medicine, College of Veterinary Medicine, Cornell University
  • 1982 1988 Assistant Professor of Medicine, New York State College of Veterinary Medicine, Cornell University
  • 1987-pres Member, Graduate Faculty, Cornell University
  • 1980 1982 Large animal practice with Dr. Frederick Erb, Lisbon, NH

Selected Courses

  • New York State College of Veterinary Medicine 1982 - present
  • VM 527 Veterinary Physiology
  • VM 560 Clinical Methods
  • VM 520 Preventive Medicine
  • VM 569 Foundations of Clinical Science, Course Coordinator
  • VM 579 General Medicine and Surgery, Course Coordinator
  • VM 529 Veterinary Pharmacology
  • VM 564 Large Animal Medicine and Surgery Equine and food animal medicine:metabolic diseases, cardiology and hepatology.
  • VM 679 Dairy Herd Management and Health
  • Block V Production Medicine
  • VM... Anatomy of Ruminants
  • VM... Special Topics in Parasitology
  • VM… Dairy Economics and Business Management
  • VM… Ruminant Surgical Exercises
  • VM… Individual animal medicine & surgery: bovine
  • Block III Rumen development & physiology
    College of Agriculture and Life Sciences
  • AN SCI 457 Dairy Herd Health Programs
  • AN SCI 341 Biology of Lactation
    Cornell Annual Student Symposium for Large Animals

Selected Publications

  1. Murrish DE and CL Guard. 1973. Peripheral vascular control mechanisms in the giant petrel, Macronectes giganteus. ANTARCTIC JOURNAL OF THE UNITED STATES VIII(4):197 198.
  2. Guard CL and DE Murrish. 1973. Temperature dependence of blood viscosity in Antarc¬tic homeotherms. ANTARCTIC JOURNAL OF THE UNITED STATES VIII(4):198 199.
  3. Murrish DE and CL Guard. 1973. Sympathetic control of non shivering thermogenesis in south polar skua chicks. ANTARCTIC JOURNAL OF THE UNITED STATES VIII(4):199 200.
  4. Guard CL and DE Murrish. 1974. Blood flow studies in the giant petrel, Macronectes giganteus. ANTARCTIC JOURNAL OF THE UNITED STATES IX:101 103.
  5. Guard CL and DE Murrish. 1975. Effects of temperature on the viscous behavior of blood from Antarctic birds and mammals. COMP. BIOCHEM. PHYSIOL. 52A:287 290.
  6. Pearson EG, CL Guard and DF Smith. 1981. A method for obtaining abomasal fluid via a rumen fistula. CORNELL VET. 71:183 187.
  7. Guard CL and JE Wilkinson. 1984. Hemangiosarcoma in a cow. J AM VET MED ASSOC. 184:789 790.
  8. Guard CL and WS Schwark. 1984. Influence of yohimbine on xylazine induced depres¬sion of central nervous, gastrointestinal and cardiovascular function in the calf. CORNELL VET. 74:312 321.
  9. Guard CL, WC Rebhun and JA Perdrizet. 1984. Cranial tumors in aged cattle causing Horner's syndrome and exophthalmos. CORNELL VET. 74:361 365.
  10. Guard CL. 1985. Pneumothorax after parturition in a cow. COMP CONT EDUC PRACT VET. 7:S191 S193.
  11. Scott DW, DK Walton and CL Guard. 1986. Sterile eosinophilic folliculitis in cattle. AGRI PRACTICE. 7(3,4):8-14.
  12. Erb HN, RD Smith, PA Oltenacu, CL Guard, RB Hillman, PA Powers, MC Smith & ME White. 1985. Path model of reproductive disorders and performance, milk fever, mastitis, milk yield, and culling in Holstein cows. J DAIRY SCI. 68:3337-3349.
  13. Guard CL, WS Schwark, DS Friedman, P Blackshear and M Haluska. 1985. Age related alterations in trimethoprim sulfadiazine disposition following oral or parenteral administration in calves. CAN J VET RES. 50:342-346.
  14. Shoaf SE, WS Schwark, CL Guard and RV Schwartsman. 1986. Pharmacokinetics of trimethoprim/sulfadiazine in neonatal calves; influence of synovitis. J VET PHARMACOL THERAP. 9:446-454.
