[troupo]

They are not done. They claim they sterilized all the dogs. If they stop doing what they're doing even for a year, they'll have to do this again.

Sterilization alone doesn't work.

[samus]

I agree. Their numbers are either so low that it counts as "done", or they actually didn't encounter any for a certain amount of time. They must either continuously sterilize the small trickle of remaining strays or plan a follow-up campaign. Implementing low-cost tree registration of pets should also help.