The Basics

What is SILEO?

SILEO is the first and only FDA-approved treatment for canine noise aversion associated with fear and anxiety. SILEO has been proven to work on its own without other treatments or training. The name is pronounced /si-lehh-o/. It’s a Latin word that means to “be silent.”

How does SILEO work?

SILEO is formulated as a gel that is absorbed into your dog’s body when you apply it to the mucous membranes between your dog’s cheek and gums. Dexmedetomidine (the active ingredient) calms your dog by preventing or reducing specific reactions in the nervous system.

What is noise aversion?

Noise aversion is the set of anxiety- or fear-based behaviors that dogs can display when subjected to “noise triggers.” More about noise aversion »

When and how do I use SILEO?

Refer to the instructions on when and how to give your dog SILEO.

What is included in my supply of SILEO?

SILEO is supplied in a 3-milliliter oral syringe. Each syringe comes with a dosing ring and end cap along with a prescribing information leaflet.

Dosage & Directions

How is SILEO administered?

SILEO is administered by placing the gel between your dog’s cheek and gums, allowing for transmucosal absorption.

The dosing chart is by body weight and associated number of dots. How much is a dot?

Each dot is 0.25 mL; 4 dots is equivalent to 1 mL. You’ll find the dosing chart here.

Why should a dose greater than 6 dots be divided between both sides of the mouth?

Six dots is equivalent to 1.5 mL, a dose volume that is too great to administer effectively to one side of the mouth without the risk of some of the dose being swallowed or flowing out of the mouth. Administering half of the dose on one side of the mouth and half on the other side maximizes absorption through the mucous membranes.

Can SILEO be administered without using the syringe provided?

No. This will cause incorrect dosing. (Also, remember to wear impermeable gloves; see more in the Human Safety questions below.)

Can a partially used syringe be reused for additional doses?

Yes, within two weeks, but only if there is enough gel remaining for a complete dose (to minimize the risk of incorrect dosing).

How should SILEO be stored?

Both new and partially used syringes of SILEO should be stored in the carton provided (protected from light) at room temperature.

How should any empty syringes or unused SILEO be disposed?

State and federal medical waste laws apply. The easiest method could be to place the used syringe back into the box and return it to the veterinary clinic. Ask your veterinarian about proper disposal of empty or partially used SILEO syringes.



Answers to most of your general dosage and directions questions can be found here.

Pet Safety

What types of adverse events have been reported?

Very few adverse events have been reported with the use of SILEO. Vomiting, sedation and/or drowsiness were infrequently reported.

Why should I avoid feeding or giving treats to my dog within 15 minutes after dosing SILEO?

Avoiding food and treats 15 minutes after dosing minimizes the risk of your dog swallowing any part of the dose.

What if my dog receives more than the required dose of SILEO?

Much of the excess gel may flow out of the mouth or be swallowed, which would limit the effects on your dog. In a worst case scenario where the entire syringe (3 mL) is accidentally applied to a smaller dog and is fully absorbed, mild to moderate sedation may occur. As always, contact your veterinarian in any situation where you feel your dog has received too much of the prescribed medication.

Human Safety

Why are impermeable disposable gloves required for administration of SILEO?

Although dexmedetomidine (the active ingredient in SILEO) cannot be absorbed through intact skin, it can be absorbed through breaks in the skin and through mucous membranes. Therefore, as a precaution, you should wear impermeable disposable gloves when administering SILEO to your dog.

What if I'm exposed to SILEO?

In the case of accidental exposure to the skin, the area should be immediately and thoroughly washed; remove contaminated clothing and contact your physician if you have questions.

If SILEO comes in contact with your eyes, nose or mouth, it can be absorbed into your body, so you should flush the exposed area with water for 15 minutes. If you are wearing contact lenses, flush the eyes and then remove contact lenses and continue flushing; seek medical advice immediately. If the drug is absorbed into your body, it can cause symptoms such as lowered blood pressure (which may result in dizziness, fainting, lack of concentration, blurred vision, nausea, cold, clammy or pale skin, rapid, shallow breathing), sleepiness and slower heart rate. Share package information with your physician and tell him/her that SILEO contains an alpha-2 adrenoceptor agonist.

Why should pregnant women avoid administering SILEO to their dog?

Although the active ingredient in SILEO, dexmedetomidine hydrochloride, is approved for use as a sedative for humans, it has not been evaluated in pregnant women. Therefore, pregnant women are warned not to administer SILEO to their dogs.

Does your dog suffer from noise aversion?

Look for these common behaviors.

Use the Checklist

Important Safety Information: Do not use SILEO in dogs with severe cardiovascular disease, respiratory, liver or kidney diseases, or in conditions of shock, severe debilitation, or stress due to extreme heat, cold or fatigue or in dogs hypersensitive to dexmedetomidine or to any of the excipients. SILEO should not be administered in the presence of preexisting hypotension, hypoxia, or bradycardia. Do not use in dogs sedated from previous dosing. SILEO has not been evaluated in dogs younger than 16 weeks of age or in dogs with dental or gingival disease that could have an effect on the absorption of SILEO. SILEO has not been evaluated for use in breeding, pregnant, or lactating dogs or for aversion behaviors to thunderstorms. Transient pale mucous membranes at the site of application may occur with SILEO use. Other uncommon adverse reactions included emesis, drowsiness or sedation. Handlers should avoid direct exposure of SILEO to their skin, eyes or mouth. Failure to lock the ring-stop on the syringe before dosing SILEO could potentially lead to an accidental overdose. Always review INSTRUCTIONS FOR USE before dispensing and dosing. See full Prescribing Information.

The product information provided in this site is intended only for residents of the United States. The products discussed herein may not have marketing authorization or may have different product labeling in different countries. The animal health information contained herein is provided for educational purposes only and is not intended to replace discussions with an animal healthcare professional. All decisions regarding the care of a veterinary patient must be made with an animal healthcare professional, considering the unique characteristics of the patient.

Terms of Use

SILEO® is trademark owned by Orion Corporation Orion Pharma Animal Health. It is manufactured by Orion Corporation and distributed by Zoetis under license from Orion Corporation Orion Pharma Animal Health.
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