Chronic bronchial disease in cats has similarities to chronic bronchitis of humans and to human asthma.  It is also sometimes called feline asthma.  In humans, chronic bronchitis and asthma are two different diseases.  Asthma is a condition where the airways suddenly become severely narrowed, usually due to reaction to an irritant or allergen.  This can cause sudden and severe breathing difficulties, and may be rapidly fatal.  Chronic bronchitis is caused by irritants being breathed in, causing inflammation of the airways and an increase in mucous production.  Eventually this inflammation can permanently damage and narrow the airways.  The most common cause of this in humans is smoking.

The signs of chronic bronchial disease in cats may include one or all of: rapid or laboured breathing, coughing, wheezing, panting or open-mouth breathing, lethargy, exercise intolerance and occasionally sudden onset of severe difficulty in breathing with gasping and wheezing (similar to an asthma attack in people).  Any difficulty breathing requires emergency treatment in a veterinary hospital, and is usually responsive to oxygen, bronchodilators and antiinflammatories.

Chronic bronchial disease is diagnosed by ruling out other causes of breathing problems, and usually involves blood tests, x-rays, scoping of the airways, and a bronchiolar lavage (sterile saline flushed into the airways then removed for examination).  Treatment is generally life-long and involves using an inhaler system to deliver antiinflammatories +/- bronchodilators into the lungs.  This is generally well tolerated by cats, and avoids the side effects associated with using long term systemic (e.g. tablets) antiinflammatory therapy.

Chronic bronchial disease is a common disease of cats.  The causes are not well understood, but are probably similar to those associated with chronic bronchitis and asthma in humans.  Signs may be fairly constant or may come and go, and they may vary in their severity between individuals.  Cats of any age, breed and sex may be affected by chronic bronchial disease, but it is most commonly seen in cats aged 2-6 years old (mean age of 4).  There is a marked predisposition in Siamese and related breeds, which may be due to a genetic influence.  Certainly a genetic factor is believed to be involved in human asthma.  Siamese also may be prone to develop more serious signs when they have the disease (as compared to other breeds) and also to develop the condition at a younger age.

Chronic kidney disease (CKD) is not a single disease, but more the end result of a number of different disease processes, and is one of the leading causes of illness and death in older cats.  It is defined as kidney disease that has been present for months to years, and there are many potential causes of CKD.  Often by the time a cat is showing signs of kidney disease, the cause may be unknown. 

By the time a cat is showing clinical signs of CKD she has already lost at least 75% of the functional capacity of her kidneys.  This means 75% of the filtering units within the kidneys (called nephrons) no longer work at all.  The remaining nephrons are working as hard as they can, but they can no longer keep up with the demands placed on them for the filtration of toxins from the body, maintaining electrolyte balance, and conserving water.  Eventually they will fail too.

The more common signs of chronic kidney disease may include excessive drinking (polydypsia) and excessive urination (polyuria), poor appetite and weight loss, vomiting +/- diarrhoea, lack of energy and less inclination to play or exercise.  Cats with CKD may become anaemic due to a lack of erythropoietin (EPO) production by the kidneys, may become weak due to low potassium levels, may have high blood pressure (hypertension) due to sodium retention, and may deposit calcium in their tissues (abnormal mineralisation) due to retention of phosphorus.  Abnormal phosphorus levels can also lead to weakening of bones and sometimes can lead to pathologic bone fractures. Hypertension can cause sudden blindness, as well as damage to organs such as the heart, brain and further damage to the kidneys.  The build up of toxins that are normally excreted by the kidneys can lead to a state of acidosis and the formation of ulcers in the mouth and other parts of the gastrointestinal tract.  Platelets may not function properly and bleeding into the stomach or under the skin can occur.

