Dog Advice

What does the heart do?
The heart is a large muscle located in the chest. The right side of the heart pumps blood to the lungs to pick up oxygen. The left side of the heart receives blood from the lungs and pumps it around the body. The left and right sides of the heart each consist of 2 chambers; these are separated by valves which ensure that blood flows only in one direction.

What can go wrong with the heart?
Rarely dogs are born with heart defects such as ‘hole in the heart’. These conditions may be noticed when puppies are examined for vaccinations. Sometimes these ‘congenital heart conditions’ may only become evident as animals age. More commonly heart diseases develop as animals age and the heart muscle starts to wear out. As dogs now live longer, heart disease is becoming more common.

You may have heard of angina and heart attacks. These occur when the supply of blood to the heart muscle is reduced or totally blocked. Whilst heart attacks are common in humans, they rarely occur in other animals. Indeed, dogs develop different heart conditions from cats, and within species heart conditions can occur more frequently in certain breeds.

Heart disease in dogs is usually caused by damage to the valves or stretching of the muscle. ‘Valvular heart disease’ most commonly occurs in Cavalier King Charles Spaniels. The valves become leaky, allowing blood to flow back into the heart and reducing blood supply to the body. In ‘dilated cardiomyopathy’ the heart swells and the contractions become weak, reducing blood supply to the body. Dilated cardiomyopathy most commonly occurs in large and giant breeds particularly Doberman’s, Great Danes and Irish Wolfhounds.

The heart muscle may also stretch in a similar manner; this stretching has been linked to low dietary levels of taurine. The condition is now rare as most pet foods are now supplemented with extra taurine.

How do you know if your dog has heart disease?
Dogs tend to show similar signs of heart disease, regardless of the actual condition. They may have reduced energy levels and be reluctant to exercise, this can be mistaken for general aging changes. In more severe cases, weight loss, poor appetite and water retention may occur. Build-up of fluid in the lungs can cause panting and coughing. Rarely, heart conditions can lead to seizures.

How does a vet diagnose heart disease?
The most useful tool for the vet is a stethoscope. A change in normal sounds can indicate heart disease. In heart disease the heart rate may be increased (or occasionally decreased). An irregular or unusual (murmur) noise may be heard. X-rays can show that the heart is enlarged or that fluid is present in the lungs. In some cases, a vet may require ultrasound to image the heart or an ECG to look at the heart’s electrical activity.

It is good advice to ask your vet to examine a new puppy. You may want to return to the breeder a puppy born with a heart defect. Alternatively, it may be possible to correct a condition surgically before any symptoms develop.

How is heart disease treated?
There is no need to treat dogs in early heart disease when no symptoms are present. Unfortunately, however, the disease does get worse. Treatment can slow the rate of progression.

Treatment includes:

• Lifestyle changes, increasing controlled exercise
• Drugs to remove retained fluid
• Drugs to increase the strength of the heart beat or change the rate of heart beat
• Dietary changes may also be of benefit

Heart disease is not the same as heart failure. Many animals with heart disease lead relatively normal lives without medication. However, heart disease is progressive and once symptoms develop, treatment will probably be needed for the rest of an animal’s life.

What is the prognosis for dogs with heart disease?
This is an impossible question to answer. While some animals can live normal lives with no symptoms, others may die quickly despite treatment. A vet may be able discuss prognosis on a case-by-case basis. The most important factor is obviously the quality of life which your pet enjoys. If you have concerns that medication is not helping or that your pet seems unwell, you should contact your vet.

Complications of heart disease include increased blood pressure which can lead to blindness or clot formation which can lead to hind limb paralysis in cats. The latter is often misinterpreted as the result of a road traffic accident.

Diabetes is an inability of the body to control the normal level of glucose (blood sugar).

Glucose provides the cells in the body with energy they need to live and function normally. Cells can only absorb glucose from the blood in the presence of the hormone insulin. Insulin is produced by the pancreas. Sometimes the pancreas becomes unable to produce enough insulin, or the cells in the body fail to respond normally to insulin. Therefore, the cells in the body cannot absorb enough glucose and too much remains in the blood.

When the blood contains a high level of glucose, some of it is able to leak through the kidneys and it begins to appear in the urine, causing increased urine production. To replace this fluid loss, the affected animal must then drink extra water.

Also, because an important energy source is being lost from the body, affected animals tend to lose weight. As the body cells are not absorbing enough glucose for their needs, this sends a signal to the brain and the animal constantly feels hungry. There may also be other signs of low energy such as lethargy and poor coat condition. The high level of sugar in the urine can cause intermittent or on-going urine infections.

Main symptoms:

• Excessive hunger
• Increased thirst
• Lethargy / weakness
• Recurrent urinary infections 

Some of these symptoms such as an increased appetite, increased drinking, urine infections or lethargy, can also be caused by a number of other diseases. Therefore, your vet will need to run some blood and urine tests to make a diagnosis.

The main aim of treatment is to restore the body’s ability to control the levels of glucose in the blood. Just as in people, diabetes can be effectively controlled by the injection of insulin. Providing the body with an easily accessible source of energy by modifying the diet as well as keeping a stress free day-to-day routine is just as vital to the successful treatment of the disease as the administration of insulin. Some animals’ diabetes is controlled purely through diet and routine alone.