  15. Powers MS, White ME, Dinsmore P, Guard CL and Dimock B. 1986. Aerobic blood culture in cows with coliform mastitis. J AM VET MED ASSOC. 189:440-441.
  16. Dinsmore RP, White ME, Guard CL, Jasko DJ, Perdrizet JA, Powers PM and Smith MC. 1987. A randomized double blind clinical trial of two GnRH analogs for the treatment of cystic ovaries in dairy cattle. CORNELL VET. 77:235-243.
  17. Kelton DF, Garcia-Blanco J, Guard CL, Dinsmore RP, Powers PM, Smith MC, Stehman S, Ralston N and White ME. 1988. Randomized clinical trial of bar suture (toggle pin) vs open surgical abomasopexy for treating left displaced abomasum in dairy cattle. J AM VET MED ASSOC. 193(5):557-559.
  18. Shoaf SE, Schwark WS and Guard CL. 1987. The effect of age and diet on sulfadiazine/¬trimethoprim disposition following oral and subcutaneous administration 0to neonatal calves. J VET PHARM AND THERAPEUTICS. 10:331-345.
  19. Guard CL, Schwark WS, Kelton DF and Dobson A. 1987. Effects of metoclopramide, clenbuterol and butorphanol on ruminoreticular motility of calves. CORNELL VET. 78:89-98.
  20. Hodges RJ, White ME, Guard CL, Powers PM, Dinsmore RP, Kelton DF, Stehman SM, Hillman RB and Yoder SS. 1987. A randomized clinical trial of the effect of the time of administration of cloprostenol on detection of estrus in dairy cattle. CANADIAN VETERINARY JOURNAL. 29:343-345.
  21. Shoaf SE, Schwark WS, Guard CL and Babish JG. 1987. The development of hepatic drug-metabolizing enzyme activity in the neonatal calf and its effect on drug disposition. DRUG METABOLISM & DISPOSITION. 15:676-681.
  22. Kelton DF, White ME, Hodges RJ, Guard CL, et al. 1987. The relationships among palpator experience, milk progesterone concentration and estrus and fertility in cows with palpable corpora lutea treated with cloprostenol. CORNELL VET. 78:105-112.
  23. Shoaf SE, Schwark WS and Guard CL. 1989. Pharmacokinetics of sulfadiazine/trimeth¬oprim in neonatal male calves: effect of age and penetration into cerebrospinal fluid. AMER J VET RES. 50:396-403.
  24. Scott DW & Guard CL. 1988. Alopecia areata in a cow. AGRI-PRACTICE. 9:16-19.
  25. Dinsmore RP, White ME, Guard CL, et al. 1989. Effect of gonadotropin-releasing hormone on clinical response and fertility in cows with cystic ovaries, as related to milk progesterone concentration and days after parturition. J AM VET MED ASSOC. 195:327-330.
  26. Guard CL, Byman KD and Schwark WS. 1989. Effect of experimental synovitis on disposition of penicillin and oxytetracycline in neonatal calves. CORNELL VET. 79:161-171.
  27. Weber ME, White ME, Guard CL et al. 1989. Effect of large palpable ovarian follicles on response to prostaglandin administration in dairy cows with corpora lutea. CAN VET J. 30:231-234.
  28. Heuwieser W, Guard CL Ferguson JD, Foote RH, Mansfeld R. 1990. Effects of gonadotropin-releasing hormone GnRH on pregnancy rate in dairy cattle: a critical review. 1990. DEUTSCHE TIERAERZTLICHE WOCHENSCHRIFT. 97:430-433.
  29. Mohammed HO, White ME, Guard CL, Smith MC, Mechor GD, Booker CW, Warnick LD, Dascanio JJ, Kenney DG. 1991. A case-control study of the association between blood selenium and cystic ovaries in lactating dairy cattle. J DAIRY SCI. 74:2180-2185.
  30. Barkema HW, Schukken YH, Guard CL, Brand A, van der Weyden GC. 1992. Cesarean section in dairy cattle: a study of risk factors. THERIOGENOLOGY 37:489-506.