Treatment of CKD usually involves dietary modification to restrict protein and phosphorus intake.  There is controversy over the restriction of protein in the diet of the feline CKD patient, as these cats often suffer from quite marked muscle wasting.  Studies have not shown any benefit in terms of survival time by restricting protein levels in the cat with CKD.  However, when phosphorus is restricted as well, survival time in one study almost tripled.  It is generally thought that the focus should be on high quality (i.e. very digestible) protein content, so that there is less metabolic waste produced for the kidneys to have to deal with, as well as focussing strongly on phosphorus control.  Phosphate binders should be given if phosphorus levels are not controlled with diet alone.

Your vet will also address any other secondary concerns such as low potassium levels, high blood pressure and anaemia.  Dehydration can be a major problem in the CKD patient, especially if vomiting is occurring or the cat is not able to drink enough to stay well hydrated.  Often fluids will be given under the skin periodically, and your vet can show you how to do this at home, to minimise the stress caused to your cat by numerous visits to the vet.  Rehydration helps the cat to feel better within herself, meaning she is more likely to eat.  Medication can also help to reduce nausea.

Chronic kidney disease cannot be cured.  All treatments, including kidney transplants, are aimed at controlling the various abnormalities associated with CKD in order to provide the patient with a good quality of life for as long as possible.  Ultimately quality of life becomes affected to the point where euthanasia will be required.

Diabetes mellitus is a complex disease that occurs when the body does not produce enough insulin, and/or does not respond to insulin properly.  Insulin is a hormone that controls the movement of glucose from the blood into cells, where it is used for energy.  By far the most common type of diabetes in cats (called feline diabetes mellitus) is a form that is very similar to type 2 diabetes mellitus of humans.  Type 2 diabetes makes up 80 - 95% of feline diabetes mellitus cases.  The remaining cases are generally associated with concurrent diseases, such as pancreatitis, Cushing's disease, hyperthyroidism and acromegaly.

Feline diabetes mellitus is thought to have a genetic component, and does show certain breed dispositions.  Burmese cats of UK ancestry are affected most commonly, although not Burmese cats descending from the USA.  (For example about 1 in every 50 Burmese cats in Australia are affected, compared to 1 in every 200 domestic cats).  This predisposition also flows to breeds descending from the Burmese, such as the Tonkinese.

The disease most commonly affects middle aged, overweight cats, and affected cats have a genetic predisposition to insulin resistance.  Environmental factors such as being overweight, low activity levels, diet and male gender (gender is not a factor in the Burmese) also affect whether or not a predisposed individual will go on to develop diabetes.

A cat with diabetes has persistently high levels of glucose in the blood, which then leads to glucose being excreted in the urine.  This causes an increase in the amount of urine produced, and so a cat will drink more to compensate.  Often a cat will eat more, although she will be losing weight because she cannot use the food she eats for energy very efficiently.  Instead of being able to use glucose from normal metabolism for energy (i.e. proteins in her food) the body will break down fat as an alternate energy source, and this causes an increase in acids in the body. 

Sometimes a cat may develop ketoacidosis, a very serious condition where she will become lethargic, dehydrated and will not eat, will be vomiting, and if not treated quickly and intensively, may die. 

Other complications of feline diabetes mellitus that may develop include urinary tract infections, and less commonly peripheral neuropathy (weakness or paralysis of the hind legs - sometimes this is painful and sometimes the cat cannot feel anything in the hind feet), and retinopathy (i.e. changes in the retina at the back of the eye leading to loss of vision).

Some cats can be managed with diet change and oral hypoglycaemic drugs; however 50 - 75% of cats with diabetes will require insulin injections.  This is an injection under the skin, and does not hurt the cat.  Weight loss is an important part of treatment, because once a cat has lost excess weight, she may not require insulin treatment any more.  This is called remission, and around a third of all diabetic cats will develop remission (i.e. will no longer need insulin) within 1 - 4 months of starting treatment for diabetes mellitus.  Studies show that feeding a high protein, low carbohydrate diet is most effective for helping control this condition.

