Cat gabapentin protocol

Decision support for shelter cats with high FAS. Includes weaning protocol. For veterinary use only. Version 1.2.

Dose calculator

Enter patient details to see recommended dose.

Decision flowchart

Step 1
Patient assessment
Shelter cat with elevated FAS. Check CKD status, pregnancy or lactation.
Step 2
Score current FAS
Use the FAS scoring reference below. Photos and behaviour descriptors for each score.
Step 3
Select starting dose by FAS
  • FAS 0-1: medication not indicated
  • FAS 2-3: 15 to 25 mg/kg PO q12h
  • FAS 4-5: 25 to 45 mg/kg PO q12h
  • CKD IRIS 2-3: 10 mg/kg PO q12h (any FAS)
Step 4 (administration)
Give by least stressful route
  • If eating reliably: sprinkle capsule contents or liquid on food
  • If not eating or highly stressed: catheter-tip syringe with liquid (100 mg/mL)
  • Do not force tablet a high-FAS cat
Step 5
Reassess at 3 to 5 days
If sedated, reduce 25%. If insufficient, increase 25% (12.5% if CKD). Once stable, reassess every 2 to 4 weeks.
Step 6 (weaning)
If FAS reduces and on medication more than 28 days
  • Day 0: ½ capsule (50 mg) BID for 7 days
  • Day 7: ½ capsule (50 mg) SID for 7 days
  • Day 14: stop
  • Reassess FAS and behaviour 3 to 5 days after each step
If used 28 days or fewer: stop abruptly when FAS no longer warrants medication. No wean needed.

FAS scoring reference

Fear, Anxiety and Stress scoring chart showing FAS 0 through FAS 5 with cat photos and behavioural descriptors
Fear, Anxiety and Stress Scores. Modified from Fear Free Pets.

Drug reference

Gabapentin

GABA analogueAnxiolyticNon-serotonergic
Class
GABA analogue, primarily renally cleared in cats
Available formulations
Capsule 100 mg; Compounded oral liquid 100 mg/mL
Anxiolytic dose (FAS 2-3)
15 to 25 mg/kg PO q12h
Anxiolytic dose (FAS 4-5)
25 to 45 mg/kg PO q12h (start 25 to 30, titrate up if needed)
CKD IRIS stage 2-3
10 mg/kg PO q12h start; do not exceed 25 mg/kg per dose; titrate by 12.5% (not 25%)
Onset and peak
Peak effect approximately 3 hours after PO administration
Pregnancy/lactation
Crosses placenta and milk. Weigh queen welfare against neonate impact
Reassessment
3 to 5 days after start, then every 2 to 4 weeks while on medication
Weaning
Only if used more than 28 days. Reduce by 25% of original weekly; drop frequency at week 3
Common side effects
Sedation, ataxia, hypersalivation, vomiting. Hypotension reported in CKD cats at higher doses

Monitor for side effects

  • Sedation: excessive drowsiness, hard to rouse
  • Ataxia: unsteady gait, stumbling
  • Hypersalivation: drooling, lip-licking
  • Vomiting: particularly within 1-2 h of dose
  • Hypotension: especially in CKD cats at higher doses
  • If any observed: reduce current dose by 25%, recheck in 3 to 5 days

Administration guidance

  • Eating reliably: sprinkle capsule contents or liquid on food
  • Not eating or high FAS: use catheter-tip syringe with liquid (100 mg/mL), or capsule contents diluted in 0.5 to 1 mL water
  • Do not force tablet a high-FAS cat; the handling stress reduces drug benefit and creates negative associations
  • Weaning preparation: open the capsule, divide the powder in half, and mix with 0.5 mL water or chicken stock to give 50 mg. Liquid formulation (100 mg/mL): give 0.5 mL per dose.
  • Sick cat not eating: address underlying cause first (pain, nausea, anorexia), use catheter-tip method for gabapentin if FAS remains high
Version 1.2. Dose ranges sourced from the shelter protocol (Dr. Juliana Xue, Jan 2025), van Haaften et al. (effective 20 mg/kg in healthy cats), Quimby et al. 2022 (CKD pharmacokinetics, supports dose reduction), and Plumb's Veterinary Drug Handbook. Many canine and feline gabapentin recommendations are extrapolated from human pharmacology and anecdotal clinical use. Wean doses are fixed at ½ capsule (50 mg) per step regardless of the pre-wean dose. Always verify against current edition references and use clinical judgement. Press Ctrl or Cmd + P to print.