Obesity In Dogs: Stroke Risk And Prevention

Being overweight can cause high blood pressure in dogs, which is a risk factor for strokes. Other risk factors include blood clotting disorders, underactive thyroid glands, and diabetes.

Obstruction in blood vessels (ischemic strokes)

Obstruction in blood vessels, or ischemic strokes, are the most common type of stroke in dogs. They are caused by a loss of blood flow to the brain, which results in tissue damage and neurological abnormalities.

Ischemic strokes are caused by a blockage in the blood vessels, which can be due to blood clots, tumours, inflammation, or infections. The most common artery to develop emboli is the rostral cerebellar artery, followed by the perforating arteries of the caudal thalamus and rostral brainstem, the cerebral striate arteries, middle cerebral artery, and rostral cerebral artery.

The signs of an ischemic stroke can include an inability to walk, abnormal eye movements, loss of consciousness, and rapid onset of symptoms.

Ischemic strokes can be identified through imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI). CT is useful for ruling out haemorrhagic strokes, while MRI is more effective at detecting ischemic infarction.

Bleeds in the brain (hemorrhagic strokes)

Hemorrhagic strokes are associated with a vessel rupture, with or without an obvious underlying cause, or a coagulopathy.

There are numerous reported underlying etiologies for hemorrhagic strokes in dogs. Both primary and metastatic brain tumors can develop spontaneous intracranial hemorrhage. Extracranial diseases that lead to disseminated intravascular coagulopathy or other causes of spontaneous bleeding, such as ingestion of anticoagulant rodenticide, can result in spontaneous intracranial hemorrhage. Additionally, bacterial infection, congenital vascular malformations, necrotizing vasculitis and brain atrophy leading to tearing of blood vessels have been reported as causes of hemorrhagic strokes.

In people, the main primary cause of hemorrhagic strokes is spontaneous rupture of an otherwise normal vessel secondary to hypertension. Conversely, hypertension leading to primary hemorrhagic strokes is rarely reported in dogs.

Cushing's disease

There are three types of Cushing's disease, each with a different cause. The most common cause (80-90% of cases) is a pituitary gland tumour, which stimulates the adrenal glands to produce excess cortisol. The second type is caused by a tumour on one of the adrenal glands, which directly produces too much cortisol. The third type, iatrogenic Cushing's disease, is caused by the prolonged use of steroids, leading to excessive cortisol levels.

The clinical signs of Cushing's disease are similar across all types. Affected dogs typically display increased appetite, water consumption, and urination. They may also exhibit lethargy, a poor hair coat, and a bloated or "pot-bellied" appearance due to increased fat within the abdominal organs and weakening of the abdominal wall muscles. Other common symptoms include panting, thin skin, chronic skin infections, dark-coloured spots, skin mineralization, poor skin healing, and persistent bladder infections.

Veterinarians use blood tests, such as the ACTH stimulation test and the low-dose dexamethasone suppression test, to diagnose Cushing's disease and differentiate between the types. Imaging techniques like X-rays, ultrasounds, CT scans, and MRIs may also be employed to detect tumours.

Treatment options depend on the type of Cushing's disease. For pituitary-induced Cushing's disease, medications like trilostane (brand name Vetoryl®) or mitotane (Lysodren®) are commonly used. Adrenal tumours may be treated with major abdominal surgery, while iatrogenic Cushing's disease requires the gradual discontinuation of the steroid.

While Cushing's disease typically shortens a dog's lifespan, proper treatment and management can help them live a good life. Close monitoring by a veterinarian and diligent care by the owner are crucial for the dog's well-being.

High blood pressure

Blood pressure is the pressure or amount of force exerted by the blood against the walls of the arteries. It is measured in two ways: systolic, which is the pressure measured during heart contraction, and diastolic, which is the pressure measured when the heart relaxes. Systolic pressure is the maximum pressure against the walls of the arteries, while diastolic pressure is the minimum.

In dogs, a systolic blood pressure of less than 150mmHg is considered normal, while a reading of 160mmHg should be investigated as pre-hypertension. Hypertension is diagnosed when the blood pressure is consistently measured above 180mmHg.

The signs of hypertension in dogs include:

• Sudden blindness
• Bleeding inside the eye
• Persistently dilated pupils
• Nervous system signs like depression, head tilt, seizures, disorientation, and weakness
• Increased drinking and urination
• Blood in the urine
• Bleeding in the nose
• Heart murmurs or abnormal heart rhythms

If you suspect your dog may have high blood pressure, it is important to consult a veterinarian. Treatment for hypertension in dogs may include medications such as angiotensin-converting enzyme (ACE) inhibitors, beta-blockers, and calcium channel blockers. Dietary changes and exercise may also be recommended to help manage hypertension.

Underactive thyroid glands

Being overweight can be a symptom of hypothyroidism, a condition caused by an underactive thyroid gland. Hypothyroidism is a common hormonal disease in dogs, affecting their metabolic rate. The thyroid gland is located in the neck and produces hormones that regulate the body's metabolic rate. If the thyroid gland is underactive, the metabolism slows down.

Hypothyroidism is usually caused by one of two diseases: lymphocytic thyroiditis or idiopathic thyroid gland atrophy. Lymphocytic thyroiditis is an immune-mediated disease, where the immune system attacks the thyroid gland. Idiopathic thyroid gland atrophy, on the other hand, is when normal thyroid tissue is replaced by fat tissue.

Signs of hypothyroidism include weight gain, lethargy, intolerance to cold, hair loss, and a dull coat. It can affect all dog breeds but is often found in Golden Retrievers, Labrador Retrievers, Doberman Pinschers, Irish Setters, Dachshunds, Boxers, and Cocker Spaniels. It usually occurs in middle-aged dogs of medium to large breeds.

While being overweight can be a symptom of an underactive thyroid gland, it is important to note that there are other potential causes as well. It is always recommended to consult a veterinarian for an accurate diagnosis and treatment plan.

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