Prevention in a predisposed cat (which includes any relative of an affected cat and any lean cat with reduced glucose tolerance) includes feeding a high protein, low carbohydrate diet, ensuring she maintains a healthy weight, and ensuring that she maintains an active lifestyle.

Feline lower urinary tract disease (or FLUTD) is a term that covers a number of conditions of the lower urinary tract of the cat, rather than being one specific disease.  These conditions all result in similar clinical signs, hence are covered by the name FLUTD.  Cats with FLUTD usually present with one or more of the following clinical signs:

*Difficult or painful urination (known as dysuria).  This may cause straining to urinate, and cats may cry when urinating.

*Frequent urination (known as pollakiuria).  Irritation leads to frequent attempts to pass urine, even if the bladder is not full.

*Blood in the urine (known as haematuria).

*Changes in behaviour.  These may include urinating outside the litter box and urinating in inappropriate places (also called periuria).  This can occur because of the frequent urge to urinate, with your cat not having enough time to reach the litter box.  Cats may also become irritated, withdrawn and may groom the area around the perineum excessively due to pain and irritation.

*Inability to pass urine.  Total inability to pass urine can occur due to physiological or physical obstruction (i.e. a blockage).  This usually occurs in male cats, and should be treated as an immediate medical emergency. A cat that cannot pass urine will develop electrolyte imbalances, acute kidney failure and can fall into a coma and die in a very short time frame (i.e. 24-48 hours). The earlier treatment is started, the better the chances for survival.

There are a number of different causes of FLUTD in cats, but the most common is idiopathic cystitis, which is responsible for 60-70% of all cases of FLUTD.  Idiopathic cystitis means inflammation of the bladder with no identifiable cause.  It is similar to a condition in humans called “interstitial cystitis”, and stress is believed to play a major role in its development.

Other causes of FLUTD include bladder stones (called urolithiasis), which accounts for around 10-15% of cases of FLUTD, obstruction of the urinary tract with urethral plugs (which may be associated with idiopathic cystitis or with crystals in the urine and associated bladder inflammation), bacterial infection of the bladder, which is uncommon and usually seen in older cats (and is thought to represent <10% of all cases of FLUTD), anatomical defects and scarring of the urinary tract (rare), and cancer (also quite uncommon and usually seen in older cats).  There may be some breed predispositions to lower urinary tract disease, for example the Burmese and Persian breeds are reported to both be predisposed to the development of calcium oxalate uroliths (stones).

It is important that a urinalysis is performed on any cat showing signs of FLUTD, to avoid treating for the wrong underlying cause.  Recurring cases should have a full diagnostic work up, including imaging studies to rule out urolithiasis. In cases of idiopathic cystitis, the main aim of treatment is to prevent recurrence and relieve symptoms.  There is rarely a justification to withhold pain relief from any cat with FLUTD.  In the longer term, stress reduction and increasing fluid intake are important management steps.

Antibiotics are not indicated for FLUTD unless bacterial infection is present and a urine culture and sensitivity test has been carried out at a lab to ensure that the correct antibiotic is being used.  Urinary acidifiers are not currently recommended for cases of FLUTD with struvite crystals, as over-acidification of the urine can lead to problems with calcium oxalate crystals (or stones) as well as a metabolic acidosis.  An appropriate cat diet should create mildly acidic urine anyway, which should control struvite crystalluria.  Bladder stones may need to be removed surgically.

The measures best employed to avoid or reduce the frequency of FLUTD are to feed a good quality, meat-based wet food diet, to provide plenty of fresh water, and to keep stress in the environment as low as possible.  This is discussed in more detail in the following chapters.

