Last month, we looked at thrush remedies that contained botanical ingredients, and Thrush Off (www.well-horse.com, 419-295-0474) was tops of the eight products included there. This time we’re covering the more traditional approaches, and that means 12 chemical-based choices. Regardless of the type of product used to treat thrush, the most important element of treatment remains to thoroughly clean out the foot and remove any diseased tissue.
Start by asking your farrier to trim back the overhanging flaps of the frog, if needed. He or she can also cut out some of the diseased tissue and give you a jump-start on treatment. To keep thrush at bay, after you pick out the horse’s hoof, finish by using a hard brush to remove all the tiny debris. If you can’t get all the mud removed, wash the hoof, but thoroughly rinse off any residue from the soap or disinfectant you used and dry the foot before treating. If you don’t rinse well, any remaining residue may interfere with the treatment product you’re using or, worse, cause a dangerous chemical reaction.
Remember, thrush is basically a mixed bacterial infection, not a fungus as is commonly believed. A dry environment is important to fighting thrush. The organism thrives in dark, moist environments with low oxygen. That’s why it enjoys being packed into the clefts of the frog, with a nice mushy cover of mud and muck. Hoof boots do help protect tender tissues and keep the feet clean, but they also trap moisture and set up a friendly environment for thrush. If you’re going to boot the horse, it should be done with medicated pad/packing or disinfectant soak solution.
Manure, muddy conditions and moist soil can all lead to thrush. Improperly trimmed hooves — especially when the frog isn’t correctly trimmed and flaps removed — can hinder air/oxygen from getting in those crevices and set up the anaerobic (low/no oxygen) environment the thrush organisms thrive upon. Injury to the hoof tissues from an imbedded stone or other materials can cause a break in the normal protective barrier and allow the bacteria to invade.
We define mild thrush as the obvious black discharge and odor but no lameness or pain on picking the feet, and no deep-tissue layer invasions. Moderate thrush is defined as pain on picking the feet or manipulation of the tissues of the heel. Severe thrush is severe pain with obvious involvement of the deep tissues.
For mild cases, simply trimming and cleaning the foot and using a mild disinfectant product may eliminate the problem. Many people like to follow this with cotton soaked in peroxide and packed into the crevices of the frog. Dilute (5 to 10%) of a chlorine bleach (such as Clorox) solution or a 7 to 10% iodine, like Durvet Povidone Iodine 10% (www.durvet.com, 800-821-5570).
Other multi-purpose options you may already have on hand and should work for mild cases are Absorbine liniment (www.absorbine.com, 800-628-9653), Venice Turpentine (www.bickmore.com, 800-356-8804), or Hawthorne’s Sole Pack (www.hawthorneproducts.com, 800-548-5658). All three are effective mild disinfectants. Sole Pack also protects and seals the bottom of the foot, which is a definite plus and makes it our top choice for mild cases. For additional tissue penetration, the liquid Sole Pack can be used on the hoof, followed by a Sole Pack patty to protect and seal the area.
Bottom Line. You will get quick results and the best price from an iodine- or copper-based product. There is residual action between treatments. We prefer the copper naphthenate products. Horseshoer’s Secret has a tiny average price advantage over D-Thrush, making it our Best Buy.
We loved the ease of the aerosol Thrush-XX, and it’s worth the extra money for ease of application. Plus, this copper-based product works well.
Severe thrush is another story. The copper and iodine products still work for killing the infection, but they can be caustic to tender tissues and slow healing. Only two products in this trial were both sufficiently antimicrobial and gentle enough to be reliable for severe thrush: Thrush Stop and White Lightning.
Both work, but Thrush Stop got stubborn cases that didn’t respond completely to several other products. It forms a barrier and has a long-lasting effect. It’s our No. 1 choice for thrush.
Article by Veterinary Editor Eleanor Kellon, VMD.