My service dog was attacked

I saw a post that made me think to share his story. I have a heart condition and my service animal like had saved me from hitting my head passing out many times, he was there when I came to as well. Usually he could tell in advance so I could get to a safe space. We were in the grocery store and this lady has a shitzu in her cart (food store so gross anyway but whatever) it was laying down and I didn't see it..... It jumped out of the cart and bit him on the head so hard that stitches were required. (Yes I threw the fuggin thing off of him) And now he is petrified of carts even if a purse is in them. Having his best interest at heart I retired him early and am working on a new puppy. For the love of all things keep fido home. I've had to be transported by ambulance twice since this happened because I didn't have him to stop me from hitting my head. Even if you think your dog is socialized and will be fine it's not. Stop it.