Bog spavin is a swelling of the

tibiotarsal joint In the anatomy of humans and many other mammals, the tibiotarsal joint is the joint between the tibia and the tarsus. In avian anatomy, it is the equivalent of the ankle. In equine veterinary science, synovial distension of the tibiotarsal joint ...

of the

horse The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million y ...

hock Hock may refer to: Common meanings: * Hock (wine), a type of wine * Hock (anatomy), part of an animal's leg * To leave an item with a pawnbroker People: * Hock (surname) * Richard "Hock" Walsh (1948-1999), Canadian blues singer Other uses: * A t ...

which, in itself, does not cause

lameness A limp is a type of asymmetric abnormality of the gait. Limping may be caused by pain, weakness, neuromuscular imbalance, or a skeletal deformity. The most common underlying cause of a painful limp is physical trauma; however, in the absen ...

. The joint becomes distended by excess

synovial fluid Synovial fluid, also called synovia, elp 1/sup> is a viscous, non-Newtonian fluid found in the cavities of synovial joints. With its egg white–like consistency, the principal role of synovial fluid is to reduce friction between the articular ...

and/or thickened synovial tissue bringing about a soft, fluctuant swelling on the front of the joint, as well as in the medial and lateral plantar pouches. Bog spavin is generally an indication of underlying pathology within the joint.

Causes

Bog spavin is a physical finding, and does not directly create

. Causes include synovitis (inflammation of the lining of the joint capsule), degenerative joint disease, or excessive strain of the joint capsule. In horses younger than the age of three, most cases of bog spavin are caused by a defect in the tibiotarsal joint, while in older, fully mature horses, it is most likely because of chronic strain of the joint capsule. Infection of the joint causes a severe synovitis, and should be treated as an emergency. Many horses with bog spavin will not be lame. However, bog spavin can be a sign that the horse has joint disease, which is a very significant finding. Usually lameness will occur if the workload of the horse is increased. Bog spavin should not be treated lightly, and it is best to have a veterinarian examine the horse to find the cause, even if the horse does not appear lame. Unlike

bone spavin Bone spavin is a bony growth within the lower hock joint of horse or cattle. It is caused by osteoarthritis, and the degree of lameness that results can be serious enough to end a horse's competitive career. Description Bone spavin is osteoarth ...

, bog spavin does not show any changes to the bone itself. For this reason it is considered to be of no interest to those studying animal

paleopathology Paleopathology, also spelled palaeopathology, is the study of ancient diseases and injuries in organisms through the examination of fossils, mummified tissue, skeletal remains, and analysis of coprolites. Specific sources in the study of ancie ...

(Baker and Brothwell, 1980).

Management

A veterinarian will usually

radiograph Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical radiography ("diagnostic" and "therapeut ...

the hocks of the horse to check for bony changes as it is important to address the underlying cause of the joint distension. It's important to have a veterinarian perform an

equine prepurchase exam In horse trading, an equine prepurchase exam is an examination of a horse requested by the buying party prior to the purchase, in order to identify any preexisting problems which may affect a horse's future performance and reduce buyer risk. The ins ...

to identify an existing condition such as a bog spavin. If the bog spavin is drained then it will simply refill unless the underlying cause has healed or been treated. In many cases it may be difficult to achieve resolution of the distension. Treatment may involve injection of

corticosteroid Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involv ...

s or

hyaluronan Hyaluronic acid (; abbreviated HA; conjugate base hyaluronate), also called hyaluronan, is an anionic, nonsulfated glycosaminoglycan distributed widely throughout connective, epithelial, and neural tissues. It is unique among glycosaminoglycans ...

into the joint and some cases may require

arthroscopic Arthroscopy (also called arthroscopic or keyhole surgery) is a minimally invasive surgical procedure on a joint in which an examination and sometimes treatment of damage is performed using an arthroscope, an endoscope that is inserted into the jo ...

surgery. Rest or controlled exercise is often indicated.

Sources

* Baker, J, and Brothwell, D. 1980. ''Animal Diseases in Archaeology''. London: Academic Press. * King, Christine, and Mansmann, Richard. 1997. ''Equine Lameness.'' Equine Research, Inc. pp. 835–836.

External links

* {{Cite NIE, wstitle=Spavin, Bog, short=x Equine injury and lameness