Musculoskeletal[1]
Hoof abscesses can occur secondary to a crack in the hoof wall or laminitis. Other common hoof abnormalities include corkscrew claw (spiral deviations of the hoof), overgrowth of the medial claw, syndactyly, and abraded hoof pads. Longstanding hoof abnormality or severe overgrowth can lead to osteoarthritis, medial condylar humoral fractures, and osteochondritis dissecans OCD. Hoof changes from these conditions often present as an overgrowth of the lateral claw with a dorsal wall concavity. Another common condition is separation of the hoof from the sole at the junction between the foot pad and hoof. Treatment for this and most of these conditions relies on proper hoof trimming every 6-12 months (or more frequently, depending on the condition). Bandaging of the hoof for sole separation may be needed after trimming. The diet may need to be evaluated for laminitis cases.
Arthritis of the radiohumoral joint is the most common cause of lameness in pet pigs. Signs include irritability, lethargy, resistance to manipulation, unwillingness to walk, and if left untreated eventually recumbency. Other signs of this are noticed in the way the pig walks, they will try to redistribute weight to their hind limbs by bringing them up under their body and using their snout as support. This can be unilateral or bilateral. Arthritis in this location is likely secondary to osteochondrosis dissecans (OCD) or other articular cartilaginous abnormalities. There is a surgical option for attempting to treat osteoarthritis and OCD, but these tend to be referral surgeries, and thus will not be discussed here.
Hind end lameness and weakness is also quite common in pet pigs. Causes could be related to arthritic changes, with similar etiology as described for the front limbs. Other causes of hind end limb weakness are related to the spine, such as arthritis, spondylosis deformans (+/- ankylosing), and intervertebral disk issues. Radiographs are key for helping diagnose these issues in general practice.
Overall, musculoskeletal issues in swine fall into 4 major categories: Traumatic, age-related, congenital deformities, and OCD. Obesity predisposes pigs to all of these conditions and worsens symptoms. See the Respiratory section of this chapter for information on Mycoplasma and how it can also cause musculoskeletal issues.
