Camelid joint disorders

Anatomical notes

• In most animals, the medial and lateral compartments of the fetlock joint are separate (unlike in cattle).

Joint issues

Stifle ligamentous injuries (cruciate tears) are not common but can be found in camelids. Both intracapsular and extracapsular repair approaches have been successful.

Patellar ligament tears have been reported in pack llamas and in breeding males. Affected camelids walk with a crouched posture (stifle stays flexed) and are unwilling to bear weight fully. Diagnosis is confirmed via surgery. Various forms of repair have been successful short term, but reinjury rates are high.

Shoulder luxation is uncommon but is seen in young male alpacas. Surgical repair is generally successful. Animals are kept in a Velpeau sling in the early postoperative period.

Hip luxation is treated as it would be in dogs.

General arthritic pain is treated with meloxicam and supportive care.

Patella luxation

Patellar luxation can be due to trauma or to congenital conformational abnormalities. Animals castrated early in life (<12 mo old)  tend to develop straight hindlimbs and are considered more prone to patellar luxation. Treatment involves lateral imbrication  and release (surgery to tighten up the ligaments on one side while releasing the ligaments on the other side). Prognosis may improve if the surgery is combined with trochleoplasty (reconstruction of a deeper groove in the femur so the patella is less likely to slip out of position). Recurrence of the luxation after surgery is common. A sling may be needed for the first two weeks postoperatively unless trochleoplasty is performed.

Septic arthritis

Septic arthritis occurs primarily due to trauma (direct wound into the joint). Hematogenous septic arthritis is less common than in cattle and horses.  Diagnosis of infection includes joint cytology and culture. Treatment is similar to other species and is focused on joint lavage and antibiotic therapy (iv antibiotics, intra-articular antibiotics, and/or iv regional perfusion of antibiotics).

Limb deformities

Limb deformities can be angular (in the lateral plane) or flexural (in the dorsal-palmar plane).

Mild bilateral carpus valgus is prevalent in camelids. More severe angular limb deformities may be related to hypophosphatemic rickets. Crias with dark hair coats are especially prone to developing low vitamin D levels because of reduced absorption of sunlight by the skin. Crias born during the cloudy months should be supplemented with 1000 IU/kg vitamin D3 subcutaneously (SQ) every 60 days. Physitis due to rapid growth has also been identified. Weaning the cria may be needed to slow the rapid growth and allow the physis to recover.

Animals with physitis typically have one side that grows faster than the other side; this leads to the angular deformity.  Camelids with severe angular limb deformities can be treated with surgery to slow the growth of the faster growing aspect.  We do this with a screw placed across the physis (transphyseal screw) or by bridging the physis with a figure 8 wire that prevents growth, similar to that done in horses [see equine chapter]. Camelid growth plates close much later than horses so more time is available for correction.

Resources

Pain management in small ruminants and camelids: Analgesic agents.Vet Clin North Am Food Anim Pract . 2021 Mar;37(1):1-16.

Llama and Alpaca Care.  Medicine, Surgery, Reproduction, Nutrition, and Herd Health.  Elsevier, 2014.