Better control of contagious ecthyma/orf
Solution name: Better control of contagious ecthyma/orf
Aim: Implement a vaccination plan and culling (the) chronic carriers to control contagious ecthyma/orf
Combining several measures to ensure the efficiency of a strategy
How to implement it:
Goal: stimulating ewes’ active immunity to limit clinical expression and transmission of disease to the lamb; stimulating the lambs’ active immunity
The Vaccine (Ecthybel®) is injected subcutaneously (1 dose of 1ml) or intradermally (with Dermojet: 1 dose of 0.2ml). Intradermal inoculation is the preferred method as it offers faster recovery rates. Several vaccination strategies exist.
- Preventive vaccination: ewes are vaccinated 3-4 weeks prior to lambing. The subsequent acquired immunity is short-lived and the chances of transmitting it through colostral antibodies are low.
- Therapeutic vaccination: as soon as the first symptoms appear (do not wait for an outbreak):
- Vaccination of all ewes. A 2nd injection may be necessary if the symptoms do not reduce (10 days after the 1st injection). Booster doses should be injected every month and a half (at the very least every two months) during periods of risk.
- Lambs born from non-vaccinated females: vaccination as soon as they turn 15 days old
The vaccine-induced immunity is short-lived (1 to 2 months), hence why annual booster doses every 1/2 months or 2 months are necessary during periods of risk. The existence of several viral strains causes an issue for the immune response to the vaccine, as it is not 100% efficient on all (of these) strains.
Culling of ewes
Goals: removal of chronic carriers
Implementation: ewes suffering from ecthyma-related persistent lesions or scars, especially on the udders, should be given a distinctive mark, before being isolated and culled. Do not put them back for reproduction
The control of ecthyma also requires prophylactic health control measures
- Annual disinfection of the sheep pen,
- Disinfection of the bedding material (spreading of superphosphates),
- In order to reduce oral lesions among lambs, remove prickly plants (thistles, branches) contained in their food which is likely to hurt them– this is often the first entry point of the virus.
- Compliance with external and internal rules relating to biosecurity (quarantine during introduction, disinfection of the farm and shearing)
Production: Dairy / Meat
Animal Category: Adult / Lamb
Issue: Sores and blisters on the lips, nose, ears and/or eyelids – (e.g. Echtyma, Orf…)
Level of Solution: Practical
Minimise losses due to contagious ecthyma among lambs and mammary forms of the disease among ewes.
Prerequisites and/or limits
The vaccination schedule has to be rigorously followed