Itchiness is a sign to show that they have some issue on their coat. We need to identify what the root cause is. Only then we can successfully treat the issue.

It may be because of mites or some other allergy ...is the itching all over body or more at specific part?Itching is Multifactorial..and need more History to Suggest proper treatment..pls consult a Vet online or offline to Get Exact Diagnosis and treatment options..mean while you can use some sprays like Reliflam or Takfapet..

A few more questions need to be answered before any treatment is started. Frequency of bathing, shampoo used, environmental factors, diet and infections may also cause itching. To pinpoint the cause and treat it kindly start a consultation or visit a vet.