SYMPTOM
Phantom scratching
A rhythmic movement of a hind leg towards the neck, shoulder or ear that does not touch the skin, often with the body and neck curved towards the foot. It can be set off by excitement, activity, light touch to the neck or ear, or a collar. Some dogs also shy away from touch to the head, neck or shoulders.
Syringomyelia / Chiari-like Malformation
Fluid-filled cavities within the spinal cord disrupt normal sensory processing and can produce a rhythmic scratching motion towards the neck or shoulder that does not make contact with the skin, typically on one side. Cavalier King Charles Spaniels carry a strong breed predisposition linked to their skull conformation, and most affected Cavaliers show their first signs before 4 years of age.
Otitis Externa
Inflammation or infection within the ear canal produces deep, localised irritation that drives scratching directed at the ear and neck region. Because this scratching is usually vigorous and repeatedly makes contact with the skin, it is generally distinguishable from the non-contact 'air' scratching typical of a neurological cause, and head shaking, an odour from the ear or visible discharge usually accompany the pattern.
Atopic Dermatitis
Underlying allergic skin disease can heighten skin sensitivity so that even light stimulation triggers a reflexive scratching motion, and affected dogs typically do make contact with the skin when they scratch, unlike the non-contact 'air' scratching seen with a neurological cause. This tends to be seasonal or progressive, and most often affects the paws, face, ears, front leg folds, armpits and belly.
Focal Seizure Activity
Focal seizures start in one part of the brain and can cause rhythmic jerking of one limb or twitching of the face, which can be mistaken for scratching. Episodes are brief, lasting seconds to minutes, look the same each time, and may come with drooling, dilated pupils or a sudden change in behaviour such as fear or restlessness.
Compulsive Behaviour / Stereotypy
In dogs prone to repetitive behaviours, scratching motions can become a fixed, self-perpetuating pattern similar in nature to tail-chasing, occurring independently of any physical skin or neurological trigger. This is more likely when the behaviour appears during understimulation, confinement or stress, and the dog can sometimes be gently interrupted. It is considered only once skin, pain and neurological causes, including focal seizures, have been ruled out.
Why timing matters
Early observation
Syringomyelia is painful and progressive, and the earliest sign is often yelping after a sudden change in posture, such as jumping down or being picked up.
Later presentation
Pain can progress from episodes lasting minutes to constant pain with great reluctance to move. Phantom scratching is linked mainly with a wide syrinx (4 mm or more), so it can mean the cavity in the spinal cord is already large.
Whether the paw touches the skin cannot confirm the cause at home. MRI is the method used to diagnose syringomyelia, and skin, ear and seizure causes are looked for alongside it.
Conditions commonly associated
Syringomyelia
A distinctive scratching motion at the air near the ear or shoulder without skin contact, strongly associated with syringomyelia.
Otitis Externa in Dogs
Otitis externa causes ear itch and pain, with head shaking and scratching at the ear that usually makes contact with the skin. It is one of the common causes to rule out before scratching is put down to a neurological cause.
Atopic Dermatitis in Dogs
Atopic dermatitis causes itch, and the scratching usually makes contact with the skin. Like ear disease, it is ruled out before a neurological cause is considered.
Compulsive Behaviour in Dogs
Scratching can become a compulsive behaviour, repeated out of context and detached from itch, often linked with chronic anxiety or too few outlets for normal behaviour. It is diagnosed only after skin, pain and neurological causes have been ruled out.
Epilepsy in Dogs
Focal seizures in dogs with epilepsy can cause brief, rhythmic jerking of one limb that can resemble scratching. Seizures are among the neurological causes investigated when a repetitive movement has no skin or ear cause.
Chiari-Like Malformation
In Cavalier King Charles Spaniels with Chiari-like malformation, owner-reported phantom scratching is significantly associated with a large syrinx in the spinal cord.
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When to explore further
When the symptom is persistent or worsening
When the scratching does not touch the skin and the skin and ears look normal
When daily activities or quality of life are affected
When there is uncertainty about the cause
Noting when episodes occur, what sets them off, which side is involved, whether the paw touches the skin, and how this changes over time, ideally with a short video of an episode, can provide useful information for veterinary discussions.
Last reviewed: 9 October 2026 · Dr Alastair Greenway MRCVS