Introduction

• Cause: usually solitary guinea pig. Extreme stress or fear reaction.  Environment unsuitable: no hide area, no cage mates/social interaction, loud noise, excessive handling. Example: young children’s day care center.
• Signs: will sit immobile or slightly trembling.
• Diagnosis: evaluation of husbandry and environment. May do full workup (including physical examination, bloodwork, imaging) as is done with anorexia to rule out other reasons for clinical signs, lack of moving around the cage.
• Treatment: initially in the clinic, an anxiolytic such as midazolam. Troubleshoot the environment and correct husbandry.
• Prognosis: good if cause of fright can be corrected.

Pathogenesis

Etiology

• Guinea pigs are a prey species and highly social animal.
• If housed singly, and in a noisy environment without a place to hide, they become so frightened and stressed that they freeze. This was called “hysteria” in older literature. Now it is usually just referred to as stress, fear responses.

Predisposing factors

General

• Solitary animal.
• Habitat without a hiding area such as a box.
• Noisy, chaotic environment such as in a children’s classroom, laboratory animal facility, pet shop.

Specific

• Guinea pigs do not adapt well to new environments.
• They imprint on specific foods and furnishings early in life and changes in food or habitat sometimes result in an extreme fear behavior.
• Abrupt diet change may contribute to stress and serious digestive disturbances.
• Lack of adequate vitamin C Vitamin C may contribute to stress Vitamin C deficiency.

Pathophysiology

• Stress/fear response of this prey species is to hide and freeze.
• In a cage, the guinea pig will sit immobile and tense, try to hide (such as face towards the rear of the cage, actually use a cloth or hide box, or even tuck head under a dish or sipper tube spout).
• A fearful guinea pig will not eat or drink which may contribute to the development of dental disease, anorexia complications (such as GI stasis Gastrointestinal stasis, dysbiosis).

Timecourse

• Usually occurs within the first few days in a new environment.

Diagnosis

Treatment

Prevention

Outcomes