From ‘Complete Guide to Knitting & Crochet’ by Nicki Trench. The original jacket is a shark jacket so I made it without the shark fin.
http://www.amazon.co.uk/Complete-Guide-to-Knitting-Croche...

I made 2 sizes. The smaller one is plain and made from left overs. I then used a snowflake pattern from a bag within the medium sized jacket which worked out a treat. http://www.themakingspot.com/knitting/pattern/snowflake-bag

The only thing to add is that I added a rib section for the tummy as my sister’s Jack Russell is slightly overweight and unfortunately, the leg holes were not big enough so if you are to make these… increase the hole for the legs. Somebody, somewhere out there in the world has a dog who has worn these jackets (I told my sister to send them to the charity shop as I’m sure they will fit somebody’s dog). Happy knitting!