Weight loss worry

Minette has lost weight - despite a raging appetite. She has also been a lot more talkative than usual. Her owners are (and Dr Kate) are suspicious that she might have hyperthyroidism. Minette very kindly let us take a sample of blood - you can see the hair under her collar was clipped so we could see her vein.
Minette is about 20 years old and very fit for her age. She is on medication for high blood pressure and has kept her kidney disease at bay with a special diet for over a year. Her owners' vigilance and care should keep her going for a few birthdays yet!

High blood pressure

Hypertension is the medical term for high blood pressure, a silent killer of older cats.

What causes hypertension in cats?

Hypertension is usually secondary to another disease. Kidney disease is the most common cause of hypertension but cats with adrenal gland tumours or treated for hyperthyroidism also develop high blood pressure at times. Sometimes no underlying cause is found.

Most cats with hypertension are older than 9 years of age.

What are the effects of hypertension?

Hypertension damages all body organs but we notice it most in:

• the eyes. The small vessels in the retina break under pressure. The bleeding detaches the retina and the cat becomes blind.
• the brain. Ruptured blood vessels cause ‘strokes’, fits, twitches or unusual behaviour
• the kidneys. Increased blood pressure damages the delicate filtration system of the kidney.
• the heart. The heart has to work harder to push the blood out into the body and the heart muscle thickens and becomes less efficient. Sometimes the heart goes out of rhythm or we hear a murmur with the stethoscope. Affected cats may show signs of heart failure such as breathlessness, lethargy, weakness or fainting.

How do we detect hypertension?

We measure the blood pressure of all cats over 9 years old as part of the regular seniors’ examination. We also check the blood pressure of all cats with kidney disease or hyperthyroidism, or with any signs of eye, brain or heart disease. 

Most cats tolerate the cat sized cuffs we put on their arms. Some don’t like the feel of the gel or the sound of the amplifier we use to hear the pulse. We try to put them at ease so that we get an accurate reading.

How do we treat hypertension?

A daily dose of amlopidine as a fragment of tablet (Norvasc), or as chicken, fish, cheese or beef flavoured drops to put on the food, brings the blood pressure down rapidly.

After a week on amlopidine we recheck the blood pressure to see if it has come down to normal. If all goes well we recheck it every 3 months. 

Sometimes other medications like benazepril (Fortekor or Vetace) are added in, particularly if we detect kidney disease.

Kitties on speed - hyperthyroidism

Hyperthyroidism is a common disorder of older cats. Owners complain that their cats have gone crazy climbing curtains and rooting in rubbish bins. An overactive thyroid gland produces and secretes too much thyroid hormone putting pressure on all body organs. Any sex or breed of cat can be affected.

What are the signs of hyperthyroidism?

Any of the following:

1.             Weight loss

2.             Increased appetite

3.            Hyperactivity and restlessness

4.             Increased heart rate, associated with irregularities in rhythm, murmurs and high blood pressure

5.             Increased frequency of defecation with occasional accidents inside

6.             Increased thirst and urination

7.             Occasional vomiting

8.             Panting

9.             Matted, greasy and unkempt coat

10.           Enlarged thyroid glands

If we suspect that your cat has hyperthyroidism we send blood for measurement of the thyroid hormone, T4. We also check for secondary liver, heart or kidney problems.

How do we treat hyperthyroidism?

1.      Anti-thyroid drug therapy

Anti-thyroid drugs interfere with the production and secretion of thyroid hormone. They control rather than cure the hyperthyroidism.

Carbimazole (brand name Neo Mercazole) tablets are given twice daily. We see mild and often transient side effects in a few cats including poor appetite, vomiting and lethargy. Rarely we see more serious side effects including a fall in the white blood cell count, clotting problems, or liver disorders. If we find any serious side effects after 2 weeks of medication we switch to another treatment.

Many owners prefer methimazole as a gel applied to the inside of the ear or made up into a palatable liquid.

2.      Radioactive iodine therapy

If kidney problems are not uncovered by anti-thyroid therapy then we suggest radioactive iodine, a more permanent cure for hyperthyroidism. Radioactive iodine destroys the affected thyroid tissue and leaves adjacent normal tissue, including the parathyroid glands, untouched.

We refer you to a special facility at Canberra Veterinary Hospital for radioactive iodine therapy. Treated cats are kept in hospital for a week after the treatment until they are no longer a radiation risk to people.

Radioactive iodine treatment has no serious side-effects. Depending on the age of the cat at diagnosis the cost of treatment is similar to long term anti-thyroid drugs or surgery.

Radioactive iodine is the only effective treatment for thyroid adenocarcinoma, the cancer that causes 1 to 2% of feline hyperthyroid cases.

3.      Surgical thyroidectomy

Removal of the thyroid glands provides an immediate cure but has some nasty potential side effects so we don’t often recommend it.

Where is Dr Kate?

