Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to treat allergies in horses [title] Don't feed your horse moldy hay. [step] Recurrent airway obstruction (rao), or " heaves, " is a respiratory condition in horses that can cause coughing and other issues. The condition is caused by irritating spores that can develop in moldy hay.

Ending1: It will eventually become a full-fledged bacterial infection, called rao, if left untreated, or therefore increases your risk for infection. [substeps] If you see rao coming towards you, avoid feeding your horse or rider any dried hay. Ending2: In order to prevent your horse from contracting the disease, feed it this moldy hay every few days. Keep feeding your horse this moldy hay after meals or sparingly at the end of your ride. Ending3: If the horse does catch these spores, they form into blockages in their digestive systems. Unfortunately, the disease is not contagious. Ending4: If you see hay that has the slightest bit of mold, get rid of it immediately. [substeps] Store your hay in a place that is protected from the elements, but not directly in or above your horse's stall, since this can expose the animal to allergens.

Answer format: ending1/ending2/ending3/ending4