What are Gastrocnemius Tendonitis?
Gastrocnemius tendonitis is not very common, but it is the most commonly torn tendon in the horse. Your horse’s Achilles’ tendon is made up of five tendons, with the gastrocnemius being the most important because it is the one that connects the heel to the upper hock. When this tendon is damaged, the limb is usually unable to bear weight at all.
Gastrocnemius tendonitis in horses is a serious condition of the gastrocnemius tendon, which is the muscle that attaches the upper part of the leg to the hock. If the tendon is ruptured, the horse’s leg will collapse when putting weight on it, causing a major case of lameness. Often, when this part of the horse is injured, a deep penetrating wound is visible as well.
Symptoms of Gastrocnemius Tendonitis in Horses
The symptoms of gastrocnemius tendonitis are pretty obvious, as your horse will be limping badly or may even not be able to walk at all. Some of the most common signs of gastrocnemius tendonitis include:
- Lameness limited to a single rear limb
- Severe limp with collapse of the limb
- Deep penetrating wound
- Blood on your horse’s upper limb around the hock
- Shortened stride
- Acute gastrocnemius tendonitis is the most common and happens suddenly from an injury to the leg
- Chronic gastrocnemius tendonitis is rare, but if the tendon is repeatedly injured without care, it can become scarred and cannot be treated successfully even with surgery
- Partial rupture includes damage to the gastrocnemius tendon but not the superficial digital flexor
- Complete rupture includes the rupture of all the tendons in the limb, usually due to a deep laceration injury
Causes of Gastrocnemius Tendonitis in Horses
- Direct injury such as a kick or blow
- Indirect injury such as a loading or unloading accident
- Idiopathic (unknown)
Diagnosis of Gastrocnemius Tendonitis in Horses
It is essential that you get treatment for your horse right away if you suspect gastrocnemius tendonitis or your pet may be permanently lame. The veterinarian (equine veterinarian is best) will be able to tell your horse is injured right away just by looking, but it is important to rule out other conditions such as equine herpes myeloencephalitis (EHM), equine protozoal myeloencephalitis (EPM), neuropathy, myopathy, or another neurological condition. The first thing your veterinarian will do is to get your horse’s complete history from you including vaccination records and what type of work your horse has been doing.
Secondly, a comprehensive physical examination will be conducted, which will usually include body temperature, breath sounds, blood pressure, weight, height, behavior, body condition score, and heart rate. Your veterinarian will want you to trot your horse around for a lameness check also. This also includes movement, flexion exam (putting pressure on the limb before movement), conformation, hoof testing, and using a joint block to numb the area before repeating the movement test.
The best test to verify gastrocnemius tendonitis is imaging. This includes a multiskeletal ultrasound, contrast x-rays, CT scan, bone scan, and MRI. In addition, certain laboratory tests will need to be conducted such as a complete blood count (CBC), serum biochemistry panel, glucose and insulin levels, blood and urine cultures, and whatever else your veterinarian believes is necessary.
Treatment of Gastrocnemius Tendonitis in Horses
Treatment for gastrocnemius tendonitis is seriously dependent on your horse’s age and health as well as the nature and severity of the damage. If it is a complete rupture and your horse is older, the treatment is limited while a younger, healthier horse may be able to recover completely with only a splint or bandage. There are a few treatments to be considered, which are:
This includes keeping your horse in a stall 24/7 for anywhere between two months to one year, depending on the injury. This means no exercise or work at all until the veterinarian says it is okay.
Repairing the tendon is the only treatment option for some animals, depending on the damage. This includes using general anesthesia while the veterinary surgeon makes an incision above the injury and uses heavy sutures for tendon repair. A special suture pattern called locking loops are used to pull the tendons together. Once the tendon is repaired, the veterinarian may use either a cast, a screw and cast, or a skeletal fixator that protects and supports the repaired tendon.
Observation and Medication
The veterinarian will want you to keep your horse under surveillance to make sure the bandages do not come off or get dirty. The only medication the veterinarian will use is an antibiotic to prevent infection and a pain reliever and corticosteroids for pain and inflammation.
Recovery of Gastrocnemius Tendonitis in Horses
Your horse will need stall rest for at least three months; gradually introducing outdoor walks while leashed. Continue to keep the bandages clean and watch for pressure sores. If your horse has a fixator, you will need to clean around the pins with peroxide and use topical antibacterial as well. Keep the pins covered with foam sponges and an Ace bandage.