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New Bolton Center Kennett Square, PA
Emergencies & Appointments:
610-444-5800
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Havemeyer Equine Behavior Research Lab

Semi-feral pony herd at New Bolton Center

The Equine Behavior Program and Laboratory at New Bolton Center has grown from within the Section of Reproductive Studies.  Since the early 1980s the program, has had research as its core activity.  The program has included involvement in related clinical and teaching in the veterinary school and continuing education programs nationally and internationally.  The initial research focus of the laboratory was on stallion reproductive physiology and behavior. 

Early research concentrated on the physiology and pharmacology of libido, erection, and ejaculation, with immediate application to clinical problems in breeding stallions and with relevance to the understanding of human sexual dysfunction. 

Another long-standing research interest of our laboratory has been the effects of experience on sexuHavemeyer Barnal function.  In the 1990s our research and clinical work expanded beyond stallions to include reproductive and general behavior problems of horses.

The Behavior Lab is housed in The Havemeyer Barn at The Georgia and Philip Hofmann Center for Animal Reproduction. 

Contact Information

Sue M. McDonnell, PhD

Email: suemcd@vet.upenn.edu
Phone: 610-444-5800
FAX: 610-925-8124

Location:
Havemeyer Equine Behavior Lab
New Bolton Center
382 West Street Road
Kennett Square, PA 19348

Historical Scope

Over the past three decades the Havemeyer Equine Behavior Program has studied a wide range of equine behavior and reproduction topics, including:

  • Equine cognition concept learning
  • Reproductive endocrinology and behavior of harem and bachelor stallions
  • Stress physiology and behavior of semi-feral equids
  • Leptin and MSH in fat and food-aggressive horses and ponies
  • Methods of acclimation of semi-feral ponies to human handling
  • The equid ethogram
    • Inter-male interaction
    • Parental behavior
    • sexual behavior
    • Developmental behavior
    • Play behavior

 semi-feral ponies, New Bolton Center

 

The herd, New Bolton Center

The Equine Behavior Program and Laboratory at New Bolton Center has grown from  within the Section of Reproductive Studies.  Since the early 1980s the program, has had research as its core activity.  The program has included involvement in related clinical and teaching in the veterinary school and continuing education programs nationally and internationally.  The initial research focus of the laboratory was on stallion reproductive physiology and behavior. 

Early research concentrated on the physiology and pharmacology of libido, erection, and ejaculation, with immediate application to clinical problems in breeding stallions and with relevance to the understanding of human sexual dysfunction. 

semi feral foal sm

Another long-standing research interest of our laboratory has been the effects of experience on sexual function.  In the 1990s our research and clinical work expanded beyond stallions to include reproductive and general behavior problems of horses.

The Behavior Lab is housed in The Havemeyer Barn at The Georgia and Philip Hofmann Center for Animal Reproduction. 

Havemeyer BarnThe Behavior Lab is housed in The Havemeyer Barn at The Georgia and Philip Hofmann Center for Animal Reproduction.

The Havemeyer Barn is a 19th Century Pennsylvania Bank Barn that was renovated by The Dorothy Russell Havemeyer Foundation specifically to house behavior and physiology research program.  It includes a stable for housing ponies, a breeding shed, semen and blood collection laboratory, a behavior library, conference room, offices, and flexibly designed facilities suitable for a variety of equine behavior studies.  Our semi-feral pony herd is housed on approximately 50 acres with a catch pen and animal handling facilities.

About Dr. Sue McDonnell

Dr. Sue McDonnell, New Bolton CenterDr. Sue McDonnell is a native Pennsylvanian, raised in a dairy farming family in the anthracite coal regions north of Scranton. She holds a 1982 master’s degree in Psychology from West Chester University and a 1985 PhD in Reproductive Physiology and Behavior from the University of Delaware. She completed post doctoral study in clinical veterinary reproduction at the University of Pennsylvania’s New Bolton Center in 1987 and became board certified in Applied Animal Behavior in 1991. She is the founding head of the Equine Behavior Program at the University of Pennsylvania School of Veterinary Medicine, where her work includes clinical, research, and teaching activities focused on horse behavior. Dr. McDonnell includes all types of behavior in her clinical case load, with stallion behavior as an area of particular interest and expertise.

