Gabapentin (20 mg/kg PO) and trazodone (8 mg/kg PO) administered together 2 hours before anesthesia or a stressful event is the best-studied combination protocol in dogs, producing a 0.33% reduction in isoflurane MAC compared to isoflurane alone (mean MAC 0.625% with premedication vs. 0.95% without).American Journa…
For situational anxiety — including veterinary visits — both drugs are appropriate for owner administration the day before and the day of the appointment. The 2015 AAHA Canine and Feline Behavior Management Guidelines list gabapentin and trazodone (as a serotonin 2A antagonist/reuptake inhibitor) among medications suitable for q12–24h or as-needed dosing around veterinary visits.AAHA Clinical G… The 2019 AAHA Dental Care Guidelines specifically recommend trazodone for anxious dogs before conscious oral examination, ideally given the evening before and at least 2 hours before presentation.AAHA Clinical G…
The MAC-reduction study used gabapentin 20 mg/kg PO and trazodone 8 mg/kg PO, both given 2 hours before the procedure, and this is the only canine combination protocol with a specific published dose pair and quantified outcome.American Journa… Heart rate was decreased but remained within normal limits; no other hemodynamic variables differed significantly between premedicated and unpremedicated dogs.American Journa…
For generalized anxiety managed on a daily basis, gabapentin can be used as a standing medication. The 2015 AAHA guidelines include gabapentin among daily medications for general fears and anxieties, with onset of effect for some medications taking 5–8 weeks.AAHA Clinical G… Trazodone is similarly listed for daily use and has been used long-term in dogs with anxiety disorders, with trazodone reserved for higher-intensity triggers such as boarding or unfamiliar visitors when gabapentin is already the baseline agent.Journal of the…+1
The combination produces additive to synergistic central nervous system depression. Gabapentin approximately 20 mg/kg combined with trazodone approximately 5 mg/kg significantly decreased electroretinographic a-wave and b-wave amplitudes in clinically normal dogs, though the effects were judged to have little clinical importance in dogs with normal retinal function.American Journa… Trazodone at approximately 20 mg/kg produced more pronounced ERG suppression than the lower dose, and heavier dogs receiving higher total trazodone doses showed greater amplitude decreases.American Journa… These findings support using the combination cautiously in dogs with known or suspected retinal disease.American Journa…
Sedation is the most consistent adverse effect of trazodone when given orally to dogs, and this effect is dose-dependent.Journal of Vete… The wide safety margin and low risk of additional adverse effects make trazodone an attractive first-line anxiolytic.Journal of Vete… Gabapentin's adverse effects are primarily dose-dependent sedation and ataxia, which can affect quality of life at higher doses.WSAVA Global Gu…
| Drug | Dose (combination protocol) | Timing | Key Outcome | Key Caveat |
|---|---|---|---|---|
| Gabapentin | 20 mg/kg PO | 2 hr before event | MAC reduced 0.33%; anxiolytic and sedative | Ataxia and sedation dose-dependent; reduce dose in renal disease |
| Trazodone | 8 mg/kg PO | 2 hr before event | Significant MAC sparing in combination | Sedation consistent adverse effect; use caution with retinal disease |
| Combination | Gabapentin 20 mg/kg + trazodone 8 mg/kg PO | 2 hr before event | Mean isoflurane MAC 0.625% vs. 0.95% without | ERG suppression at higher trazodone doses; monitor in retinal disease |
Would you like guidance on how to adjust these doses when the dog is already on a daily SSRI or other serotonergic medication?