Canine Distemper

• Ferrets can contract canine distemper and experience severe reactions as a result. Swollen feet leading to hardened foot pads is one of these symptoms. You can prevent this by having your ferret vaccinated against canine distemper; you will have to have one or two vaccines to start and then a booster shot each year. If your ferret is showing swollen feet along with symptoms of diarrhea, extreme thirst, lack of appetite, or a rash under his chin, take him to the vet immediately for treatment.
  
  

Scabies or Skin Mites

• Swollen feet (or ears, feet, or head) can also be a sign of scabies or skin mites. Your ferret may also present with skin sores, itching, or hair loss. For scabies, your vet will give your ferret shots every two weeks for a six-week period.