DOGS · Symptom guide
Dog scratching ears and shaking head: what real cases show
Constant ear scratching and head shaking is one of the most common reasons dogs end up at the vet — otitis externa (ear inflammation/infection) is the second-most-prevalent diagnosis in UK primary-care dogs. Most owners think of an ear infection as a one-off event. In reality, repeat ear problems are almost always a downstream sign of something else — usually allergy.
Published cases consistently identify: yeast (Malassezia) overgrowth, bacterial otitis (cocci or, more difficultly, Pseudomonas), ear mites (Otodectes — actually much more common in cats but seen in puppies), foreign bodies (grass awns are a classic in working breeds), aural haematomas from violent head shaking, and underlying atopic dermatitis or food allergy driving the whole cycle.
The cases below show real veterinary workups of dogs presenting with ear scratching and what the cytology, otoscopy, and follow-up actually revealed.
When to see a vet now
- Sudden head tilt or loss of balance — possible middle/inner ear involvement, urgent.
- Painful swelling of the ear flap (aural haematoma) — needs same-week vet attention.
- Bleeding, discharge, or strong foul odour from the canal.
- Recurrence within weeks of finishing drops — almost always means an underlying allergy isn't being addressed.
- Refusal to let you touch the head, hiding, sudden aggression — these are pain signals.
Real cases from the veterinary literature
A teaser of peer-reviewed reports our semantic search surfaces for this complaint. Click into any case for the full abstract — or run a personalised search with your pet's exact details.
- Ear Mite Infestation in Four Imported Dogs from Thailand; a Case Report
Iranian Journal of Arthropod-Borne Diseases · 2010 · United States
Four puppies, including a Siberian husky, a Cocker spaniel, a Terrier, and a mixed Pekingese, were brought to a veterinary hospital in Iran after being imported from Thailand. They all had a lot of dark brown discharge in their ears, and a closer look revealed tiny white moving mites, identified as Otodectes cynotis, which are known to cause ear problems. Lab tests also found t
- Malassezia pachydermatis isolated from normal and diseased external ear canals in dogs: a comparative analysis.
Veterinary journal (London, England : 1997) · 2006 · Brazil
This study looked at a type of yeast called Malassezia pachydermatis to see if it causes ear infections in dogs. Researchers collected samples from the ears of dogs with ear infections and from healthy dogs. They found that 63.7% of the dogs with ear infections had signs of this yeast, while only 21.43% of healthy dogs with one infected ear showed it. Most of the dogs with the
- Epidermal dysplasia and Malassezia infection in two West Highland White Terrier siblings: an inherited skin disorder or reaction to severe Malassezia infection?
Veterinary dermatology · 2001 · United States
Two 9-month-old West Highland White Terrier siblings were brought to the clinic because they were very itchy, had hair loss, and their skin was thickening. Tests showed they had a skin infection caused by a type of yeast called Malassezia, along with some skin changes. They were treated with a special medicated shampoo and two medications, which helped clear the infection and a
- Identification and antimicrobial susceptibility of bacteria and yeasts isolated from healthy dogs and dogs with otitis externa.
Journal of veterinary medicine. A, Physiology, pathology, clinical medicine · 2007 · United States
Researchers looked at the types of bacteria and yeast found in the ears of healthy dogs and those with otitis externa, which is an ear infection. They found that the most common bacteria in dogs with ear infections was Staphylococcus intermedius, followed by several others, including a type of yeast called Malassezia pachydermatis. The study showed that these microorganisms are
- Canine atopic dermatitis and recurrent otitis
Pubvet · 2024 · United States
This case study discusses a mixed-breed dog that was adopted at one year old and suffers from canine atopic dermatitis (CAD), which is a skin condition, and recurrent ear infections caused by a type of yeast called Malassezia. The dog's treatment involved a thorough evaluation, allergy testing, and a combination of medications to help control itching and inflammation, including
Frequently asked questions
- Why do my dog's ear infections keep coming back?
- Almost always because the underlying cause hasn't been addressed. The most common driver is allergy — atopic dermatitis or food allergy. Until the allergy is managed, the ear environment stays primed for repeat infections. If your dog has had ≥3 ear infections in a year, ask your vet about allergy workup or a strict food trial.
- Can I just use a cleaner from the pet shop?
- For routine maintenance in healthy ears, yes. But once there's an active infection, the eardrum status must be confirmed first — many topical antibiotics can damage the inner ear if the eardrum is ruptured. Vinegar, hydrogen peroxide, and other home remedies can worsen inflammation. Get a cytology before starting anything medicated.
- What's the worst-case scenario?
- Pseudomonas otitis is the toughest infection in primary practice — it forms biofilms, develops resistance fast, and can rupture the eardrum if mismanaged. Untreated chronic disease leads to ear-canal scarring and end-stage otitis, sometimes requiring total ear canal ablation (TECA) surgery. Don't ignore chronic ear problems — early aggressive management protects long-term hearing and comfort.