Sheep and Goat Lameness

Question 1

Outline the lameness scores 0 - 4 and what each mean

Answer 1

Score 0 – bears weight evenly on all four feet

Score 1 – uneven posture and shortened stride

Score 2 – uneven posture, shortened stride, nodding of head

Score 3 – uneven posture, shortened stride, nodding of head, non-weight bearing on affected leg while standing

Score 4 – uneven posture, shortened stride, nodding of head, non-weight bearing on affected leg while standing and moving

Question 2

You decide to turn some sheep and inspect their feet. These photos demonstrate the type of foot lesions you found on inspection.

Based on the lesions, what is your diagnosis?

Answer 2

Interdigital dermatitis (scald) and footrot.

As seen from the photographs scald lesions are confined to the interdigital space with white pasty scum and loss of hair from interdigital space. Footrot lesions are characterised by under-running (separation of hoof horn).

Question 3

What is the pathogenesis of footrot?

Answer 3

The route of infection is via the skin between the digits. The first stage involves damage to the healthy foot by moisture/damp conditions or frost and/or mechanical damage from long grass, thistles etc. followed by invasion by bacterium, Dichelobacter nodosus.

The first stage is scald/interdigital dermatitis.

The second stage is separation of hoof horn from underlying tissue leading to footrot lesions.

Question 4

You inform Mr. West that he has footrot on his farm leading to lameness in his flock. There are a few sheep with scald/interdigital dermatitis but that might just be because these cases have not yet progressed to footrot. Mr. West wants to know how to manage footrot on his farm and lameness in general.

Before you could give him appropriate advice you need to ask him a few key questions.

Answer 4

What handling facilities has he got?

Has he got any portable handling facilities?

What is the stocking density?

Does he buy in any replacements?

Does he quarantine?

What is his culling policy?

How does he currently manage lameness?

Does he footbath? If so, how often?

Does he vaccinate or foot trim?

Does he catch individual lame sheep?

If No, Would he consider catching individual lame sheep?

Question 5

Mr. West informs you that:

• He stocks ewes 3/acre
• He footbaths lame sheep with formalin
• He turns them out straight to a new field after footbath
• He regularly footbaths all sheep once a month
• He does not vaccinate
• He used to routinely foot trim in the past but has not been doing it for the past two years due to labour issues
• He catches only severely lame individual sheep and gives a dose of long acting oxytetracycline
• Since he has recently bought a new portable handling facility “prattley”, he would consider catching individuals
• He has no policy for culling repeatedly lame sheep
• He buys his replacement ewes from a known contact and quarantines for a week

1. Consider what Mr. West has told you about his current practices to manage footrot.

What advice would you give to Mr. West to control prevent footrot in the future?

Answer 5

• Formalin shouldn’t be stronger than 3% for footbathing.
• Rather than turn straight out onto a new field after footbathing, sheep should stay on concrete first.
• Consider vaccination (if he doesn’t use moxidectin or cydectin)???
• Separate and treat any lame sheep – score 2 or above.
• Anything with a locomotion score of 2 or above should be caught and treated accordingly, not just severely lame sheep.
• Treatment of lame sheep à topical (spray), allow to dry and re-spray antibiotic as well as an injectable form.
• Cull persistent offenders – 2/3 episodes and the sheep should be culled (record keeping) and do not breed from these ewes.
• Quarantine bought in sheep for 3 weeks not 1 week and reject any lame sheep.