1. Seasonal Reasons. This is a normal phenomenon; The dog itself needs to adapt to changes in climate, outside temperature, humidity, etc. 2. Human Factors. Many people bathe their pets with man using soap, shampoo, detergent, and other products. Because of skin difference between dogs and human, it will cause discomfort for dog’s skin. 3. Lacking of Elements like minerals and vitamins in the dog’s body. Foods such as dog food, meat and bones cannot supplement some trace elements needed by dogs, which includes vitamin A, vitamin B, vitamin C, vitamin D, vitamin E, etc. 4. Some Other Factors. Other factors will cause moulting such as temperature, humidity, natural environment, sun exposure, etc. Some short-haired dogs like Dalmatians and Labradors are more likely moulting when you caressing.