Mertens Mammals Equine Veterinary Medicine is the only equine practice in the Pacific NW to combine veterinary expertise with positive reinforcement training for horses. We are based in Boring, OR and serve horses in Clackamas County and the greater Portland area.

We aim to help all horse owners improve the mental and emotional health of their animals, with a special emphasis on overcoming problem behaviors as may be encountered during veterinary procedures and handling.

If you have a challenging behavior dilemma, please don't hesitate to call or text (503) 663-6400. We look forward to helping you find science-based, ethical, and effective solutions.

Kath Mertens, DVM - Veterinarian; Practice Owner

Dr. Mertens earned her DVM from the Purdue University School of Veterinary Medicine in 2000, and also holds a degree in English from Harvard.

Kath’s interest in horses has taken her across the ocean and the continent, working at internships in Ireland and France and hitting the trails in Long Island, NY; Wyoming, Montana, and now Oregon. She is a dedicated student of the horse and enjoys studying equines from both a medical and horsemanship perspective. Her primary riding interests are back-country trail riding, three day eventing, and dressage.

Kath enjoys leisure time with her son and their black Labrador, Makai, and a recently adopted cat. She also enjoys training her 10 yro OTTB mare, Luna; reading, writing, long-distance running, and yoga.

Sammi Jones, R+ trainer

Sammi Jones joined Mertens Mammals as a trainer in the Winter of 2022. She has had a lifelong passion for animals, especially horses. Learning about positive reinforcement training in 2019, Sammi was instantly hooked by the ability to train animals with empathy and without force. Sammi has used positive reinforcement to train horses—from Percheron Draft to American Miniature—as well as dogs, donkeys, llamas, alpacas, and house cats.

Outside of training, Sammi spends her down time playing sports (ultimate frisbee is a favorite), reading, and enjoying friends and family. Sammi lives in Gresham, OR with her husband and two cats.

Positive reinforcement training allows the animal to have choice and control. The relationship this training builds between animal and human is truly special. –Sammi Jones

Makai - Vet Dog

Many clients are delighted to see that lab work is available wherever Dr. Mertens might travel–expert endorsed Black Labrador Work, that is. (We also provide the other kind.)

Rest assured that she will not exit the vehicle at your farm unless she has your permission!

Makai, age 10, is trained to stay right where she’s pictured: perched and waiting to give love and tail wags to any approaching friends from the barn. In our newest rig, she’s usually found in the cab of the pick up, but her moral support functions remain unchanged.

She has been Vet Dog since the age of 8 weeks and considers it a career goal.