Anyone know what this is?? 

abcess...soak in epsom salts with a teaspoon of alum added to it. 

Ive never had one look like that, and never had one on a back hoof. But sure hope your right! Ty

Agree, busted out abscess. 

Thank you! I can deal with an abscess..relieved that that’s all it is ??

Was she off at all for it to be an abscess?  I've never seen a Vesicular Stomatitis hoof lesion, but that's always a possibility ??

Kind of a different abscess called a gravel. Horse has probably been on/off lame. Soak and/or use drawing salve.

That is what mine started out as . Soaked it for 9 days with no results. Called the vet out and it ended up being VS. I felt so bad because I was soaking those sores and blisters in salt water!

There’s a small chance that could be Vesicular Stomatitis. I see you’re from Texas, there are several counties that have cases of VS.  I wouldn’t haul him anywhere until you figure it out.

Keeping it simple here ..... my gelding stepped on himself in the trailer couple days ago and when I cleaned it off, wound looked identical to that. It could be same thing , just stepped on himself. 

Totally agree on keeping it simple and not going into panic mode... it's so easy to do online lol! I self diagnose allllll the time on myself and get so worked up over usually nothing. If it were mine, I'd hydro it a few days and if no improvement, for peace of mind, go to the vet. Keep us posted on how it's going. Not trying to downplay the seriousness of VS because I know it's going around, OP if you are that concerned just take him to the vet and have it looked at. 

Not to mention I looked up VS once I read that and it says there are major mouth sores and discomfort from it. Not just feet. 

Totally not true!

All my horse had was one foot affected. I have 6 horses on my place and none of the other horses are or were showing symptoms,  no mouth lesions at all!!  I went through the 14 day quarantine with no one else affected. Weird!! It seems like this year is different than in years past. They are getting it on the coronet band and in the ears. VS was the least of my concerns when he first came up lame. It was CLASSIC abscess, toe touching acute lameness with a little spot or sore on the side of his hoof . We treated it for 11 days like an abscess. This certainly didn't do the blisters any favors and probably made them worse, not to mention I did not put him on any insaids because that is supposed to slow the abscess down! My poor guy!

Not saying that is what you have, just be aware. I definitely don't want to be a Debbie downer, but this caught me, the Veterinarian and even the veterinarian at the lab totally off guard. 

First pic is first day of onset. 

Second pic is day 7 of soaking

She hasn’t shown any lameness. The hoof directly superior to the lesion looks like it has been cut away...making me think she stepped on something in the pasture possibly, her hooves have been super soft lately with all the moisture and it could’ve pushed up Into to her hoof and coronet band there.

The blister appearance threw me off. I’ve been keeping it clean and dry. I will research the vs, I have not heard of that! Thank you! 

No lameness is great news!  My horse was barely toe touching like his leg was broken!

Didn't want to scare you, just want to tell everyone my experience so people are aware of the non-classic symptoms that I have dealt with.

Hope she has a speedy recovery!

Best to assume Vessicular Stomatitis, since you live in Texas.  If a vet thinks that’s what it is, your horses will likely be quarantined.  

Read up on it.

14 days from onset of symptoms is what they do, I believe. 

What County are you in? 

Better safe than sorry - VSV is incredibly contagious.  It can be fomite transferred (buckets, your shoes, your hands, etc), from animal to animal ( including cattle and horses), or through insect vectors - midges, black flies and sand flies. 

This is a good overview article on the diesease for anyone interested - https://aaep.org/horsehealth/vesicular-stomatitis-horses 

Quarantine is imperative. 

For those noticing and asking about why the ear plaques and coronary band blisters are more common this year - the current theory is that this is a strain (serotype) that we haven't seen in the last several outbreaks. 

Source - am a USDA ARS researcher working with viruses (including VSV) spread by insects to livestock and horses. Feel free to PM me questions. 

We had an outbreak at our place.  Haven’t been hauling, and we notified our vet right away.  We quarantined our place immediately, even before the vet arrived. 6 of our 8 horses had VS symptoms, which were actually mild. It didn’t effect feeding.  In fact, none of them developed vesicles or sores in their mouths.  We had some with quarter-sized sores on the inside of their ears.  Some developed ventral sores in the midline.  Two developed painful, weeping areas on their muzzles....they were the hardest to handle.  Only one developed one sore on the coronet band.  I don’t think any had a fever.  The muzzles looked like a burn-type injury.  As soon as we suspected it, we called the vet and he came out to check them out and draw blood.  The TX state vet fella called me and said it was senseless to run the blood test, since clinically that’s what it looked like.  I called the neighbors and gave them a heads up.

At first we tried to keep the 2 initially effected horses separated from the rest, but that became unnecessary, once the others developed symptoms.  We just washed them with surgical soap 2X a day, hosed them off, and applied Desitin on them.......the muzzles were the hardest.  They are almost all entirely cleared up....about 10 days after the first ones developed symptoms.   VS can be passed directly from horse to horse, either through human contact, buckets, grooming tools, etc..., but probably the biggest mode of transmission is via biting flies.

People also need to realize that the VS virus CAN infect humans, particularly if they are immunocompromised.  It usually only causes mild illness, and most people don’t develop symptoms, but if you are immunosuppressed, all bets are off.  Use gloves, bleach water, and hand washing.