An abscess is an infection in the hoof. Abscesses are extremely painful because, like a tooth ache, the infection causes inflammation, and the hoof capsule constrains the inflamed tissue, causing the pressure to build up..
Abscesses are so excruciating that I've had clients think their horse had a broken bone, severed tendon or ligament because horses often refuse to weight the hoof with the abscess.
Eventually the pressure from the inflammation, following the path of least resistance, expands into areas with weaker connective integrity, allowing the necrotic material to work its way to the surface. As the abscess material moves, it causes a separation that eventually grows out.
A "vent" is a naturally occurring external opening that abscess contents are expelled through.
Strong Digital Pulse?
If you suspect an abscess, check for a digital pulse. The Digital Pulse (the pulse in the fetlock joint) is normally faint and can be hard to find at the back near the sesamoids, but when a horse has laminitis or an abscess, this pulse begins to "bound", becomes a throbbing or "bounding pulse". For more information see the Digital Pulse article.
Abscesses can be the result of laminitis or mild laminitis, puncture wounds, stone bruising or any internal damage.
A friend in BC has lots of abscessing in the spring in horses on great diets, and after some online discussion, the group concluded that this early spring abscessing is probably because these horses are walking over partially frozen pock-marked ground and bruising their soles, and that the very low temperatures may be contributing.
Another friend had a laminitic 17 year old horse that all of us trimmers felt was a Cushing's case. He kept on foundering and abscessing even after his diet was corrected. The vet did a blood test and the horse tested as not-Cushings, andcontinued to abscess even though the diet was perfect and the trim was appropriate.
Because the horse was in so much pain that he was put down. Later, another friend who is a vet specializing in PPID, Cushing's, IR, Founder and Laminitis said that she will often put these horses on Pergolide even after Cushing's is ruled out by a blood test because it often will stop the abscess cycle. It's something to try.
When a client says their horse appears to have an abscess and there is any possibility that the horse was in an area where it could have stepped on a nail, I have clients clean and inspect the sole and frog carefully looking for puncture wounds or a sign of a nail or nail hole!
Punctures are potentially life threatening. If your horse has picked up a nail, screw or other sharp object, contact a vet immediately. If the object is still in the hoof, call the vet before removing it!! Many vets want to x-ray with the offending object in place so they can treat the horse appropriately.
I have had three presumed "abscesses" actually be nails or nail puncture wounds, two were serious. When I think a hole may be from a puncture vs an abscess vent (a puncture has different edges and stays open further), I suggest a vet call.
I prefer to soak the hoof several times a day in a warm Epsom salts solution and bandage with one of the recommended poultices (below) until it vents. I cover a poultice with a disposable baby diaper and cover with duck tape or Elasticon, gauze and duct tape to make a durable bandage.
If I suspect serious laminitis or founder, instead of soaking the hoof, I dry-bandage it with a drawing poultice. Soaking a seriously laminitic hoof may weaken it and cause more damage.
1 - Cleanse the hoof
Wash the foot in warm water, and clean with Betadine soap & lots of water. I put a piece of tarp or a clean mat down so that the wound won't get contaminated if the horse steps down.
2 - Look for a puncture wound or vent
Punctures are potentially life
threatening. If your horse has
picked up a nail, screw or other
sharp object, contact a vet
immediately. If the object is
still in the hoof, call the
vet before removing it!!
3 - Soak the hoof and/or use a wet disposable baby diaper compress or use a Dry Bandage Poultice
See the Hoof Soaking page or Poultice section for a few methods of doing this without it making you and your horse crazy. I have had clients use wet baby diaper compresses, sometimes in conjunction with clay or other poultices, to soften the hoof and help draw abscesses. Apply poultice material, apply the dry baby diaper, wrap well with Duck Tape and add warm water in the top. Add more warm water every few hours.
I have had clients use a poultice in a soaker boot successfully; it keeps the hoof damp and soft, protects the hoof from external dirt and secures a poultice.
4 - Bandage a surgically vented abscess or detached heel
Dry the foot with paper towels
& wash hands. Apply an antibacterial solution, squirting
it into any abscess hole as
far as you can.
