Archive | Medical and Health Info

What is hyperthyroidism?

Hyperthyroidism is the most common endocrine (hormonal) disorder that affects cats. It is rarely seen in cats less than eight years of age and there is no sex or breed predisposition. It is caused by an excessive production of thyroid hormone by the thyroid glands situated in the neck.

Thyroid hormone controls the body’s metabolic rate, or activity level, and too much of it (hyperthyroidism) causes your cat to be hyperactive and to lose weight even if he is eating well.

What causes hyperthyroidism?

Usually, hyperthyroidism is caused either by excessive growth (hyperplasia) of the thyroid gland, or by a benign tumor of the thyroid (adenoma). Both thyroid glands are usually involved, although one gland may be more severely affected than the other. The cause of this benign change is unknown. However, it is likely that multiple factors are involved, including genetics, diet, environment and the immune system.

In rare cases, the disease may be due to a malignant tumour (thyroid adenocarcinoma).

What are the signs and symptoms of hyperthyroidism?

Clinical signs of hyperthyroidism are usually subtle at first, and get more severe as the disease progresses.  The most characteristic signs are:

• Weight loss
• Increased appetite
• Hyperactivity and restlessness

Less common signs include:

• Increased heart rate (tachycardia)
• Increased urination and/or thirst
• Vomiting or diarrhoea

In advanced cases, your cat could become lethargic and weak and lose her appetite.

Are there any complications of hyperthyroidism?

Yes.  Cats with untreated hyperthyroidism can develop hypertrophic cardiomyopathy (in which the heart muscle becomes abnormally thickened) and hypertension (high blood pressure). Initially, these complications may require specific treatment, but usually resolve once the underlying hyperthyroidism is well controlled.

How is hyperthyroidism diagnosed?

Once hyperthyroidism is suspected, a thorough physical examination and some blood tests will be required to confirm the diagnosis.

On physical examination, an enlarged thyroid gland may be felt as a small, soft mass, on either side of the neck. It may be difficult to detect, as the glands are freely movable and can slide along and behind the windpipe (trachea). In some cats, it may not be able to be palpated.

Diagnosis is confirmed by determination of serum thyroid hormone levels. In most affected cats, both thyroxine (T4) and triiodothyronine (T3) are elevated. However, elevation of T4 is a more reliable indicator of hyperthyroidism.

In rare cases, a cat may have normal thyroid hormones, but has all the symptoms of hyperthyroidism.  In those cases, your vet may do further testing. Usually all that is required is to repeat the thyroid hormone testing at another time.

Other laboratory tests that might be ordered are:

• Liver enzymes, which may be elevated with hyperthyroidism
• Chest x-ray or ultrasound if cardiomyopathy is suspected
• Doppler blood pressure monitoring to check for high blood pressure
• Testing for renal failure before starting treatment.

How is hyperthyroidism treated?

There are three options available for the treatment of hyperthyroidism: administration of anti-thyroid drug therapy, surgical thyroidectomy and radioactive iodine therapy.

Anti-thyroid drug therapy

Anti-thyroid drugs act by interfering with the production of thyroid hormone. These drugs control hyperthyroidism, but do not cure it.  Your cat will need treatment for the rest of his life.

Most of the time you will need to give your cat the medication three times a day for two or three weeks, until her thyroid level is normal.  After that, she will need the medication twice a day.  She will also need regular follow-up appointments with the vet.

Some cats experience mild and usually transient side effects from the medication.  They usually go away within a few weeks. You could see:

• Poor appetite
• Vomiting
• Lethargy

More serious side effects include low white blood cell count, clotting problems or liver disorders.  Your vet will perform routine blood tests to monitor for these problems.

Surgical thyroidectomy

Surgical removal of the affected thyroid gland (thyroidectomy) can produce a permanent cure. However, in some cats, signs of hyperthyroidism may recur, due to the production of thyroid hormone at other sites previously unaffected.

Surgical skills and experience are necessary to minimise the risk of post-surgical complications.

The major risk associated with thyroidectomy is inadvertent damage to the parathyroid glands.  They lie just next to the thyroid glands and are essential in regulating blood calcium levels.

