Current perspectives on the optimal age to spay/castrate dogs and cats

Figures & data

Table 1 Benefits and risks of disease process with and without gonadectomy

Benefit	Risk with gonadectomy	Risk without gonadectomy
Longevity in dogs	Males: 13.8% increase in life span Females: 26.3% increase in lifespan	–
Pyometra	0	Dogs: 25%–66% in those over 9–10 years old Cats: risk unknown, but less than in dogs
Mammary tumors	Dogs: 0.5% if prior to the first estrus Cats: 86% decreased risk if before 1 year	Dogs: 23%–63%, with 50% being malignant Cats: half the risk of dogs, with 85%–93% being malignant and 80% already metastasized when diagnosed
Benign prostatic hyperplasia	0	75%–80% of intact dogs by 6 years: predisposes to other life-threatening prostate diseases 95%–100% of intact dogs by 9 years: predisposes to other life-threatening prostate diseases
Testicular neoplasia	0	Risk unknown, but <1% will die from tumor

Table 2 Breed-specific lifetime risk of disease processes based on neuter status and timing of gonadectomy

Breed	Sex	Risk	Gonadectomy ≤12 months	Gonadectomy >12 months	Intact
Rottweiler	M	OSA	28%	–	8%
	F		25%	–	8%
Golden retriever	M	Hip dysplasia	10.2%	3.1%	5.1%
Golden retriever	M	CCL rupture	5.1%	1.4%	0
	F		7.7%	0	0
Golden retriever	M	LSA	9.6%	0	3.5%
Golden retriever	F	HSA	1.8%	7.4%	1.6%
Golden retriever	F	MCT	2.3%	5.7%	0
Labrador retriever	M	CCL rupture	<6 m – 7.6%	12–23 m – 1.9%	2.3%
			6–11 m – 2.8%	2–8 y – 0
Labrador retriever	M	Elbow dysplasia	<6 m – 4.2%	12–23 m – 0	0.6%
			6–11 m – 0	2–8 y – 2.2%
Labrador retriever	F	Hip dysplasia	<6 m – 5.4%	12–23 m – 4.3%	1.7%
			6–11 m – 5.1%	2–8 y – 0
Vizsla	M	LSA	0.3%	0.4%	0.2%
	F		0.3%	1.1%	0.1%
Vizsla	M	HSA	0	0.6%	0.4%
	F		0.5%	1.1%	0.1%
Vizsla	M	MCT	0.5%	1.3%	0.5%
	F		1.1%	1.9%	0.6%

Abbreviations: M, male; F, female; OSA, osteosarcoma; CCL, cranial cruciate ligament; LSA, lymphoma/lymphosarcoma; HSA, hemangiosarcoma; MCT, mast-cell tumor; m, months of age; y, years of age.