Contagious Ecthyma (also known as Orf, Sore Mouth and Contagious Pustular Dermatitis) is an infectious dermatitis of sheep and goats. Oral (lip) lesions (scabs) are the primary clinical findings at the mucocutaneous junction. Infections can also occur on the coronets, ears, anus, vulva or prepuce. The causative agent is a parapox virus. Man can occasionally become infected if the virus (scab) contacts damaged skin.
Contagious Ecthyma can be seen any time of the year and affects mainly young animals, but can affect mature sheep as well if they have had no previous immunity. The disease is spread by direct contact. Morbidity can be greater than 70-80% of the flock but mortality is usually very rare (less than 5-15 %). Bad infections usually cause unthriftiness and decreased feed consumption due to the soreness of the lip lesions. Uncomplicated cases usually recover in about three weeks.
The virus is highly resistant to temperature and desiccation and can survive at room temperature for greater than 15 years.
Treatment And Control (Vaccination)
Once detected in a flock, isolate the infected animals and vaccinate the remainder. Mild cases require no treatment. Treatment of more advanced cases involves nursing care, soft food and antimicrobials for secondary bacterial infections. In severe cases mild scrubbing of the lesions with Betadine® can help, but care must be taken when applying topical medications as this can be transmitted to people. Wear gloves and wash hands well afterwards.
In endemic areas, vaccinate the lambs at 6-8 weeks, and vaccinate range lambs at least two to three weeks before shipment to feed lots. In the event of an outbreak, you can vaccinate uninfected lambs at a few days of age and illicit some protective response. Pre-lamb vaccination of the ewes does no good as there is no placental or colostral antibody transfer to lambs.
Immunity after infection is for two to three years. Immunity from vaccination is about two years, but lambs should be inspected two to three days after vaccination to ensure a scab has formed.
Vaccination involves scarifying the inside of the thigh or other wool-free area and brushing the reconstituted vaccine into the scratched area. In one to three days a scab will form-which is necessary to achieve an immune response. Absence of a scab usually means either:
- Existence of prior immunity, or
- Poor application technique
Because the vaccine is of live virus origin, use precautions and wear gloves.
It is important to note that the vaccine will not prevent contagious ecthyma, but will greatly decrease the severity and duration of the disease.
Colorado Serum Company is proud to manufacture Ovine Ecthyma Vaccine to help reduce the incidence of this disease. Please read the instructions from the package insert when using this vaccine.
For specific management recommendations to control this disease, it is recommended that producers consult with a veterinarian before instituting a prevention or control program.
Colorado Serum Co., Professional Biological Co., & Western Instrument Co. (collectively referred to as Colorado Veterinary Products) manufactures USDA-licensed large animal biologics and precision engineered veterinary instruments. Since 1923, high levels of integrity have earned the respect and trust of producers and veterinarians around the world-ask for company labeled products when consulting with your local veterinarian or animal health supplier. Visit their website www.colorado vetproducts.com or call 800/525-2065 for additional information.