Gingivitis refers to the inflammation of the gums (or gingiva), and in the cat this appears as a thin red line just above the gum margin.  Gingivitis is caused by the body's immune response to certain types of bacteria that become adhered to dental calculus which is sitting against the gums.  Calculus (also called tartar) forms when plaque becomes mineralised.  Plaque is a thin film that forms on the surface of the tooth, and minerals such as calcium and phosphate from saliva and the gingiva themselves lead to the formation of hard calculus.  This calculus allows certain bacteria to colonise and grow, and these disease-causing bacteria growing in the gap between the tooth and the gums, excrete toxins, and lead to inflammation.  This causes reddening, swelling and pain.  Cats may have pain on eating and be reluctant to eat, may drool when eating or may turn the head when eating, and may only eat soft food.  They may develop bad breath.

Gingivitis in cats has also been associated with certain infectious diseases, most notably feline calicivirus, and less commonly feline herpes virus, FIV and FeLV.  There is thought to be a genetic predisposition to gingivitis in some breeds, as juvenile forms of the disease are seen in some breeds, such as the Persian, the Abyssinian and Somali, the Siamese and other Oriental short hair breeds, the Burmese, and the Maine coon.  Breeds with brachycephalic conformation are thought to be predisposed, due to overcrowding of the mouth.  Gingivitis is relatively common in cats.  These predisposed cats are generally affected at a young age, between 1-2 years, whereas in the general cat population this condition is more common as age increases, from 4 years up to 13 years. 

Gingivitis is treated by veterinarians under anaesthesia, by using professional dental instrumentation to remove calculus and plaque, and then polish teeth to smooth the enamel.  Cleaning the teeth at home to remove plaque in the future is an important part of management in most cases.  Professional dental chews have been shown in studies to reduce plaque accumulation (but not stop it) between veterinary dental teeth cleaning visits.  Barrier gels have also been shown to have a similar effect.

Periodontal disease occurs as a natural progression from gingivitis, and refers to inflammation of the soft and hard tissue structures that anchor the tooth to the jaw.  Calculus and gingivitis lead to gingival recession and widening of the pocket between the tooth and the gum, allowing food debris, further plaque and calculus to accumulate. Harmful bacteria lead to ongoing inflammation that moves deeper into the structures below the gum-line, where the root of the tooth is located.  While gingivitis may be reversed with professional dental treatment and improved dental hygiene at home (+/- antibiotic therapy for a time), periodontal disease does reach a point where it becomes irreversible.  The periodontal ligament and alveolar bone which attaches the tooth root are slowly destroyed, leading to loose teeth, and eventually loss of the teeth involved.  Chronic periodontal disease has also been associated with a shortened life span, damage to the kidneys leading to chronic kidney failure, as well as possible chronic damage to the heart and liver.

Periodontal disease is associated with pain, and signs of gingivitis.  In addition to the signs described above cats may paw at their mouth or drop food from the mouth when eating, and occasionally cry out in pain.  The gums may bleed and may be receded away from the root of one or more teeth.  X-rays are needed to fully assess how much destruction has occurred below the gum-line.  Teeth with damaged periodontal structures often need to be removed, and part of the bony socket is also removed to provide a bacteria-free environment for healing without further inflammation.  All teeth are scaled and polished to treat associated gingivitis.

Most consistent results for treating and eliminating periodontal disease have been reported when all teeth located behind the canine teeth are removed. In addition, some of the affected gingiva (gum-line) is removed from around these extracted teeth and a healthy "flap" is formed and sutured together.  This is to aid healing.   Medications such as antibiotics, antiinflammatories and/or immunomodulators may also be beneficial. 

Some cats with periodontal disease may develop inflammation not just of the gums but of the entire mouth (called stomatitis, or faucitis).  This is an incredibly painful and debilitating condition.  Medical therapies are often trialled, but in general it will be necessary to remove all the teeth, including the roots and root sockets, to finally stop the inflammatory response (and therefore pain) within the mouth.  These cats are thought to have developed an allergic-type of response to the bacteria that grow on the plaque that is associated with tooth structures.  Not all cats will recover, but often remission can be achieved if every single structure associated with a tooth is meticulously removed from the mouth, and x-rays are carefully checked to ensure nothing is missed during this process.

