Dog’s bald patch worry
QAMy son’s border collie/poodle cross has developed bald patches on either side of his body. Blood tests were normal but we are worried as we don’t know the cause, or whether it could be a symptom of a wider problem. Could you advise? There are several possible causes for bald (alopecia) patches, and some of these have underlying systemic causes. Your vet was probably seeking to rule out hypothyroidism and hyperadrenocorticism (Cushing’s disease) with the blood tests.
Assuming your dog is otherwise well, these diseases are lower down the differential diagnosis list as nothing suggestive has emerged from the screening tests.
Hypothyroidism is mainly seen in older dogs and, apart from alopecia, is often associated with lethargy, poor exercise tolerance and weight increase.
Dogs with Cushing’s disease usually drink more, become pot-bellied, and the alopecia can extend over most of the trunk. Other causes of alopecia in this area include demodicosis (an infection with demodex mite), bacterial infection and rare hormonal problems, perhaps requiring a specialist opinion.
Another skin condition, canine cyclic flank alopecia, is confined to the flanks and could be worth discussing with your vet. In the northern hemisphere dogs lose hair on both flanks from November to March.
Over the summer the hair grows back. In many cases alopecia returns the following winter. An unlicensed hormonal treatment has been suggested in papers but a recent article found it no better than placebo.
Q AMy rag doll/persian cat has started to pull his fur out and now has a bald patch on his side. We can’t see any soreness. Any ideas?
This common problem can require some patience and detective work. It’s helpful that you have recognised that the cat is pulling his fur out, because often they do this without owners being aware. Cats groom themselves as a means of calming themselves, and this can lead to overgrooming.
There are two distinct pathways that you and your vet could follow to make a diagnosis. Which one to pursue first is the tricky part.
Two problems to investigate are those caused by allergies to parasites (particularly fleas), and less often to food and environmental allergens – and also psychogenic alopecia caused by stress.
Many veterinary dermatologists tend to regard psychogenic alopecia as rare compared to allergies, and therefore tend to investigate these first. But it’s not always the case as sometimes there is compelling evidence of a stressful event preceding the overgrooming.
Cats that overgroom tend to lick the ventral abdomen and the inner thighs. Before investigating psychogenic alopecia, fleas and other parasites must be ruled out, with your vet’s advice.
The detective work, sometimes with help from a qualified feline behaviourist, looks for stressors and devises strategies to ease stress. This can be aided by veterinary prescribed licensed sedatives.
Failure to respond could than lead to a food/environmental allergy investigation, although there are some vets who will do this earlier.