Sunday, June 08, 2008

The Not so Pretty...a basic lesson in equine wound care

The above photo is a bit gross; it's Buck's wound. It looks a slightly revolting, but it is progressing as it should. Horses' lower leg wounds are tricky to deal with. There are plenty of bones, tendons, ligaments and blood vessels, but very little muscle tissue. They are not often stitched because the strain and movement of the limb will generally tear out any sutures. Neat tidy wounds that are sutured heal quickly by a process called primary intention; the edges knit themselves together and soon all is well. Ugly wounds like Buck's can't heal that way. Instead, they heal from the wound base to the surface, and from the wound edges to the centre. This is called healing by secondary intention. It can be a long, slow, tedious business.

Buck hurt himself two ways, first with a traumatic injury, and then with prolonged pressure, which caused further tissue damage. Tissue denied blood flow for a long period will die. The dead stuff can present several ways; as hard black leathery eschar, or as grey or yellowy stringy slough, either loosely or firmly attached. Before a wound can heal, the dead tissue needs to be removed. The best and most conservative way to remove it is to keep it moist, but not wet, and it will gradually come away from the wound, once that stuff is out of the way, the wound can heal.
Horses are different from people and other animals in that their wounds will often hypergranulate, or form excessive tissue ("proudflesh"). Some of the wound products we use on people shouldn't be used on a horse because of this.

Buck's first week of treatment has consisted getting of a bucket of grain every afternoon and happily munching while I cut away the old dressing. Next comes cleaning the wound with water. We don't take a garden hose to people wounds, but it's just the ticket for a horse. It helps clean the wound, and wash away any sloughing necrotic stuff. Next comes an antimicrobial silvercoated dressing which fits right into the wound, then a non adherent dressing, followed by kling gauze bandaging, and finally an outer layer of vetwrap, which is among the best things ever invented.

I'll be watching Buck carefully for signs of infection. A wound that is unhealed for any length of time will be colonized with bacteria, and that's normal (actually, we're all covered with bacteria all the time!). If they become invasive, or if the wrong bacteria are introduced to the wound, then problems can arise. The dressing is a bit stinky when it's removed, and that's normal too. It's absorbing drainage from dead tissue, and dead stuff smells after a while! What you need to do is get rid of the dressing, clean the wound, and then have a shouldn't smell. I'll be noting the amount and colour of the drainage. I'll be checking his leg by comparing it to the healthy one for warmth or swelling. I'll be noting how he walks, and whether he favours the leg. I'll be checking to make sure he's eating and drinking well, and if I was concerned about any of these things, I'd check his temperature and call the doc. We might then swab the wound to see what bacteria are growing, and put him back on an antibiotic. I don't expect these complications, but they may arise.

I'm awaiting a product called Equaide to arrive, and then we'll switch to that. That little pink nub near the front edge of the wound is hypergranulation tissue.

Thus endeth the lesson. You probably didn't want to know all that, but perhaps you learned something new today.
(Sorry for the odd paragraph spacing, Blogger won't let me space them with a blank line tonight!)


Cicero Sings said...

Interesting lesson! Interesting the healing process in such a wound.

Jean said...

Thanks for the info, Karen - very interesting! (But I do wish I had not decided to read the blog while eating my lunch!! LOL)

I hope Buck makes a great recovery with no complications.

Ruth said...

That is quite a wound. And your pictures are not yucky at all. Yucky describes the infected ulcers our patients have. Hope he stays free of infection!

Amy said...

I actually found this post very interesting (perhaps a throw-back to my nursing student days). What a job to do all that cleaning and bandaging every day. Poor Buck! He's lucky to have you nursing him back to health.

Vic Grace said...

My goodness that is the first time I have seen what Buck did to himself. That is pretty nasty fortunate you know what to do.