Any change in the appearance or behavior of your hedgehog could indicate that he is sick. If your pet suddenly stops eating, changes his behavior or is sneezing, a visit to the vet is in order.
Look for Skin Changes
Hedgehogs can suffer from a number of skin parasites and fungi that can cause illness. Mites, particularly common in hedgehogs, can cause your pet to scratch constantly. Other signs of skin problems are crusty or flaky skin and the loss of spines. Hedgehogs do lose their spines around 2 months to 3 months of age, but if yours is losing spines at any other time or if the loss of spines comes together with other symptoms -- such as bleeding or an overall feeling of sickness -- you should talk to your vet right away.
Observe Overall Appearance
While hedgehogs can be shy, sudden changes in activity level can indicate that your pet is sick. Lethargy, a dull expression and paralysis are signs that something is wrong. Look for changes in behavior too. Lethargy, especially if it accompanies loss of appetite and weight loss, can signify cancer. Hedgehogs are prone to developing cancers related to the digestive system, especially after the age of 3. Lumps and bumps, which can also indicate cancer, should get a vet's attention as soon as possible.
Pay Attention to Respiratory Problems
Hedgehogs are prone to pneumonia and other respiratory diseases. These can be caused by a cold environment, as hedgehogs need an environmental temperature of between 72 and 85 degrees Fahrenheit to be healthy and comfortable. The most common sign of a respiratory infection is nose discharge, but your hedgehog can also sneeze, sound wheezy and have difficulty breathing. Hedgehogs can contract kennel cough from your dog, so it's important that all pets in the house are properly vaccinated.