Stroke in dogs – symptoms, diagnosis and treatment

Overview

Oxygen deprivation damages a particular brain region

The brain needs a constant supply of oxygen and nutrients through the blood. A disturbance of circulation can therefore damage nervous tissue quickly. In an infarction, a blood vessel becomes blocked; in a haemorrhage, the vessel wall breaks and blood enters the tissue. In dogs, ischaemic stroke is more common than haemorrhagic stroke.

An infarction can affect the area supplied by a large artery or a small, deep arterial branch. An extensive infarction of a vascular territory is called territorial, while a small-vessel infarction is called lacunar. Signs depend on the location and extent of tissue deprived of blood and oxygen.

Strokes are fairly uncommon in dogs. They have been estimated to account for around 1.5–2% of neurological patients at one referral hospital. This figure describes that hospital's patients, rather than the risk of disease in all dogs.

Causes

A blockage can form locally or travel in the blood

A blood clot can block a brain blood vessel. Obstructing material carried in the blood from elsewhere causes an embolism. Less commonly, a fragment of tumour tissue, fat or parasitic material may be responsible.

An underlying condition may be identified, such as high blood pressure, chronic kidney disease, Cushing's disease or diabetes. These diseases are investigated as part of the overall assessment. In around 50% of dogs with a stroke, no underlying cause is identified despite thorough investigation.

Bleeding has a different mechanism

Brain haemorrhage may be caused by a clotting disorder, low platelet count, a tumour or blood vessel inflammation. An accident can also cause bleeding into the brain. The mechanism of sudden signs is therefore investigated before selecting treatment affecting clotting.

The inflammatory response following an ischaemic stroke can contribute to worsening brain tissue damage. Inflammation here does not automatically mean bacterial infection.

Risk factors

Strokes are diagnosed most often in middle-aged and older dogs, frequently at 8–12 years of age. Age is partly linked to the type of underlying disease present. Cavalier King Charles Spaniels and Greyhounds have been described as more predisposed.

High blood pressure can also damage brain blood vessels and cause neurological target organ damage. Kidney and hormonal diseases are therefore important to investigate in an affected dog. Heart disease alone is not the same common explanation for embolism in dogs as it is in cats.

The available information does not provide a reliable risk ranking by sex or breed-specific disease rates.

In a follow-up study of dogs with ischaemic stroke published in 2013, the median age was 9 years. The youngest dog was 2 and the oldest 17. Ischaemic stroke therefore does not affect only very old dogs.

Typical symptoms

Signs of an ischaemic stroke typically start suddenly and may be clearly one-sided. Changes seen at home may include:

• Unsteady walking, uncoordinated movement and loss of balance.
• Falling or continually leaning to one side.
• A head tilt or turn in an abnormal direction.
• Circling.
• Rapid, involuntary eye movements.
• Sudden deterioration in vision.
• Muscle weakness on one side or in all limbs.
• A sudden behavioural change and difficulty finding the way around.

A severely unbalanced dog may paddle their legs in a way that looks like a seizure. True epileptic seizures are possible with a stroke, but are not the most typical sign in every dog. The distribution of signs varies because different brain regions can be affected.

Complications and consequences

Early deterioration can occur

Brain swelling developing during the first 24 hours can worsen stroke signs. The dog's condition is therefore monitored after the initial examination as well. An infarction can leave permanent movement or behavioural changes. Behavioural changes may be harder to resolve than movement problems.

In an ischaemic stroke follow-up study published in 2013, 5 dogs, or 23%, died within the first 30 days. Dogs surviving at least 30 days had a median survival time of 505 days. This describes a group already surviving the early stage; the same survival time does not apply to every newly affected dog.

Recovery and recurrence

In the same study, recovery was rated excellent in 7 dogs, or 41%, among the 17 early survivors. New sudden neurological signs developed in 7 surviving dogs within 6–17 months. Only 2 of these cases had a new infarction confirmed by MRI. Not every return of signs was therefore a new infarction established by imaging.

Many dogs recover with time and supportive care, but recovery can take weeks to months. A dog with an underlying disease can also recover well when that disease is controlled.

Diagnosis at the vet

Examination distinguishes other sudden brain diseases

Your vet assesses alertness, walking, proprioception and cranial nerve function. Findings help locate the lesion and select further investigations. An infarction is confirmed primarily through brain MRI. Brain imaging is performed under general anaesthesia.

Images are assessed for a lesion in a distribution consistent with a vascular territory and for possible bleeding. Certain imaging sequences highlight signal changes caused by blood. CT may also be used where necessary. A tumour, inflammation or infection may additionally require cerebrospinal fluid sampling.

Blood pressure measurement and blood and urine tests form part of investigating underlying causes. Urine can be checked for abnormal protein loss. Clotting tests help investigate a bleeding or coagulation disorder. Depending on the signs, hormonal function, the heart, chest or abdomen may be investigated for hidden disease.

Blood pressure is measured calmly because stress at the practice can raise the reading. The average of 5–7 consistent measurements may be used for assessment. High blood pressure can also cause sudden vision loss through retinal damage. Examination of the back of the eyes therefore complements a neurological examination in a suddenly blind dog.

