Unless the dog is VERY cleaver they might not be able to pop out and and by their owner a birthday card so this is the next best option.
A birthday card with cute picture of a shaggy dog wearing a birthday hat sat behind a birthday cake with candles. Lower case rounded text above reads Happy Birthday from the dog.
Card dimensions: 126x178mm
Packed in a cellobag with envelope
Printed and Manufactured in the UK
Standard letter post