Ben Update

I've had several requests for an update on Ben's foot.  In truth, I am not entirely certain what to think about the canker.  The foot is looking OK with some decent frog growth.  However, he still has this large crevice in the frog to the right of the central sulcus...

The crevice in the center is normal, although deeper than it should be, the crevice to the right is not normal.  It should look like the left half of the heel....

Ben is completely sound on this foot and shows no signs of distress.  In this odd crevice though,(which I have taken to calling the Troll Cave) is this one spot that still looks funky (that's the technical term).

That spot is nasty looking like canker, but is not sensitive nor does it bleed like canker.  So, I am not sure if it is canker or, perhaps, scarring from treating the canker.  I don't like the look of it regardless and I am not happy that the Troll Cave is not filling in with healthy tissue.  However, I am not sure that cutting into it to remove the funky spot would be warranted at this point as there is healthy looking tissue under it.

Treating canker is not a straightforward or simple thing and I am groping my way through this, as everyone does.  However, my instinct is to treat it as aggressively as possible without causing permanent damage.

The wet ground definitely seems to encourage canker growth as this funky spot only turned nasty looking with the arrival of the Fall mud season.  I had left the foot unwrapped while the ground was dry, but the real Fall rains showed up in earnest this past weekend and all is wet, wet, wet.  I have reapplied a liberal dose of Magic Cushion, which has worked well to fend off the canker so far, and I will be keeping the foot wrapped for the foreseeable future.

I will also be sending all of this to my vet to see if there is anything else I should be doing.  Another round of the metronozidole/acetone concoction might be in order.  Maybe more cryotherapy too?

With the soggy wet has also come some white line separation and some seedy toe.  I have trimmed the hoof wall back with a strong bevel all the way around and the Magic Cushion should help with that as well.

The good news is that Ben is not at all bothered by any of this.  He has plenty of nice concavity in the foot with nice thick soles and walls, which are all good things.  Aside from the canker and the problems associated with being water-logged, he has nice feet.

It may be that keeping the canker in check will be an ongoing management issue rather than conquering it all at once.  I am not happy about the idea, but it is not unbearable either.  It is much like the ongoing management issues I employ to keep Ramsey's bad foot healthy.  He too is sporting a wrapped foot today to protect it from the wet.  Because of the missing chunk of coffin bone, he is prone to abscesses during the Spring and Fall mud seasons.  I want to prevent further pain and damage to his foot so it is wrapped with Magic Cushion for the duration as well.

The boys will be sporting matching outfits, like twinsies.

The Daily Regimen

I wrote about our big canker adventure in my last post.

I have been doing daily bandage changes/medicating since last Thursday and this is what things look like now....

The white stuff is a remnant of the powdered antibiotic. The crevice right in the center is the normal sulcus, although there is a bit of thrush in it.  That is being treated as well.

The curved crevice just to the left of the central sulcus is where the canker was.  The wedge shaped piece between the crevices is the healthy frog tissue.  It looks rather naked as it is normally covered by thick, callused frog.  Hopefully it will be again.

I have never treated canker before and there is no real data about what to expect from this treatment so I can't really say if this is progressing well or not.  The first couple of days after surgery, I could still detect some of the odd, musty odor that comes with canker, but I can't any longer.  I am taking that as a good sign.

Each day, I pack the area with the crushed antibiotic pills and I pack it down into those crevices as far as I can.

I cover this with gauze soaked in the acetone/benzoyl peroxide mixture and wrap the whole thing with elastikon.  I never use vetwrap for wrapping feet anymore as it won't stay on in the field unless you cover the coronary band as well.  I don't like to do that, it is not good for the foot.  Elastikon is a bit more expensive, but it stays where I put it and can take a lot more abuse.

Ben is still sound on the foot and doesn't seem to know there is any problem with it.  He is still feeling good and is very well behaved about the whole wrapping procedure.  He gives me very mournful, long-suffering looks when I start messing about with his foot again then stands stoically with a deep martyred air about him.  He generally gets a cookie when all is done though and the martyrdom miraculously disappears and all is forgiven.

The Canker

I've been meaning to write more about the canker issue in Ben's foot and answer some of the questions I've had about it.  At the same time, I have been trying desperately hard not to dwell on it and make myself crazy worrying about it.  I have already done everything it is humanly possible to do to get Ben the care he needs.  Writing about it and not dwelling on it have become mutually exclusive.  However, today was the day for the vet to come out so we could try to tackle this so it is time to address the issue on all fronts.

The most common question about canker is: what is it?

The answer to that is, despite what you may read, no one really knows.  When I was in college, studying equine science, I was taught that it was a type of cancer.  These days, many researchers believe it is a type of bacterial infection that triggers out-of-control growth.  The problem with this theory is that it does not respond to antibiotics and canker can't be reproduced even when the suspected bacteria are injected into a foot.

There is also an environmental component, although it is not hygiene (despite that often being cited, canker occurs in the most immaculate settings as well as dirty ones).  I had never heard of canker occurring in donkeys, but clearly it does.  Canker can occur in any horse, of any size, but it most often occurs in draft horses and is seen most frequently in the southeast US.   Because of this, it seems there has to be some kind of environmental factor, but no one knows what that is.  Ben did spend time in North Carolina before coming to New York, for what that is worth.

Fiona asked if canker is related to sarcoids and there is some evidence to support that, but again, no one yet knows.  There is speculation that both sarcoids and canker may be triggered by bovine papiloma virus.  There is an interesting article about the correlation between sarcoids, canker and BPV that can be found here along with a discussion about using chemotherapy to treat canker.  It has shown some success.