Plug the vents/holes with cotton balls, then apply an Ichthamol or Nitrofurazone dressing or a poultice (see below). Wrap the foot in a disposable baby diaper, thin cotton or gauze. The foot can then be wrapped in strong cotton bandage or Elastikon tape,
An alternate way of keeping the hoof clean is to place an oversized hoof boot over the diaper or bandage as a waterproof walking bandage. Hoof Boots need to be checked daily to ensure that 1) they are staying in place and 2) aren't rubbing. I usually like to let horses walk during recuperation, but if you don't have a dry paddock for your horse, consider stalling it.
Another suggestion is to make a boot using a waterproof tarp and duct tape; this wears through fast, so don't count on more than one use per piece of tarp. A used drip IV bag (ask you vet for discards) also works well.
Another option is to put a sole pack like Hawthorns on the sole, packing it around the abscess, and cast the hoof to protect the vent. I personally prefer to boot or bandage a horse that has a surgically vented abscess so that I can check on it, but some horses are hard to keep booted and bandaged. I remove these casts weekly to check the hoof, and check the foot at least twice a day for a bounding pulse to verify that the abscess hasn't heated up again. You can soak an abscess through a cast as well, and if you want to do that, om mitt the sole pack.
Most of the abscesses I see in this coastal northern California region vent at the coronet band in the heel area, or in the coronet on the sides of the hoof. I also see solar abscesses that vent at the white line or frog, and bar abscesses that often result in the heel and bar in that area "shedding" in a huge chunk. In arid climates, it's common to have abscesses vent at the bar-sole junction.
Abscess vents will occur at any junction of two different materials, because "intersections" of unlike materials always constitute a weak point. Abscesses vent in the while line, between the bar or sole and frog, and in the heel buttress. I've seen abscesses come through the wall and sole, too, but only on weak walled or thin soled horses; this is because abscess vents choose a path of least resistance.
A healing abscess vent in the coronet area appears to be a slit or cut 1/2 inch long parallel to the coronet, and as the wall grows down, the slit will grow down with it until it grows out. Solar abscesses result in the eventual shedding of the sole in several huge chunks, and the new sole underneath frequently has a dark coating on the surface, residue of the abscess that once covered the sole. And, as I said above, a bad bar or heel abscess often loosens the heel and bar material, requiring that it be removed and the hoof protected until new bar and heel has grown out.
When an abscess blows out under a heel and/or bar, the heel and bar can detach. The detached material is initially protective but will eventually become irritating and need to be removed. I ask clients to let their vet know what happened in case they want to do this, but most of the vets in my area prefer to let me deal with vented abscesses.Bandaging the hoof
I leave the separated bar and heel in place for a week or so to give the underlying structures time to build new material over the corium. To protect the hoof in the meantime, I clean the hoof and area around the crack thoroughly with an antiseptic scrub, place a gauze pad,around the vent to absorb any residual seepage, bind the hoof with vet elastic adhesive tape and cover with a "duck tape boot" made of overlapping strips of Duck Tape.
The bandage needs to be changed after a few days (I follow the vets recommendations) and when the heel section seems weakened at about 2 weeks time, I carefully remove it with nippers. Because the coffin bone isn’t as protected as it is with an intact heel, I re-bandage it , have clients keep the foot clean and dry and either put a good vet-type hoof bandage on the hoof (essentially a soft cast) or vet-wrap the foot with a thick layer of gauze over the heel and boot the horse to protect it.
Because of the location, I recommend that clients wait until the whole heel re-grows to ride or use the horse athletically, and until that happens to keep the horse quiet - no herd turn-out - for a few weeks. Heels grow out in about 2 months on a barefoot horse.
If a horse with a seeping abscess is being put into a boot for protection, I suggest buying "puppy training pads" to wrap the hoof and keep the boot clean. They are available at pet stores!
The few horses I’ve seen with this sort of abscess all had laminitis, so I would watch this horse carefully from now on, just in case!
Why are some horses more inclined to get abscesses?
Horses with laminitis, particularly horses who are foundering, are the most prone to getting abscesses. For many owners, an abscess is the first indication they notice that a horse has the dietary or metabolic problem.
Abscesses are the result of infection in the hoof capsule. A healthy hoof provides a formidable barrier to contaminants, so most internal infection is the result of either a puncture wound or necrotic tissue from a bruise or laminitic episode.
