Sometimes it may seem as if dog sweaters exist only for the amusement of humans. We dress dogs up in their hooded and patterned sweaters, stand back and take in the abundance of cuteness. And cute they are, no doubt about it. Who could resist a small dog in a studded sweater with "guard dog" or "security" embroidered on it? Or a large dog in a sweet holiday-themed sweater? Or, perhaps the ultimate, a pug in a hoodie sweater?
Beyond the fun, however, sweaters for dogs do serve a real purpose. Many dogs are uncomfortable in cool or cold weather, and can experience considerable distress. Extreme weather can even present a health risk to your pet. Lighter sweaters in Spring and Fall help acclimatize your dog to the changing seasons, while heavier sweaters protect your pet from debilitating cold in winter.

Some dogs are more likely to need sweaters than others. Generally, small dogs are more susceptible to cold than larger dogs. Smaller dogs can't produce enough heat to withstand the cold and can cool down very rapidly. Older dogs, very young puppies and dogs that are sick will feel the cold more acutely and may need sweaters also. You should consider a sweater if your dog is recovering from an illness or injury. Short-haired dogs are also at a disadvantage, being less capable of fending off the cold than their longer haired and thicker coated brethren. Greyhounds and whippets are examples of the type of short haired dog that would require protection in colder climates. It would be a mistake, however, to assume automatically that a larger dog with a thick coat doesn't need a sweater. It's best to observe your dog closely in cold weather. If he seems cold, then get a sweater to protect him. He'll be far more comfortable and he'll be grateful for the warmth.
You need to measure your dog carefully to get the best fitting sweater. Measure length from the base of the tail to the base of the neck. Girth is measured at the chest's deepest point. If your dog's measurement is between two sizes, buy the larger size. It's better for the sweater to be a little loose rather than a little tight.

Great designer dog collars like Martingale dog collars, Up Country, Dog Couture and various leather dog collars and personalized collars from other brands are great. They can be embroidered, rhinestone, rolled leather, reflective, nylon, hemp and can come in a preppy style, pink and even christmas themes.
Sweaters are available in a wide array of colors, patterns, fabrics and styles, some with hoods and some without. Fabrics range from 100% cashmere or wool at the high end.to synthetics at the lower end. Some are machine washable, and some are not. Some sweaters are made to be beyond cute, while others are preppy, with argyle and cable knit patterns. Most sweaters with high necks or hoods will have an opening in the neck for the leash. If you use a harness, it will simply go over the sweater. Look for a sweater that fits well around your dog’s torso and legs, but is open underneath to avoid soiling. In extreme cold weather, a sweater is good for quick walks, but not necessarily for long exposure to the elements.