Many hoof trimmers and veterinarians routinely apply tetracycline, oxytetracycline or copper sulfate and then tightly wrap hoof lesions in the belief the treatment will speed healing.
But new research suggests such treatment may actually delay healing and, at least initially, cause unneeded discomfort to the cow. That, in turn, prolongs lameness and recovery, says Jan Shearer, a veterinarian and hoof specialist with Iowa State University.
Shearer’s first rule of thumb: “Don’t do anything to the cow’s foot that you wouldn’t do to yours.”
Usually the best treatment is to clean and trim the affected area of the hoof claw, and then place a hoof block on the opposing claw. Severely lame cows should then be moved to a clean, dry, bedded area where they have lots of room and ready access to feed and water.
Like a thorn in your finger
To better understand hoof lesions, think of what happens when you get a thorn in your finger, Shearer says. The thorn punctures your skin, causing pain, redness and swelling as the skin tissue tries to first prevent infection and then promote healing. Much the same thing happens with claw lesions.
“The objective of wound healing is to fill the defect with new tissue,” says Shearer. Cells near the wound eventually regenerate to the fill the void, but it make take as long as three to four weeks to cover this area with a thin layer of new horn. Complete recovery may require several more weeks, or in severe cases several months.
In a small study of 18 cows, Shearer found that applying tetracycline or copper sulfate tended to delay this healing. ”New horn formation on lesions was more consistently observed in the no treatment group,” says Shearer.
If possible, recently treated cows should also be diverted around foot baths for a few days, particularly if you’re using caustic compounds such as copper sulfate or formalin.
Yet another potential concern is antibiotic residue. Cows with large lesions had higher residue levels in milk and blood after treatment, he says. None of the residues were above the 300 parts per billion tolerance level for tetracycline, but this study confirms that a small amount of tetracycline or oxytetracycline is absorbed following topical treatment with these compounds.
Also, the use of oxytetracycline or copper sulfate can cause a painful, burning sensation when applied to an open wound or exposed lesion. Cows treated with these antibiotics exhibit nearly three times as many pain-related behaviors as untreated cows, says Shearer.
Wrapping prevents healing
Shearer does not recommend wrapping or bandaging lesions following trimming. “The problem with wrapping is that within a matter of hours, the wrapping becomes very contaminated with footbath solution and organic matter. A footbath contaminated manure wrap isn’t likely beneficial to the raw corium not is it of value to prevent oxygen from getting to the lesion to help with healing,” he says.
If your trimmer is going to wrap a claw following trimming, the claw should be loosely wrapped and the wrapping removed within the next two or three days. The best thing to do is to carefully clean and trim the affected area, and then apply a hoof block on the opposite claw. The hoof block will relieve weight bearing on the affected claw which reduces pain and permits healing, says Shearer.
Note: This story appears in the April 2017 issue of Dairy Herd Management.