Dr. McDonnell’s research interests include several areas within equine physiology, behavior and welfare. She has also traveled to study equids throughout the world. In addition to laboratory and field studies, she maintains a semi-feral herd of ponies specifically for the study of their physiology and behavior under semi-natural conditions. This affords veterinary and animal behavior students the opportunity for long-term observation of equine social and developmental behavior and for first-hand comparison of horse behavior under free-running and traditional domestic conditions.

Dr. McDonnell is the author of two introductory level books on horse behavior entitled Understanding Horse Behavior, and Understanding Your Horse's Behavior, published by The Blood Horse in their Horse Health Care Library Series, and the recently released catalog of horse behavior, The Equid Ethogram, A Practical Field Guide to Horse Behavior, published by Eclipse Press. Along with Dr. Danny Mills, she co-edited The Domestic Horse: Evolution, Development and Management. Among Dr. McDonnell's honors are The George Stubbs Award given by the American Association of Equine Practitioners for contributions to equine veterinary medicine by a non-veterinarian and a Gold Medal from the Agricultural University of Krakow, Poland, their highest honor for distinguished scientific collaboration.

Equine Behavior Publications (PDF) 
2017 
Martinez de Andino E, McDonnell SM (2017) Evaluation of operant learning performance in foals using target training. Applied Animal Behavior Science 193:67-72.
McDonnell SM (2017)  Preventing and rehabilitating common healthcare procedure aversions 63rd  Annual Convention AAEP, San Antonio, TX Nov 17-21, 2017, pp 262-268. 
McDonnell SM (2017) Behavior Problem: ovaries or not? 63rd  Annual Convention AAEP, San Antonio, TX Nov 17-21, 2017, pp 131-134. 
2016 
McDonnell SM (2016) Revisiting stallion sexual behavior: Ethology in the breeding shed. Journal of Equine Veterinary Science 43: S18-22. 
Stawicki RJ, McDonnell SM, Giguere S, Turner RM (2016) Pregnancy outcomes using stallion epididymal sperm stored at 5°C for 24 or 48 hours before harvest. Theriogenology 85 (4): 698-704. 
2015
Robinson MA, Guan F, McDonnell SM, Uboh CE, Soma LR (2015) Pharmacokinetics and pharmacodynamics of dermorphin in the horse. Journal of Veterinary Pharmacology and Therapeutics 38 (4): 321–329. 
Bonnell MK, McDonnell SM (2015) Evidence for sire, dam, and family effect on learning efficiency in horses. . Journal of Equine Veterinary Science: 36:69-76. 
2014
McDonnell SM, Miller J, Vaala W. (2014) Modestly Improved Compliance and Apparent Comfort of Horses With Aversions to Mildly Aversive Routine Health Care Procedures Following Short-Term Alpha-Casozepine Supplementation, Journal of Equine Veterinary Science.
McDonnell SM, Whitesell KJ, Sertich P (2014) Endometrial histology in a semi-feral pony herd of known high lifetime reproductive efficiency. Journal of Equine Veterinary Science 34 (1): p 130.
Whitesell KJ, McDonnell S, Turner R. (2014) Modernizing the stallion breeding soundness evaluation. Journal of Equine Veterinary Science 34 (1): 50-51.
2013
Pozor MA, Macpherson ML, McDonnell SM, Nollin N, Roser JF, Love C, Runyon S, Thomas BF, Troedsson MH. (2013) Indenopyride derivative RTI-4587-073(l): A candidate for male contraception in stallions, Theriogenology.
Whitesell KJ, McDonnell SM (2013) How we select, prepare, and maintain a stimulus/mount mare. 59th Annual Convention AAEP, Nashville, TN, pp 23-27.
2012