In rare cases cats with severe periodontal disease have to be euthanised due to severe ongoing pain, suffering and weight loss associated with the condition.

Hyperthyroidism is a common disease of cats where there is an overproduction of thyroid hormone.  There are two thyroid glands, one on each side of the neck.  In most cases (more than 70%) hyperthyroidism occurs due to a benign disease of the thyroid glands called “nodular hyperplasia”, the underlying cause of which is not fully understood.  Some cases are due to a benign tumour called a thyroid adenoma, which generally affects just one thyroid gland, not both.  Rarely, hyperthyroidism may be due to a malignant tumour of the thyroid, called a thyroid adenocarcinoma.

Recent studies have suggested possible links between an increased rate of hyperthyroidism in cats and a diet high in fish, which tend to accumulate fire retardant chemicals called PBDEs.  This is by no means the only mechanism involved in the development of feline hyperthyroidism, with other postulated factors including dietary iodine levels, dietary soy content and dietary bisphenol A (BPA) to name just a few.

Hyperthyroidism affects almost all organs in the body, and so can have quite a wide variety of clinical signs.  The most commonly seen include:  weight loss despite a normal or often increased appetite, increased thirst, restlessness or irritability, an increased heart rate, and often a poor coat.  Sometimes vomiting and/or diarrhoea is seen, and occasionally cats may become depressed and develop a poor appetite.

Hyperthyroidism is diagnosed by your veterinarian, usually by measuring the level of thyroid hormone (T4) in the blood.  A full blood screen and urine test is carried out to screen for other illness that can be present either at the same time as, or as a consequence of the hyperthyroidism.  Because hyperthyroidism is generally a disease of middle aged to older cats, other diseases such as chronic kidney disease (CKD) may also be present.  In fact, the hyperthyroidism can mask the signs of CKD.  Heart disease can result from hyperthyroidism, which causes persistently high heart rates and increased force of contraction of the heart.  Sometimes liver enzymes are also increased.  Hypertension (high blood pressure) is another common consequence of hyperthyroidism, and can lead to further damage to organs such as the eyes, kidneys, brain and heart.

There are three main classes of treatment for hyperthyroidism, and treatment of secondary diseases such as heart disease or hypertension may also be required initially.  The treatment of choice in most cases is radioactive iodine.  This involves a hospital stay of around a week in a specialised facility, where an affected cat is given an injection of radioactive iodine.  This iodine accumulates in the abnormal thyroid tissue which is producing the excess thyroid hormone, and the radioactivity kills the abnormal cells.  The cat stays in hospital while the radioactive material is excreted from the body.  This procedure has a 95% success rate, with few side effects and in most cases a cure is obtained.

The other treatment options are medical management with anti-thyroid medications, such as carbimazole tablets or methimazole transdermal cream.  This medication is required twice daily for life, and blocks the production of thyroid hormone, thereby controlling the levels of thyroid hormone.  It is relatively cheap, and usually associated with few side effects.  Some cats may experience transient vomiting and inappetance, although this is usually less so with carbimazole than methimazole tablets, and also occurs less with transdermal creams, which are usually applied to the inside of the ear, and are very well tolerated.

Less commonly performed now than in the past is surgical resection of the abnormal thyroid tissue.  This may be the preferred option for a malignant tumour however, so nuclear scanning at a specialist facility may be a good idea if you want to rule this out.  Malignant tumours occur in 1-3% of feline hyperthyroid cases.  Surgical removal of abnormal thyroid tissue does provide a cure, however there are risks with anaesthetising hyperthyroid cats, especially if some degree of heart disease is present.  There is also a major risk of damage to the parathyroid glands, which sit next to or within the thyroid glands, and are responsible for the regulation of calcium levels in the blood.  Low calcium levels post-operatively can cause seizures.  The risk is not as high with disease in only one thyroid gland (i.e. surgery to one side of the neck only).

