how do I combine trazodone and gabapentin for situational or generalized anxiety in dogs and what are the dosing protocols?

Question

Accepted Answer

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).1 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.4 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.3 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.1 Heart rate was decreased but remained within normal limits; no other hemodynamic variables differed significantly between premedicated and unpremedicated dogs.1 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.4 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.24 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 a