De-sexing complications

Etiology (cause)

Complications arise primarily from the removal of functional gonads (ovaries or testes), which disrupts normal hormone production. Gonadectomy eliminates estrogen, progesterone, and testosterone, all of which play critical roles in:

• Calcium metabolism and bone remodeling
• Pituitary gland feedback and endocrine balance
• Immune function
• Tissue proliferation regulation, including mammary and reproductive organs

Loss of gonadal hormones can lead to secondary pathologies in multiple organ systems.

Clinical Signs

Post-gonadectomy complications may present immediately or develop chronically, including:

• **Skeletal and metabolic changes:**

 * Osteoporosis, osteopenia, or early-onset osteoarthritis  
 * Poor calcium absorption and increased urinary excretion, leading to bladder sludge and urolithiasis  

• **Endocrine disturbances:**

 * Pituitary hyperplasia or adenomas due to loss of negative feedback  
 * Altered prolactin, cortisol, and gonadotropin levels  
 * Increased susceptibility to adrenal or mammary tumors  

• **Cancer risks:**

 * Elevated incidence of mammary and hormone-sensitive tumors in spayed females  
 * Potential increase in pituitary or adrenal neoplasms  
 * Increased cumulative lifetime risk of osteosarcoma or other bone-related malignancies  

• **Behavioral and physiological effects:**

 * Altered metabolism, obesity  
 * Reduced immune surveillance, potentially allowing earlier or more aggressive tumor development  

• **Surgical complications:**

 * Immediate post-operative mortality due to anesthesia or GI stasis  
 * Adhesions, hemorrhage, or infection  

Treatment, Prevention, and Control

• **Treatment:**

 * Management of osteopenia/osteoporosis: dietary calcium optimization, vitamin D supplementation, weight-bearing activity  
 * Monitoring for endocrine tumors via ultrasound or bloodwork (hormone panels, prolactin, cortisol)  
 * Prompt intervention for urinary stones or sludge: hydration, medical dissolution, surgical removal if necessary  
 * Cancer treatment as indicated: surgical excision, chemotherapy, or palliative care depending on tumor type and stage  

• **Prevention and Risk Mitigation:**

 * Delay elective spay/neuter until rabbits are fully grown and bone mineralization is near complete, when feasible  
 * Maintain balanced diet with appropriate calcium:phosphorus ratios and vitamin D  
 * Provide enrichment and exercise to support musculoskeletal health  
 * Avoid unnecessary gonadectomy in low-risk populations or in lines with reduced genetic predisposition to uterine or mammary neoplasia  
 * Regular veterinary screening for endocrine abnormalities or neoplasia in middle-aged and older rabbits  

• **Long-Term Monitoring:**

 * Bone density and body condition scoring annually  
 * Routine reproductive and adrenal imaging where clinically indicated  
 * Hormonal panels for at-risk or symptomatic rabbits  

References

• Whitehead, M.L. (2017). Letter: Rabbit health. *Veterinary Record*, 180(3):77. https://doi.org/10.1136/vr.j826
• Bradbury, A.G., & Dickens, G.J.E. (2016). Should we advocate neutering for all pet rabbits? *Veterinary Record*, 179(24):654–655. https://pubmed.ncbi.nlm.nih.gov/28008120/
• McClellan, L., et al. (2020). Long-term endocrine consequences of gonadectomy in lagomorphs. *Frontiers in Veterinary Science*, 7:123. https://doi.org/10.3389/fvets.2020.00123
• Harcourt-Brown, F.M. (2002). Calcium metabolism and urolithiasis in rabbits. *Journal of Exotic Pet Medicine*, 11(3):143–152.
• Pieper, E.G., Carter, J.E., Firestone, S.M., & Baron, H.R. (2025). Perioperative mortality in pet rabbits in Australia. *Australian Veterinary Journal*, 103(1–2):3–12. https://doi.org/10.1111/avj.13391
• Baine, K., Newkirk, K., Fecteau, K.A., & Souza, M.J. (2014). Elevated Testosterone and Progestin Concentrations in a Spayed Female Rabbit with an Adrenal Cortical Adenoma. *Case Reports in Veterinary Medicine*, 2014:239410. https://doi.org/10.1155/2014/239410