"I see collar-related pressure sores about once a week. It's almost always a GPS collar — thirty to seventy grams of rigid plastic sitting on the ventral neck, eight to ten hours a day, combined with leash tension. The owners don't notice until the fur thins and the skin is already inflamed. The other issue I hear constantly is charging anxiety — clients tell me they take the collar off to charge it and forget to put it back on. One client forgot for four days. The dog got out on day three. I switched Birch to this because it weighs nothing, it doesn't need charging, and I know from the exam-room side of this that less hardware on the neck is better medicine. The tracker that isn't on the dog is the one that fails."