Dr Kate is at the annual conference of the International Society of Feline Medicine (that's the ISFM) in the beautiful city of Vienna keeping up to date with the latest information and trends in cat medicine from all over the world!
It is wonderful to concentrate on just cats and to hear the experience of vets from a wide variety of situations.
Today we heard all about cats' endocrine (or gland) diseases, so common in our older cats.
The common ones are hyperthyroidism and diabetes, but others such as acromegaly, a growth hormone disorder, and diseases of the adrenal gland are being diagnosed more often too.
There is much controversy over the treatment of hyperthyroidism in the veterinary world, but if some research work I heard about today is confirmed with further trials the arguments might be a thing of the past.
Simply controlling the iodine content of the diet in a specific way may treat feline hyperthyroidism!
This will be good news for many of you and I hope that the research work is completed and the special diet makes it onto the Australian market at a reasonable price very soon.
I'll bring you more breaking news as it happens here in Vienna.

Surprising seniors!

Our cats are living longer lives than ever before because of desexing, better diet and improved health care. Many of Hall Veterinary Surgery’s feline patients live well into their teens and your cat could too.

Cats are very good at hiding illness and discomfort. It is easy to overlook subtle changes in appetite and behaviour. Changes in bodyweight are often the first sign of disease. Regular examinations of the mouth, joints and eyes pick up some signs of disease. Increased blood pressure warns of kidney or thyroid disease. Many serious health problems in cats are only picked up with blood and urine tests.
Diseases commonly seen in older cats include arthritis, dental disease, kidney insufficiency, hyperthyroidism, diabetes mellitus and bowel disease. Often cats have several of them at a time. If we detect problems early and manage them appropriately then our feline friends can enjoy longer, happier and more comfortable lives.
The key to detecting and managing most of these diseases is regular monitoring of body weight, body condition and blood pressure. Urine and blood tests are important in kidney and thyroid disease while serial examination of joints, eyes and teeth triggers early preventative strategies.

Annual checkups are adequate until 10 years of age. Because cats age four times more rapidly than humans we recommend twice a year checks from 10 years of age on.

Weight loss is not always good...

You might think that vets are obsessive about recording cats’ weights. They have good reason – sometimes gradual weight loss is the only sign of serious disease in cats. By the time a cat goes off her food or starts vomiting disease can be quite advanced.
Fur or hair ball vomits coupled with gradual weight loss indicate gastrointestinal disease. Causes of gut disease include parasites like worms and giardia. These are easy to diagnose and treat compared to other gut diseases.
Food sensitivities are uncommon but inflammatory bowel disease and bowel cancer occur relatively often in cats. Diagnosing and treating these can be quite a challenge and require much patience on the part of owner and vet.
A myriad things cause weight loss with a patchy appetite. We will nearly always order blood tests to check for kidney or liver disease, particularly in older cats.
Weight loss despite a good appetite can be due to diabetes or an overactive thyroid (hyperthyroidism). Annual check-ups and weigh-ins in cats under 10 years pick these problems up early. Cats over 10 years of age should be checked at least twice a year. With appropriate treatment affected cats go on to live long and happy lives.
Even if your cat is aiming to lose weight regular weigh-ins and veterinary supervision are essential. We want gradual loss of weight because rapid weight loss in cats can lead to liver disease.

Senior health care

Why is it that dogs are taken to the vet twice as often as cats? Dogs average 2.3 visits per year while cats are only taken 1.1 times per year.
I don’t think it’s because their owners care less about them, but I also don’t think that they are inherently healthier!
Signs of illness in cats are often subtle. An unwell cat will often curl up away from you, reducing the chance of you noticing anything amiss. Cats pride themselves on their hardiness and self-reliance and are stoic in the face of chronic pain or illness.
Sometimes the only obvious sign of illness and pain is weight loss. Gradual loss of appetite and behaviour changes are harder to identify unless you are very observant.
Cats age FOUR times faster than us at equivalent ages. A 2-6 year old cat is in her prime. By 11 years of age she is starting to show signs of age but is not considered geriatric until 15. At 15 years of age she is equivalent to a 76 year old human. Many cats live up to 20 years with regular health checks and veterinary care.
To ensure that those years are healthy and happy we recommend an individualised preventative health care programme.
From about 10 years of age all cats deserve at least two wellness exams a year. This lets us detect and treat chronic diseases like bad teeth, failing kidneys, arthritis and hyperthyroidism early and reduce long term health care costs.
We will also discuss changing dietary requirements and any supplements that might improve your cat’s health and happiness.
Regular visits ensure that your cat’s quality of life is maintained and that she shares many comfortable and happy years with you.

George's spectacular appetite

My cat George was always hungry.  When he was young we called him Fat George.  As he aged he became thinner and thinner.  When he was 12 years old I noticed that his activity levels as well as his appetite were reaching record levels.
At first I thought he'd reverted to kittenhood but soon found that one of the thyroid glands on the lower part of his neck was as big as a lima bean.  A blood test confirmed the diagnosis of hyperthyroidism.
I surgically removed the gland and he was normal for a few years before I noticed his appetite rocket again.  This time I medicated him with an anti-thyroid drug that worked very well.  I gave him a tablet twice a day until he became too cunning for me. I switched to applying a medicated gel to the inside of his ears and won the battle.
Like most old cats George eventually developed kidney disease.  I had to ease off the antithyroid medication and nurse his old kidneys along.
This candid shot is of George not long before he died.  Even when his kidneys were about to collapse his overactive thyroid drove his appetite to spectacular heights (depths?!)