In our veterinary practice, we occasionally instruct a horse owner to apply nitroglycerine topical cream over their horse’s digital arteries (in the pastern) to prevent the onset of laminitis.
Nitroglycerine ointment is a vasodilator, and it is used in human heart patients to help open narrowed coronary vessels. The ointment works by opening vessels and may have a beneficial effect in horses at risk for or in the early stages of laminitis. There is debate about the effectiveness of this therapy, but I still believe there are times when it is of value.
Make contact with your horse and remove the old bandage. Put on latex gloves and cut a piece of the wax paper (supplied with the cream) into two roughly equal halves. Apply the recommended strip length of nitroglycerine to the two pieces. This is usually 1/2"-3/4" (1-2cm). Set these carefully in the carry-all or on a work surface.
Using your fingertip, you may be able to feel a digital pulse on the medial and lateral artery. If so, the wax paper with the strip of nitroglycerine can be applied directly over this area. Gently smear the ointment by squeezing the now adhered wax paper against the skin. Now apply Elasticon directly over the two papers.
If you lay the elastic tape down flat over the top of the papers, it will not move them as you secure the tape. Now make 1-2 wraps gently laying the Elasticon on the skin and press it onto the skin with your hands to secure it. Ensure that the tape end is well adhered to the underlying tape to prevent unraveling.
Tips for safety & Success
DO NOT perform this skill unless instructed by your vet to do so. Follow your vet's instructions carefully, and only apply as much cream as instructed.
If you have a known heart condition or other serious health condition, inform your vet. You should probably not handle nitroglycerine at all.
Always wear gloves when applying this cream to your horse to prevent any effect on your own health. Although it is only applied locally, nitroglycerine can have an active and rapid effect on your blood pressure. Be very careful when handling this medication.
The goal is to apply the desired strip of ointment directly over the digital arteries of the pastern. The pasterns often are clipped of hair, making it easier to palpate the pulse and define the location of the arteries. These arteries are the same arteries used for assessing a digital pulse, only further down the pastern.
Occasionally, horses will develop skin irritation from the use of this product. Consult your vet if you notice reddening and flaking of the skin.