Animal welfare experts have warned that dog owners who dress their pets are putting them at risk of overheating.
Dog disguises are pitched as a piece of harmless fun, but the RSPCA claims that 'canine couture' can be as harmful as leaving animals locked in hot cars and could even lead to owners being prosecuted.
Owners and experts have also claimed the fad of dressing dogs in "fashionable" clothing - is demeaning and encourages bad behaviour.
Dog clothing has become a big business in recent years. Among the products now available are all-in-one trouser suits, which only leave the head and paws exposed, "jumpers", which cover the body and the front legs, and even "hoodies".
Fancy dress designs, such as Elvis Presley-style jumpsuits and pirate costumes, are also available.
Designers, including Vivienne Westwood and Ben de Lisi, have also created dog accessories and clothing, while Harrods holds an annual fashion show for canine clothing, called Pet-a-Porter.
However, experts say that, barring a few exceptions - such as very small dogs with short hair, thin breeds like greyhounds, or those bred for much warmer climates, like the Saluki - any form of clothing is unnecessary and impedes a dog's ability to regulate its own temperature.
"There are very few occasions when an animal needs a coat, even in the recent cold weather," the Telegraph quoted Mark Johnston, from the British Small Animal Veterinary Association, as saying.
"Dogs have developed a very effective coat of their own, which will protect them from the elements. Dressing them in a coat diminishes the animal's ability to regulate their own body temperature and could be detrimental if the animal gets too hot.
"Too high a temperature is more of a risk to the dog's health than too low a temperature," he added
RSPCA spokeswoman Helen Briggs, said: "Under the Animal Welfare Act, you are obliged to provide appropriate conditions and environments for your dog. So if you are slapping a great big coat on it when it really doesn't need it, then that could cause it to suffer if it is overheating. It is the same as if you leave a dog in a car in hot weather.
"Some breeds have been bred to have less fur, so in some cases it is quite appropriate for a dog to wear a coat in very cold weather. But if an owner is just doing it for a fashion statement I certainly would question that," Briggs added.