Introduction

• Difficult to define but includes: growling, snarling or biting in an attempt to 'see off' intruder.
• Seen in post-parturient bitch or pseudopregnancy stimulated by real or perceived threat to her litter.

Pathogenesis

Etiology

• Neurophysiological influences: instinctive protective behavior of mother towards her young.
• The level of stimulus (of perceived threat).
• Bitch's experience/learned effects of consequences of behavior.
• Bitch's hormonal status.
• Bitch's phenotype.

Pathophysiology

• The probability that threat and attack will be generated under defined circumstances is determined by:

• Natural protective maternal behavior real or adopted items.
• Aggression directed against a perceived threat to her puppies.

• Probably subtle interaction between bitch's genotype and environment.
• Disposition to aggression.

• Previous experience.
• Actual situation in which bitch finds herself.
• Hormonal status: sex steroids may have direct effect on brain.
• Metabolic disturbances.
• Irritability due to maternal disease, eg mastitis.
• Hunger.

• Aggression is difficult to define and relate to physiological mechanisms but it is likely that this behavior is under the influence of groups of neural units rather than a specific aggression center of the brain.
• Hormonal status modifies intensity of response.

Timecourse

• In acute episodes the behavior may only last as long as threat is perceived.
• As the litter gets older and is weaned, the intensity of maternal aggression will often reduce.
• Intensity of aggression may increase if final response is perceived to be effective by aggressor and threats ineffective.

Diagnosis

Treatment

Prevention

Outcomes