Early Spay/Neuter: An Overview, conclusion

Several of these studies addressed the question of long-term effects on the health of the animal by comparing, at maturity, groups of animals neutered at 6 to 7 weeks and at 6 to 7 months. The resulting resting metabolic rate and predisposition to obesity of cats neutered in these two age categories have been compared after 24 months of age (5,7). The urethral diameters of male or female cats neutered in these categories was compared at 22 months of age (8).

Many aspects of skeletal dimensions, body weight and composition, physical maturation, secondary sex characteristics or behavioral development of cats (6) and dogs (11,13) neutered/spayed in the two groups were compared at one year of age. The only notable difference found was that the animals neutered at 6 to 7 weeks of age were more likely to have immature external genitalia at maturity; this has no known clinical significance (6,8,11). The benefits of neutering are the same at either age: reduced risk of reproductive disorders and of mammary neoplasia.

Animal shelters, being closest to the tragedy of mass euthanasia, were first to adopt early spay/neuter policies. [The LA/SPCA adopted its policy, requiring mandatory spay/neuter of all adoptable dogs and cats prior to leaving the shelter, in 1992] Even though the majority of animal care and control facilities have a mandatory spay/neuter policy, typical compliance rates are from 50% to 60%, in spite of pre-adoption screening, spay/neuter contracts, and follow-up reminders (14). Early spay/neuter provided the potential for 100% compliance by requiring pups and kittens to be neutered before being adopted out. However, only a small percentage of pets are acquired from animal shelters, so neutering these animals can only have a small effect on the overpopulation problem (10). If veterinarians were to recommend neutering pups and kittens at an early age, a significant decrease in unwanted animals could result.

These studies indicate that early spays benefit the animal, the owner, animal population control, and you, the veterinarian. The animal benefits because the anesthesia is fast and uneventful; surgical procedure is well tolerated and animals recover faster. If made part of the standard puppy/kitten vaccination program, it would also benefit owners by decreasing the number of veterinary office visits necessary upon acquiring a new pet. This convenience to owners would lead to increased compliance on their part and thereby decrease the number of unwanted dogs and cats produced each year. The veterinarian benefits because spays and neuters at 6 to 7 weeks of age are easier and faster than at 6 to 7 months, they help reduce animal overpopulation, and higher owner compliance means more business. It also gives veterinarians the opportunity to interact with shelters, pet stores, and breeders and be seen as leaders in animal welfare in our communities.

References

1. AVMA News Spaying/neutering comes of age JAVMA 1993; 203:591-593.

2. Aronsohn MG, Faggella AM. Surgical techniques for neu-tering 6- to 14-week-old kittens JAVMA 1993; 202:53-55.

3. Faggella AM, Aronsohn MG. Anesthetic techniques for neutering 6- to 14- week-old kittens JAVMA 1993; 202:56-62.

4. Guarneri-Boe MA, Lange D. When to Neuter: the Con-troversy Iowa State University Veterinarian 1995; 57:6-9.

5. Root MV. Early Spay-Neuter in the Cat: Effect on Development of Obesity and Metabolic Rate Veterinary Clinical Nutrition 1995; 2:132-134.

6. Stubbs WP, et al. Effects of prepubertal gonadectomy on physical and behavioral development in cats JAVMA 1996; 209:1864-1870.

7. Root MV, et al. Effect of prepuberal and postpuberal gonadectomy on heat production measured by indirect calorimetry in male and female domestic cats Am J Vet Research 1996; 57:371-374.

8. Root MV, et al. Effect of prepuberal and postpuberal gonadectomy on penile extrusion and urethral diameter in the domestic cat. Veterinary Radiology & Ultrasound 1996; 37:363-366.

9. Mackie WM. It's Time For Early Age Neutering. California Veterinarian 1992; 46:19-21.

10. Theran P. Early-age neutering of dogs and cats JAVMA 1993; 202:914-917.

11. Salmeri KR, et al. Gonadectomy in immature dogs: Effects on skeletal, physical, and behavioral development JAVMA 1991; 198:1193-1203.

12. Faggella AM, Aronsohn MG. Evaluation of anesthetic protocols for neutering 6- to 14-week-old pups JAVMA 1994; 205:308-314.

13. Crenshaw WE, Carter CN. Should dogs in animal shelters be neutered early? Veterinary Medicine 1995; 90:756-760.

14. Moulton C, Early Spay/Neuter: Risks and Benefits for Shelters American Humane Shoptalk 1990; 7:1-6 and 8:1-9.

* American Veterinary Medical Association
** Illinois State Veterinary Medical Association

Illinois Veterinary Bulletin Volume 6, Number 1, April 1998

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