Introduction

• Adrenal disease is an infrequent condition in rabbits that commonly presents with clinical signs related to the excess of sex hormones.
• Cause: adrenal tumors, probably associated with neutering.
• Signs: increase in sexual behaviors.
• Diagnosis: clinical signs, clinical history, determination of serum sex hormones.
• Treatment: adrenalectomy.
• Prognosis: fair.

The adrenal glands

Anatomy

• Adrenal glands lie near the craniomedial border of their respective kidneys, against the dorsal body wall (their position is retroperitoneal).
• The left adrenal is adjacent to the cranial mesenteric artery (cranial abdominal arteries) and the right lies in close proximity to the caudal vena cava .

• As the kidney, the right adrenal gland is more cranial than the left adrenal gland.
• Average size right adrenal gland: 0.88 x 0.42 x 0.16 cm (length x width x thickness).
• Average size left adrenal gland: 0.72 x 0.46 x 0.17 cm (length x width x thickness).
• The right adrenal gland is significantly more elongated than the left one.
• There is no difference in size of adrenal glands between males and females.

Function/physiology

• Adrenal glands have important endocrine roles: secrete catecholamines, mineralocorticoids and glucocorticoids (including sex steroids).
• The adrenal gland has two structurally and functionally different tissues: outer cortex and inner medulla.

• Sex hormones are produced in the cortex of the adrenal gland.

Pathogenesis

Pathophysiology

• The pathogenesis of adrenal disease in rabbits is not well or completely understood.
• It is possible that, similar to other species such as ferrets or mice, gonadectomy contributes to adrenocortical hyperplasia and later tumorigenesis:
  • Using this hypothesis, adrenocortical hyperplasia might be secondary to the loss of feedback inhibition from the gonads to the hypothalamic-pituitary axis, which leads to chronic elevation in circulating luteinizing hormone (LH) causing synthesis and secretion of sex steroids from the adrenal cortex.
  • If this hypothesis is assumed, then it is likely that the condition will be, ultimately, bilateral.
• Excess testosterone can increase aggressive behaviors in both male and females, but excess progesterone can also increase aggressive behavior in female rabbits.

Diagnosis

Treatment

Prevention

Outcomes