If your cat has hypertrophic cardiomyopathy because of the hyperthyroidism, using general anaesthesia is a concern.  To reduce the risk of anaesthetic complications, these cats are usually stabilised with medications for a few weeks prior to surgery.

Radioactive iodine therapy

Radioactive iodine therapy (I131) can be used to provide a safe and effective cure for hyperthyroidism. Radioactive iodine is selectively taken up by active thyroid tissue and destroys the tissue.  Radioactive iodine therapy is a good option when surgery is contraindicated, or when the excess thyroid tissue can’t be surgically removed.  A single dose is curative in the majority (98%) of cats.

Radioactive iodine is the only effective treatment for cats with thyroid adenocarcinoma.

The treatment can only be performed in a specially licensed facility.  Your cat will usually have to stay in the hospital until the radiation level has fallen to within acceptable limits. This is usually for a period of 7 days following treatment.

Summary

Hyperthyroidism is a common disorder of older cats and is due to an increased production of thyroid hormone. Due to the action of thyroid hormone on multiple body organs, it can have wide and varied effects. However, if recognised early and treated appropriately, the outlook for affected cats is generally good.

Gastroenteritis is inflammation of the stomach and intestinal tract.  Its signs are most commonly vomiting and/or diarrhoea.  Potential causes are many and varied, the main ones being intestinal worms, infections (bacterial or viral) and eating something that upsets the gut (eg, ‘garbage’, cooked bones, excessively fatty meals).

Often when cats have gastroenteritis they will still be quite bright and happy.  If they present with lethargy/depression as well as vomiting/diarrhoea, other more serious conditions may be present and blood tests (or other diagnostic tests) may be required.

The treatment of gastroenteritis involves ruling out worms and intestinal parasites as a cause first. This is done by either knowing the cat has recently been effectively wormed or by worming them at the time. A faecal sample is usually analysed to help with the diagnosis. Then we give the stomach and intestines a rest.  A common problem we see is that cats have been fed too much too soon after the signs started, which triggers another bout of vomiting or diarrhoea.

In most cases the best course of action is to feed nothing for 24 hours (allowing free access to water) and then introduce regular, small, bland meals.  ‘Bland’ means that the type of food is not ‘rich’ and will not upset the gut (easily digested).  ‘Small’ means that the volume of food will not over stretch the gut and cause further irritation.  Bland food may be boiled chicken (no skin, no fat, no bones) and boiled white rice; or one of the commercially prepared prescription diets available from us.

When the vomiting/diarrhoea has stopped, the meals are gradually increased in size and the frequency is reduced, then normal food is added little by little.

Many cats will get better if they revert to normal feeding earlier than this, but some will return to vomiting/diarrhoea.  You cannot know which ones will do this until it happens, so it is best to treat all patients as if they will be one of the more sensitive ones.  If at any time the vomiting or diarrhoea recurs it is very important to let us know so we can reassess the diagnosis and treatment.

Cats with gastroenteritis can lose significant amounts of water quickly and can find themselves severely dehydrated quickly. Some cats need to be hospitalised and rehydrated with intravenous fluid therapy. An injection may be given to settle the nausea/vomiting and sometimes a course of antibiotics will be prescribed if bacterial infection is suspected.  Antibiotics are often held in reserve as most patients improve rapidly even without them. Unidentified viral diarrhoea will usually resolve without medications.

Regular worming, flea control, vaccinations and being careful with your cat’s diet will greatly reduce the chance of gastroenteritis reoccurring.

Food Allergies

Just like dogs, cats get allergies too. They can cause one or more of the following signs:

• Itching
• Rashes
• Diarrhoea
• Hair loss
• Red ears
• Vomiting

Cats can become allergic to protein in food, treats or table scraps. They can develop skin problems, such as rashes, itchiness, reddened ears and hair loss, or gastrointestinal problems, including vomiting and diarrhoea.

The signs of food allergies can look like those caused by allergies to fleas, plants or pollen. Just like people, cat can be allergic to bites and some plants (contact) and pollens (inhaled). Usually though, allergies to pollen and plants show up more during Spring and Summer while food allergies can occur any time of year. Some animals develop multiple allergies.

