Vaccination lesions are reactions, such as an abscess or scar tissue, at vaccination sites. Sheep vaccinated with the Gudair® OJD vaccine often develop a large vaccination reaction at the injection site.
- Incorrect vaccination technique, e.g. not placing the injection correctly.
- Vaccinating wet sheep
- Unhygienic vaccination equipment/processes
- Firm swelling usually develops at the site of injection, followed by a nodule 7–15 days later.
- In a small proportion of animals, the lump may be more than 5cm in diameter or develop into an abscess and burst, which may predispose to flystrike.
- Correct vaccination technique.
- The vaccine should be administered subcutaneously high on the neck behind the ear.
- Producers should avoid vaccinating sheep which will be slaughtered as lambs.