A Show Sheep's Enemy: Orf

Murphy's Law: If something can go wrong, it will go wrong. This is what happened in my last year of 4-H just before my favorite event: 4-H on Parade. Weeks before the show one of the lambs in our herd(that was in a separate pen from the 4-H lambs) exhibited what looked like a crusty cold sore on his lips. Now if you are a sheep breeder you know what this means, your whole herd will inevitably be infected with orf which is more commonly known as sore mouth and there is nothing you can do about it. We are still not sure where our sheep picked up the virus, but it was here.

We thought our 4-H lambs would be safe because they had been separated from the herd, but we were wrong. It was not long before we found the first 4-H animal with sores on its mouth. Gradually more and more lambs in the 4-H pen definitely were infected. As we noticed a lamb develop sores we removed it from the pen trying to prevent direct contact with the lambs that hadn't gotten any sores in the hope that there would be some that were still able to go to 4-H on Parade. By May 26 (the day before the sheep were supposed to travel to Calgary for 4-H on Parade) there was only four lambs and one ewe in the 4-H pen that did not have any sores, meaning that they would still be able to attend the show. However there was still the risk that sometime during the weekend they would break out and have to be trailered back home. Sheep shows have strict rules regarding sore mouth because it is highly contagious. Any animal with active sore mouth(sores present) are not allowed to attend the show. So we ended up not going because we are responsible producers and wouldn't want to infect anyone else's sheep while we were at the show, even though we did have some animals who could have attended because they did not have any sores. 
Two weeks later and those same five animals still have not gotten any sores. My explanation is they are the lucky ones who have an immunity to this strain of sore mouth. As for the rest of the lambs we have tried a few things to speed up the healing of the sores but to no avail. We tried spraying iodine and putting diaper cream that contains zinc on the sores but the sores only spread and got worse. The sheep in the herd got over the infection faster than the 4-H lambs that were being treated. We have came to the conclusion that the best remedy when treating sore mouth in sheep is time. 

Here is some more information about orf :

A badly infected sheep,
luckily none of our animals
got it this bad.

A less severe case of orf.

The virus is transmitted via direct contact with an infected individual. It enters the body through any small crack in the skin, which is the body's strongest defense against pathogens. For sheep who eat grasses and other vegetation that can easily poke their lips when eating it is easy for them to have the potential to contract the virus. 
The body's immune system does build immunity to the virus but different strains of sore mouth exists. This means that just because a sheep has had sore mouth once doesn't mean it won't contract it again. 
Sores have a brown colored crusty scab and are most commonly observed on the mouth and nose area, but can appear anywhere on the hair covered parts of a sheep. The scabs are a great way for bacteria to spread because after they fall off they are still in the presence of animals that may not have been infected. 
This virus is most commonly seen in sheep and goats. Humans are also susceptible to the virus, so when working with infected animals you have to be very careful. 


This weekend is our club 4-H Achievement Day and most of our lambs have been healthy for awhile now, but as for the ones who had more severe sores they are still healing and won't be able to attend. The only good news about having orf now is that by the time Summer Synergy comes along in August all of our lambs will be completely over the virus and will all be able to attend the show.