Osphos Treatments on Horses

Most veterinarians in our area do administer Osphos (a Bisphosphonate) for treatment of arthritis. I am one of the few (maybe the only one!) who does not. Here are my reasons why:


-The way it works is by killing osteoclasts which are the normal, healthy cells in the bone. Osteoclasts work in conjunction with osteoblasts and osteocytes to constantly remodel bone which is an important process for many reasons:


 1) This is how the body repairs bone damage and regenerates aging bone.  Osphos inhibits bone resorption and decreases bone turnover. This means the body is unable to undertake the normal process of removing and replacing bone which in is normally happening every minute of every day to keep bones strong. Without this happening as it is supposed to, the body is unable to repair microdamage within a bone. This is especially important in athletic horses. 


2) Osteoclasts play a crucial role in calcium balance and metabolism in the body.  Interfering with this mechanism is dangerous. Osteoblasts remove bone as a way of releasing calcium into the bloodstream when it is needed to maintain the proper balance of electrolytes in the blood, cells and extracellular spaces of the body. This is important in any living creature but especially so in an athlete. 


3) 9% of horses receiving their first Osphos treatment will colic within 2 hours of treatment. This incidence goes up with each administration of the drug. 


This drug was designed for people with osteoporosis but is not commonly used as most doctors believe it is not worth the risks. Here is the link to a fantastic article about Osphos (and Tildren, the other Bisphosphonate used in horses). It was written by Natalie Voss based on her interview with one of the most respected orthopedic veterinarians in the world, Dr. Larry Bramlage: https://www.paulickreport.com/horse-care-category/bramlage-price-pay-bisphosphonate-use-delayed-healing/


I don't feel it is in the horse's best interest to mess with normal homeostatic mechanisms as a treatment for everyday aches and pains.