Idiopathic vestibular signs can start very suddenly. Many affected dogs improve considerably within 2–3 days. Full recovery often occurs within 1–2 weeks. A head tilt may nevertheless remain. These times concern idiopathic vestibular disease and do not automatically apply to the outlook for an infarction.

Blood tests do not replace brain imaging

A blood test study published in 2026 included 17 dogs with cerebrovascular accidents and 20 healthy controls. It examined measures including the neutrophil-to-lymphocyte ratio, which partly reflects the body's inflammatory response. Such markers remain subjects of investigation as additional measures, rather than definitive standalone tests for ischaemic stroke. Comparison with healthy dogs does not establish how well a test distinguishes infarction from other brain diseases.

In the small 2026 comparison, a neutrophil-to-lymphocyte ratio threshold of 3.92 distinguished affected from healthy dogs with 70.6% sensitivity. Specificity was 90.0%. These figures concern a group combining infarctions and haemorrhages, rather than confirmation of ischaemic infarction alone. A normal D-dimer result also does not reliably rule out a cerebrovascular accident.

Treatment

Supportive care and treatment of the underlying cause

The treating vet selects care according to the diagnosed brain disease and your dog's general condition. No specific curative medicine can reverse brain damage that has already occurred. Supportive treatment and good nursing care are therefore central to recovery. High blood pressure, diabetes or Cushing's disease, for example, are treated where needed.

The benefit and use of clot-dissolving drugs used for human ischaemic stroke have not been established in animals. Antiplatelet medication may sometimes be used to reduce the risk of new clots. This differs from dissolving an existing blockage. Haemorrhagic stroke may require hospital monitoring and control of bleeding.

The brain and kidneys, adapted to long-standing high blood pressure, may be harmed by an overly abrupt pressure reduction. Blood pressure treatment is therefore tailored to the clinical situation and maintenance of organ blood flow.

Rehabilitation supports function

Physiotherapy and nursing care can provide considerable support for recovery. A dog may initially need help with ordinary daily activities. With balance problems, a support harness or sling can help with safe movement and toileting. Grip aids can improve footing on slippery floors. Stairs can be blocked off to prevent unsupervised access.

A regular daily routine and safe environment make rehabilitation easier. Treatment results are assessed through the dog's ability to function and repeat examinations. Severe signs on the first day alone do not describe the whole course of later recovery.

Prevention

Not every ischaemic stroke can be prevented because some have no identifiable underlying cause. Appropriate treatment of a diagnosed blood pressure, kidney or hormonal disease forms part of managing recurrence risk. Health checks in an ageing dog may detect underlying disease before neurological signs occur.

Blood pressure monitoring is particularly important if your dog has a disease predisposing to high blood pressure. Monitoring an at-risk patient also includes examination of the back of the eyes and kidney function, including protein loss in urine. Prevention focuses on your dog's own diagnosed diseases, because human lifestyle risks do not directly describe canine stroke.

Important for dog owners

Record when your dog was last normal and when sudden signs began. Sudden onset and one-sided signs are important observations for the investigation. Record a short video if you can do so without delaying help. A dog unable to move can be transported using a flat, firm supporting surface.

Keep feeding, rest and exercise routines predictable during recovery. Monitor walking, vision, behaviour and ability to toilet separately. New neurological signs require reassessment because they can indicate a new event or another disease.

Do not start human clot-dissolving or clotting medication on your own initiative. Agree rehabilitation goals and monitoring of underlying diseases with the treating vet. Improvement in movement and recovery of behaviour may progress at different rates.

Frequently asked questions

Is an ischaemic stroke the same as a brain haemorrhage?

No. In an infarction, a brain blood vessel becomes blocked and tissue receives insufficient blood flow. In a haemorrhage, a vessel ruptures and blood enters or surrounds the brain. Both can cause similar sudden signs, so imaging investigates the mechanism.

Can a dog recover from an ischaemic stroke?

Many dogs recover with supportive care and time, but rehabilitation can take weeks to months. Some retain movement or personality changes. A dog with concurrent diseases can also recover well when those conditions are treated appropriately.

Can a head tilt be something other than an infarction?

Yes. Inner ear and balance system diseases can cause very similar balance signs. Idiopathic vestibular disease in an older dog is one possible explanation. The same sign is therefore not definitively labelled an ischaemic stroke at home: a vet investigates its cause.

Does an ischaemic stroke show up in a routine blood test?

Routine blood tests help look for underlying diseases, but brain damage is investigated primarily through MRI. Ratios of inflammatory blood cells and similar indices are being studied as additional markers. Their use does not yet replace diagnosis based on imaging and neurological examination.

Can a dog have another ischaemic stroke?

Recurrence is possible. In the 2013 follow-up study, 7 dogs later developed new neurological signs. Only 2 cases had a new infarction demonstrated by MRI. Not all new signs are therefore counted as a confirmed new infarction. Control of underlying disease forms part of ongoing care.