HEALTH MATTERS By Matthew Jackson

of Paragon Vets

LAMENESS in sheep is thought to cost the industry over £28 million a year and accounts for two thirds of total antibiotic usage in sheep. Footrot is one of the leading causes of lameness in sheep, and the arrival of wetter weather sees numbers skyrocket. It is caused by the bacteria dichelobacter nodosus, which thrives in damp areas such as at feed troughs, water troughs and gateways. It can also survive in foot trimmings for up to six weeks, so it is vital that trimmings are cleared away promptly following foot trimming. Treatment of footrot involves a combination of systemic antibiotic injection and a topical antibiotic aerosol spray. Using this combination together ensures all bacteria are killed, helping to reduce development of antibiotic resistance. Foot trimming was once thought to be essential in the treatment of footrot however several studies have now proven it is not only unnecessary, but delays the healing process significantly. In addition, hoof trimmers can facilitate the spread of bacteria between sheep.

Outlined is a five point plan by MSD animal health to prevent footrot: 1. Quarantine new arrival: there are several different strains of footrot, and each farm will only have a few strains present. As such, it is important to quarantine new arrivals to avoid bringing new strains onto your farm. If a new strain is introduced, your flock will have little to no immunity, and this can lead to widespread outbreaks. New sheep should be isolated for a minimum of three weeks and you should examine their feet at the beginning and end of this period to look for any lesions or thickening. Any animals with evidence of footrot should then be promptly treated or sent back. Quarantine is also very important in stopping the introduction of CODD (Contagious ovine digital dermatitis) onto farms. 2. Reduce spread at gathering: the stocking density is very high so there is a much greater potential for transmission. Specific precautions can be put in place to reduce spread at gathering and these include: Avoiding unnecessary gatherings and keeping gathering time to a minimum. Gathering animals on a hard, well drained surface with no loose stones. Cleaning and disinfecting the gathering surface between groups. Foot bathing animals after gathering. 3. Reduce spread at high traffic areas: move feed troughs regularly to stop the area from getting waterlogged and ensure high traffic areas are well drained. 4. Culling: some sheep can become chronic carriers of footrot and these will persistently shed bacteria from their feet. A strict culling policy is a very effective way of building flock resilience to footrot and other contagious causes of lameness. All lame sheep should be marked and recorded and animals that have two or more bouts of lameness within 12 months should be culled. This will cull out sheep that are genetically susceptible to footrot and build up immunity within the flock, as well as reducing contamination from chronic shedder animals. 5. Vaccination: Footvax covers the 10 most common strains.