TL;DR: Constant ear scratching in dogs is usually caused by infection or allergies and requires a vet visit within 24–48 hours, unless you notice urgent signs like a head tilt or swelling.
Why is my dog constantly scratching behind their ears?
When a dog constantly scratches behind their ears, it is a clinical sign of localized itching known as pruritus. This behavior usually indicates inflammation or irritation within the ear canal or on the surrounding skin. Common culprits include ear infections (bacterial or yeast), ear mites, fleas, or environmental allergies. The scratching is your dog's attempt to soothe the discomfort, but it can often lead to further skin damage if left untreated.
Is my dog's ear scratching a medical emergency?
- The urgency level for constant ear scratching is typically Low, as it is rarely a life-threatening situation.
- Schedule a veterinary visit within the next 24 to 48 hours to address your pet's discomfort.
- Seek care sooner if you notice a significant head tilt, loss of balance, or if the ear flap itself becomes thick and puffy (an aural hematoma).
How does taking a photo of my dog's ear help with triage?
- High-quality images allow a professional to look for markers such as the color of discharge, crusting, or the severity of redness.
- Visual data helps determine if the issue is a superficial skin irritation or a deeper infection.
- Clear photos help ensure your dog receives the most appropriate priority level for an appointment.
Clinical Context (Merck Veterinary Manual)
In dogs, constant scratching behind the ears may be caused by allergic disorders such as environmental allergies (e.g., house dust, house dust mites, pollens of trees, grasses, and weeds, molds) or food allergies, which cause erythema and pruritus of the pinnae and external ear canals. These allergic conditions can predispose the dog to secondary bacterial or yeast otitis externa, which can extend to the pinna, resulting in papules, crusts, and lichenification in addition to erythema. Arthropods can also cause dermatitis of the pinnae either through direct damage from the bite or as a result of hypersensitivity; ticks can cause irritation at the site of attachment and may be found on the pinna or in the ear canal. Clinical signs associated with arthropod bites include head shaking, head rubbing, or drooped pinnae.
Chapter: Dermatology, Allergy
Source: The Merck Veterinary Manual, 11th Edition (Page 522)