You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Old dogs often develop thinning of the hair and baldness...and sometimes there is a hormonal problem which can be treated

Many old dogs lose their haircoat. Often the coat thins evenly on both sides of the body - called "bilaterally symmetrical alopecia" and in some cases this can lead to almost total baldness. 

A Yorkshire Terrier with bilateral hair loss on the body

The skin is not usually itchy but it may become discoloured (black pigment) and there may be other apparently unrelated signs as well such as an increase in thirst, weight gain, or swelling of the abdomen. There are several hormonal disorders which can cause hair loss but the commonest are :

• Insufficient thyroid hormone (called hypothyroidism). This is the commonest hormone disorder in dogs and can be treated by giving thyroid hormone replacement therapy.
• Too much hormone from the adrenal glands (called hyperadrenocorticism or Cushings Disease) 
• Sex hormone-responsive disorders.

All of these conditions can be treated successfully by your veterinarian, but of course the treatments are different, so make an appointment to get an accurate diagnosis if you notice that hair loss is occurring  

Updated October 2013