30/ DECEMBER 2025 THE RIDER Rate of Penicillin Administration Affects Arterial Blood Pressure


Guelph, ON - Oct. 9, 2025 Vet- erinarians often give penicillin to horses during surgery to prevent infection, but the speed of injec- tion may influence how the horse’s cardiovascular system re- acts. In a study of 29 horses under general anesthesia, re- searchers compared two methods of giving penicillin: a fast injec- tion over one minute and a slower one over ten minutes. Both methods caused a drop


in blood pressure, but the fast in- jection led to a more dramatic de- crease. The slower, more diluted injection resulted in a gentler de- cline, suggesting it may be safer during surgery. Sudden drops in blood pressure during surgery can be risky. This study suggests that slowing down the penicillin injection and diluting it more could help keep horses safer


under anesthesia. These findings highlight the importance of not just what medication is given, but how it’s administered. Another Ontario Veterinary


College (OVC) study comparing two lidocaine infusion protocols to further explore how intraoper- ative management affects cardio- vascular stability and recovery quality is also soon to be pub- lished. “In equine anesthesia, every


decision—from drug choice to administration


technique—


should prioritize minimizing pa- tient risk. Our goal is always to support the horse in all phases of anesthesia (from induction to full recovery) to achieve optimal out- comes,” said Dr. Alexander Valverde, Professor, DVM, DVSc., Diplomate ACVAA at OVC.


Research paper: Henderson ARP, Valverde


A, Marchiori J, Tisotti T, Torrent A, Côté N, Gomez DE. Effect of rapid and slow intravenous injec-


tion of sodium penicillin on arte- rial blood pressure in isoflurane- anesthetized horses during surgery. Vet Anaesth Analg. 2025 Mar-Apr;52(2):200-207. doi:


10.1016/j.vaa.2025.01.001. Epub 2025 Jan 6. PMID: 39863515. Equine Guelph supports a


number of high-quality projects at the University of Guelph, by virtue of funding provided largely by the racing industry (Standardbred, Thoroughbred and Quarter horse organiza- tions): the Horse Improvement Program from the Horsemen’s Benevolent and Protective Asso- ciation and the E.P. Taylor Foun- dation, started by veterinarians in the Thoroughbred industry, and now maintained in trust by the University and Equine Guelph.


About Equine Guelph: Equine Guelph is the horse


owners’ and care givers’ Centre at the University of Guelph in Canada. It is a unique partnership dedicated to the health and well-


being of horses, supported and overseen by equine industry groups. Equine Guelph is the epi- centre for academia, industry and government - for the good of the equine industry as a whole. For further


information, www.equineguelph.ca.


Story by: Jackie Bellamy-Zions, Equine Guelph


Photo Credit: Ontario Veteri- nary College


Story web link: https://thehorse- portal.ca/2025/09/rate-of-peni- cillin-administration-affects-arter ial-blood-pressure/


Research paper:


https://pubmed.ncbi.nlm.nih.gov/ 39863515/


An exciting adventure awaits you just outside Or- angeville: Artistic Integrity Tattoo Ranch Inc.


Artistic Integrity Tat-


too Ranch Inc is based both figuratively and literally on the marriage of Dr. Jennifer MacNicol (P.H.D. Equine Physiology U of Guelph) and renowned Tattoo Artist Ian Greening (International award winning artist and owner of Artistic Integrity Mississauga and Grand Cayman for over 20 years.) Shortly after the Pan-


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demic had come to an end and just prior to Jen com- pleting her Degree, the cou- ple decided to merge their love of animals and artwork away from the Cities and onto their Family farm in East Garafraxa, just outside Orangeville. After a long labour of


love, the new shop was born! “Artistic Integrity Tat- too Ranch Inc.” Custom built to exact-


ing standards the purpose was to create a clean, relax- ing, and stress free environ- ment to collaborate towards a unique one of a kind Tat- too experience on their pic- turesque landscape. The studio is private


and serves only one client, couple, group or family per day.


“While on premises


limited. We are not open to the public (though we are li- censed and health board ap- proved).” If this unique, exclu-


sive experience and quality artwork interests you or you’re looking for just the right gift for that special someone, just reach out to Ian and Jen on Instagram and they will work with you. You can also follow them to receive invitations to their parties and events throughout the year. “We look forward to


seeing you at the Ranch!” said Greening.


Ian Greening and Dr. Jennifer MacNicol


guests are encouraged to stroll around the pond out- side the shop and feed the many beautiful koi fish, make new friends in the goat pens, cuddle up with some Highland Cows or get familiar with our horses,” said Ian Greening. “We have both indoor and out- door arenas, jumps and bar- rels for those already in the zone! Or, for those with lit- tle or no experience, Jen can help get you started.” Greening continues


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