About Orf Virus (Sore Mouth Disease)

Key points

  • Sore mouth disease or "orf" mostly affects sheep and goats.
  • People can get it too if they have contact with infected animals.
  • People get painful sores and also sometimes have a fever or other symptoms.
  • People and animals usually recover without long-term effects.
Orf infection on the hand of a person with a weak immune system

What it is

Sore mouth disease is caused by orf virus, a type of poxvirus. It occurs worldwide, anywhere sheep, goats and similar animals live.

People can get painful sores called lesions if they have contact with animals infected with orf virus. Certain activities like feeding, petting and getting bitten by infected animals put people more at risk for infection.

Simple prevention steps can protect people from the virus, even if they are handling infected animals infected with orf.

Signs and symptoms

An animal infected with orf virus typically has sores (lesions) around its lips and muzzle and in its mouth.

People infected with orf virus usually get sores or nodules on their hands or forearms. This rash is infectious, meaning it can spread to areas of a person's body if they scratch or touch the sores. The sores progress through stages over six weeks. They may also have mild fever, tiredness or swelling of the glands in their neck and underarms (lymph nodes).

People with weakened immune systems can develop more serious symptoms if they get infected with orf virus. They may have multiple sores or large tumor-like sores. They may also develop a second type of rash that isn't infectious (called erythema multiforme).

How it spreads

People can get sore mouth disease if they have a cut or abrasion and touch an animal with orf virus. People can also get orf by handling equipment used with sick animals.

Activities that may put people at more risk for infection include:

  • Bottle feeding, tube feeding or shearing sheep or goats
  • Petting or having casual contact with the sores of infected animals
  • Handling infected animal equipment such as a harness
  • Being bitten by an infected animal.

Orf virus does not spread between people.

People can get infected with orf virus multiple times. Infections after the first one are usually less severe and may heal faster.

Reducing risk

Wear rubber or latex gloves when handling sheep or goats. This is especially important if you have cuts on your hands or are touching an animal's mouth or muzzle.

Wash your hands often using clean, warm water and soap for at least 20 seconds. Use this method if your hands look dirty while working with animals. If no soap is available, use an alcohol-based hand rub. Use this method if your hands don't have visible dirt on them.

Testing

The CDC offers a test that can determine if your sores are caused by orf virus. Healthcare providers or health departments can send lesion specimens to CDC for testing. More information is available in the CDC test directory.

Treatment and recovery

There is no specific treatment to cure orf virus infection. But it's important to protect the sores from getting infected with other germs.

Keep the sores dry and covered with a bandage. Use a bandage that keeps water out when working with animals or doing manual labor. If your sores are dry at bedtime, keep them uncovered while you sleep. If they are wet, cover sores loosely with a bandage. This will help them heal faster.

See your doctor if you have pain, fever or if your sores are getting bigger or spreading. If this occurs, it could mean your sores are due to a different, more serious germ. Your doctor can help determine what's going on.