To help understand Phoenix’s navicular diagnosis, we asked Dr. Devine from Pilchuck to write up a brief explanation of the diagnosis and treatment options. We are currently managing him with shoe that have a lift in the heels and he seems happy and is looking good.
To Whom it May Concern:
I first saw Phoenix in August 2015 for a lameness in the left front limb. The horse was a grade 2/5 lame in the left front, which means that the lameness was consistently evident in a circle. A nerve block was performed and the pain was localized to the foot. Radiographs showed navicular disease and a negative palmar angle to the coffin bone. The negative palmar angle means that the coffin bone is tipped back within the foot and puts extra strain on the deep digital flexor tendon. This condition can be helped with shoeing changes to help modify the angle of the foot. The abnormalities that were seen in the navicular bone on radiographs showed sclerosis, or hardening of that bone. Shoes that decrease pressure on the navicular bone were put on Phoenix and have helped him significantly. Recently, he has been sound and he has started back to being ridden and getting into shape.
Navicular disease is a chronic, progressive and bilateral condition that typically affects the front limbs. The navicular bone is a finger shaped bone in the back of the hoof capsule. This disease causes permanent changes in that bone that can result in chronic pain. Some horses with this condition are managed with shoeing changes and/or anti-inflammatories and can go back to being ridden. Anti-inflammatories such as bute or firocoxib can be prescribed by a veterinarian on either a daily or as needed basis. In other cases, the horses need local anti-inflammatory therapy in the form of coffin joint or navicular bursa injections. This procedure is where steroids are injected into these areas to decrease pain and inflammation. These injections can be safely done 1–2 times a year and this can keep some horses serviceably sound as well. Another option for treatment is a class of drugs called bisphosphonates, such as Tildren and OsPhos, which are drugs that inhibit bone resorption. These medications are administered by a veterinarian and can improve lameness in some cases. For horses that are refractory to these therapies, there is a surgical procedure that can be done to cut the nerves that innervate the heel. In a typical case, this surgery only helps for a few years and can have complications associated with it, so it is usually used only after other treatments have been tried. Navicular disease is a very common problem and even though it does not have a cure, it can be managed in a lot of cases.
Please do not hesitate to call or email me if you have questions about this condition or how it relates to your individual needs/expectations for Phoenix.
Liz Devine DVM, MS, DAVCS-LA
Pilchuck Veterinary Hospital