Injury

• The dog may have an injury to her paw, pad or nail, or have something stuck to it like tar or a thorn. Check the dog's pads and nails thoroughly. If you notice a minor wound, clean the area with soap and water.
  
  

Allergies: Food

• Some dogs may have food allergies, such as to corn or wheat. Trying a different type of food might help, such as an all-natural or organic food.
  
  

Allergies: Environment

• Some dogs have allergies within their environment. This can range from lawn fertilizer to poison ivy to mold to a seasonal allergy. Your vet may prescribe medication, such as a steroid or antihistamine.
  
  

Stress

• Some dogs chew their feet out of habit or stress. This might be treated by isolating stress triggers, using positive reinforcement or consulting with an animal behaviorist.
  
  

Hypothyroidism

• In more rare cases, some skin-related issues are caused by hypothyroidism. A dog with hypothyroidism would likely have other symptoms besides just itchy feet. This is identified through lab tests and treated through medication.