Molly, a four year old female Boxer who had bald patches along both sides of her back

Molly was a young, healthy Boxer, in her prime. She had bright clear eyes and a shiny coat. But her good looks were spoiled by an obvious problem: baldness. There were large irregular patches of hairless skin on both sides of the mid-section of her body. Molly seemed very well in every other way, but the hair loss was so dramatic that Clare was worried. What could be causing her pet to be going bald?

Baldness can affect animals of all types and all ages. The technical term for baldness is ‘alopecia’, which literally means ‘without hairs’. Alopecia is a common reason for owners to bring their pets to the vet. Alopecia does not upset the animal at all. Animals are not vain – they do not worry about their appearance like humans. However, owners of balding animals are understandably concerned about their pets. An animal without hair looks peculiar. Owners of bald animals often feel that other people may think that they are in some way maltreating their pets, which is of course not true.

In addition to the cosmetic appearance, baldness can cause physical problems. A balding animal is likely to feel the effects of cold or windy weather. A coat or a woolen jacket can be a sensible precaution against this type of discomfort. However, the main concern with balding animals is that the loss of hair can be an outward indication of a more serious internal problem. If the hair loss is ignored, the internal condition may progress, and other symptoms may then develop. Any unusual hair loss in a pet should be taken seriously. A visit to the vet is always advisable.

When I examined Molly, the first thing that was obvious was that her bald patches were not itchy. This immediately ruled out a range of common problems such as mange, fleas and other parasites. Molly was suffering from genuine, classical alopecia. She was not itchy, and the bald skin appears fairly normal, apart from being hairless.

Most types of true alopecia are caused by hormonal problems. There is a long list of possible causes and it is not always easy to diagnose the precise cause. Detailed investigations are necessary, starting with a careful history of an animal’s lifestyle and habits, then carrying out a detailed physical examination, and finally taking samples for laboratory tests, including blood profiles and skin biopsies. Establishing a diagnosis can be time consuming and expensive, but it is worthwhile, in order to determine the correct treatment.

Boxers seem to be particularly prone to baldness, and Claire mentioned that she had met another Boxer which was showing similar, but less severe, hair loss. She had spoken to the dog’s owner, and it turned out that the dog had a condition called ‘seasonal flank alopecia’. Could Molly have the same problem?

“Seasonal flank alopecia” is common, especially in Boxers. It is caused by the changing light patterns and temperatures during different seasons of the year, and is seen more often in spring or autumn. Treatment is not needed and the hair grows back in naturally after a few months. It was possible that Molly could have an unusually severe case of this disease, but it was important to make sure that there was nothing else going on. “Seasonal flank alopecia” is difficult to diagnose, and the best that can be done is to rule out all of the other common causes of baldness. If there is definitely no other illness going on, then the only remaining diagnosis is “seasonal flank alopecia”.

I started off by asking Clare a long list of questions about Molly’s background. She seemed to be a fit, healthy dog in most ways, with a normal thirst and appetite. She did seem to be more sluggish than when she was younger, but Clare thought that she was just being lazy. When I examined her, Molly had a few subtle abnormalities. Her skin was cold to touch, and her temperature was a couple of degrees below normal. Her heart rate was only 80 beats per minute, whereas a normal Boxer is more like 120 beats. Otherwise, Molly was physically in perfect condition.

I took a blood sample for immediate screening in our practice laboratory, and again, almost everything was normal. I then sent a blood sample off to a commercial laboratory for specialised tests. A couple of days later, the results confirmed what I had suspected: Molly had hypothyroidism, caused by an underproduction of thyroid hormones.

She is now being treated with daily thyroid supplement tablets. Her heart has already speeded up to normal, and Clare has noticed that she is more enthusiastic about exercise again. But it will take many months for her fur to regrow.

Tips

• Baldness in pets is common and can often be treated
• An accurate diagnosis is essential, and often requires blood tests
• Even with treatment, it can take a long time for fur to regrow in the bald patches