Jacobson CC, Sertich PL, McDonnell SM. (2012) Mid-gestation pregnancy is not disrupted by a 5-day gastrointestinal mucosal cytoprotectant oral regimen of misoprostol, Equine Veterinary Journal (online).
McDonnell SM, Miller J, Vaala W. (2012) Calming benefit of short-term alpha-casozepine supplementation during acclimation to domestic environment and basic ground training of adult semi-feral ponies, Journal of Equine Veterinary Science (online).
Guan F, Uboh CE, Soma LR, You Y, Li X, McDonnell S (2012) Ex vivo spontaneous generation of 19-norandostendione and nadrolone in equine plasma and urine. The Journal of Steroid Biochemistry and Molecular Biology 10: 128 (1-2):1-11.
McDonnell SM (2012) Mare and Foal Bonding Behavior and Problems and Raising an Orphan Foal In-Depth. 58th Annual Convention AAEP, Anaheim California, Dec 2012, pp 407-411.
Soma LR, Uboh CE, You Y, Guan F, McDonnell SM (2012) Plasma concentrations of terstosterone and nandrolone in racing and nonracing intact male horses. Journal of Veterinary Pharmacology and Therapeutics 35(2):132-8.
2011
McDonnell SM (2011) How to train a stallion to use a dummy mount. AAEP Proceedings 57: 37-47.
Knobbe MG, Maenhoudt C, Turner RM, McDonnell SM. (2011) Physical, behavioral, endocrinologic, and cytogenetic evaluation of two Standardbred racehorses competing as mares with an intersex condition and high postrace serum testosterone concentrations, JAVMA 238(6) 751-754.
Baumann C, Daly C, McDonnell SM, Viveiros M, DeLaFuente R (2011) Chromation configuration and epigenetic landscape at sex chromosome bivalent during equine spermatogenesis. Chromosoma 120: 227-244.
McDonnell SM (2011) How to Train a Stallion to Use a Dummy Mount, 57th Annual Meeting American Association of Equine Practitioners, November 18-22, 2011, San Antonio, TX, pp 37-47.
2010
Terry RL, McDonnell SM, van Eps AW, Soma LR, Liu Y, Uboh CE, Moate PJ, Driessen B (2010) Pharmacokinetic and behavioral effects of gabapentin in the horse. Journal of Veterinary Pharmacology and Therapeutics 33 (5):485-494. 
Janson K, McDonnell, SM (2010) Estrus detection in mares using contextually congruent stallion vocalization playback with and without stallion scent. Animal Reproduction Science 121S : S123–S125.
2009
Canisso IF, Carvalho GR, Davies-Morel MC, Guimarães JD, McDonnell, SM (2009) Sexual behavior and ejaculate characteristics in Pêga donkeys (Equus asinus) mounting estrous horse mares (Equus caballus). Theriogenology 73:56-63.
Canisso IF, Davies More MCG, McDonnell SM 2009. Strategies for the management of donkey jacks in intensive breeding systems. Equine Veterinary Education 21: 652-659.
Canisso IF, daSilva MAC, McDonnell SM 2009. How to manage jacks to breed mares. AAEP Proceedings 55: 342-348.
2008
McDonnell S (2008) Practical review of self-mutilation in horses. Anim Reprod Sci 107:219–228.
Verrill S, McDonnell S (2008) Equal outcomes with and without human-to-horseeye contact when catching horses and ponies in an open pasture. J Equine Vet Sci 28(5): 309–312.
Soma LR, Uboh CE, Guan F, McDonnell SM (2008) Plasma concentrations of testosterone and 19-nortestosterone (nandrolone) in the nonracing intact male horse by liquid chromatography-mass spectrometry. J Vet Pharmacol Therap 3: 587–590.
Sleeper MM, McDonnell SM, Ely JJ, Reef V (2008) Chronic oral therapy with enalapril in normal ponies. J Vet Cardiol 10: 111-115.
Brito LFC, Sertich PL, Durkin K, Chowdhary BP, Turner RM, Greene LM, McDonnell SM. (2008) Autosomic 27 trisomy in a Standardbred colt. Journal of Equine Veterinary Science 28 (7): 431-436.
2007
