Updated April 13, 2021
I want you to see these pictures of severe facial sores in a dog. Note especially how quickly they developed and then went away with the right treatment. This is canine eosinophilic furunculosis.
I will discuss it and other causes of lesions on the face of dogs afterwards.
Canine Eosinophilic Furunculosis
This is a rare condition whose exact cause is unknown, but believed to be hypersensitivity to bite from an insect (e.g. wasp, hornet, bee, mosquito, ant) or spider. In this dog’s case, the cause was probably bull ants.
Raised, swollen sores appear, and enlarge extremely rapidly. They are mostly found on the sides and top of the nose and muzzle, and more rarely around the eyes, on the underside or the legs. Eventually they become ulcerated, moist, crusty or even bleeding.
Dogs may find the sores very painful or itchy. Severely affected dogs can appear unwell and lethargic.
Treatment Of Eosinophilic Furunculosis
Treatment is very successful via anti-inflammatory corticosteroids (‘cortisone’), and antibiotics for secondary infection. However, as corticosteroids can just as easily be the wrong treatment for some skin conditions, it’s best to get a diagnosis first.
Therefore, before starting the prednisolone I took a biopsy; that’s the single stitch you can see in later photos. The speed of improvement was as fast and impressive as the speed that it initially worsened. By the time the results were back, it was already 80% better.
Canine eosinophilic furunculosis is an incredibly dramatic and rare reaction that your vet might not have seen, and (like me) might fear the worst. However, if you recognise what it is, it’s not nearly so bad.
What Else Causes Facial Sores?
Here are three much more common causes of swellings on dogs’ faces.
The lesion below is a solitary, circular and much drier lump we call a granuloma. Sometimes it has a hard crust. They also mostly appear on the nose or face but cause less discomfort and irritation. These granulomas appear to be infections, and respond slowly to antibiotics.
Then there’s the classic bee sting. This causes a rapidly developing swelling of the affected area, usually the lips, eyelids and muzzle. There should be no specific sores visible. Such dogs are shown below.
Lastly, there’s the tooth root abscess. These mostly appear underneath the eye like in the picture below, and will eventually burst. Again, you can read more at the link.
There are far too many other causes of facial sores to be able to document them all. Some will be specific to certain parts of the world. That’s why, even if your dog looks like the pictures here, you always need your local vet to confirm the diagnosis.
Here are just a few extra examples:
- Nasal solar dermatitis (‘collie nose’) in high UV places like Australia
- Leishmaniasis in South America, the Mediterranean basin and East Africa
- Autoimmune diseases like discoid lupus erythematosis, pemphigus and uveodermatologic syndrome
- plus any of the Skin lumps of dogs can also be found on the head
Related: Causes of Ear Tip Sores In Dogs
Much gratitude is due to Alaska’s mum, Kate for taking and sharing these excellent pictures.
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By Andrew Spanner BVSc(Hons) MVetStud, a vet in Adelaide, Australia. These help topics are from a series regularly posted on email and Twitter. Subscribe via email here to never miss a story! The information provided here is not intended to be used as a substitute for going to the vet. If your pet is unwell, please seek veterinary attention.