This jumper fits my rescue Jack Russell ‘Red’, whose size and shape varies as he undergoes his cancer treatment.

Sizes:
Finish garment measures:
Neck: 30 - 50 cm (the smallest measurement is when not stretched at all, and the largest measurement is when stretched).
Length from neck to tail: 36 cm. Chest size: 34 - 60 cm

Materials:
Shearing elastic - to thread through the neck to help prevent the jumper slipping down the body. Every jumper I try on Red slips down him, but he gets so cold I persevere with keep pulling them up.
100g (approx 334m) Double kitting (DK) yarn
I used 100g of Paintbox Baby DK in shade Slate Grey (705)

Equipment:
4mm needles. Personally I prefer working on shorter 25cm needles as I usually have a very cute dog cuddled up tight to the side of me and find the shorter needles easier in the confined space.
1 stitch marker. It is not essential to use a stitch marker, but does make completing the garment much easier as it involves less counting.
Row counter. Or you can use a piece of scrap paper and a pen or pencil. A needle for sewing up.

Tension:
You will hopefully be pleased to hear that due to the stretchy nature of this jumper, tension isn’t as important as in other patterns. That being said, you should try to keep an even tension throughout.

Abbreviations:
sts. = stitches. St. = stitch.
1 x 1 rib = Knit one st. (K1), purl one st. (P1). OR P1, K1 depending upon which row you are on, either a front row (where the outside of the jumper faces you), or a reverse row (where the inside of the jumper faces you).
2 x 2 rib = Knit two sts. (K2), purl two sts. (P2). OR P2, K2 depending upon which row you are on, either a front row (where the outside of the jumper faces you), or a reverse row (where the inside of the jumper faces you).
M1 = make one stitch by knitting or purling into the loop between the last st. worked and the next st. waiting to be worked on your left needle.
(fs) = front section (1 x 1 rib). (bs) = back section (2 x 2 rib).