Soma LR, Uboh CE, Guan F, McDonnell S, Pack J (2007) Pharmacokinetics of boldenone and stanozolol and the results of quantification of anabolic and androgenic steroids in race horses and nonrace horses. J Vet Pharmacol Therap 30: 101–108.
2006
Florence L, McDonnell SM (2006) Hoof growth and wear of semi-feral ponies during an annual summer self-trimming period. Equine Veterinary Journal 38(7): 642-645.
Dallmeyer MD, Turner RM, McDonnell SM, Sertich PL, Dolente BA, Parente EJ, Seco Diaz OM (2006) Vet Med Today: Theriogenology Question of the Month (August). JAVMA 229(4): 511-513.
Wilkins PA, Glaser AL, McDonnell SM (2006) Passive transfer of naturally acquired specific immunity against West Nile Virus to foals in a semi-feral pony herd. J Vet Intern Med 20: 1045-1047.
Turner RM, McDonnell SM, Feit EM, Grogan EH, and Foglia R (2006) Real-time ultrasound measure of the fetal eye (vitreous body) for prediction of parturition date in small ponies. Theriogenology 66(2): 331-337.
2005
McDonnell SM (2005) Is it physical or psychological? AAEP Proceedings 51: 231-238.
Grogan EH, McDonnell SM (2005) Mare and foal bonding and problems. Clin Tech Equine Pract 4: 228-237.
McDonnell SM, Hinze AL (2005) Aversive conditioning of periodic spontaneous erection adversely affects sexual behavior and semen in stallions. Animal Reproduction Science 89: 77-92.
McDonnell SM, Grogan EH, Glaser, Wilkins PA (2005) West Nile Virus titers in a semi-feral herd of Ponies in Pennsylvania, presented at ACVIM Annual Forum, Baltimore, MD, June 1-4, 2005 and Univ of Penn, School of Veterinary Medicine Faculty Research Retreat, June 24, 2005
Grogan EH, McDonnell SM (2005) Behavioral responses to two intranasal vaccine applicators in horses and ponies. JAVMA 226(10): 1689-1693.
Donaldson MT, McDonnell SM, Schanbacher BJ, Lamb SV, McFarlane D, Beech (2005) Variation in plasma adrenocorticotropic hormone concentration and dexamethasone suppression test results with season, age and sex in healthy ponies and horses. J Vet Intern Med 19: 217-222.
Grogan EH, McDonnell SM (2005) Injuries and blemishes in a semi-feral herd of ponies. JEVS 25(1): 26-30.
2004
McFarlane D, Donaldson MT, McDonnell SM, Cribb AE. (2004) Effects of season and sample handling on measurement of plasma α-melanocyte-stimulating hormone concentrations in horses and ponies. AJVR 65(11): 1463-1468.
Pozor MA, McDonnell SM (2004) Color Doppler ultrasound evaluation of testicular blood flow in stallions. Theriogenology 61: 799-810.
2003
McDonnell SM (2003) How to manage the stallion with a paralyzed penis for return to natural service or artificial insemination. AAEP Proceedings 49: 291-292.
Turner RM, McDonnell SM (2003) Alkaline phosphatase in stallion semen: characterization and clinical applications. Theriogenology 60: 1-10.
2002
Pozor MA, McDonnell SM (2002) Ultrasonographic measurements of accessory sex glands, ampullae, and urethra of normal stallions of various size types. Theriogenology 58: 1425-1433.
Strand S, Tiefenbacher S, Haskell M, Hosmer T, McDonnell SM, Freeman DA. (2002) Behavior and physiological responses of mares to short-term isolation. Applied Animal Behavior Science 78: 145-157.
McDonnell SM, Poulin A (2002) Equid play ethogram. Applied Animal Behavior Science 78: 263-290.
Pozor MA, McDonnell SM (2002) Doppler ultrasound measures of testicular blood flow in stallions. Theriogenology 58: 437-440.
Limone LE, Shaughnessy DW, Gomez-Ibanez S, McDonnell SM, Bedford SJ (2002) The effect of artificial vagina lubricants on sperm motion measures and semen pH during cooled storage. Theriogenology 58: 333-336.
2001

