Here are some common signs of Mestinon OVERDOSE that several of us MG owners have experienced. The pet may exhibit one, or multiple signs:

1. Eyelids twitching (not in a synchronized manner)
2. Leg and/or head and/or ear spasms
3. Eyes tearing significantly, about 20 min after Mestinon dose
4. Nose dripping about 20 min after Mestinon dose
5. Severe drooling, especially “ropey” or stringy drool with some dogs
6. Ears lifted up sort of horizontal to the floor and stiff
7. Very aggressive behavior or other behavioral issues
8. Diarrhea or extreme urgency, inability to hold stool in
9. Swallowing is fine, no regurge10. Breathing spasms and some form of respiratory distress

UNDERDOSE is different because usually when underdosed the following happened with my dog. The pet may exhibit one, or multiple signs:
1. Eyes halfway open – loss of palpebral reflex (see YOUTUBE.COM canine palpebral reflex).
2. Very tired, unable to jump onto furniture
3. occasional collapsing episodes
4. back legs shaking
5. inability to swallow well (some laryngeal paralysis)
6. decreased esophageal motility (some regurg events happening)
7. inability to close eyes when sleeping
8. general muscle weakness
9. breathing shallow (or not breathing at dog’s normal rate)
10. very low energy – sleeping a lot