Abscess – Foot Abscess ‘Sweerklou’
By Dr Mackie Hobson BSc(Agric),BVSc

1. Diseases

Background

Foot abscess (‘sweerklou’) is a significant problem on many Angora farms leading to the loss in condition, loss in mohair and reproductive performance. The term ‘sweerklou’ or ‘foot abscess’ is often confused with ‘footrot’’ vrotpootjie’ which is a different condition effecting the hooves of the goat.

The reason that the joint is so susceptible to infection and abscess formation is that on the interdigital aspect the joint capsule protrudes (dorsal and volar pouches) above the coronary (hoof) border. At these sites the joint capsule is only protected by the interdigital skin and minimal amount of subcutaneous tissue.

The infection causing the foot abscess enters through the disruption of the skin and entry into the joint capsule due to:

• Mouthparts of ticks Rhipicephalis glabroscutatem (smooth brown tick) and R. simus (glossy brown tick) as well as Ambyomma (bont tick) and Hyalomma (bont legged tick) species.
• Softening of the interdigital skin after rain predisposes the skin to injury and the hoof sink deeper into soft soil causes abrasion of skin by soil particles.
• Thorn penetration of skin around hooves
• Grass seed penetration.

Clinical signs

The symptoms are obvious in terms of lameness. Initially the foot becomes warm to the touch and is painful if pressure applied.

The swelling then develops above the hoof margins. The digit is markedly swollen and can burst open with discharging pus.

Treatment and control

Treatment is frustrating and antibiotic penetration into the site of infection is limited due to the encapsulated nature of the abscess. Antibiotic combinations and anti-inflammatories are also used with mixed response. Individual animals the abscess can be lanced and flushed but this is not viable when treating a flock.

The key element to controlling foot abscess is control the ticks.

A. Preventive methods used by farmers: (based primarily on tick control)

1. Footbaths with tick control (dip), 5-10% Zinc sulphate and 5% formalin footbaths.

• For footbath options and residues see

        https://www.angoras.co.za/article/ectoparasite-treatment-guidelines#357

• Copper sulphate OR Zinc Sulphate: 5g/litre water
• Formalin diluted to make 5% solution (dilution depends on initial strength. Eg. 40% solution: 1 litre in 8 litres water would make 5% solution)

     2.Pour on tick treatments applied between hooves.

      https://www.angoras.co.za/article/ectoparasite-treatment-guidelines#357

B. Treatment options used by farmers:

1. ISOLATE effected goats
2. Long acting Antibiotic (Repeat for minimum 3 treatments). Example Penicillin LA (1ml/10kg i/m)
3. Anti-inflammatory . (example vetcam 2%, 1ml/33kg s/c)
4. Footbaths with combinations of 10% Zinc Sulphate, Tick treatment (dip) and Kerol Veterinary Fluid 1ml/litre water) or 5% formalin. (Dilutions as above)

Effect of vaccination on Foot Abscess outbreaks.

Objective of the trial:

• Determine if vaccinating Angora goats reduces the incidence of foot abscess occurrence in a flock where Corynebacterium ovis and Actinomyces pyogene are administered.

Results