Why does my dog have itchy patches of hair loss? | arlo.® Atlas
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Overview
If your dog has itchy patches of hair loss, the skin is reacting to something. Common causes include parasites, allergies, irritation from grooming or products, a skin infection, or repeated scratching and licking. You usually can't tell the cause from the look of the patch alone, but you can check a few useful clues at home.
Things To Check
1. Check where the patches are. Some causes affect the ears, belly, paws, armpits or base of the tail more than other areas.
2. Look for redness, scabs, flakes, broken skin, a bad smell, dampness or heat in the area.
3. Think about timing. Has it started after a change in shampoo, bedding, food, grooming, walks or time outdoors?
4. Notice whether your dog is scratching, licking, chewing or rubbing the same spot a lot.
5. Check for fleas or flea dirt, even if you don't see live fleas straight away.
6. See whether the hair loss is spreading, or whether the skin looks sore, thickened or darkened.
7. Consider whether any other pets in the home are itchy too, which can point towards an environmental cause.
8. Make a note of any new signs such as ear irritation, watery eyes, tummy upset or changes in appetite.
Common Causes
Fleas and other biting insects are a very common reason for itchy patches and hair loss, especially if your dog is scratching near the tail, back or thighs.
Allergies are another common cause. Dogs can react to food, pollen, house dust mites or something they come into contact with in the environment.
Skin infections, including bacterial or yeast overgrowth, can cause itchiness, redness, smell and patchy hair loss. These can sometimes happen after scratching has already damaged the skin.
Irritation from grooming products, washing, collar rubbing or over-licking can also leave the skin sore and patchy.
Less commonly, hair loss and itchiness may be linked to hormone issues, mites or other skin conditions that need a vet to confirm.
What To Do
Keep a simple note of when the itching happens, where the patches are and whether anything seems to make it better or worse. A few clear photos over several days can be very helpful.
Use a gentle grooming routine and avoid harsh shampoos or home remedies that might further irritate the skin. If the area is very sore, try to stop your dog from licking or scratching as much as possible.
Check bedding, bedding washes and the home environment for anything that could be irritating the skin. If fleas are a possibility, make sure your dog's usual parasite control is up to date and suitable for your vet's advice.
If the skin is only mildly irritated, monitoring for a short period while you note any changes can be sensible. If it is spreading, very sore, smelly or not improving, arrange a vet check.
When To Contact A Vet
Speak to your vet if the hair loss is spreading, the skin looks infected, your dog seems uncomfortable, or the itching is lasting more than a few days. You should also get advice sooner if there is swelling, discharge, crusting, a strong smell, or your dog is also unwell.
Products That May Help
If your dog has itchy skin or patchy hair loss, routine grooming and gentle washing can sometimes help you keep an eye on the skin and support day-to-day coat care.
Related Questions
Could itchy patches of hair loss be caused by fleas?
Why is my dog licking one spot until the hair falls out?
When should I worry about a patch of missing fur?
Atlas is here to support owners with practical, easy-to-understand guidance. It is not a substitute for professional veterinary advice. If you're concerned about your animal's health, symptoms worsen, or something doesn't feel right, contact your vet.