Signs of Hock Problems in Your Horse

Noticing your horse isn't bringing their back legs under them like they use to? Not getting quite as must spring off the ground when approaching a fence? Is your horse pulling down in the bit more than usual? It may not be that your horse is not in the shape they use to be; those could be signs of hock problems.

While you may prefer to hear that your horse needs a boost in his training regime, hock problems don't mean the end to you and your horse's success. When noticed earlier enough, there are steps you can take to prolong your horse's career.

What is the Hock?

The hock joint isn't just one thing, rather an area.

The hock links the lower leg bones to the tibia in a horse's upper leg. It consists of four basic joints and multiple bones and ligaments.

The upper joint (the tibiotarsal joint) is responsible for extensions and the majority of the hock mobility. The bottom three joints handle the remaining movement (about 10%).

With so many working parts, wear and tear is typical and expected —especially in working horses. No one breed is more prone to hock problems. Instead, breeds that are taken out of their historical use (like asking a draft horse to be a jumper) are more susceptible to hock injuries and problems.

Signs of Hock Problems in Horses

With hock problems ailing all breeds, it's important to keep an eye for signs. What is lameness shouldn't be mistaken for laziness. While not preventable, when noticed and treated early enough hock problems won't stop your horse in their tracks.

Here are a few common signs of hock problems in horses.

Stiffness

Or rather stiffness at the start of a ride that eventually goes away. When a horse is suffering from a hock problem, all of the ligaments in the joint tense up and become tighter, trying to protect the joints and bones.

This tightness will eventually be worked out as your horse stretches and moves.

Shifting Their Weight

Not all hocks are created equal — even in one horse.

With hock problems, your horse wants the weight off of their bad hock even when standing.

Shifting weight while standing isn't always a sign of hock problems as it's natural to change weight on and off a leg while standing. However, if you notice your horse always takes the pressure off a particular leg, it's worth checking out.

Changes in Gait

Pain alters the movement of any animal. With pain in the back legs, horses will shorten their gait to take weight off their back. If the pain is severe, they may even shift more weight onto their forelegs, ending up in a hunched position.

Less Spring in Their Jump

When approaching a fence, horses shift their weight into their hind in, allowing them to spring off of the ground and clear the fence.

Horses with hock problems are reluctant to do that. In developing injuries, they may still jump, but with less spring. Keep an eye out if your horse gradually begins hanging their back legs and catching rails.

With horses in severe pain from a hock injury, they may start refusing. If your horse wasn't in the habit of stopping before fences and you cannot figure out why they are starting too, take a look at their hocks.

Changes in the Appearance of Their Hock Joint

One of the apparent signs of hock problems is a change in the hock's appearance.

The hock joint has a particular, recognizable anatomy. If you notice any deviations from this or notice swelling, tenderness or heat at the hock, it's time to call your vet.

Treating Hock Problems

While it always breaks your heart when your horse is in pain, the good news is that hock injuries can be addressed.

While not 100% treatable, there are different injections and exercises that will reduce pain and tenderness. With working horses, hock injections are relatively common. Using naturally-occurring injections that act as anti-inflammatories, vets can reduce swelling and discomfort, allowing you and your horse back in the ring.

Hock problems are common in horses — especially working horses. Knowing the signs of hock problems can give you the time to address them with your vet before they take over your horse's career.

Have questions? Think your horse is suffering from a hock injury? Give PHD Veterinary Services a call at 352-258-3571.

Hock Arthritis in a Horse

A 14 year-old gelding presented to PHD veterinary services for the complaint of left hind limb lameness. The lameness had been noted for 6 months with minimal clinical improvement after several months of pasture rest. On presentation the gelding was a grade 3/5 lame in the left hind limb when trotted in a straight line. Flexion of the lower limb and upper limb did NOT worsen the lameness. In addition, the lameness did NOT worsen when lunged in either direction. Physical exam of the left hind limb did not identify any swelling or joint effusion however the gelding's range of motion of the hock joint was reduced. Radiographic evaluation of the limb was elected as the best option for identifying the source of lameness in this horse.  In Figure 1 and 2, the lower hock joints are identified as the following: PIT= proximal intertarsal joint, DIT= distal intertarsal joint, and TMT= tarsal metatarsal joint. 

Figure 1

Figure 2

In Figure 3, the lower hock joints are circled in blue and the yellow arrows are highlighting areas of significant arthritis across the front of the lower hock joints. For comparison, in Figure 4, the right hock is imaged in a radiograph and there is no evidence of arthritis in any of the hock joints.

Figure3

Figure 4

In Figure 4, the front of the lower hock joints appear disfigured (yellow arrows) by the advanced arthritis present. In addition, there is evidence of arthritis in the most proximal hock joint (tibio-tarsal joint) which significantly worsens the prognosis for this horse (Figure 4, red arrow).

Figure 4

The cause of such advanced arthritis in only one hock suggests trauma or a previous infection. Unfortunately, the full history of this horse was not available. Recommendations included a daily anti-inflammatory medication and intra-articular therapy with corticosteroids. Prognosis is guarded for soundness due to the involvement of the tibio-tarsal joint and the degree of arthritis noted in the lower hock joints.

Equine Hock Arthritis

Figure 1

The radiograph above (Figure 1) is of a horse's hock or tarsus. This view is also known as the "Lateral" view or side view. The equine hock joint is made up of 4 individual joints which are labelled above. The bottom two joints are also known as the distal hock joints and include the distal inter-tarsal joint (DIT) and the tarsal metatarsal joint (TMT). When "injecting" hocks, these are the most common joints treated and are often referred to as the "upper and lower hock joints". Degenerative joint disease (DJD) or osteo-arthritis is most common in the distal hock joints and  often results in poor performance plus/minus lameness. Bog spavin is the term that refers to increased joint fluid within the tibiotarsal joint. This is the "high motion" joint of the hock and is NOT commonly injected with "hock injections". However if increased fluid is noted, a radiographic exam is definitely indicated prior to instituting a treatment plan. Generally speaking, arthritis of the distal hock joints is more acceptable and can be managed with intra-articular therapies. However, arthritis of the tibiotarsal joint and/or the proximal inter-tarsal joint is more concerning and is reason for concern when predicting future performance.

Figure 2

In Figure 2 and 3, there are radiographic changes that indicate osteo-arthritis of the tarsal metatarsal joint space. These changes were noted during a prepurchase exam of a 5 year old horse. The horse was sound during the exam and did NOT respond to hock/stifle flexion. The million dollar question is what to recommend to the buyer based on these findings. In my clinical experience, most horses with these changes will eventually need intervention via intra-articular cortisone injections. I believe that horses with these changes are MORE likely to need hock injections than those with "normal" radiographs. However, these findings are not necessarily a negative prognostic indicator with regards to the horse's future performance. 

With management, i.e, hock injections, these horses can compete at the highest level and succeed!  As such, these findings do NOT constitute a FAILING grade during the prepurchase exam however the buyer needs to be prepared for the strong likelihood of routine "maintenance". This can easily result in hundreds to thousands of dollars per year that should be considered into the price of the horse. 

Figure 3