There are several reasons why a dog's paws may dry up. The weather is the most common one. During winter or summer, paws dry up. The paws may even get burnt or scorched by the hot roads in the summer. Other reasons can be allergic reactions to chemicals. For instance, when your dog walks on snow in the winter, his paws will be exposed to chemicals. Also, when your dog walks all over your lawn in the summer, he may suffer an allergic reaction to fertilizers.