Chest girth and back length are the two numbers that decide whether a dog jumper fits, and this is one of the few festive knits where the maker publishes both for every size. Chest runs from 25cm to 38cm across six sizes, back length from 21cm to 44cm, and the scarf is sized alongside them from 16cm to 29cm rather than being one length thrown in regardless.

The knit is acrylic, the practical fibre for a garment worn by an animal: it takes a cool machine wash without shrinking, dries fast, and holds a jacquard reindeer pattern crisply instead of going bobbly by January. The grey ground keeps it wearable well past Christmas, and the matching scarf is a separate piece, so it can simply be left off with a dog who objects to anything round the neck.

• No.6: chest 25cm, back length 21cm, scarf 16cm
• No.8: chest 28cm, back length 26cm, scarf 19cm
• No.10: chest 31cm, back length 32cm, scarf 22cm
• No.12: chest 34cm, back length 34cm, scarf 25cm
• No.14: chest 36cm, back length 40cm, scarf 26cm
• No.16: chest 38cm, back length 44cm, scarf 29cm
• Acrylic knit in grey with a reindeer motif

On sizing: notice that the chest measurements stay narrow even as the back length grows. At the largest size the chest is still only 38cm, which describes a long, slim dog rather than a broad one. A Dachshund or a Whippet will find their size in this range; a Staffie or a French Bulldog almost certainly will not, whatever the back length suggests.

Who it's for: Owners of long-bodied, narrow-chested dogs — Dachshunds, Italian Greyhounds, Whippets, Miniature Poodles — who never find festive knitwear that fits properly.