I personally know the frustration of trying to find a horse that I enjoy riding, fits my age/experience criteria, is sound on clinical examination, AND has radiographs that don't make me run for the hills! It's hard enough to find a horse in your price range that fits all the above, let alone spend money doing potentially numerous purchase examinations only to come up empty-handed. I wanted to share some examples of why we urge horse buyers to take radiographs before purchasing a horse.
Although the price of the horse and intended use do play a role in if and how many radiographs we obtain; very few of us horse buyers can afford to keep extra horses that didn't fulfill their jobs due to a medical issue. It's all too often that I have buyers say, "no, I'm not planning on taking any radiographs because (insert horse name) is only 2 years old." After the physical examination is completed and I have found an effusive (increased synovial fluid) joint, radiographs reveal an osteochrondosis lesion that would have prevented the horse from a competitive career without surgery. Making the decision to not take any radiographs can be well intentioned, but remember that you may end up with a horse that is relegated to being a pasture ornament. As veterinarians we try to help you assess risk and avoid surprises by completing a detailed examination.
So what is common to find on radiographs before purchasing a horse? Let's split that answer into 2 groups- young horses (<5 years) and mature horses (>6 years). For young horses, our major concern on radiographs of joints is osteochondritis dissecans (OCD), an all too common finding of cartilage and/or bone fragments. Left alone, the fragments can cause further damage to the joint and result in early arthritis and joint pain (1). Not only joints of the limb are involved, OCD has been found in joints of the spine as well, including cervical/neck facet joints. A valuable large study in 2 year old Quarter Horses showed the highest frequency of radiographic changes were in the hocks (69% of horses), then stifles (44%), hind fetlocks (43%), fore fetlocks (36%), then carpi/knees (7%) [2].
Example of an OCD lesion in a sound 4 year old gelding- fragment of the Distal Intermediate Ridge of the Tibia (in the hock):
Young horses can have a variety of other findings that make a successful purchase examination difficult. Just this Summer I evaluated a 4 year old with advanced sidebone (ossification of the collateral cartilages in the feet). Age is not a valid reason to assume that abnormalities will not occur on radiographs!
In mature horses, we start to look for bony changes relative to joints and arthritis, past injuries, or current sources of lameness. Chronic proximal suspensory desmitis of the hindlimbs (common in dressage horses) can cause bony changes in the cannon bone that can be seen on hock radiographs. Or the dreaded term Navicular disease can come into play in mature horses. The more experienced the horse, the more likely that we will find chronic repetitive injuries and some arthritis. The goal is to sort the horses who have adapted and are still sound, from those that are heading towards the end of their careers quickly. All horses deserve a happy retirement and a good home, but it's nice to know upfront what kind of future your potential riding partner will have.
A very common group of radiographs we recommend is front feet, hocks, and stifles. This all depends on the intended use of the horse, but it does cover a lot of the common locations for radiographic abnormalities. Additionally, we often take fetlock (all 4) views as well as neck and back (dorsal spinous processes) radiographs. We offer a pre-purchase radiographic package that includes 38 views, to make the whole process more affordable. Our equipment is the latest techonology- wireless digital radiography, so we can deliver the highest quality images that can be sent quickly- especially to out of state buyers' veterinarians. We are always willing to answer questions about purchase examinations- you can reach us here.
References
1. https://www.acvs.org/large-animal/osteochondritis-dissecans-horses
2. CONTINO, E. K., PARK, R. D. and MCILWRAITH, C. W. (2012), Prevalence of radiographic changes in yearling and 2‐year‐old Quarter Horses intended for cutting. Equine Veterinary Journal, 44: 185-195.