Background and history

Bursitis is a common condition that arises from constant pressure and trauma to the skin overlying any bony prominence. The membrane or periosteum covering the bone reacts by creating more bone, a swelling develops and the skin becomes thicker until there is a prominent soft lump. Bursitis may cause the skin to become broken and secondary infection can develop. Mycoplasma hyosynoviae can also infect the fluid in the swelling.

It can commence in the farrowing houses, particularly if there are bad floors but it usually starts in the weaner accommodation on slatted floors which have large gaps. As the pig increases in weight there is increased pressure on the leg bones.

Under normal circumstances, if there is no secondary infection, the condition is not commercially important but if breeding stock is being produced then the system needs to be adjusted or there will be a drop in selection rates.

Clinical signs

• Swellings develop over the lateral sides of the hocks and elbows and over the points of the hocks.
  • With repeated trauma the lesions increase in size and ultimately fluid appears. This is common in pigs 30–70kg weight.

Diagnosis

Visual examination for clinical signs.

Causes

• Poor floor surfaces.
• Lack of bedding.
• High stocking densities on slats.
• Bad slats in confinement.
• Wire mesh, woven metal and metal bar floors.

Prevention

• Move severely affected animals onto deep bedded floors.
• Identify the point at which disease first appears and alter the floor surfaces or change the environment.
• If the problem is arising in flat decks in breeding gilts it may be necessary to change the slats to those covered with plastic. Tri-bar or metal slats and woven mesh are bad surfaces.
• Keep flooring clean and dry to prevent secondary infection.

Treatment

There is no specific treatment that will reduce the bone reaction.

• Remove pigs to pens that are well bedded.
• If the swellings have become infected with bacteria inject with either oxytetracycline or ampicillin.
• If Mycoplasma hyosynoviae is causing infection use either lincomycin or tiamulin.
• Most lesions do not require treatment.