FDA Warns About Accidental Overdose Risk of Noise Aversion Drug Sileo

fourth of july dog under blanket

The Fourth of July is no holiday for many dogs who are terrified by the sound of fireworks. If you plan on giving your dog the noise aversion drug Sileo, please take heed of the U.S. Food and Drug Administration’s continued warning to avoid an accidental overdose.

Since the prescription gel Sileo was introduced just two years ago, the FDA has received 54 adverse event reports from dog owners. The problem is that Sileo is packaged in an oral dosing syringe with a ring-stop mechanism on the plunger that must be turned and locked into place to set the correct dose — and the ring-stop mechanism does not always lock, causing an overdose.

Last year the FDA advised Sileo’s manufacturer, Zoetis, to improve the product’s labeling to emphasize the need to secure the ring-stop mechanism. Zoetis changed the labeling and added videos on its website that show how to properly administer Sileo.

Yet the FDA reissued an advisory today about Sileo “because adverse events are continuing to occur,” it stated. “The agency continues to advise veterinarians to carefully educate owners and handlers how to properly use the syringe to avoid accidental overdosing.”

Fortunately, no dogs have died — yet. But some have experienced the clinical signs of an overdose, which include loss of consciousness, trouble breathing, impaired balance, muscle tremors, slow heart rate, low blood pressure and lethargy. The FDA says it has not determined whether the overdoses were caused by improper use of the ring-stop mechanism.

If you still want to give your dog Sileo, make sure your veterinarian shows you exactly how to use the syringe. Be sure to keep an eye on your dog for any of the above symptoms of an overdose, and and immediately contact your vet or an emergency animal hospital if your dog shows any of these signs.

Noise Aversion without Drugs

My dogs Leroy and Ella luckily have no fear of fireworks, but that wasn’t the case years ago with my dogs Larry and Sophie. Once, and only once, I gave them a sedative prescribed by their veterinarian to help relax them on the Fourth of July. They did sleep through most of the noise, but then I read that tranquilizers don’t actually help relieve the anxiety of dogs and cats. In fact, drugs like acepromazine are like a “chemical straitjacket,” according to Dr. James Nicholas.

“This is because acepromazine does little to nothing to help mitigate the fear and anxiety that these suffering pets experience from fireworks and thunderstorms,” Dr. Nicholas wrote. “What it does do though, and do well, is make them unable to move and/or exhibit any of the other outward signs of their fear and anxiety.”

The following Fourth of July, I created a “safe room” in the bathroom, with their beds, toys and a radio loudly playing classical music. Larry and Sophie were still a little agitated, but much less so than in previous years. Even after the holiday, the dogs would instinctively run into the bathroom when they heard a firecracker or other loud noise. One time I had the radio on while cleaning the house, and the dogs suddenly retreated to their safe room. Why? The song “You Dropped a Bomb on Me” by the Gap Band, which includes fireworks sound effects, was playing!

If you want your dog to have a safe and sane Fourth of July without drugs, here are some helpful tips I’ve compiled from American Humane and Humane Society of the United States.


  • Bring your dog inside your home.
  • Play loud music, or turn up the volume on the TV or radio.
  • Create a “safe area” in a bathroom or other quiet, escape-proof spot, filled with blankets and your dog’s favorite toys.
  • If possible, have someone stay with your dog if you’re going to a fireworks display or party.


  • Coddle your dog by saying something like, “It’s okay” or “Poor baby!” Just act naturally and go about your business as usual.
  • Take your dog to fireworks displays. (Duh.)

Photo: anneheathen



Laura Goldman

I am a freelance writer and lifelong dog lover. For five years, I was a staff writer for i Love Dogs. When that site shut down, I started this blog...because I STILL Love Dogs!