Combatting Cattle Scab Spread From the Continent07 November 2012
UK - Thought to have entered the UK from livestock imported from Belgium in 2006, cattle scab is spreading from its South Western epicentre and has travelled as far north as Yorkshire, reports Michael Priestley, TheCattleSite editor.
Helen Carty, Scottish Agricultural College Veterinary Services, told 5m that the disease caused by Psoroptes mites can be spread from animal to animal and is at its worst in the winter months where it is particularly visible on the tail head and shoulders of stock.
“The mites cause skin legions that cause cattle great discomfort," Ms Carty said. "If not caught early, the condition affects farm income due to production decreases caused by feed intake dropping."
It is for this reason that conducting skin tests on suspect cattle is important.
“If mites are present on the skin, they will be seen when a deep skin scraping is examined under the microscope," she said. “The mite that causes this condition is very similar to the mite that causes sheep scab, but it is currently thought that the mites are host specific i.e. sheep mites should not cause lesions in cattle and vice versa,” Ms Carty added.
The industry is hopeful that a blood test can be developed at the Moredun Research Institute to identify the condition. A test has already exists for sheep and its effectiveness is being verified.
According to a paper in the Veterinary Record, “Clinical features of Psoroptic mange in cattle in England and Wales”, effective treatment can be achieved by injecting Doramectin (Dectomax 10mg/ml solution). Utilising two other drugs, Moxidectin and Permethrin, has also been observed as an effective.
Resistance is building to the medication and measures should be taken to ensure effective treatment, warns Ms Carty.
“Unfortunately, there appears to be resistance to commonly used products and none are licensed for lactating dairy cattle," she said. "Most cases have failed to respond to macrocyclic lactones, the licensed treatment for psoroptic mange. After treatment, follow up skin scraping samples should be taken to a veterinarian to ensure the infection has been cleared.”
Many cases have responded to pour-on permethrin products but at an increased frequency of treatment. In outbreaks where both of these drugs have failed to be effective, Amitraz has been imported from the Republic of Ireland under a special licence, added Ms Carty.
The Veterinary Record observed that infected cattle, once treated, did not show stark compensatory growth. Despite this, the industry urges housed cattle need diligent observation this winter to limit the spread of Psoroptic mange through the United Kingdom.
For more information about the condition, click here.
TheCattleSite News Desk