In the past, to diagnose food allergy, a diet had to be formulated that was expensive, fiddly and very difficult to balance. This usually required choosing a novel protein source and a novel carbohydrate source, ie. one that the animal has never been fed before.

The most innovative advancement for managing food allergies in cats is hydrolysed Prescription diets. Hydrolysation breaks down the proteins in food so they are too small to cause an allergic reaction. This same process is also being used to manufacture formula for human babies who are allergic to milk protein. Examples of these Prescription diets are Hill’s z/d and Royal Canin Hypoallergenic.

If your cat does have a food allergy, it can be diagnosed & controlled easily. We place the cat on this Prescription diet ONLY (ie. no other food source) for 4-6 weeks. If the signs disappear, owners can elect to keep the cat on this diet, or to “challenge" the cat with a different type of food every week. If the cat is allergic to one of these foods, signs will start again within the next day or so. If no response is noted, then a different food is added the next week.

There are two levels of diet: one has only hydrolysed proteins so it won’t cause an allergic reaction at all; the other has low allergen loads with hydrolysed animal proteins and some whole plant proteins. These plant proteins are considered “safe" because they have very little chance of causing a reaction.

The benefits of this Prescription Diet are:

• Virtually no chance of reaction. There is very little chance allergy symptoms will return if you feed your pet Prescription Diet exclusively.
• 100% complete nutrition
• Highly palatable
• Convenient - you won’t have to worry about changing your cat’s diet again or fixing homemade food. This diet requires no preparation on your behalf.

The transition period for changing from feeding your cat old food to a Prescription Diet should be spread over seven days or so, gradually adding the new food to your pet’s previous diet. Remember, your cat can have no other food besides the Prescription Diet once the transition period is over. When the symptoms disappear, you might be tempted to start feeding your cat its old food or treats, snacks and table scraps. A cats’s food allergy is like a human food allergy. If you’re allergic to milk or chocolate, you have to stop ingesting it if you want to avoid the return of symptoms. Even a small amount may cause the allergy symptoms to come back.

FAD or Flea bite hypersensitivity is a hypersensitive reaction to the bite of the flea. When a flea bites a dog or cat (or human), it injects a small amount of saliva into the skin. It is this saliva that the patient develops an allergy to. Consequently, even one flea bite can cause intense itching and irritation. In turn, it can occur even when no fleas or flea dirt is found.  A severe flea infestation, where lots of fleas or flea dirt is found, can cause the same signs in non-allergic patients. FAD is most commonly seen in the summer months when fleas are more prevalent, but can occur even in Winter, because even low numbers of fleas can cause a reaction. Pets suffering from flea bite hypersensitivity will bite, chew and lick their skin continually.

Dogs typically attack their back, just above the tail, the back and insides of their hind legs, their belly and around the anus. This leads to scabs, hair loss, thickening and increased pigmentation of the skin and scaling, and eventually to weepy skin and sores.

Cats are affected slightly differently. Some cats develop small scabs over their back, or in severe cases over their whole body, which is called ‘miliary dermatitis’. Meanwhile, others lick until they develop bald patches especially on their belly and the back of their hind legs.

Conditions other than flea bites may cause similar signs, so we may recommend tests to confirm the diagnosis, especially when there is no evidence of fleas.

This condition is not life threatening but is not curable.  In the short term, hypersensitive pets who have been exposed to fleas and are suffering from FAD need medication to relieve the itching, stop them scratching and give their skin a chance to heal. Some will also need antibiotics for infections that have developed in the damaged skin.

In the long term, all pets suffering flea bite hypersensitivity need to have their exposure to fleas minimised - constantly.

There are many excellent products available to kill adult fleas, larvae and eggs both on your cat and in the environment. Easy to use spot-on applications include Revolution, Advantage, Advocate and Frontline. Where large environmental contamination with flea eggs exists, we usually recommend treatment with frontline spray.

Other pets in the household also need treatment constantly. Even though they are not affected (if they are not allergic), they do carry fleas which then can bite the allergic cat
.
Please talk with staff regarding a specific flea prevention treatment program for your cat.

