Christmas Dog Sweaters and Pajamas: How to Measure Your Dog and Pick the Right Size

Does your dog need a sweater at all?

For many dogs a Christmas sweater is for the photos. For some, it does a real job in winter. Cornell's Riney Canine Health Center says: "Especially for smaller breeds, older dogs or those with a thin coat, a jacket or sweater will help keep them warm," and notes that "short and thinly-coated breeds will not tolerate the cold as well as thick, double-coats."

Breed matters too. A Texas A&M veterinarian put it this way: "Dog breeds such as Siberian Huskies or Saint Bernard's are bred to handle cold weather, while others like Chihuahuas or Greyhounds are not."

If warmth is the goal, coverage matters more than the pattern. For short-haired dogs, the ASPCA suggests a coat or sweater with "a high collar or turtleneck with coverage from the base of the tail to the belly." And for long-haired dogs, the ASPCA's advice is about the coat itself: "Never shave your dog down to the skin in winter. A longer coat will provide more warmth."

How to measure your dog

Use a soft tape measure, have your dog standing on all four legs (a treat helps), and write the numbers down in inches, or in centimeters if the brand's chart uses them.

• Chest (girth). Wrap the tape around the widest part of the chest. Ruffwear describes the spot as "the widest part of your dog's chest just behind the front legs." Many brands, including Ruffwear, size by chest girth, while others, such as Barbour, use back length and width instead, so follow the chart you are buying from. Take it twice.
• Neck. Measure around the neck where a collar sits. This tells you whether the collar of a sweater will go over the head and sit without pulling.
• Back length. Barbour's guide measures "the length between your dog's neck (from where their collar sits if they wear one) and the base of their tail." This decides how much of the back the garment covers.

For full-body pajamas, the same three numbers do the work. Some size charts also list a breed or weight range as a rough guide, but your measurements matter more. For long, low dogs and deep-chested dogs, check both the chest and the length before you order.

Reading the size chart

Brands use their own size charts, and they do not all measure the same way, so a "medium" from one brand may not match a "medium" from another. Always compare your dog's numbers with that brand's own chart, not with the size your dog wore before.

• Start with the main measurement. Use the one the brand sizes by (often the chest, sometimes the back length) and find the size whose range includes your dog.
• Then check the other numbers. If one measurement fits but another is far off, look for a brand cut for your dog's shape.
• Between two sizes? For a puppy that is still growing, Ruffwear's advice for its harnesses and apparel is simple: "If your growing pup is truly between two sizes, choose the larger size." For an adult dog, compare the neck and the length to decide.
• Check the return policy before you order, especially for a gift. Fit is easier to judge on the dog than on paper.

How a good fit looks

A Texas A&M veterinarian described the two ways a sweater can go wrong: "The sweater should not be large enough to hang loosely or produce gaps that can prevent the animal from keeping warm," and on the other side, "you do not want a sweater that is too tight and can cause circulation problems."

• At the neck: snug, not tight. Ruffwear's check for collars, "allowing you to fit two fingers comfortably between the collar and your dog's neck," is a handy test for a sweater collar too.
• Around the chest: no gap at the sides, no fabric pulling across the shoulders when your dog walks.
• Legs and belly: your dog can walk, sit and lie down without the leg holes cutting in, and the belly cut leaves room for your dog to go to the toilet without soiling the garment.
• The first time on: put it on for a few minutes indoors and watch. If your dog freezes, keeps trying to rub it off or will not move, take it off and try a different cut or skip it.

Christmas pajamas: a few extra checks

Pajamas cover more of the body than a sweater, so the fit checks above matter even more at the legs and belly. They are made for cozy time indoors with you around, and for the photos. Texas A&M's advice covers pet clothing in general: "If you choose to provide your pet with clothing it is important to remember to never leave the animal unattended." We read that as: take the pajamas off before bed or when you leave the house. That is our reading; Texas A&M does not mention pajamas.

Winter safety with dog clothes

• Never unattended. "Pet's clothing can get caught on numerous things outside and that can injure the animal," as the Texas A&M veterinarian explained.
• Watch your dog as well as the thermometer. Cornell lists "lifting paws off the ground" and "reluctance to walk" among the signs that a dog is not coping with the cold. The ASPCA's rule of thumb: "if it's too cold for you, it's probably too cold for your pet."
• Snow on the belly. Cornell notes that "some jackets that cover most of the body will help deter snowball accumulation on the belly and chest."
• Paws. Cornell suggests you "train your dog to wear well-fitting booties to protect their paws," and the ASPCA recommends paw protectants or booties against salt and de-icing chemicals.