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*.
  • Diazepam*   Diazepam  . Not first choice in cats, due to risk of rare but sometimes fatal idiosyncratic hepatocellular necrosis.
  • 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.


  • If behavioral symptoms related to seizure activity - see Therapeutics: anti-epileptics   Therapeutics: anti-epileptics  .
  • Thought to have a non-specific mood stabilizing effect.
  • Phenobarbitone  Phenobarbital  .

Opioid antagonists

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


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

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 fromPubMed.
  • Johnson C (1999)Chemical restraint in the dog and cat. In Practice21, 111-118.
  • Karas A Z (1999)Sedation and chemical restraint in the dog and cat. Clin Tech Small Anim Pract14(1), 15-26.

Other sources of information

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