Why hasn't my dog lost any weight even though I'm feeding less?

This is one of the most common and frustrating ones, and there's usually a reason hiding in plain sight. The big one is treats and extras. A few dental chews, the crusts off the kids' toast, a bit of cheese to hide a tablet: it all adds up, and it can quietly cancel out everything you've trimmed from the bowl. For a small dog especially, one biscuit is a bigger deal than it looks.

The next thing to check is whether "feeding less" is actually less. If you're eyeballing a scoop, portions creep up without you noticing, so kitchen scales sort that out in about ten seconds a meal. It's also worth a quiet word with everyone in the house, because two people each giving "just a little bit" is a classic way for a dog to stay exactly the same weight.

If you've genuinely tightened everything up, measured food, treats counted in, no table scraps, and there's still no movement after a month or so, it's time to see your vet. Some conditions like an underactive thyroid make weight loss genuinely hard no matter how well you feed, and they're very treatable once they're picked up. Better to rule that out than to keep cutting food and getting nowhere.