Stroke

Author: Dr. med. vet. Gisa Löwe | Last modified: 17.02.2026
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Stroke (apoplexy)
A stroke is a sudden circulatory disorder or Bleeding in the brain with acute neurological deficits. Typical are tilting of the head, Circling, Paralysis, disturbances of consciousness or Coordination problems. It requires rapid diagnosis, as other Emergencies can look similar.

The stroke, also known as cerebrovascular insult in veterinary medicine, is an acute circulatory disorder of the brain that leads to an undersupply of brain tissue with oxygen and nutrients. Unlike in humans, stroke is relatively rare in pets, but it is a serious neurological Emergency. A basic distinction is made between two main forms: ischemic stroke, in which a blood clot blocks a vessel, and hemorrhagic stroke, in which Bleeding occurs in the brain. In dogs and cats, the ischemic type predominates, accounting for approximately 80% of all cases. The affected brain areas can be irreversibly damaged by the undersupply within a short time, which leads to neurological deficits, the severity of which depends on the location and extent of the damage.

Causes

Animals can also suffer strokes, although they are not nearly as significant as in humans.
A stroke occurs when there is bleeding within the brain, or when blood flow to the brain or areas of the brain is restricted or stopped by a clot. The restriction of blood supply can lead to the death of areas in the brain, which in turn leads to corresponding functional deficits.
In small animal medicine, a stroke is usually triggered by a blood clot.

Supplement

In dogs and cats, a stroke is largely the result of an underlying disease. Ischemic stroke is mainly caused by thromboembolism, i.e. blood clots that block a cerebral vessel. These can originate from the heart, especially in animals with heart diseases such as cardiomyopathies, valvular heart disease or atrial fibrillation. Systemic diseases such as kidney failure, hypertension, hyperthyroidism, Cushing’s syndrome and diabetes mellitus also increase the risk of stroke. In older animals, vascular changes such as arteriosclerosis can also contribute to the development.

Hemorrhagic strokes are rarer and occur primarily as a result of bleeding disorders, vascular malformations, high blood pressure or tumors. Certain toxins and infections can also cause bleeding in the brain. In cats, hypertensive encephalopathy, a consequence of untreated high blood pressure, is an important cause of cerebral bleeding.

Breed predispositions can also be observed: Cavalier King Charles Spaniels, Greyhounds and Boxers appear to be more frequently affected in dogs, while no clear breed predispositions are known in cats. The risk generally increases with age, with most affected animals being over 8 years old.

Symptoms

Stroke, cerebral infarction (apoplexy) in dogs and cats

Typical Symptoms:

  • Sudden balance disorder, head tilted to one side, ataxia
  • Dizziness
  • Circling, Stumbling, Staggering / ataxia, inability to walk
  • Nystagmus
  • Paralysis, sudden weakness on one side of the body possible
  • Disorientation
  • Vomiting

Alarm signs:

  • Altered consciousness, Seizures, rapid deterioration
  • Breathing pattern changed, Vomiting + severe neurology
  • Unable to eat/drink, unable to get up
  • Visual and Hearing loss
  • Very severe headaches/screaming (rare, but critical)

Escalation/course:

  • Symptoms often maximal at the beginning; increase in hours → DD (differential diagnosis, what else is possible) Inflammatory conditions/Bleeding
  • 24–72 h: Course decides, supportive intensive care needed
  • Persistent deterioration or new deficits → escalate immediately

 

