Definition

Human-directed aggression in cats

Pathophysiolgy

The more common causes for human-directed aggression in cats include play, fear/pain-related, redirected, maternal, and petting intolerance. Context is going to contribute greatly when making the correct diagnosis. For example, play aggression is likely to be seen in a young, solitary cat, while pain-related/fear aggression is a common behavior seen in the clinic setting.

Systems Affected

• Behavioral
• Gastrointestinal-decreased appetite if fear and/or pain-related
• Hemic/Lymphatic/Immune-chronic stress effects on immune function
• Ophthalmic-dilated pupils in response to autonomic nervous system stimulation
• Skin/Exocrine-may show displacement behaviors such as overgrooming

Genetics

There is no known genetic basis for human-directed aggression in cats.

Incidence/Prevalence

Aggression is second only to inappropriate elimination for feline cases seen by veterinary behavior specialists.

Geographic Distribution

None

Signalment

Cats of any age, gender/neuter status, breed can be affected. Play-motivated aggression more likely in juvenile, solitary cat.

Signs

• Play-motivated: cat approaches its “victim,” crouches in wait, stalks and chases; tail is twitching and ears are forward. Typically will attack moving target.
• Fear/Pain-related: ears back, body and tail lowered, piloerection, pupils dilated; may hiss and growl. Avoidance of person(s) who elicit the aggression. Attacks possible if approached and/or cornered. Extreme cases: expression of anal glands, urination, and/or defecation. Hiding behavior.

• Redirected: cat is highly aroused by stimulus and seeks out less appropriate target. Aggression can be very severe given the cat's level of arousal.

• Maternal: usually predictable and self-limiting. Queen will act to protect her kittens.

• Petting intolerance: cat signals its “displeasure” by twitching its tail and skin when being petted in an undesired location and/or for too long. Ears are usually back; mydriasis; may hiss and growl before turning to bite person.

Causes & Risk Factors

• Play-motivated: lacking in opportunities for normal play-no other cats, insufficient and/or inappropriate toys; history of owner using hands/feet to play with kitten and/or playing roughly with the kitten.
• Fear: poor socialization with humans and/or feral living, an aversive event associated with a person, or people in general.
• Pain-related: obvious medical/physical condition.
• Redirected: occurs during interference in, or interruption of, situations that have caused the cat to become aggressively aroused-such as a cat fight (between familiar household cats), the presence of a cat outside or noise.
• Maternal: recent birth of litter.
• Petting intolerance: exact etiology unknown. Cats tend to groom each other on head/neck so human grooming of cat in other locations may contribute to aggressive reaction.

Differential Diagnosis

See causes above

CBC/Biochemistry/Urinalysis

Rule out contributing medical conditions based on presentation.

Other Laboratory Tests

• Senior cats: a complete thyroid panel.
• Urinalysis if inappropriate elimination and/or urine marking is presented as part of the aggression.

Imaging

Based on clinical examination and/or suspected pain component

Diagnostic Procedures

Thorough behavioral history including a description of the cat's postures during aggression and injuries inflicted, context, presence of outside cats, early historical information, litter box use, food consumption, and hiding behaviors.

Pathologic Findings

N/A

Appropriate Health Care

Applicable only if health/medical issue diagnosed.

Nursing Care

Applicable only if health/medical issue diagnosed.

Activity

• Play-motivated: cat should be provided with increased opportunity for appropriate play-either in the form of toys, human interaction, or additional housemate.
• Redirected: cat should be denied access to windows where outside cats can be seen.

Diet

• Hill's Science Diet c/d Multicare Feline Urinary Stress
• Royal Canin Feline Calm
• Either may be beneficial in helping to decrease anxiety.

Client Education

• Play-motivated: normal play behavior and the importance for opportunities for appropriate play.
• Fear: avoidance of fear-inducing situations-ongoing exposure may worsen signs, cause severe stress, and compromise animal welfare.
• Redirected: importance in addressing primary stimuli-such as outside cats.
• Maternal: normal maternal and kitten-protective behavior-same as for fear-motivated aggression.
• Petting intolerance: normal feline grooming patterns; observation of cat's warnings so that behavior does not escalate.

Drug(s) Of Choice

Contraindications/Precautions/Possible Interactions

• None of the drugs listed are approved for use in cats.
• All of the medications are to be administered orally, as they have not been shown to be effective through transdermal dosing.
• Azapirones: side effects are uncommon but occasional excitement is noted. Should not be given in combination with an MAOI. Avoid use in the aggressor cat; may increase any “bully” behavior.
• Neither SSRIs nor TCAs should be given with each other, nor in combination with MAOIs.
• SSRIs: side effects include mild sedation and decreased appetite, constipation, and urinary retention. Competitive inhibition of cytochrome P450 liver enzymes; when administered concurrently with medication utilizing the P450 enzymes, elevated plasma levels of the medications may increase, causing toxic levels.
• TCAs: side effects include sedation, constipation, diarrhea, urinary retention, appetite changes, ataxia, decreased tear production, mydriasis, cardiac arrhythmias, tachycardia, and changes in blood pressure.
• Benzodiazepines: side effects include sedation, ataxia, muscle relaxation, increased appetite, paradoxical excitation, and increased friendliness. Idiopathic hepatic necrosis has been reported in cats.
• Specific recommendations for the use of diazepam: baseline physical exam, CBC, and blood chemistries to confirm good health. Repeat the blood chemistries at 3–5 days. Elevated ALT or AST, discontinue the medication.

Alternative Drugs

Patient Monitoring

Weekly follow-up is recommended in the early stages of treatment, especially when on medication(s). Monthly follow-up once stable. For cats on medication, follow-up blood testing recommended every 6–12 months.

Prevention/Avoidance

• Play-motivated: provide opportunities for appropriate play.
• Fear: avoidance of the fear-inciting stimuli if at all possible. Early socialization to people and events may help prevent some occurrences of fear-related responses to people.
• Pain: treat underlying condition(s).
• Redirected: address possible arousing stimuli-indoors and outdoors.
• Maternal: as for fear.
• Petting intolerance: limit amount of time petting the cat; desensitization and counter-conditioning to increase petting time.

Possible Complications

Potential human injury in all of the above cases, especially if the cat is approached or cornered and/or when highly aroused.

Expected Course and Prognosis

Progress occurs slowly. Relearning is a process and each case is individual. If medications are indicated, begin at a low dose and work up as necessary. To discontinue medication, wait until the new behavior is stable (8–12 weeks) and wean off slowly, usually over weeks. If aggressive behavior recurs, return to the last dose that controlled the anxiety/reactivity and continue treatment.

Associated Conditions

N/A

Age-Related Factors

Play-motivated: typically seen in young, solitary cat in household.

Zoonotic Potential

People injured during an aggressive attack should seek prompt medical attention. Infection by Bartonella henselae can result from a cat scratch or bite.

Pregnancy/Fertility/Breeding

Avoid medications in breeding/nursing cats.

Synonyms

N/A

See Also

• Aggression Overview-Cats
• Fears, Phobias, and Anxieties-Cats

Abbreviations

• CC = classical conditioning
• DS & CC = desensitization and counter-conditioning
• MAOI = monoamine oxidase inhibitor
• SSRI = selective serotonin reuptake inhibitor
• TCA = tricyclic antidepressant

Author Terry Marie Curtis

Consulting Editor Gary M. Landsberg