  31. de Groot K, Guard CL, Schukken YH, Noordhuizen JPTM. 1992. De konditie bij afkalven jeeft invloed op de prestatie van melkkoeien. VEETEELT. 9(5):208-210.
  32. Barkema HW, Schukken YH, Guard CL, Brand A, van der Weyden GC. 1992. Fertility, production, and cullilng following cesarean section in dairy cattle. THERIOGENOLOGY. 38(4):589-599.
  33. Eltom SE, Guard CL, Schwark WS. 1993. The effect of age on phenylbutazone pharmacokinetics, metabolism, and plasma protein binding in goats. J VET PHARMACOL THER. 16(2):141-151.
  34. Gilbert RO, Grohn YT, Guard CL, et al. 1993. Impaired post partum neutrophil function in cows which retain fetal membranes. RESEARCH IN VETERINARY SCIENCE 55:15-19.
  35. Brand A, YH Schukken, CL Guard. 1995. Principles of herd health and production management programs. HUNG VET J. 50:701-706.
  36. Pankowski JW, Galton DM, Erb HN, Guard CL, Grohn YT. 1995. Use of prostaglandin as a postpartum reproductive management tool in lactating dairy cattle. J DAIRY SCI 78:1477-1488.
  37. Heuwieser W, Ferguson JD, Guard CL, et al. 1994. Relationships between administration of GnRH, body condition score and fertility in Holstein dairy cattle. THERIOGENOLOGY. 42(4):703-714.
  38. Enevoldsen C, Sorensen JT, Thysen I, Guard C, Grohn YT. 1995. A diagnostic and prognostic tool for epidemiologic and economic analyses of dairy herd health management. J DAIRY SCI. 78:947-961.
  39. Brand A, Schukken Y, Guard C. 1996. Principles of herd health and production management programs. Simposio Internacional O Futuro dos Sistemas de Producao de Leite No Brasil, Juiz de Fora, MG, Brasil, pp. 109-125.
  40. Valentine BA, Credille KM, Lavoie JP, Fatone S, Guard C, Cummings JF, Cooper BJ. 1997. Severe polysaccharide storage myuopathy in Belgian and Percheron draught horses. EQUINE VET J. 29:220-225.
  41. Matsas DJ, LD Warnick, GD Mechor, LN Seib, S Fatone, ME White, and CL Guard. 1999. Use of a water hardness test kit to measure serum calcium concentration in cattle. J AM VET MED ASSOC. 214:826-828.
  42. Delgado-Lecaroz R, LD Warnick, CL Guard, MC Smith, DA Barry. 2000. Cross-sectional study of the association of abomasal displacement or volvulus with serum electrolyte and mineral concentrations in dairy cows. CAN VET J. 41:301-305.
  43. Rajala-Schultz PJ, TY Grohn, CE McCulloch, CL Guard. 1999. Effects of Clinical Mastitis on Milk Yield in Dairy Cows. J DAIRY SCI. 82:1213-1220.
  44. Wilson DJ, RN Gonzalez, LH Southwick, CL Guard. 2000. J DAIRY SCI. 83:2004-2007.
  45. Peek SF, TJ Divers, C Guard, A Rath, WC Rebhun. 2000. Hypokalemia, muscle weakness, and recumbency in dairy cattle. VETERINARY THERAPEUTICS. 1:235-244.
  46. Warnick LD, D Janssen, CL Guard, YT Grohn. 2001. The effect of lameness on milk production in dairy cows. J DAIRY SCI. 84:1988-1997.
  47. Vokey FJ, CL Guard, HN Erb, DM Galton. 2001. The effect of alley and stall surfaces on indices of claw and leg health in dairy cattle housed in a free-stall barn. J DAIRY SCI. 84:2686-2699
  48. Aubry P, LD Warnick, BW Hill, MF Witt, CL Guard. 2001. Effect of vaccination against M. hemolytica and P. multocida on respiratory disease in dairy calves: a clinical trial. JAVMA. 219:1739-1742.
  49. Warnick LD, DV Nydam, A Maciel, CL Guard, SE Wade. 2002. Uder cleft dermatitis and sarcoptic mange in a dairy herd. J AM VET MED ASSOC, 221:273-276.