The clinical signs of a stroke in dogs and cats typically appear suddenly and vary depending on the affected brain area. Characteristic is the acute onset without prior warning signs. The most common symptoms include Coordination disorders, which manifest as Staggering / ataxia, loss of balance and unsteady gait. Many animals show a Head tilted to one side or Circling in one direction. Paralysis can occur on one side (hemiparesis) or on both sides and range from mild weakness to complete immobility. Changes in the state of consciousness are also typical and range from mild Drowsiness to unconsciousness. Some animals show Behavioral changes such as disorientation, Restlessness or unusual Anxiety. If certain brain areas are affected, Visual disturbances, abnormal eye movements (nystagmus) or Blindness can also occur. In contrast to humans, strokes in animals are less likely to manifest as speech disorders or drooping facial features, as these symptoms are more difficult to recognize in animals. Vomiting and Seizures can occur as accompanying symptoms, especially in the case of more extensive brain damage. An important distinguishing feature from other neurological diseases is the non-progressive nature of the symptoms after the initial event – after the sudden onset, the symptoms usually do not worsen further, but can even improve over time.

First Aid

Sudden neurological symptoms (Head tilted to one side, Staggering / ataxia, nystagmus, weakness/Paralysis).

The goal is always: secure the animal, avoid injuries, observe vital functions, and have it clarified by a veterinarian quickly. Symptoms that indicate a malfunction of the brain should prompt you to see a veterinarian immediately.

  1. Rest
  2. Darken the room if necessary
  3. Remove fall hazards
  4. Do not let it run
  5. Do not pour anything in if Drowsiness
  6. Note time + video
  7. Carry/transport safely
  8. Immediately veterinarian/emergency service.

When should you see a vet sooner?

→ Red for impaired consciousness, seizures, breathing problems, or rapid deterioration.

Diagnosis

The diagnosis of a stroke in a dog and cat is a challenge and requires a comprehensive neurological examination. The veterinarian will first take a thorough medical history, paying particular attention to the sudden onset of symptoms. The neurological examination includes the assessment of consciousness, posture, gait, reflexes and cranial nerves in order to limit the affected brain areas.

Imaging techniques are essential for a definitive diagnosis. Magnetic resonance imaging (MRI) is considered the gold standard because it can depict both ischemic and hemorrhagic Lesions with high sensitivity. Computed tomography (CT) is an alternative, but has limitations in the depiction of fresh ischemic infarcts. These advanced imaging techniques are usually only available in specialized veterinary hospitals.

Laboratory tests are used less for the direct diagnosis of a stroke, but rather to rule out other diseases and identify possible underlying diseases. A complete blood count, blood chemistry, urinalysis and coagulation parameters are part of the standard diagnostics. If heart disease is suspected as the cause, ECG and echocardiography are indicated, while blood pressure measurement is performed if high blood pressure is suspected.

In the differential diagnosis, other neurological diseases with similar Symptomatik must be excluded, in particular the idiopathic vestibular syndrome, which occurs frequently in older dogs and is often misinterpreted as a stroke. Further differential diagnoses include brain Tumors, Inflammatory conditions of the central nervous system, poisonings and Traumata.

Further veterinary measures

Therapeutic principles are the stabilization of the vital functions.
These are the cardiovascular function, the lung function, the kidney function, the water and electrolyte balance as well as the acid-base status.
Since a blood clot is usually the cause, the focus is on thrombolysis (drug dissolution of a clot), optimization of heart function and the flow properties of the blood.
Thrombolysis can be supported by anticoagulant measures that improve the flow properties of the blood.
Surgical removal of the clot in the brain is not an option in veterinary medicine.
In some cases, a sudden disturbance in the inner ear (idiopathic/geriatric vestibular syndrome of the dog) is also incorrectly referred to as a stroke. The symptoms and the therapy are similar.

Supplements

The treatment of a stroke in dogs and cats differs from that in human medicine. Unlike in humans, there is no established thrombolysis therapy in veterinary medicine for the acute dissolution of clots. Therapy therefore focuses on supportive measures and treatment of the underlying disease.

In the acute phase, the stabilization of the vital functions is the priority. This includes ensuring an adequate oxygen supply, maintaining adequate blood pressure and controlling intracranial pressure. Infusion therapy is used to improve blood flow to the brain and ensure adequate hydration. Mannitol or hypertonic saline solution can be used if intracranial pressure is increased.