A new treatment is being promoted in the form of a diet low in iodine, with the idea that low iodine levels in the diet will prevent thyroid hormone from being formed.  There is some controversy regarding this approach, as some have postulated than chronic low iodine in the feline diet may be a contributing factor to the development of hyperthyroidism as a disease.  Also a chronic low iodine state may have other deleterious health effects on the body.  This approach is recommended by most feline practitioners currently as a last resort option only.

Hypertrophic cardiomyopathy (HCM) is the most common heart condition in cats, with familial (inherited) forms of the disease having been recognised in a number of breeds.  The disease in cats is assumed to be similar to the disease in humans, where currently 434¹ have been shown to cause HCM.  Ragdolls, Persians and Maine coons are amongst breeds with the highest rates of disease due to HCM.

HCM causes abnormal thickening of the heart muscle, and this means that the heart cannot function properly.  Thickening of the ventricle of the heart leads to muscle stiffness and less effective contraction.  Blood tends to become “backed up” through the atrium and into the veins of the lungs.  Eventually this leads to leakage of fluid into the air spaces, which is called pulmonary oedema.  When this happens, the cat has congestive heart failure.  As well as congestive heart failure, HCM can lead to arrhythmias (abnormal heart rhythms) and sometimes this can cause sudden death without any prior clinical signs being seen.  Another uncommon complication of HCM is aortic thromboembolism, where a blood clot forms in the enlarged left atrium and at some point leaves the heart and lodges in the aorta - often where it narrows and branches to go to the hindlimbs.  This leads to a lack of blood flow to and subsequent paralysis of the hind legs, and is very painful.  Clots may less commonly lodge elsewhere, such as in the lungs or brain.

HCM can occur at any age, although is more often seen in adult to middle aged cats.  The exception is in the ragdoll, where it is common to see heart failure by 2 - 3years of age.  Diagnosis of HCM is based on a cardiac ultrasound (echocardiogram), and should generally be performed by a specialist. 

There is no cure for HCM, although if thickening of the heart muscle is secondary to another disease, such as hyperthyroidism, treatment of the primary condition may resolve the cardiac condition.  Treatment of HCM aims to manage signs of congestive heart failure, and reduce the abnormality of muscle relaxation as much as possible.  Recent studies have shown that calcium channel blockers have shown good results at improving heart function and blood flow around the body.  Drugs to control arrhythmias are given if needed.  Therapy is often given to try to prevent blood clots from forming in the heart (e.g. aspirin), although studies have shown that this treatment is not all that effective, and will not get rid of clots that have already formed.  This treatment must be monitored carefully, as it can also lead to an increased risk of bleeding. 

Genetic testing is available for several breeds, including MYBPC3 mutations that occur in the ragdoll and Maine coon.  These are both dominant mutations with variable expression.  There is also a test for the HCM2 mutation that occurs in several breeds (British shorthair, Maine coon, Norwegian forest cat, Persian, ragdoll) however this mutation has low penetrance and cats with this mutation may never go on to develop clinical disease.  Ultrasound screening remains important in breeds with this form of cardiomyopathy.

1. Kittleson, Mark. 2007.  In: Bengals Illustrated, Origins and Inspirations Edition.  https://www.bengalsillustrated.com/products-page/back-issues/origins-and-inspirations/

There are several types of deafness which vary depending on the location of the abnormality that causes the loss of hearing.  Congenital deafness in cats is generally inherited in association with the genes for white pigmentation and blue eyes, and although this is described as a dominant type of inheritance, the pattern of inheritance is not a simple one and is thought to be influenced by other genes (polygenic mechanism).

