Desexed animals still have sex, trust me that doesn't stop it.
How can they do it if their sexual organs were removed?
Huh? you think they have their penis removed?
No.
The operation involves a short general anaesthetic, and usually just the day in hospital. Both testicles are removed through small incisions in the scrotum, but no stitches are required. And the animal can still function sexually but only discharges Pre Cum fluid and no sperm. Because the testicles are not there to produce it.
They still are able to preform all sexual needs.
As for females, the operation involves a short general anaesthetic and the dames full reproductive organs are moved either through a large incision on the belly or side, requiring 10 -12 stitches. Also need to monitor her for 12-14 days before the stitches are removed by a vet. if they come out can course infection and organ damage. As you can well imagine far more involved with female desexing than a males.
the Dame will be left with a hollow inside, which will not hamper any sexually activity she wishes to preform.
The thing is, unlike humans, animals mate to breed or show dominance, not for pleasure.