  50. Hassan L, CL Guard, HO Mohammed. 2002. Feeding practices associated with the presence of Listeria monocytogenes: A case-control study in New York dairies. Dairy, Food and Environmental Sanitation, 22:326-332.
  51. Nydam DV, Linndergard G, Guard CL, Schaaf SL, Wade SE, Mohammed HO. 2002. Serological detection of exposure to Cryptosporidium parvum in cattle by ELISA and its evaluation in relation to coprological tests. Parasitology Research. 88:797-803.
  52. Barr SC, Linke RA, Janssen D, Guard CL, Smith MC, Daugherty CS, Scarlet JM. 2003. Detection of biofilm formation and nanobacteria under long-term cell culture conditions in serum samples of cattle, goats, cats and dogs. Am J Vet Res. 64:176- 182.
  53. Booth CJ, LD Warnick, YT Gröhn, DO Maizon, CL Guard, D Janssen. 2004. The effect of lameness on culling in dairy cows. Am. J. Dairy Sci. 87:4115-4122.
  54. Gilbert RO, ST Shin, CL Guard, HN Erb, M Frajblat. 2005. Prevalence of endometritis and its effects on reproductive performance of dairy cows. Theriogenology. 64:1879-1888
  55. Rosenbaum A, Guard CL, Njaa BL, McDonagh PL, Schultz CA, Warnick LD, White ME. 2005. Slaughterhouse survey of pyelonephritis in dairy cows. Veterinary Record. 157:652-653.
  56. Bicalho RC, Cheong HS, Warnick LD, Nydam DV, Guard CL. 2006. The effect of digit amputation or arthrodesis surgery on culling and milk production in Holstein dairy cows. J Dairy Sci. 89:2596-2602.
  57. R. C. Bicalho, SH Cheong, LD Warnick, and CL Guard. 2007.
    Evaluation of Progesterone Supplementation in a Prostaglandin F2 -Based Presynchronization Protocol Before Timed Insemination
    J Dairy Sci 90: 1193-1200
  58. Lamm CG, CL Guard, HN Erb, BL Njaa. 2007. Characterization of rupture of abdominal artery aneurysm in dairy cattle. J Vet Diagn Invest. 19:273-278.
  59. Bicalho, RC, S H Cheong, and C. L. Guard. 2007. Field technique for the resection of the distal interphalangeal joint and proximal resection of the deep digital flexor tendon in cows. The Veterinary Record 160:435-439
  60. Bicalho, RC, SH. Cheong, G Cramer, and CL Guard. 2007. Association between visual and an automated locomotion score in lactating Holstein cows. J Dairy Sci. 90:3294-3300.
  61. Bicalho, RC, KN Galvao, SH Cheong, RO Gilbert, LD Warnick, and CL Guard. 2007. Effect of stillbirths on dam survival and reproduction performance in Holstein dairy cows. J Dairy Sci. 90:2797-2803.
  62. Bicalho, RC, FH Vokey, HN Erb, and CL Guard. 2007. Visual locomotion scoring in the first seventy days in milk: Impact on pregnancy and survival. J Dairy Sci. 90:4586-4591.
  63. Bicalho, RC, SH Cheong, KN Galvao, LD Warnick, and CL Guard. 2007. Effect of twin birth calvings on milk production, reproductive performance, and survival of lactating cows. J Amer Vet Med Assoc. 231:1390-1397.
  64. Cramer G, KL Lissemore, CL Guard, KE Leslie, DF Kelton. 2008. Herd and cow level prevalence of foot lesions in Ontario dairy cattle. J Dairy Sci. 91-3888-3895.
  65. Cramer G, KL Lissemore, CL Guard, KE Leslie, DF Kelton. 2009. Herd level risk factors for seven different foot lesions in Ontario Holstein cattle housed in tie stalls of free stalls. J Dairy Sci. 92:1404-1411.
  66. Galvao KN, M Frajblat, SB Brittin, WR Butler, CL Guard, RO Gilbert. 2009. Effect of prostaglandin F2a on subclinical endometritis and fertility in dairy cows. J Dairy Sci. 92:4906-4913.