McDonnell SM (2001) Oral imipramine and intravenous xylazine for pharmacologically-induced ex-copula ejaculations in stallions. Animal Reproduction Science 68: 153-159.

McDonnell SM (2001) How to select and fit a breeding dummy mount for stallions. AAEP Proceedings 47: 417-419.
2000
McDonnell SM (2000) How to rehabilitate horses with injection shyness (or any procedure non-compliance). AAEP Proceedings 46: 168-172.
McDonnell SM (2000) Reproductive behavior of stallions and mares: comparison of free-running and domestic in-hand breeding. Animal Reproduction Science 60-61: 211-219.
McDonnell Sue M (2000) Stallion sexual behavior. In Juan C Samper (Ed) Equine Breeding Management and Artificial Insemination Philadelphia: WB Saunders, pp 53-61.
Bedford SJ, McDonnell SM (2000) Vet Med Today: Theriogenology question of the month. Journal of the American Veterinary Medical Association 216: 491-493
Bedford SJ, McDonnell SM, Tulleners E, King D, Habecker P (2000) Squamous cell carcinoma of the urethral process in a horse with hemospermia and self-mutilation behavior. Journal of the American Veterinary Medical Association 216: 551-553.
1999
Freeman DA, Cymbaluk NF, Schott HC, Hinchcliff K, McDonnell SM, Kyle B (1999) Clinical, biochemical, and hygiene assessment of stabled horses provided continuous or intermittent access to drinking water. American Journal of Veterinary Research 60: 1445-1450.
McDonnell SM, Freeman DA, Cymbaluk NF, Schott HC, Hinchcliff K, Kyle B (1999) Behavior of stabled horses provided continuous or intermittent access to drinking water. American Journal of Veterinary Research 60: 1451-1456.
Forney BD, McDonnell SM (1999) How to collect semen from stallions while they are standing on the ground. AAEP Proceedings 45: 142-144.
Bedford SJ, McDonnell SM (1999) Measurements of reproductive function in stallions treated with trimethoprim-sulfamethoxazole and pryimethamine. Journal of the American Veterinary Medical Association 215: 1317-1319.
McDonnell SM (1999) Libido, erection, and ejaculatory dysfunction in stallions. Compendium 21 (March), pp 263-266.
McDonnell SM (1999) Le comportment sexuel de l'etalon. Prat Vet Equine 31: 17-24
1998
Martin BB, McDonnell SM, and Love CC (1998) Effects of musculoskeletal and neurologic disease on breeding performance in stallions. Compendium 20: 1159-1169.
Freeman DA, Cymbaluk NF, Kyle B, Schott HC, Hinchcliff K. McDonnell SM (1998) Health and welfare of stabled PMU mares under various watering methods and turnout schedules: 1. Physiology. AAEP Proceedings 44: 19-20.
McDonnell SM, Freeman DA, Cymbaluk NF, Kyle B,Schott HC, Hinchcliff K, Kyle B. (1998) Health and welfare of stabled PMU mares under various watering methods and turnout schedules: 2. Behavior. AAEP Proceedings 44: 21-22.
Bedford SJ, McDonnell SM (1998) Semen, testicular volume, sperm production efficiency, and sexual behavior of stallions treated with trimethoprim-sulfamethoxazole and pryimethamine. AAEP Proceedings 44: 1-2.
McDonnell SM (1998) Reproductive behavior of donkeys (Equus asinus). Applied Animal Behaviour Science 60: 227-282.
1996
McDonnell SM and Kristula MA (1996) No effect of drinking water temperature on consumption of water during hot summer weather in ponies. Applied Animal Behaviour Science 49: 149-163.
Sweeney CR, McDonnell SM, Russell GE, Terzich M (1996) Effect of sodium bisulfate on ammonia concentration, fly population, and manure pH in a horse barn. American Journal of Veterinary Research 57: 1795-1798.
Sweeney CR, McDonnell SM, Habecker, PL, Russell GE (1996) Effect of sodium bisulfate on ammonia levels, fly population, and manure pH in a horse barn. AAEP Proceedings 42: 306-307. Denver, Colorado, December.
1995
McDonnell SM, Turner RM, Diehl NK (1995) Modifying unruly breeding behavior in stallions. Compendium on Continuing Education 17(3): 411-417.
Turner RMO, McDonnell SM, Hawkins JF (1995) Use of pharmacologically induced ejaculation to obtain semen from a stallion with a fractured radius. Journal of the American Veterinary Medical Association 206(12): 1906-1908.
McDonnell SM, Haviland JCS (1995) Agonistic ethogram of the equid bachelor band. Applied Animal Behaviour Science 43: 147-188.
McDonnell SM, Murray SC (1995) Bachelor and harem stallion behavior and endocrinology. Biology of Reproduction Monograph Series 1: 577-590.
McDonnell SM (1995) Stallion behavior and endocrinology: What do we really know? AAEP Proceedings 41: 18-19.
