Strokes in Dogs

Over the last few years, research has established that dogs can suffer strokes more often than it was previously thought. This is all thanks to the new specialist tests that are now available which help vets determine whether a dog has suffered a stroke. The tests also help confirm an underlying cause. Although worrying, a dog can recover and cope very well and unlike humans, they easily adapt providing no serious damage has been done to an essential part of their brain.

The Causes

A stroke is what is referred to as a cerebrovascular accident and it happens when blood supply to the brain is seriously reduced or interrupted for any reason. There are two types of strokes seen in dogs which are as follows:

• Ischaemic stroke which happens when the blood supply to the brain is suddenly interrupted
• Haemorrhagic stroke which is when bleeding occurs within the brain which typically happens when a blood vessel bursts

When the brain does not receive a constant and reliable blood supply which takes valuable oxygen and nutrients to it, certain parts of the brain can be irreversibly damaged or brain function is impaired so badly it cannot do its job properly.

The reasons why a dog might suffer an ischaemic stroke is often because they have developed the following health issues:

• Disorders that result in a narrowing of the arteries
• Diseases that result in clogging of the arteries
• Kidney disease
• Heart disease
• An under or over-active thyroid gland
• Cushing’s disease
• Diabetes
• High blood pressure known as hypertension

All too often and despite many tests, the underlying reason why a dog has suffered from this type of stroke is never determined.

Should a dog suffer an haemorrhagic stroke, the causes are typically as follows:

• Blood leaking into the brain or between the skull and the brain
• Exposure to certain toxins which includes rat poison
• Immune-mediated thrombocytopenia
• Congenital clotting diseases
• Kidney disease
• Heart disease
• Cushing's disease
• Thyroid disease
• Inflammation of the arteries a condition known as vasculitis
• An abnormal development of the blood vessel found in the brain
• Trauma to the head

Recognising the Symptoms

The symptoms a dog displays when they are suffering a stroke are quite different to those manifested by people in the same situation. The most common signs of there being something wrong with a dog could include the following:

• A head tilt
• Head held at an angle or turned
• A lack of balance
• Their vision is impaired
• Circling
• Falling over

It's worth noting that the above symptoms are also associated with other brain disorders and as such immediate veterinary attention should be sought so a correct diagnosis can be established sooner rather than later.

Diagnosing the Problem

A vet would need to know how the onset of any symptoms first manifested themselves and they would need to thoroughly examine a dog suspected of suffering from a stroke. The tests a vet would typically recommend carrying out could include the following:

• X-rays
• CT scan
• MRI scan
• A sample of spinal fluid - known as a spinal tap which would help rule out other underlying causes

A dog would need to be given general anaesthetic for these tests to be carried out. The tests would help a vet identify which part of the brain has been most impacted and once they have established this, they would then recommend the best treatment option.

Treatment Options

There are no specific treatments for dogs when they suffer a stroke that can effectively repair any damage that may have occurred to their brains. If there is an underlying cause that's led to a dog suffering a stroke, if possible this can be treated to prevent them from having another one. Supportive care is an all-important factor in a dog's recovery.

Testing for Strokes in Dogs

As previously mentioned there are many tests now available that help vets establish whether a dog has had a stroke and these include the following:

• Blood tests
• A urinalysis
• CSF analysis
• Spinal X-rays
• Myelography - dye is injected into fluid that surrounds a dog's spinal cord
• CT scan
• MRI scan
• EMG - electromoyography
• Tissue biopsy

The Prognosis

Most dogs recover well after they have suffered a stroke, but it does depend on which part of their brain has been most impacted. The chances of them having another stroke depends on the cause of the first one and whether a vet successfully treated the underlying health issue. If the damage is not great and certain parts of a dog's brain were not seriously damaged, they usually cope very well after having suffered a stroke and go on to lead full and happy lives.