Felis ISSN 2398-2950

Therapeutics: behavior modifiers

Contributor(s): Kyle Braund, Hill J, Lauren Trepanier

Drugs to modify behavior

  • Relatively new field of treatment - wide range of drugs, many with other indications.
  • Must recognize limitations of medical treatment without behavioral modification programs.


  • Antipsychotics   →   sedation, antimuscarinic effects, alpha-adrenergic blocking activity and extrapyramidal effects.
  • Sedation can limit efficacy of behavioral modification programs (by limiting ability to learn).
  • Acepromazine  Acepromazine maleate.


  • Anxiolytic; minimal side-effects; serotonin agonists.
  • Buspirone hydrochloride*: for aggression, including fear related aggression but ineffective if exposed to intense stimuli; gradual onset of action.


  • Anxiolytics, low risk of toxicity; but long-term use   →    dependency, withdrawal anxiety (withdraw gradually) and interference with memory and learning.
  • Use mainly for short-term relief; very short half-life so needs frequent administration.
    Risk of disinhibition   →   paradoxical increase in aggression.
  • Clorazepate dipotassium*.
  • DiazepamDiazepam. Not first choice in cats, due to risk of rare but sometimes fatal idiosyncratic hepatocellular necrosis.
  • Alprazolam Alprazolam.


  • Tricyclic antidepressants:
    • Prevent re-uptake (  →  inactivation) of noradrenaline and 5-hydroxytryptamine.
    • Also have anxiolytic properties and useful in stereotypic conditions.
    • Non-selective re-uptake inhibitors:
    • Selective 5-HT uptake inhibitor:

Beta-adrenoceptor blocking drugs

  • To reduce anxiety and decrease the somatic symptoms of anxiety - tremors and palpitations; may be useful in aggression.
  • Propranolol*  Propranolol. Non-selective beta blocker.


Opioid antagonists

  • Stereotypic behavior, eg excessive grooming.
  • Concern about effect on other aspects of behavior.
  • Naloxone hydrochlorideNaloxone: injectable only.
  • Naltrexone hydrochloride*.


  • For car travel and mild sedation to counter apprehension, ie using side-effects of the drugs.
  • Chlorpheniramine maleate* Chlorphenamine.
  • Diphenhydramine hydrochlorideDiphenhydramine.

Hormonal preparations

  • Anti-androgen therapy for aggression or where there is a sexual component to behavior - progestogens have anti-androgenic properties  →  non-specific CNS depression.
  • Modern psychoactive drugs have largely superseded progestogens.
  • Delmadinone acetate Delmadinone: chemical castration useful to predict effect of surgical castration on hypersexual behavior; but it also acts on limbic system, so surgical castration may not have same effect; may be disinhibition →  increased aggression.
  • Medroxyprogesterone acetate Medroxyprogesterone.
  • Megestrol acetate Megestrol acetate. Not recommended in cats due to risk of diabetes mellitus.

Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Johnson C (1999) Chemical restraint in the dog and cat. In Practice 21, 111-118.
  • Karas A Z (1999) Sedation and chemical restraint in the dog and cat. Clin Tech Small Anim Pract 14(1), 15-26.

Other sources of information

  • Plumb D C (1999) Veterinary Drug Handbook. 3rd edn. Iowa State University Press, Ames Iowa.