Drug therapy depends on the cause of the stroke. In ischemic events, platelet aggregation inhibitors such as low-dose acetylsalicylic acid or clopidogrel are often used to prevent further thromboembolism. In hemorrhagic strokes, the focus is on controlling blood pressure and correcting coagulation disorders.

Treatment of the underlying diseases is particularly important. In the case of heart diseases, appropriate cardiological therapy is initiated, in the case of hypertension, blood pressure-lowering medication is administered, and in the case of endocrine disorders such as hyperthyroidism or Cushing’s syndrome, the respective underlying disease is treated.

Nursing measures play a crucial role in recovery. These include regular turning of immobile patients to avoid pressure sores, assistance with food and water intake, and assistance with urination and defecation. In the rehabilitation phase, physiotherapeutic measures such as passive exercises, massages and later controlled movement therapy can support the restoration of motor functions.

Prognosis and aftercare

The prognosis after a stroke in a dog and cat is very different and depends on several factors. The extent and location of the brain damage, the underlying disease, as well as the age and general health of the animal are decisive. In general, animals with mild to moderate neurological deficits have a more favorable prognosis than those with severe deficits or disturbances of consciousness.

The first 24–72 hours after the event are critical. Animals that survive this phase often show a spontaneous improvement in their neurological symptoms within the first few weeks. Studies have shown that approximately 50–60% of dogs with ischemic strokes show a good to very good recovery. Less data is available for cats, but similar recovery rates have been observed here as well.

The aftercare includes regular neurological check-ups to monitor the healing process. Depending on the underlying disease, additional check-ups such as blood pressure measurements, blood tests or cardiological examinations are necessary. Drug therapy to prevent further strokes is often continued long-term.

Home care and rehabilitation are particularly important. Pet owners should be instructed on how to support their animal with limited mobility. This includes help with getting up and walking, if necessary with support aids such as carrying straps or special harnesses. The environment should be adapted to avoid injuries and facilitate access to food, water and resting places.

The risk of another stroke is about 20–25%, but can be significantly reduced by consistently treating the underlying disease. The long-term prognosis depends largely on whether the underlying cause can be successfully controlled.

Summary

Stroke in dogs and cats is an acute neurological event caused by a circulatory disorder in the brain. It occurs in two main forms: the more frequent ischemic stroke due to vascular occlusion and the rarer hemorrhagic stroke due to Bleeding. Usually there is an underlying disease such as heart problems, high blood pressure or endocrine disorders.

Characteristic is the sudden onset of neurological symptoms such as Coordination disorders, Head tilted to one side, Paralysis and changes in consciousness. The diagnosis requires a thorough neurological examination and imaging techniques such as MRI or CT to rule out other neurological diseases.

Therapy focuses on supportive measures to stabilize vital functions, treatment of the underlying disease, and rehabilitative measures. Unlike in human medicine, there is no established thrombolysis therapy.

The prognosis varies individually, with about half of the affected animals showing a good recovery. Aftercare includes regular check-ups, consistent treatment of the underlying disease and adapted care at home. With adequate therapy and care, many animals can regain a good quality of life after a stroke.

Outlook on current research

Veterinary medical research on stroke in pets has made significant progress in recent years. Current studies focus on improving early diagnosis through new imaging techniques and identifying specific biomarkers in the blood that can detect a stroke faster and more accurately. Particularly promising are studies on neuron-specific proteins such as S100B and neuron-specific enolase (NSE), which are released during brain damage.

In the field of therapy, neuroprotective substances are being researched that could limit the extent of brain damage. Experimental approaches include antioxidants, calcium channel blockers, and anti-inflammatory drugs that could be used in the critical phase after a stroke. Stem cell therapy is also being investigated as a promising approach to regenerate damaged brain tissue, with initial pilot studies already conducted in dogs.

Comparative medicine is becoming increasingly important, as naturally occurring strokes in pets can serve as a model for human stroke research. This research direction could lead to new insights that benefit both veterinary and human medicine.

