One of the most common diseases in sheep is a herpes virus infection called Orf. Much like human oral herpes it is massively prevalent in the general population, and as sheep don’t practice disease hygiene like humans, if one sheep in your flock has it, they all will soon.
Just like human oral herpes it is generally not a big deal. Only immunocompromised individuals really have anything to fear from it, and something else worse is likely to do them in before Orf gets a chance. The most serious common issue is that ewes can get sores on their teats that will make them hurt enough that they wont let their lambs nurse... We then have to intervene and milk them, both to feed their lambs, and to prevent mastitis.
Being a herpes virus family disease, Orf is zoonotic, meaning it can be transmitted to humans. Typically there is a breakout of active Orf sores a few weeks after lambs are born, as stressed, infected adults get breakouts. Just like cold sores in humans are a result of the normally repressed herpes virus taking advantage of an immune system that is busy elsewhere to spread itself, nursing ewes are sleep deprived, and dedicating lots of metabolic effort to milk production, and the virus is opportunistic. This also assures that new lambs will get it (it is not spread to the lamb until after it comes in contact with the virus outside the womb) We take caution to avoid Orfy sheep, and I, in particular, ALWAYS wear gloves when interacting with she sheep in Orf season. As humans are not Orf’s preferred host, it usually only infects broken skin.
This year Mrs. BoostAddict caught it, probably from a hay splinter. And it seems my glove wearing has not saved me either :/ I pinched my finger and got a blood blister while handling a sheep feeder, I thought I cleaned it well enough, and wore a bandaid with antibiotic creme over it... But about a week later it become obvious that Orf found a foothold :P
Treating it with Acyclovir, which is an anti-viral commonly prescribed for genital herpes treatment in humans... And other than keeping it clean and covered so it doesn’t spread, that’s about all I can do. Mrs. BoostAddict's cleared up in about three weeks, hopefully mine does too.