Small dog setting off motion sensors

You're going to get many different people suggesting many different things, such as putting the sensors upside down and lower.  But here's what works.  I've been doing this for years.  Place the sensors as high as you can on the wall, near the ceiling.  Put the sensor switch on low.  This will stop triggering from the cats for sure, dog probably.  You'll have reduced coverage in the room for humans, but you can put it in test mode to find out.  Add additional motion sensors to the room to fill in the gaps.  We've always had cats in the house and have not had a false alarm in years since taking this approach.

I would also suggest putting the motion sensors in secret alert mode for a while until you are sure the problem is solved.  This way you'll get a text message that the sensor went off, but won't sound the alarm.

I have a 7 lb dog and a 50 lb dog and have never had a false alarm.  Make sure the sensors are not pointed anywhere that an animal can jump (cough, chair, bed, etc).  Also make sure that it is not pointed towards a window or other heat source.  Also try to change sensitivity on the back and then run a couple tests with a human.  Lastly if you have a camera put it pointing the same direction so you can pin point what is setting it off.

As for the notification, but no alarm was this from a camera or from the motion sensor itself?