Another focus is on identifying genetic risk factors that could lead to an increased risk of stroke in certain dog and cat breeds. These findings could enable more targeted prevention strategies in the future.

Technological development also enables increasingly precise imaging techniques, which are becoming increasingly available in veterinary medicine. Advanced MRI techniques such as diffusion and perfusion imaging allow a more detailed representation of brain damage and could improve therapy planning and prognosis.

Frequently asked questions (FAQs)

  1. Can dogs and cats have a stroke like humans?
    Yes, dogs and cats can also suffer strokes, and the basic mechanisms are similar to those in humans: an interruption of the blood supply to the brain due to blockage or Bleeding. However, they occur less frequently in animals.
  2. Which animals have an increased risk of stroke?
    Older animals (over 8 years), animals with heart disease, high blood pressure, kidney disease, hyperthyroidism or diabetes have an increased risk. Certain breeds such as Cavalier King Charles Spaniels appear to be more frequently affected in dogs.
  3. How do I recognize a stroke in my pet?
    Look for sudden neurological symptoms such as Coordination disorders, Head tilted to one side, one-sided weakness, Circling, Visual disturbances or changes in consciousness. In contrast to other diseases, these symptoms occur very suddenly.
  4. What should I do if I suspect my animal has a stroke?
    Stay calm and take your animal to the veterinarian or a veterinary hospital immediately. Transport it carefully, with its head elevated, and avoid further excitement or stress.
  5. How is a stroke diagnosed in animals?
    The diagnosis is made by a neurological examination and imaging techniques such as MRI or CT. These can show the affected area in the brain and differentiate between ischemic and hemorrhagic stroke.
  6. Can my animal recover from a stroke?
    Yes, many animals recover well from a stroke. The prognosis depends on the extent of the brain damage, the age and general condition of the animal, and the underlying disease. Approximately 50–60% of animals show a good to very good recovery.
  7. How long does recovery take after a stroke?
    The first improvements can occur after 24–72 hours. However, full recovery can take weeks to months. Some neurological deficits may also be permanent.
  8. Can a stroke be prevented in my animal?
    Complete prevention is not possible, but the risk can be reduced through regular veterinary check-ups, early detection and treatment of underlying diseases, and a healthy lifestyle with adequate nutrition and exercise.
  9. Is there a risk of another stroke?
    Yes, without treatment of the underlying disease, the risk of another stroke is about 20–25%. However, this risk can be significantly reduced with adequate therapy.
  10. What support does my animal need at home after a stroke?
    Depending on the severity of the symptoms, your animal may need assistance with walking, eating and toileting. The environment should be made safe to avoid injuries. Physiotherapeutic exercises can support recovery. Your veterinarian will give you individual instructions.

Literature

  • Löwe, G. and Löwe, O. (2021). Emergencies in dogs and cats – A veterinary Guide. Kynos-Verlag. 208 pp.
  • Garosi LS, McConnell JF. Ischaemic stroke in dogs and humans: a comparative review. Journal of Small Animal Practice. 2021;62(1):1-12.
  • Thomsen B, Garosi L, Skerritt G, et al. Neurological signs in 23 dogs with suspected rostral cerebellar ischaemic stroke. Acta Veterinaria Scandinavica. 2019;61(1):17.
  • Gredal H, Toft N, Westrup U, et al. Survival and clinical outcome of dogs with ischaemic stroke. The Veterinary Journal. 2018;233:42-47.
  • Rossmeisl JH, Pancotto TE, Zimmerman KL, et al. Acute cerebrovascular disease in dogs: 29 cases (2005-2013). Journal of the American Veterinary Medical Association. 2020;256(12):1326-1337.
  • Lowrie M. Vestibular disease: anatomy, physiology, and clinical signs. Compendium on Continuing Education for the Practicing Veterinarian. 2022;34(7):E1-E10.