While spaying can have some behavioral effects on dogs, decreased playfulness is not a typical outcome. In general, spaying does not significantly impact a dog's personality or activity levels. Factors such as breed, individual temperament, socialization, training, and environmental influences play more significant roles in shaping a dog's behavior and playfulness.
Spaying can primarily affect behaviours related to reproduction and heat cycles. These include reduced instances of roaming, decreased attraction from male dogs, and the elimination of heat-related behaviours such as bleeding, nesting, and mood changes.
Spaying can also have some positive behavioral effects, such as reduced aggression, as reproductive hormones can influence aggression in some dogs. However, the impact on aggression varies and is not a guarantee.
Overall, spaying does not usually lead to a dog becoming less playful. If you're concerned about any behavioral changes in your dog after spaying, it's best to consult with your veterinarian or a qualified animal behaviorist.