Venlafaxine for Treatment of Behavioral Disorders in Cats

In the Literature

Masson S, Metz D, Bleuer-Elsner S, Schwobthaler F. Retrospective study on the use of venlafaxine in 176 cats diagnosed with behavioral disorders. J Vet Behav. 2025;77:1-10. doi:10.1016/j.jveb.2024.11.004

The Research …

Psychopharmaceuticals are commonly prescribed to treat behavioral disorders in cats. Venlafaxine is a serotonin and norepinephrine reuptake inhibitor with serotonergic effects that mainly occur at low doses and noradrenergic effects that are enhanced at higher doses.¹ Venlafaxine has been proposed as a treatment for narcolepsy–cataplexy, neuropathic pain, and behavioral disorders in dogs^2-5 and has effectively treated idiopathic cystitis, refractory misdirected play, and refractory impulsive aggression in cats.^6-8 Venlafaxine capsules contain small granules (Figure) that can be easily ingested, which can help facilitate administration in cats.

FIGURE Venlafaxine granules displayed next to a dime for scale. Image courtesy of Amy Learn, VMD, DACVB

This retrospective study evaluated the use of venlafaxine in cats (n = 176) for treatment of behavioral disorders, including aggression toward familiar humans, aggression toward unfamiliar cats, and periuria. All patients were managed with an environmental and behavioral modification plan in conjunction with medication. Venlafaxine was administered at ≈1 mg/kg PO, which corresponds to ≈4 granules/kg from the brand-name capsule.

Pet owner compliance was high due to ease of granule administration, with 94.3% of owners reporting no difficulty. Adverse effects were present in 35.4% of cats (decreased energy level was most common) but typically dissipated within 2 weeks. Treatment outcomes were good to excellent in >80% of cats.

… The Takeaways

Key pearls to put into practice:

• Venlafaxine is an effective behavior-modifying drug in cats and should be considered in cases of high arousal and impulsive aggression due to its noradrenergic effect. Most owners in this study reported improvement in >50% of behavioral signs. About 20% of cats were weaned off the medication without relapse of clinical signs.

• Venlafaxine is easy to administer in cats. Brand-name capsules should contain approximately the same number of granules, but the number of granules in generic capsules may vary. Generic forms are prescribed more often due to cost. As an alternative, the author prescribes one-fourth of a generic 25-mg tablet (6.25 mg) to achieve a similar dose.

• Adverse effects were transient in this study. Decreased energy level was most frequently reported and has also been observed with other common behavior-modifying drugs.^9,10

• Venlafaxine may be preferable to fluoxetine or clomipramine for use in cats with a history of idiopathic cystitis or constipation, as venlafaxine has less of an anticholinergic effect.¹