A compulsive disorder, feline hyperesthesia syndrome usually begins in cats at 1 to 4 years of age. It is also known as self-mutilation syndrome, rolling skin syndrome, twitchy cat disease, and atypical neurodermatitis. What happens is that affected cats have episodes in which the skin twitches, the body jerks around suddenly, and the tail moves far more than usual. Hyperesthetic cats vocalize and groom excessively, don't want to be touched, and zoom around at high speed. Sometimes the skin on the cat's back, just above the tail, will seem to ripple. Some affected cats will groom/chew at themselves so much that they will lose their hair, develop skin irritation, and even create skin sores. While some of this may sound a bit like normal fun behavior, it is different in how far it goes. The cat will appear to be in distress, rather than having a good time; pupils will be dilated, and the cats may appear to be scared and depressed -- or stare into space. Episodes will last from a few seconds to several minutes.
Any breed can be affected, but Siamese, Burmese, Himalayans, and Abyssinians are the most commonly affected breeds.
In some cases, the problem may turn out to be strictly behavioral. In other cases, there may be a physical cause. There is no specific test that can diagnose this problem, so this syndrome requires diagnosis by exclusion. (The veterinarian will have to eliminate every other possible cause of this behavior, thus leaving hyperesthesia syndrome as the final diagnosis.) Diagnostic tests will include a complete neurologic exam, blood work, spinal radiographs, skin scrapings, etc.
Treatment for hyperesthesia syndrome may require anti-seizure medications, corticosteroids, anti-anxiety drugs, or behavioral/environmental modification. It may take time to determine which medication will be most effective. Once an effective medication has been found, your veterinarian may try decreasing the dosage over time, to see what the lowest effective dose is. The signs typically return if medication is discontinued, so treatment is usually lifelong. Some veterinarians think that behavioral and environmental stresses should be reduced, as some cats resolve all symptoms when they move to a new house or environment. Meals should be given on a regular routine, and feeding several small meals a day is better than feeding one or two large ones. If there is a specific environmental condition that causes signs, such as excessive noise or a disliked companion cat, eliminating that environmental cause can be successful in eliminating the syndrome.

There are some great advantages to be gained by keeping your cat confined indoors. These include decreased risk of injury and disease, and as a result, a significantly longer life expectancy. There is the added benefit for wildlife and the appreciation of the non-cat lovers in the community. With a bit of extra effort, these cats can still have a lifestyle that meets their needs.
Even cats that spend some time outdoors can benefit from additional opportunities for mental and physical activity in their home environment. This is particularly true for individuals prone to anxiety disorders. The following suggestions allow cats to focus their energies in a healthy, positive way that helps to relieve stress. Cats are individuals so it is important to trial as many of the following as possible so that you can identify the elements that your cat appreciates the most.

TOYS

Cats are very sight sensitive to moving objects, so providing toys with an element of movement will help to attract your cat’s interest and enthusiasm for play. These can vary from simple home-made items such as scrunched up pieces of newspaper on the end of elastic, attached to a stationary object or tied to your belt so they bobble around on the floor behind you as you walk. Various types of toys are also available commercially and these include such things as balls containing bells, cat dancers and various furry items such as mice. Some cats have a genetic predisposition to respond pleasurably to catnip. Toys are available that contain this substance or you might like to grow your own indoor garden and include catnip, catmint or catgrass. Simple items such as table tennis balls or non-toxic soap bubbles can provide avenues for fun interaction.

INTERACTING WITH THE OUTSIDE WORLD

Cats will often be content with a view of the outside world, even if they can’t venture into it.  Some are quite happy with access to a window ledge while others may be more satisfied with an enclosed outdoor run that extends out into the garden area. There are companies that specialise in erecting and designing these structures with cats’ particular needs in mind.  Supervised access to the outdoors on a harness is another alternative.
If you have more than one pet and consider there is some tension between different members of the household, you could consider allowing your cat exclusive access to one viewing area that is particularly favoured. It can then become an area of relaxation for this cat that will be identified as a haven from potential threat. Providing a cubby, such as a cardboard box containing an unwashed sweater, in this or other areas of the house will also help your cat feel secure. Making an entry and exit hole and placing it up high also adds to the feeling of security.