When I ever bother to think about canker (which was very rare up until Ben entered my life) I take a more practical view of the problem: if it looks like cancer, acts like cancer and has to be treated like cancer, maybe we should just call it cancer until someone figures out what the hell it really is.

The reality is that canker is a rare, mysterious, bizarre hoof disease that has semi-randomly plagued horses (and donkeys) for centuries and will likely continue to do.

The next question everyone asks is:  how do you treat it?

That too is a topic of great debate.  Fortunately, despite not knowing exactly what it is, there has been some progress on this front.  Canker often used to be a death sentence.  Canker still has a guarded prognosis, but the success rate for treating it is now about 70%.  What it really comes down to for successful treatment, is that the canker has to be gotten rid of entirely.  How that is done is (of course) a matter of controversy.

Just about every chemical you can imagine (and some I'm sure you haven't) has been used to try to treat canker.  Sometimes they work.  However, the miracle cure for one horse often has no effect whatsoever on another, making topical treatments a frustrating matter of guess work, anecdotal stories and hope.

The treatment that has the most consistent and highest success rate so far, is radical excision of the canker followed by topical treatment.  The most important aspect is to make sure that all of the canker has been removed with a clear margin all around it - just like cutting out a tumor.

There are various protocols for this as well.  The one with the highest documented success rate involves excision followed by cryo or laser therapy to kill any missed cells.  That is then followed by daily topical application of a drug (metronidazole) that is both an antibiotic and anti-protozoal combined with benzoyl peroxide (the acne medicine) mixed in acetone.  It is a bizarre combination that certainly covers all the bases.  It is hard to imagine a bacteria, fungus or protozoa that would survive this combined onslaught.  The full protocol can be found at: 
http://www.equipodiatry.com/canker1.htm 

Like cancer, early detection greatly increases the likelihood of successful treatment.  Unfortunately, canker often hides under healthy seeming tissue and is usually only discovered when the animal shows lameness.  By the time this happens, the canker has grown large enough to invade the inner structures of the hoof.  Even if successfully excised and treated, it may have caused too much damage for the animal to recover.

Maybe it is fate, destiny, luck or a guardian angel that brought Ben to the home of a true hoof nerd because I did catch it fairly early.  Hopefully, it will make a difference.  

On first acquaintance, Ben's foot looked very normal with the exception of a small, narrow crevice in the center of the frog.  It looked exactly like sulcus thrush, which is what I assumed it was when I first saw it.  

Ben had a complete veterinary checkup two days before coming to my house, he is not lame and he has always had regular farrier care.  I don't hold the previous owner responsible for this as he had no way of knowing it existed.  I certainly missed it until I took a knife to the foot.  

I do think the previous farrier should have at least seen that there was some kind of issue, but I know the farrier in question and this is just out of his depth.  He does a fair job on healthy feet, but just does not have the skills to deal with odd problems like this.  I could rage against that, but there is no point.  He is what he is.  As are we all.  

My first real hint that something was seriously wrong came when I used my hoof knife to open that sulcus crack up a bit to expose the area to air.  This is what I found....

That wet, grey, nasty looking area right in the top center of the hoof is canker in it's oozing, smelly, gross state.

Be warned, the pictures get more gross from here.

The canker is a fleshy, damp growth that bleeds profusely with the tiniest of scratch.

It has a very odd, musty, fungal sort of smell.

At this point, I trimmed Ben's feet and wrapped the affected hoof with a liberal dose of Magic Cushion, which is my go-to cure-all for hoof problems.  I love that stuff.

A week later, I removed the bandage and you can get a much clearer picture of the canker itself.  The Magic Cushion cleaned up the nasty, grey ooze and now you can see the white canker growing in the center of the frog.  There is a small amount of blood because I just barely scraped it with my knife.

By the time the vet got here yesterday, I had had the foot wrapped with the Magic Cushion for two weeks and the canker had actually shrunk because, hey, it's magic.  I am even more fond of Magic Cushion now.  Although, I will in no way say that this topical treatment will work on all cankers because it helped on this one.  I am a big fan of Magic Cushion, but it would be remiss of me to say it will work on every case.  It would certainly be worth trying, but remember what I said earlier about topical treatments either working or not with no obvious rhyme or reason.

Despite some progress with the Magic Cushion, we proceeded with the excision and cryo-therapy.  Ben was sedated, given a nerve block to the foot and a tourniquet was wrapped tightly just above the hoof because cankers bleed like crazy. I don't have many photos as I was holding the foot and wielding the hoof knife, but this was taken after we cut out the canker and done the cryo treatment. The white is actually frost from the freeze spray.

This was followed by application of the crushed metronidazole pills.  That was covered by gauze soaked in the benzoyl peroxide/acetone mixture and the whole wrapped in a pressure bandage.  As long as the weather stays clear and the ground dry, Ben does not have to be locked in.  The foot has to stay bandaged and dry, but exercise is a vital part of healthy hoof growth and he is better off outside.  He is still not lame and is, in fact, feeling quite well and full of himself.

From here, I will be doing daily bandage changes to medicate the foot.  If we start to see healthy tissue taking over, I will continue the medication for one-two weeks and then switch back to the Magic Cushion until the area is completely healed.  If that happens, then we can put this whole crazy episode behind us and ride into the sunset.

If the canker comes back.........?