Welcome autumn rain elevates footrot risk
Livestock producers have rightly welcomed a promising break to the season, but with it comes increased biosecurity risks.
Footrot, a contagious and notifiable bacterial disease in sheep, requires warm and moist conditions to develop.
The disease caused by Dichelobacter nodosus bacteria results in inflammation and lesions in the hoof and can cause significant economic loss to producers, reducing ewe fertility, wool growth, growth rates and sheep sales.
Footrot is generally categorised into two forms; virulent footrot, which causes severe lameness and can severely affect production, and benign footrot, which causes mild lameness and slight loss of body condition.
National Sheep Health Declarations require producers to declare all forms of footrot if they are present on the property.
NSHDs are compulsory for all movements of sheep into and within SA.
Since July 2018, infected properties have the increased ability to trade sheep based on their flock’s diagnosis, meaning buyers are responsible for checking the status of the animals from NSHDs prior to purchase.
Livestock SA has two biosecurity extension officers who can provide properties with information regarding biosecurity risks surrounding footrot, along with progressing properties to PIRSA if they require footrot testing and diagnostic support.
Testing provides an indication of the potential virulence of an infection regardless of seasonal conditions or sheep type.
Foot bathing in a zinc sulphate solution can assist in controlling the spread of footrot until animals are slaughtered or prepare them for footrot eradication. This treatment must be concluded at least six weeks prior to implementing the eradication program to enable accurate diagnosis during the first treatment inspection.
To eradicate footrot, all infected sheep must be successfully treated or removed from the property.
If destocking to eradicate footrot, paddocks must be cleared of all sheep and cattle for at least seven days.
When restocking, it is important for the properties to source replacement stock from flocks that use PIRSA’s One Biosecurity program and have a current ‘independently assessed’ status for footrot.
If electing to undertake an on-farm eradication program, sheep must be re-inspected for infection in spring following treatment to ensure no infection remains.
Eradication program treatments should begin once pastures have dried off.
Antibiotics and strain-specific vaccines can assist with treatment and can only be sourced through a veterinarian.
Sheep must be kept in dry conditions for 24 hours post-treatment and re-examined every four weeks to ensure the disease is eradicated.
A producer suspecting any footrot symptoms must report it to the property’s veterinarian, the nearest animal health adviser, Biosecurity SA or the Footrot Program manager on 08 8568 6415.
– ANDREW CURTIS, Chief Executive Officer, Livestock SA