Turner-Oristaglio RM, Love CC, McDonnell SM, Sweeney RW, Twitchell ED, Habecker PL, Reilly LK, Pozor MA, and Kenney RM (1995) Use of imipramine hydrochloride for treatment of urospermia in a stallion with a dysfunctional bladder. Journal of the American Veterinary Medical Association 207 (12): 1602-1606.
1994
McDonnell SM, Odian MJ (1994) Imipramine and xylazine-induced ex copula ejaculation in stallions. Theriogenology 41: 1005-1010.
McDonnell SM, Turner RMO (1994) Post-thaw motility and longevity of motility of imipramine-induced ejaculates of pony stallions. Theriogenology 42: 475-481.
Kristula MA, McDonnell SM (1994) Drinking water temperature affects consumption of water during cold weather in ponies. Applied Animal Behaviour Science 41: 155-160.
1993
McDonnell SM (1993) More on self-mutilative behavior in horses (letter). Journal of the American Veterinary Medical Association 202(10): 1545-1546.
Houpt KA McDonnell SM (1993). Equine stereotypies. Compendium on Continuing Eduation 15 (9): 1265-1272.
1992
McDonnell SM, Love CC, Pozor MA, Diehl NK (1992) Phenylbutazone treatment in breeding stallions: preliminary evidence for no effect on semen or testicular size. Theriogenology 37: 1225-1232.
McDonnell SM (1992) Normal and abnormal sexual behavior (letter). Veterinary Clinics of North America 8(1): 71-89.
Love CC, McDonnell SM, Kenney RM (1992) Manually assisted ejaculation in a stallion with erectile dysfunction subsequent to paraphimosis. Journal of the American Veterinary Medical Association 200(9): 1357-1359.
McDonnell SM (1992) Ejaculation-physiology and dysfunction. Veterinary Clinics of North America 8(1): 57-70.
McDonnell SM (1992) Sexual behavior dysfunction in stallions. In: Current Therapy in Equine Medicine 3. Robinson EO (ed), Philadelphia: WE Saunders.
McDonnell SM, Love CC, Martin BB, Reef VB, Kenney RM (1992) Ejaculatory failure associated with aortic-iliac thrombosis in two stallions. Journal of the American Veterinary Medical Association 200(7): 954-957.
1991
McDonnell SM, Love CC (1991) Xylazine-induced ex copula ejaculation in stallions. Theriogenology 36(1): 73-76.
Pozor MA, McDonnell SM, Kenney RM, Tischner M (1991) GnRH facilitates copulatory behavior in geldings treated with testosterone. Journal of Reproduction and Fertility Supplement 44: 666-667.
Henry M, McDonnell SM, Lodi LP, Gastal EL (1991) Pasture mating behaviour of donkeys (Equus asinus) at natural and induced oestrus. Journal of Reproduction and Fertility Supplement 44: 77-86.
McDonnell SM, Pozor MA, Beech J, Sweeney RW (1991) Use of manual stimulation for collection of semen from an atactic stallion unable to mount. Journal of the American Veterinary Medical Association 199(6): 753-754.
McDonnell SM, Henry M, Bristol F (1991) Spontaneous erection and masturbation in equids. Journal of Reproduction and Fertility Supplement 44:664-665.
1990
McDonnell SM, Love CC (1990) Manual stimulation collection of semen from stallions; training time, sexual behavior and semen. Theriogenology 33(6): 1201-1210.
McDonnell SM, Diehl NK (1990) Computer-assisted recording of live and videotaped horse behavior: reliability studies. Applied Animal Behaviour Science 27: 1-7.
1989
McDonnell SM, Diehl NK, Garcia MC, Kenney RM (1989) Gonadotropin releasing hormone (GnRH) affects precopulatory behavior in testosterone-treated geldings. Physiology and Behavior 45: 145-149.
McDonnell SM (1989) Spontaneous erection and masturbation in equids. AAEP Proceedings 35: 567-580.
Crump J, Crump J (1989) Stallion ejaculation induced by manual stimulation of the penis. Theriogenology 31(2): 341-346.
1988
McDonnell SM, Hinrichs K, Cooper WL, Kenney RM (1988) Use of an androgenized mare as an aid in detection of estrus in mares. Theriogenology 30(3): 547-553.
1987
McDonnell SM, Garcia MC, Kenney RM, Van Arsdalen KM (1987) Imipramineinduced erection, masturbation, and ejaculation in male horses. Pharmacology, Biochemistry and Behavior 27: 187-191.
McDonnell SM, Garcia MC, Kenney RM (1987) Pharmacological manipulation of sexual behavior in stallions. Journal of Reproduction and Fertility Supplement 35: 45-49.
1986
McDonnell SM, Kenney RM, Meckley PE, Garcia MC (1986) Novel environment suppression of sexual behavior in stallions and effects of diazepam. Physiology and Behavior 37(3): 503-505.
McDonnell SM (1986) Reproductive behavior of the stallion. Veterinary Clinics of North America 2(3): 535-555.
McDonnell SM, Garcia MC, Blanchard TL, Kenney RM (1986) Evaluation of androgenized mares as an estrus detection aid. Theriogenology 26(2): 261-266.
1985
McDonnell SM, Kenney RM, Meckley PE, Garcia MC (1985) Conditioned suppression of sexual behavior in stallions and reversal with diazepam. Physiology and Behavior 34: 951-956.