When I hear that a client horse has an abscess, I request that they pull the horse off all pasture and stop feeding all higher-carb feeds until I have a chance to check the feet out. My favorite summary of diet information is here on Pete Ramey's web site http://www.hoofrehab.com/diet.htm, and excellent comprehensive information is available on Dr Kellon's web site http://www.drkellon.com/ as well as Katy Watts' SaferGrass site http://www.safergrass.org/.
Horses on low carb mineral balanced diets and who have tight wall connections and durable soles are the least likely to develop abscesses. Horses on pasture in the early spring when night temperatures get below 45 degrees and daytime temperatures are warm frequently develop abscesses as a result of mild laminitis. If your horse has one or more abscess a year, I strongly suggest that you revisit your horses diet. Pete Ramey has several interesting articles on Laminitis; my favorite is http://www.hoofrehab.com/end_of_white_line_disease.htm#laminitis%20update
Laminitis can be very mild and have subtle symptoms that your veterinarian and farrier may dismiss . The most common symptoms are stretched white line, wall cracks, wall flares, loss of concavity, sudden tenderness in the late winter, spring or fall, sudden tenderness after vaccinations or changes in feed.
I don't personally "dig out" an abscess; it's an invasive surgery, and when clients want it done, I refer it to vets. Surgically opening an abscess will provide immediate relief, but the hole created to relieve the abscess needs to be carefully cared for until it has healed over, a period of as much as a month. A naturally venting abscess seals itself immediately, so I prefer to soak the hoof and try to get a natural vent.
I use my fingers (feel for heat and throbbing) or hoof testers to try to locate abscesses.
If an abscess location is soft, I'll prepare a clean working space and try lightly scraping the area where I think the abscess it trying to vent, or will use light pressure to see if an abscess will vent voluntarily. If it does, I try to get as much puss out as I can, then soak in Epsom Salts solution and bandage for a day or two.
If I feel like the abscess is moving towards the white line in a particular area, I'll use my hoof knife to pare a small hole at the junction of the white line and wall to encourage the abscess to vet there... this has worked 4 times out of 5, the hole is not near sensitive tissue and in conjunction with soaking, the hole seems to encourage a solar abscess to vent through it. I may just be lucky!.
Surgically cut abscess vents are an excellent way to get lots of bacteria into your horses foot, so protect the abscessing foot carefully to avoid making it worse. Use sterile bandages and work with throw cloths or mats to protect the hoof from further contamination.
Here's what the contents of my "abscess kit" looks like. I go out of my way to pro actively educate clients about laminitis so haven't had to use my kit is a few years, but if you have problems with abscesses, these items are good to have on hand:
Poultice, Icthamol or Nitrofurazone
Betadine solution or iodine
Disposable diapers (sized same as EasyBoots)
Soaking bucket or soaker boot
Water bucket or large thermos
My vet has suggested MSM
, Bute and homeopathic remedies Oral
Arnica or Hepar Sulph (both are thought to help abscesses
vent and encourages healing) .
- Ichthamol or Nitrofurazone Dressing Option - Until the abscess has erupted, coat the sole with Ichthamol or Nitrofurazone.
- Magna Paste
- Clay Poultice - Ice Tight is affordable and easy to find, but dry clay is cheaper to have shipped and works as well. Aztec Clay (available in health food stores) works well too. The whole hoof (particularly the sole, frog, heel bulbs and coronet) can be covered in a thick layer of clay, vet wrapped and bandaged with duck tape to help to "draw out" infection.
- Antiphlogistine by Absorbine. Good for deep abscesses. [Antiphlogistine is clay with methyl salicylate, menthol, eucalyptol.
- Epsom Salt Poultice by Kaeco Group. Draws well and controls swelling (contains Magnesium Sulfate)
- Numtizine Cataplasm by Hobart Labs. Contains Methyl Salicylate, guaicol (a disinfectant) and creosote
- Animalintex - A 3M product. Boric acid and tragacanth, a herb that forms a gel- like substance. The Poultice Pad is a 100% cotton wool with a non-woven cover on one side and plastic backing on the other. Contains mild antiseptic (boric acid) plus natural poultice agent (Tragacanth). Use as a poultice or wound dressing. Here's a 3M PDF with lots of info on it: http://www.3m.com/us/healthcare/professionals/animalcare/pdfs/equine.pdf
- Hawthorne Sole Pack http://www.hawthorne-products.com/catalog.asp?prodid=635861