When an animal’s treatment requires insulin, each animal’s individual requirement is different and your vet will need to tailor the dosage to your particular pet needs. It can take several months to achieve full stabilisation, although overall improvements in your animal should be seen within a few weeks of starting treatment.

Insulin is given at least once daily by injection and this is something that most owners can learn to do for their pet at home. While it feels very daunting at first, you will be shown how to draw up the correct dose of insulin and how to give the injection just under the skin. It is surprising how easy this all becomes with a little practice.

With well controlled diabetes, many animals can live for many years with a good quality of life. For more information please contact us directly.

What is Addison's Disease?
Addison's disease (or hypoadrenocorticism) is a disease in which the adrenal glands are destroyed, usually by the dog's own immune system, resulting in their loss of function. This means that the steroid hormones which are normally produced by the adrenal glands can no longer be produced.

Addison's disease usually develops in young to middle-aged dogs (most commonly between 4-6 years of age) and is more often reported in female dogs.

Signs of Addison's Disease
The clinical signs are often vague and may be episodic, and include lethargy, anorexia, vomiting, weight loss and general weakness. Dogs may drink and urinate more. Unfortunately, these signs are not specific to Addison's disease and may also be noted in a variety of other diseases. Occasionally dogs can experience an ‘Addisonian Crisis' and become suddenly seriously unwell.

Diagnosing Addison's Disease
Due to the unspecific nature of the clinical signs, diagnosing Addison's disease often requires several tests to be performed. A combination of physical examination, blood tests and ultrasound imaging can be used to aid a diagnosis. Then, once Addison's disease is suspected, a test called an ACTH stimulation test can be used to confirm the diagnosis.

Treating Addison's Disease
Fortunately, Addison's disease is generally relatively easy to treat. Tablets can replace the glucocorticoids and mineralocorticoids that are not being produced from the adrenal glands. Once the diagnosis is conformed and treatment has commenced, dogs generally do very well; although lifelong treatment and ongoing monitoring will be required.

Hypothyroidism is a condition in dogs which results from an underproduction of thyroid hormones from the thyroid gland. This lack of thyroid hormone in the bloodstream results in several changes in the body as thyroid hormones are responsible for maintaining a normal calorie burning level, normal tissue repair levels and a healthy immune system.

Hypothyroidism is more common in medium to large-sized dogs. There are some breeds affected more commonly that include: Golden retriever, Doberman, Poodle, Boxer, Great Dane, Airedale terrier and Old English sheepdog. It is more common in middle-aged dogs from four-years-old and up.

The most common signs are increased tiredness, weight gain, patchy hair loss or excessive shedding, recurrent skin infections and dullness (often noted as a decrease in interactions with people and other dogs, particularly a reduction in play behaviours). Sometimes, you might notice your dog appears colder than it used to, trying to seek out warmth more regularly. Occasionally, hypothyroidism can contribute to the development of aggression problems. These clinical signs often develop slowly over a number of months.

There are a number of causes of hypothyroidism, but the most common is thought to be an immune mediated condition where the body’s own immune system creates antibodies that attack the normal thyroid hormones. A small proportion of cases can be caused by a cancerous destruction of the thyroid gland.

The vet will examine your dog to look for signs that suggest hypothyroidism. It is a common finding to see bilateral symmetric baldness (alopecia) on the trunk of the body and the tail, rarely on the head. This hair-loss is usually not itchy and the bare skin can feel thickened and be darker than other normal areas of skin. Skin infections are common in dogs with hypothyroidism due to the weakened immune system, and this infection can lead to red areas and spots which are often itchy. Your dog may show signs of generalised weakness and a stiff, stilted gait sometimes alongside the development of a puffy face. Occasionally, they may also show signs of in-coordination and imbalance. Your dog should be weighed to assess for any abnormal weight gain.

To confirm the diagnosis of hypothyroidism your vet will need to perform some blood tests. This will often start with a test to measure the level of thyroid hormones. It may also be appropriate to perform a generalised blood test at the same time to ensure there are no additional internal diseases that might have triggered the low levels of thyroid hormone and also to check there are no additional problems that might affect the successful treatment of hypothyroidism. There are times when the routine blood screens do not confirm a case which is highly suspicious of hypothyroidism. In these cases, we will recommend that we perform further tests, including a blood test after an injection which should stimulate the thyroid gland to assess if it is able to react normally and produce thyroid hormones.

Dogs with hypothyroidism normally respond well to treatment with synthetic thyroid hormones given to them daily in the form of a tablet. The appropriate dosage varies between individual dogs so it may be necessary for us to repeat the blood tests to assess if the correct dose has been found. We recommend that once this correct dose is found, your dog should have regular blood tests to monitor that the thyroid levels remain within normal limits as the damage to the thyroid gland can be ongoing and overtime we may have to increase the amount of synthetic hormone your dog receives in order to keep your dog healthy. Treatment will be lifelong but most symptoms resolve over a few weeks or months. Dogs with well managed hypothyroidism have an excellent prognosis and life expectancy is normal.