GAMES

Cats often enjoy chasing concentrated dots of light from a penlight or similar source. They like to explore items such as paper bags and boxes, which you can encourage by popping the odd surprise inside. A commercially available “ Busy Kitty” takes advantage of this natural curiosity. Cats can be trained to search the house for small piles of food, rather than providing them in one spot. Gradually sprinkle the food away from the bowl until your cat catches onto the idea that it is worth looking in hidden spots for its ration. A Kitty Kong can also have food items placed inside it to extend the pleasure of meal time. Raw chicken wings can help keep teeth and gums healthy and provide a suitable chew item.

Scratching posts can prevent damage to furniture items while allowing the cat to enjoy scratching indoors. A climbing post can provide access to areas such as exposed beams and double as a scratching post if covered in a suitable material such as cut pile carpet.  Some young, exuberant cats will appreciate the company of a slightly older, energetic cat who they can play with; however some individuals prefer solitude.

QUALITY TIME

There is quite a marked variation in the amount of time different cats like to spend being cuddled. Many will appreciate extended periods of sitting on your lap, being patted or groomed while others dislike too much physical contact at one time. Some owners like doing some obedience work with their cats which can include teaching tricks or games such as retrieve or hide and seek. With patience they can respond very well to this type of attention.
Taking time to make life more interesting for your cat can really increase the quality of life that it enjoys and is an opportunity to give back some of the pleasure that their company gives to us.

What is cardiomyopathy?

Cardiomyopathy is a term used to describe diseases of the heart muscle. Cats can suffer from primary cardiomyopathy, or they can get cardiomyopathy as a result of another illness.  In either case, it can lead to heart failure.

What symptoms indicate my cat might have cardiomyopathy?

Early on, there won’t be any symptoms.  As the disease progresses, your cat will adjust her activities to compensate for cardiomyopathy.  In fact, your cat will probably not have any symptoms until the disease is advanced.  At that point, you may notice rapid or difficult breathing, loss of appetite, lethargy or loss of the use of her back legs.

What causes the symptoms of advanced cardiomyopathy?

• The breathing problems, loss of appetite and lack of energy are because your cat’s heart cannot pump very well.  Fluid backs up into her lungs, just like it does in people.
• Sometimes the blood flow within your cat’s heart gets stagnant enough that clots form.  If a clot breaks off and travels through the body, it may lodge at the bottom of the aorta and block circulation to her legs.  This is an extremely painful and possibly fatal complication of cardiomyopathy.

How is cardiomyopathy diagnosed?

Your veterinarian may suspect that your cat has cardiomyopathy based on his symptoms.  Your vet may perform the following tests to confirm the diagnosis:

• Chest x-ray
• Electrocardiogram (ECG).  The ECG isn’t very helpful in diagnosing cardiomyopathy, but it will help determine if there are any other heart problems.
• Cardiac ultrasound.  This helps determine which kind of cardiomyopathy your cat has (there are at least three major types).
• Specific tests to determine if another disease is causing the cardiomyopathy.

What causes cardiomyopathy?

There are many causes of cardiomyopathy.  The most frequently seen ones are:

• Thyroid disease (hyperthyroidism).  This is most often seen in older cats.
• Taurine deficiency.  Taurine is an essential nutrient for cats.  Taurine deficiency is rarely seen in cats who are fed fresh meat or commercial cat food.
• Idiopathic cardiomyopathy.  That means that no cause can be found.

How is cardiomyopathy treated?

If an underlying cause is found, that is treated first.  Sometimes that is all the treatment that is needed. Hyperthyroidism is the most treatable cause of cardiomyopathy, and treating the thyroid problem can cure the cardiomyopathy.

If no cause is found, or if treating the cause doesn’t help, your vet may suggest different medications.

• Diuretics for congestive heart failure
• ACE inhibitors—another medication for congestive heart failure.
• Beta blockers and calcium channel blockers—to regulate the heart rate and help the heart muscle relax
• Aspirin—to decrease the risk of clots.  Aspirin is not always used because aspirin can be toxic to cats, and the dose has to be carefully regulated.  DO NOT give your cat aspirin without a veterinarian’s advice.

