Here's why:
* Ejaculation vs. Erection: Dogs can still experience a "pseudo-erection" after castration, meaning the penis may become engorged with blood and appear erect. This is usually due to reflexive muscle contractions in the penis and is not related to sexual desire. It's often triggered by things like petting, being excited, or even urinating.
* Hormones: Castration significantly reduces testosterone levels, the primary hormone responsible for sexual desire and behavior in dogs. While a dog might still engage in mounting behavior after castration, it's usually not motivated by sexual desire.
Therefore, it's more accurate to say that dogs can experience a pseudo-erection after castration, rather than a true erection.
If you have concerns about your dog's behavior after castration, it's always best to consult with your veterinarian for professional advice.