If I am right it means that vasodilators like NO are contraindicated during the fever, developmental, stage of laminitis. I have no problem with GTN patches, along with other vasodilators like isoxuprine and ACP, when the metabolic crisis is over and the foot is trying to heal. One California farrier saw the patches used on a miniature horse which had suffered repeated bouts of acute laminitis. The patches were credited with swift recovery. When the horse was sent home, it was accidentally overfed, relapsed, and the owner applied additional patches and averted more disaster.
Nitroglycerine patches come in several dosages, sizes, and shapes.
How much to use and how often to replace them are large variables. The skin can become inflamed when the stronger patches are used. Texas farrier Burney Chapman, known for his successful treatment of laminitis with the use of heartbar shoes, reports that he has been working on foundered and injured horses treated with the patches for about 16 months. He believes that the patches were very helpful, both to acute and chronic cases, and to horses suffering from coronary band lacerations and even navicular-type lameness. Chapman has a high rate of success even without the patches, and his enthusiasm for including them in the treatment regimen is spreading across the United States.