The Department of Agriculture, Food and the Marine (DAFM) has said that 44 blackleg outbreaks have been confirmed so far this year.
Blackleg is a common disease of cattle worldwide caused by the bacteria Clostridium chauvoei.
The disease leads to acute muscle damage and usually results in sudden death of the affected animal or death after a short illness.
Cattle can become infected by consuming clostridial spores from soil, which remain dormant in muscle until bruising, torn muscles, or certain unknown metabolic factors cause the conditions in the local tissues that allow the spores to germinate, and cause the disease, normally with fatal consequences.
Blackleg
Last month, the department said that regional veterinary laboratories (RVLs) had noted a “sharp increase” in the prevalence of blackleg diagnoses in cattle.
DAFM has warned that the RVLs have seen “some quite large” outbreaks in farms around the country with no prior history of the disease.
The department has confirmed to Agriland that 44 blackleg outbreaks have been recorded this year where there was “at least one death in a herd”.
During 2023, there were 62 outbreaks involving at least one death in a herd.
21 of the outbreaks this year were confirmed during August, which is up from 13 in the same month last year.
However, the department noted that the figure for August 2024 may increase as confirmatory results are outstanding on additional suspect cases.
11 blackleg outbreaks were confirmed by RVLs in July, which is almost double that of a year previously.
Month 2023 2024 January 1 0 February 1 0 March 1 1 April 2 3 May 6 3 June 5 5 July 6 11 August 13 21 (subject to change) September 10 October 9 November 5 December 3
DAFM said that it does not have records of the numbers of animals that die from blackleg.
The data from the department is based on voluntary submissions by farmers of animals to DAFM Regional Veterinary Laboratories for post-mortem examination.
The department noted that there were more deaths on farm at the time of these submissions during July and August in 2024 compared to 2023.
There were five outbreaks with three or more deaths recorded in August 2024 compared to one outbreak with three or more deaths recorded in August 2023.
The department has advised farmers that the primary method of prevention for blackleg is vaccination in advance of exposure, particularly for young stock going out on grass for the first time.
“Vaccination should always be done according to recommended schedules, including booster doses where these are indicated.
“Incomplete vaccination programmes will not provide adequate immunity. Farmers are advised to contact their veterinary practitioner for advice on prevention strategies,” a DAFM spokesperson said.