Making the most of the Sheep Lameness Assessment
As part of Scottish Government's ‘Preparing for Sustainable Farming’ initiative, farmers can claim £250 per intervention for undertaking up to two animal health interventions per year in 2023 and 2024. The standard payment is £250 per intervention, regardless of the size of the flock or the number of tests done. You do not have to provide details of their expenditure in order to claim. With the first claim, an additional £250 will be received to fund further on-farm development activities appropriate to the flock. Further information on the scheme can be found here.
One of the interventions included in the scheme is to carry out a veterinary flock lameness assessment to identify conditions and their prevalence in the flock, then provide a written prevention and control plan, including biosecurity measures. Since infectious lameness peaks in late summer/early autumn, now is a good time to engage farmers in controlling lameness in their flocks.
Lameness in Sheep
The main causes of infectious lameness in sheep are:
- Interdigital dermatitis aka IDD / Scald / Strip / Benign footrot (Dichelobacter nodosus*)
- Footrot (D. nodosus +/- Fusobacterium necrophorum*)
- Contagious Ovine Digital Dermatitis (CODD) (Treponema sp*)
*other bacterial pathogens and environmental factors often involved in development of disease
Other causes of lameness include:
- Foot/toe abscess
- Shelly hoof (white line disease)
- Toe granuloma
- Post dipping lameness (Erysipelas rhusiopathiae)
- Strawberry footrot (orf virus and Dermatophilus congolensis)
Diagnosis of the cause of lameness is usually done on the gross appearance of lesions. The University of Bristol diagnositic laboratory offer a PCR for virulent strains of D. nodosus and Treponeme sp at £55.80 each (samples from up to 2 sheep can be pooled), however note that D. nodosus and Treponeme sp can be found on healthy feet, and CODD lesions can become infected with D. nodosus therefore results should be interpreted alongside the clinical findings.
Control of Lameness in flocks
Where foot trimming (routine or of lame sheep) is practiced, the prevalence of lameness on a farm is generally higher, likely due to increased spread of pathogens during gathering and handling as well as direct trauma to feet. When foot bathing is recommended in the management of scald or to disinfect feet after handling, ensure the correct concentration of product is used, applied for the correct amount of time and feet are allowed to dry on a hard standing after bathing. When done badly, foot bathing can increase lameness due to caustic concentrations of active or increased spread during gathering/handling followed by ineffective treatment. Note that there are no licenced antibiotics for use in footbaths, and foot bathing to control CODD is ineffective at flock level. In a study of 28 flocks, where whole flock metaphylactic tilmicosin treatment was carried out, this failed to eliminate footrot and CODD from flocks.
There are no silver bullets to managing infectious lameness. On farms where ID/footrot and/or CODD has been diagnosed, implementation of the 5 Point Plan (5PP) for lameness control has been shown to be effective in reducing lameness. Broadly speaking, the more points of the plan which are effectively implemented, the lower the prevalence of lameness on a farm.
The 5 aspects of the plan are:
- TREAT: Prompt detection & treatment of lame sheep
- AVIOD: Farm hygiene
- QUARANTINE: Biosecurity for incoming stock and infected individuals
- VACCINATE: Vaccination with Footvax
- CULL: Chronically/repeatedly lame sheep
Lameness control plans need to be tailored to the resources farmers have available to them (infrastructure, facilities, labour, time, budget) as well as engaging the farmer in the plan and obtaining buy-in and ownership of the recommendations within the plan.
Some useful resources include:
- Green, L. and Clifton, R. (2018), Diagnosing and managing footrot in sheep: an update. In Practice, 40: 17-26
- HealthyFeetHappySheep campaign website. Available at #healthyfeethappysheep
- AHDB (2020), ‘Reducing Lameness for Better Returns’. Available at: https://ahdb.org.uk/knowledge-library/reducing-lameness-for-better-returns
- Webinar with Jennifer Duncan Recent advances in our understanding of CODD - YouTube
- SRUC Webinar ‘Infectious Lameness: An update for the busy practitioner’. Available via the SRUC e-learning platform
Posted by SRUC Veterinary Services on 03/10/2023