CODD prevalence on Irish sheep farms higher than initially thought
The prevalence of CODD (Contagious Ovine Digital Dermatitis) – an infectious disease causing lameness in sheep – may be higher than initially thought, results of a recent survey of Irish sheep farmers have shown.
Completed by Jake Delaney as part of the Teagasc Walsh Scholarship Programme, the survey tasked farmers to identify both the prevalence and causes of lameness in sheep on their farms. Some 248 lowland flocks returned completed surveys, making it representative of what’s happening nationally.
Joining Ciaran Lynch on a recent episode of the OviCast podcast to share some of the initial results of this research conducted through Teagasc and University College Dublin (UCD), Jake explained that on average throughout the year farmers reported a lameness prevalence of 8.9% in their flocks, with the worst offenders in descending order being cited as scald, CODD and footrot.
Through the survey, farmers were tasked with identifying various causes of infectious lameness through the use of images. Jake explained that 80% of farmers were correct in the diagnosis of scald and footrot, while 65% of farmers were able to identify CODD.
Furthering this, farmers were presented with images of sheep with various lameness ailments and were asked to verify if they had in fact witnessed the condition on their farms.
On this, Jake explained: “Over 90% of farmers had seen a case of scald on their farm before, and over 85% of farmers had seen cases of footrot, but when it came to CODD, we got some really interesting results.
“Originally, we thought CODD wasn’t that high in Irish flocks; we didn’t think many Irish flocks had CODD, but from our survey and farm visits we are seeing CODD is present in approximately over 45% of flocks.”
This confirmation brings the prevalence of CODD close the levels being witnessed in the UK and marks the spread of the disease in Irish flocks since it was first identified in the early 2000s.
Prompt treatment and quarantine
Interestingly, the survey results also illustrated the importance of prompt treatment for lameness, with Jake noting that farmers that delayed treatment of lame sheep were actually more likely to have CODD on their farms. This occurs as cases of scald or footrot may develop into more severe cases of footrot or CODD, once the causative bacteria for CODD are present on farm.
Additionally, the survey examined which farms are more likely to have sheep with CODD, with Jake noting: “Farms that were purchasing replacement ewes or store lambs every season were more likely to have CODD on the farm.”
This generally occurs due to inadequate quarantine procedures, thus increasing a farmer’s risk of inadvertently introducing CODD into their flock. For farmers engaged in purchasing, Jake recommended: “It can take CODD some time to progress in sheep. By quarantining purchased sheep in a separate paddock for a month or more, you can see what they have, you can treat any lameness cases that become apparent and get an idea of what you are dealing.”
Further highlighting the importance of ensuring CODD isn’t introduced when purchasing and an appropriate quarantine procedure is followed, Jake explained that the disease can have devastating effects on the flock when first introduced, as reports from the UK suggest infection spread of up to 40% of the ewes within the flock after disease introduction.
For farmers who think CODD may be an issue on their farm, Jake encouraged them to identify the cause of the problem and seek veterinary advice, adding: “CODD can be controlled. It is not something farmers should resign themselves to having or give up on. With the right treatment method, it can be controlled, cured and prevented.”
For further insights on the results of this study and an assessment of farm management practices to control lameness, listen to the OviCast podcast below: