We are now using a drug named Tildren™ with increasing frequency at the clinic as part of our treatment plan for horses suffering from bone spavin (hock arthritis) and/or navicular disease. Tildren™ is composed of Tiludronic acid, a bisphosphonate which inhibits bone resorption. It has been a licensed product in other parts of Europe for the past few years and has been used successfully in treating lameness caused by bone spavin and navicular disease.

How does it work? In normal horses bone is constantly being remodelled (re-shaped) in order to adapt to the biomechanical stresses the environment, and us as riders place on their skeletal structure. There are two types of bone cells, which work in harmony to achieve this fine balance of production and resorption of bone within the skeleton:

Osteoblasts – Are cells responsible for ‘bone synthesis’, they produce collagen and help with mineralization in order to create a dense bony framework.

Osteoclasts – Are cells responsible for ‘bone resorption’ resulting in bone lysis (areas of reduced bone density). Areas of reduced bone density are a pathological change common to most cases of navicular disease and bone spavin and are due to inappropriate resorption of bone (osteolysis). Tildren™ has been designed to reduce this bone resorption by inhibiting the activity of the osteoclasts. 
It has also been demonstrated to have anti-arthritic properties by inhibiting the effects of enzymes which degrade the cartilage surface of joints.

Is my horse a candidate for this treatment? The clinical effect of Tildren™ depends on the presence of osteolytic processes causing pain leading to lameness. Tildren™ can only be used after a full lameness work-up has been carried out by your vet. This includes; local anaesthesia (nerve blocks) and appropriate imaging techniques (x-rays, bone scan, MRI (Magnetic resonance imaging) etc.) to confirm the site of pain and type of lesion.

What evidence do we have that it works? At Chiltern, we have been using the drug for several years now, long enough to see the long-term outcome of horses with respect to athletic soundness, and results have been excellent. Double-blind, placebo-controlled clinical trials carried out in horses with bone spavin and navicular disease at other centres have shown a clear improvement following treatment as demonstrated by long-term reduction in lameness and progressive resumption of sporting activity (approx. 60%). For further information visit www.tildren.com