If your concerned about founder maybe its time to consider moving her to a barn where her needs will be considered more. The slow feed net isn't really limiting her consumption, its just slowing her down. The point of putting her hay into the slow feed net would be so she doesn't inhale the her designated amount of food. It would be like saying "I need to go on a diet so I'll get a smaller spoon". A smaller spoon might slow you down but its not going to help with portion control.
As for the grazing muzzle there are a few options. They make ones on a Velcro halter, of the muzzle gets stuck it will release very quickly. The other is attaching a muzzle to a breakaway halter. If your horse is anything like the smart, obese haflinger at my barn this is the better option. She learn how to pull the velcro muzzle off on the fence.
Posted via Mobile Device