Sileo is a dexmedetomidine oromucosal gel approved for the treatment of noise aversion in dogs older than 16 weeks of age. Dexmedetomidine is an α-2 adrenergic agonist that acts as a sedative and anxiolytic.

The concentration is 0.1 mg/mL. The dose for noise aversion is 125 µg/m2. Sileo comes in a pre-measured dosing syringe where each dot represents 0.25ml of medication. A full syringe contains 3ml of medication.

Select the proper dose by moving the ring stop on the syringe. Remove the tight-fitting cap. Administer dose in the cheek pouch by positioning the syringe and depressing the plunger. If this dose is more than 6 dots, it is recommended to divide the dose between both sides of the mouth. The gel is not effective if swallowed. Avoid giving food, water, and treats for 15 minutes.Instructions for Use

Instructions for use

  • Latex or non-latex gloves should be worn when handling the syringe.
  • The first dose should be administered 30-60 minutes before the stimulus or immediately after the patient exhibits signs of noise aversion or anxiety.
  • The dose may be repeated if the noise and/or symptoms last longer than 2-3 hours. No more than 5 doses should ever be administered during a single noise/anxiety event.
  • Return syringe to original packaging to reduce exposure to light.
  • Once opened, the medication within the syringe is good for up to 2 weeks when stored properly.


  • Severe cardiovascular, respiratory, liver, or kidney disease
  • Shock or hypotension
  • Severe debilitation
  • Stress related to heat, cold, or fatigue
  • Pregnancy
  • Bradycardia

Side effects

  • Mild vomiting, gastroenteritis
  • Pale gums (transient)
  • Severe debilitation


  • Over-sedation and collapse
  • Bradycardia
  • AV block
  • Elevated ALT

Treatment of overdose

  • Antisedan (IV or IM depending on severity of signs)
  • Supportive care as needed

Additional resources

Last updated: 2017-03-09