Alpha-2 Agonist Sedatives for Dogs in Canada 2025: Veterinary-Reviewed Top 5 Options (Dexdomitor, Domitor, Sileo, Zenalpha, Antisedan) — When to Use Each

Dexdomitor is positioned as a best-in-class injectable alpha-2 agonist for precise sedation and analgesia in dogs thanks to dexmedetomidine's high alpha-2 selectivity and predictable cardiorespiratory profile. Compared with medetomidine-based options on this list, Dexdomitor typically achieves target sedation at lower active-molecule doses, offering clinics a technically efficient option that can be cost-effective despite a higher unit price. Its reliability for controlled procedural sedation makes it a premium injectable choice relative to oromucosal or older medetomidine formulations.

Domitor has long been a market leader among medetomidine injectables due to broad clinical familiarity and a deep track record for routine sedation and premedication in dogs. While less alpha-2 selective than dexmedetomidine brands, Domitor's major advantage is economic: it is widely available, often more affordable or genericized than newer agonists, and pairs predictably with the reversal agent Antisedan. For practices prioritizing cost and well-established protocols over maximum selectivity, Domitor remains a dependable standard.

Sileo stands out as the leading non‑injectable formulation, offering dexmedetomidine in an oromucosal gel optimized for situational anxiety (e.g., noise phobias) and at‑home use, which reduces the need for clinic visits and injections. Compared with injectable dexmedetomidine and medetomidine products, Sileo provides a technical and financial advantage for outpatient management by lowering chair time and enabling targeted dosing for episodic stress, albeit at a premium retail price. Its unique route of administration complements the injectable options on this list rather than replacing them.

Zenalpha is a newer medetomidine product that competes by offering an updated formulation and modern packaging aimed at improving dosing convenience and tolerability for clinics. Technically similar to Domitor in active ingredient, Zenalpha's market position is built on formulation refinements and competitive pricing intended to capture practices that want medetomidine's clinical profile with improved usability. Compared to dexmedetomidine products, it remains a cost-conscious medetomidine alternative while relying on the same established reversal strategies.