07/10/2026
One of the things that I am seeing a lot of when I visit client's houses for training are doggy allergies. Itchy skin, thinning hair, redness between the toes and sometimes even scratching until the skin bleeds - these are all examples of symptoms of allergies. We all see ads on the internet and on the TV for dog allergy medications and treatments. Something that I have to stress is that if you think your dog has an allergy, take it to the vet and have that confirmed first.
There are various dog conditions that mimic allergies. One of the most prevalent is demodectic mange, the lesser known of the manges. We all have probably heard about sarcoptic mange, and the bad effects that it can have on your dog. Demodectic mange is a non-contagious condition that is also referred to as "red mange." It's an inflammatory skin condition caused by a microscopic mite, "Demodex Canis."
The funniest thing about this is that every dog has these mites. They live deep inside the oil glands and hair follicles. On a healthy dog, the immune system keeps the mite population low and harmless. The mange condition only happens when something goes wrong with the immune system "shield," allowing the mites to breed completely out of control.
The mange condition usually shows up as one of two types: localized and generalized. Localized usually occurs in puppies under a year old. It shows as a few isolated, patchy bald spots, usually around the face, eyes or front legs. The skin may look red or scaly. In most cases, the condition resolves itself, the skin clear up, and the puppy goes on to live a normal life.
Generalized mange can affect pups with severe immune defects or older dogs with sudden underlying health issues, like diabetes, cancer or Cushing's syndrome that absolutely tank their immune system. It shows up as widespread hair loss across the body. The skin becomes crusty, darkens significantly, and frequently develops secondary bacterial infections.
This is the type of infestation that requires the treatment of a vet. It won't clear up on it's own because the dog's immune system has completely lost it's ability to control the mite population.
Demodectic mange is not contagious to humans. The dog doesn't need to be quarantined because this condition is purely an internal breakdown of that specific dog's immune system control.
Now, the big thing is that the two manges, sarcoptic and demodectic, look a lot alike. Both cause hair loss, raw red skin, crusting and sores from secondary infections. Demodectic usually doesn't cause itching unless a secondary bacterial infection sets in, whereas sarcoptic causes intense skin irritation. Demodectic usually starts on the face, muzzle and around the eyes, while sarcoptic mange usually starts on the belly. hock and ear edges.
Both mange conditions may eventually require veterinarian treatment, but only sarcoptic mange is transmissible to humans, causing the condition known as scabies.
So, while your dog may just have allergies, there are specific things to look for when he is itching and scratching. Examine your dog and look for thinning rings of hair around one or both eyes, making it look as though your dog is wearing spectacles. Run your hands along the muzzle, forehead and front legs. You are looking for small, discrete circular patches where the hair has fallen out. Check your dog's feet, especially between the toes and the nail beds. When demodex hits the feet, it causes the skin to swell, turn a deep reddish-purple and lose its hair. The paws can become quite tender, and the dog may lick at them frequently, leading to misdiagnosis as simple environmental allergies.
If your dog has thinning hair, look closely at the skin surface. Look for what appear to be dark blackheads or plugs blocking the pores. Because the mites are overcrowding the hair follicles, the follicles overproduce keratin and sebum, plugging the pores and causing the remaining hairs to slide out.
Finally, give the dog a sniff. If the mite population is high enough to cause generalized demodectic mange, it compromises the skin's natural moisture barrier. This allows normal skin yeast and bacteria to proliferate wildly, producing a very distinct, heavy, stale or "musty" smell that doesn't disappear even after a bath.
So, please remember, especially in puppies and some immunocompromised animals, if your dog suddenly starts showing some of the symptoms mentioned earlier, don't brush it off as "just allergies." Sometimes, it can be something that is serious but treatable, like Demodectic mange. As always, enjoy your furry friends and if you need some training help, we are a phone call away.