BREATHING IT IN
Inhaled medications are an effective way to deliver treatment directly into the airways of horses with recurrent airway obstruction. Indeed, this mode of delivery may be the best option for horses who need low doses of medications to keep the airway inflammation under control over the long term. “If you have a horse who needs more than just environmental changes, we suggest an aerosolized medication as a maintenance therapy,” says Johnson. “This involves a big up-front cost, but in the long term the horses benefit enough that it is worthwhile. Most horses tolerate these devices pretty well, but once in a while we find one that wants nothing to do with it.” Two basic types of inhalation devices are available:
use metered dose inhalers (MDIs) to deliver a drug via a miniature aerosol can, much like those used with human patients. To administer this to a horse, the MDI is attached to a chamber with a nose piece or mask that can be placed over one or both of the horse’s nostrils. When the MDI is activated, it “puffs” a dose of medication into the chamber, which is then inhaled by the horse. The horse may need to be acclimated to the sound of the MDI as well as the mask or cup. The Equinehaler and AeroHippus are the more common models available in the United States.
“Administering medications by metered dose delivery can be done fairly quickly once the horse gets used to the process. However, the medications can be expensive. If the long-term cost of providing metered dose medication is a financial burden for the owner, nebulization provides another option for delivering inhaled medications that generally are less expensive in the long term,” says Virginia Buechner-Maxwell, DVM, MS, DACVIM, of the Virginia–Maryland Regional College of Veterinary Medicine.
• Nebulizers are electric- or batterypowered devices that vaporize liquid medications and deliver them into a mask that covers the horse’s muzzle; they can also be used with MDIs. One of the newer ones on the market is called the Flexineb. “When clients can afford this, it is the product I recommend,” says Buechner-Maxwell. “All of the material for nebulization is contained within the mask. It also delivers a very consistent mist and most horses tolerate the mask well once they are used to it. In many cases, owners can place the mask on the horse and then work nearby in the barn until the medication has been delivered and it’s time to remove the device.”