Background and history

Bush foot results from infection of the claw which becomes swollen and extremely painful around the coronary band. It arises through penetration of the sole of the foot, cracks at the sole-hoof junction, or splitting of the hoof itself. It usually occurs in one foot only and is more commonly seen in the hind feet especially the outer claws, which are the larger ones carrying proportionately more weight. Infection sometimes penetrates the soft tissues between the claws and this is referred to as foot rot.

As the infection progresses inside the hoof, the claw becomes enlarged and infection and inflammation of the joint (arthritis) often develops. The condition is important because of the effect on reproductive performance of the breeding female. Foot rot involves both superficial and deep infection of the soft tissues between the claws often caused by fusiformis bacteria.

Foot pain in the boar at mating causes poor ejaculation and a shorter mating time.

Similar diseases

These include:

• Erysipelas.
• Glässers disease.
• Leg weakness or osteochondrosis (OCD).
• Mycoplasma arthritis.
• Trauma

Clinical signs

The pig is very lame with a painful swollen claw. Always try and examine the feet when the animal is lying down. In most cases a swelling will be visible around the coronary band which may form an abscess and burst to the surface.

Invariably only one claw is involved. With foot rot the infection will be confined to the tissues between the claws.

• Lameness.
• Painful swollen claw.
• Cracks at the sole-hoof junction, or splitting of the hoof itself.
• As the infection progresses inside the hoof, the claw becomes enlarged and infection and inflammation of the joint often develops.
• In most cases a swelling is visible around the coronary band which may form an abscess and burst to the surface.

Diagnosis

This is based on the clinical signs described above. Bush foot has to be differentiated from other forms of trauma and infection but the painful swollen claw is obvious.

Causes

• It arises through penetration of the sole of the foot.
• Cracks at the sole-hoof junction, or splitting of the hoof itself predispose.
• Poor floor surfaces.
• Poor concrete surfaces with sharp aggregate cause damage.
• Biotin deficiency predisposes.

Prevention

• Badly worn floor surfaces predispose.
• Sharp flint aggregates in concrete predispose.
• Pay particular attention to floors in boar pens, mating pens and loose sow housing.
• Check the quality of the floor surface around drinkers and feeders - particularly concrete slats.
• Use straw or shavings as bedding if practicable.
• Check the biotin levels in the diet.
• Wash and disinfect concrete surfaces regularly.

Treatment

There is a poor blood supply to the infected tissues and therefore higher dose levels of antibiotics are required for longer periods of time.

• Antibiotics which can be used, depending on the advice of your veterinarian, include:
  • Lincocin 11mg/kg liveweight (gives a good response).
  • Oxytetracycline 25 mg/kg liveweight.
  • Amoxycillin 15mg/kg liveweight.
• Inject daily for 5 to 7 days. If there is no improvement in three days change the antibiotic. Complete recovery may take 3-4 weeks.
• Anti-inflammatory injections of cortisone may be given provided the sow is not pregnant.
• An anti-inflammatory medicine such as phenylbutazone or ketoprofen may be administered either by mouth or injection.
• If there is a herd problem a foot bath containing either 1% formalin (only use in the open air) or 5% copper sulphate will help. Walk the sows through once each week on 2-3 occasions. However if there are dry cracked claws in the herd, this treatment might make them worse.