Poorly puppy. Medical alert tag.

Hi everyone

I recently rescued a very poorly puppy. He has a loud, grade four heart murmur and IBD (Irritable Bowel Disease) amongst other problems. He's on a special diet and is currently trailing different medications.
I want to get a medical alert ID tag engraved for him today (I'm hoping it will deter thief's from stealing him, stop others from feeding him food/treats that could be harmful to him and encourage people to return him ASAP should he go missing)

I've seen example tags that say "medication required. Return ASAP to:......" or "I have allergies. Do not feed me". Here is another example tag: https://www.google.co.uk/search?q=en...ml%3B640%3B362

Do you think a medical alert tag is a good idea? What should I have engraved on my puppy's tag?

I had one done for my epileptic border collie - it was just his ordinary tag but on one side it said 'epileptic requires regular medication' or something like that.

What about something like this or this

Great idea. What did you go for in the end?