Does a cat with cardiomyopathy need a special diet?

For most cats with cardiomyopathy we recommend moderate salt restriction. The diets that best meet this requirement are diets for senior cats and diets for kidney disease. If your cat has taurine deficient cardiomyopathy then taurine supplementation will be necessary. Many cat treats that are sold are very high in salt and are probably best avoided.

What is the prognosis for a cat with cardiomyopathy?

The prognosis depends on what caused the cardiomyopathy and how advanced it is.  Some cats remain stable and live near-normal lives for several years after being diagnosed with cardiomyopathy.

Entropion is an inward rolling of the eyelids. Lower lid entropion is more common than upper lid entropion.

Why does my cat have this?

• Congenital (since birth)
• Spastic
• Result of injury or inflammation

Entropion permits the lid hairs to rub against the cornea.

Symptoms:

• Chronic conjunctivitis
• Purulent ocular discharge
• Corneal ulceration
• Neovascularisation
• Weeping eyes
• Painful eyelid spasm

Etiology

Anatomic entropion is uncommon in cats, although pure breeds are more likely to be affected. Brachycephalic cats (Persians and Himalayans) typically have lower lid entropion close to their nose (medial canthal entropion).

Aquired entropion occurs in the cat and often only affects one eye. Spastic entropion may develop secondary to corneal disease, conjunctivitis, ocular pain, etc. in any age and breed of cat. Spastic entropion can become permanent if allowed to persist. It is believed that ocular surface diseases associated with feline herpesvirus-1 (FHV-1) may be the most common cause of acquired entropion in the cat. These cases eyelid conformation is normal at birth but entropion develops later, usually after chronic ocular irritation has occurred.

Older cats may develop secondary entropion with profound weight loss.

Clinical Signs

Many cats with entropion have mucoid ocular discharge, painful eyelid spasms and are often treated for conjunctivitis without any clinical improvement. The irritation from the hairs rubbing on the cornea and the conjunctiva can cause mucoid conjunctivitis, corneal vascularization and/or ulceration. With prolonged irritation to the cornea, cats with entropion may develop corneal sequestration.

Diagnosis

In most cases the diagnosis is obvious on the clinical examination. The eyelid hairs can be visualized rubbing on the cornea. Spastic entropion usually reverses after application of topical local anaesthetics. Anatomic entropion does not reverse with local anaesthesia. Local anaesthetic is used to further examine the eye. Fluorescein staining of the cornea is done to assess for ulcers and closely examine for secondary changes (e.g. vascularization, pigmentation, scarring, sequestrum formation) from the entropion.

 Treatment

In almost all cases surgery is required to correct feline entropion. This involves excising an elliptical piece of skin in the area of inrolling and suturing the defect closed to roll the eyelid out (similar to a face lift for the eyelid!!). It is a matter of clinical judgement and experience as to how much tissue should be removed.

What is a durogesic patch?

A durogesic patch provides continuous pain relief to your cat.  The medication is absorbed through the skin.  As such, a small area of fur is clipped from the back of your cat’s neck in order that the medication can be absorbed. A bandage is placed around the cat’s neck in order to prevent the patch from being scratched off.

How long does the durogesic patch last?

Each patch lasts 3-5 days.  An appointment is then to be made in five days to see a nurse.  The nurse will remove the patch and dispose of it appropriately.

Care of the durogesic patch.

Do not allow the patch to become wet or overheated as this will cause the rate of absorption of the medication to rapidly increase and can lead to overdosage. If the patch does become wet contact the vet clinic immediately.

What if I think my cat is still in pain despite the patch?

Contact your veterinarian immediately and they will advise you on the appropriate course of action.

What are potential side effects of the patch?

Your cat may be more drowsy than usual.  You may also notice dilated pupils.  The patch does effect decision making so please keep your cat indoors while the patch is in place.  If you are concerned that your cat is displaying unusual behaviour please contact The Cat Clinic.

The patch is potentially very dangerous if swallowed by your cat or a child. Please seek medical attention immediately if you believe this may have happened.