Heart - Disease, Failure and Strokes
Heart Problems - General
Heart problems are much harder to detect in cats compared to dogs. Owners of dogs will usually notice a reduced exercise tolerance so when out on a walk or playing with a ball the dog will give up, start coughing or panting or even collapse but will tend to recover with resting.
Animals with heart problems often cough due to a build up of fluid in the lungs and also because the heart often becomes enlarged due to disease and pushes on the windpipe. They often pant or breathe with their mouth open as this is a way of increasing the oxygen in the lungs. They may drink more and because of this wet in the house over night. They will tend to get tired more quickly because the heart is not able to pump blood round to the muscles as well. When the heart condition progresses, fluid can build up in the abdomen and this can be very uncomfortable as it puts pressure on the animal’s organs and stops them working properly.
Around 15% of dogs in the UK are affected by heart disease and the initial signs can often go unnoticed. The three most common signs of heart failure in dogs are:
lack of energy,
loss of appetite and
coughing, especially at night.
Owners may not necessarily associate these symptoms with heart disease.
Heart Disease and Heart Failure
The common heart diseases suffered by dogs often lead to heart failure. Dogs will generally suffer what is called Congestive Heart Failure (CHF), a relatively slow worsening of symptoms. However, there have been major advances in veterinary medicine over the years and the outlook for a dog with heart failure is often not as gloomy as it once was.
Disease usually starts to affect one part of the heart and goes on to damage other parts. Disease can be acquired (more common) or congenital (less common).
Acquired heart diseases are those that a dog acquire during its lifetime, usually as a result of normal wear and tear, infection or injury. Acquire heart disease accounts for 95% of all heart disease seen in dogs and usually appears after they reach middle age.
The earlier heart disease is diagnosed the better. Usually a dog will not show any obvious symptoms until the condition is irreversible.
Congenital defects are those that have been present since birth and are comparatively rare. Congenital defects will usually cause the blood flow through the heart to become turbulent, making a distinctive whooshing noise that vets can hear using a stethoscope – this is what is meant by a “heart murmur”. If your dog is diagnosed with heart murmur however, it is not necessarily cause for concern. Sometimes puppies are born with a slight heart murmur which clears up by itself after 4-6 months. A later checkup is advisable to ensure the condition has resolved itself.
Diagnosis & Treatment
Your vet may recommend all or any of the tests we can now do to help decide on the best treatment for your dog – listening to the heart with a stethoscope, blood and urine tests, x-rays of the heart and lungs, and ECG (electrical trace of the heartbeat) and ultrasonography (a real-time picture of how the heart is functioning).
Heart failure is rarely a sudden cessation of the heart’s function, but a slow process which affects almost every part of the body. Unlike the underlying disease, heart failure can often be managed with medication that improve and extend the dog’s life.
A special exercise regime for your dog will also be very important.
Senior dogs suffer from many similar conditions to old people – strokes being one of them. Strokes occur when a particular part of the brain is starved of oxygen and this results in that area of the brain being affected and not working properly. Often the clinical signs are one-sided, meaning that one half of the brain is altered but the other half is fine. The big difference between dogs and humans is the dog’s ability to recover. With medication our canine friends can return to normal or cope with mild signs.
Dogs who have had a stroke give varying signs but most commonly they will have a head tilt to either the right or left. This affects their balance so can make them walk round in a circle or wobble or stagger. They can also have nystagmus - this is when the eyes flick quickly from side to side and this contributes to the dog’s disorientation. Sometimes the signs can be worse and involve collapse or the inability to get up. The signs come on very quickly and urgent medical attention at your vets is required.
As the signs of a stroke are quite specific, the vet can usually diagnose the problem on a thorough clinical examination of your dog. The main area to rule out would be an inner ear infection as that would result in the same balance problems.
Initially, the dog is given an injection of anti-inflammatory medicine. This is often given into the vein and at a high dose so that it acts as quickly as possible to prevent further swelling and brain damage. This medication is then continued for a short period in tablet form to help continued reduction in swelling of the brain tissue.
Long-term treatment is aimed at preventing further strokes from occurring. This is done with medication that helps increase the blood circulation and so stops the brain being starved of oxygen. It also helps the other organs such as the liver and kidneys by improving their blood supplies and it often gives elderly dogs a lot more energy.
Other supplements can help improve the removal of free radicals, which can build up in the brain and affect how well the nerves transmit information resulting in the dog appearing slightly senile.
The balance problems and eye flicking usually resolve within a few days but the head tilt often takes longer and some dogs remain with it but usually cope very well.