Inherited deafness is most commonly seen in white cats with two blue eyes.  It is less commonly seen in white cats with one blue eye, and even less commonly in white cats with no blue eyes (i.e. with two non-blue coloured eyes).  Deafness is thought to occur due to a lack of pigmented cells within the inner ear, which appear to be vital for maintaining the blood supply to the sensory hair cells of the cochlear.  Deafness is not present from birth, but is lost at around 3 - 4 weeks of age.  Hence hearing testing on white cats should be carried out at around 6 - 8 weeks of age.

In a large study of mixed breed white cats, 50% of cats in the study were affected by inherited deafness to some degree (i.e. were deaf in one or both ears).  In cats with two blue eyes, 85% were affected by deafness, while cats with one blue eye suffered deafness in 40% of cases.  White cats with no blue eyes showed deafness only 17% of the time.  It has also been found that the only reliable way to diagnose unilateral deafness (that is, deafness in one ear only) is by specialised testing known as the brain stem auditory evoked response (BAER).  This testing involves putting electrodes over the kittens head, and measuring the brain waves occurring in response to a noise that is introduced into the ear canal.

Deaf kittens may fail to wake up in response to a loud noise, or may fail to react to the source of a sound.  These kittens rely on their littermates for visual cues, and may cry loudly when separated from their littermates.  They may also be rougher than usual with their littermates, as they cannot hear them cry, which would be the usual signal that they are hurt and it is time to stop rough play.  A deaf cat from an at risk breed should be assumed to have hereditary deafness unless very strong evidence exists for an acquired form (e.g. known exposure to an ototoxin).  Even then, it may be prudent to desex a deaf animal to prevent inherited deafness from possibly being passed on.

A deaf cat can make a very good indoor pet, but she should not be allowed outside, as she will be at high risk of injury due to vehicles or dogs that she cannot hear coming.  People in her home, especially children, should be taught not to startle her (e.g. wake her suddenly or touch her from behind when she is not expecting it) as cats have a very strong startle response, and she may lash out and injure them in fright.

Lymphoma is the most common cancer affecting cats, and is a cancer of a type of white blood cell called a lymphocyte.  Lymphoma (which used to be called lymphosarcoma) is a solid cancer that may occur in the lymph nodes (which contain lymphocytes) or in almost any other tissue of the body.  This is because as well as being a white blood cell, the lymphocyte is an immune cell that is widespread throughout the body and moves through the tissues of the body constantly.  Lymphoma is a malignant tumour of the lymphocytes, and so can occur anywhere where there are lymphocytes.

Previously, in areas with high levels of feline leukaemia virus (FeLV), the majority of lymphoma cases in cats were attributed to infection with this retrovirus.  However as recent studies in the USA suggest, vaccination programs from the 1980s onwards in that country has largely removed this disease as a source of lymphoma in today’s pet cat population.  FeLV infection was associated with certain types of lymphoma, including multicentric (where many lymph nodes are affected) and mediastinal (where the thymus, located in the middle of the chest, was affected).  The most common form of lymphoma in cats today is gastrointestinal, and not associated with retroviral infection.

Chronic inflammation has been shown to be important in the development of cancer in cats, and it is thought that conditions such as inflammatory bowel disease may predispose a cat to gastrointestinal lymphoma.  Cats with vaccine-induced sarcomas (an inflammation-associated tumour) are also more likely to develop lymphoma, and there is also thought to be a link between tobacco smoke and the development of feline lymphoma.

There are also noted breed dispositions, with the Siamese breed having a noted predisposition to developing lymphoma.  A potentially recessive pattern of inheritance has been suggested based on linage studies.  Siamese cats in Australia, Europe and the USA tend to develop mediastinal lymphoma in particular, and at a young age (less than two years old).

Unlike dogs, most cats are obviously ill when diagnosed with lymphoma, and signs will be attributed to the location(s) of the tumour.  For example, with mediastinal lymphoma, there may be free fluid accumulating in the chest cavity, and a cat may show signs of respiratory distress, as well as weight loss.  There is generally no cure for lymphoma, and the average survival time after diagnosis is 4-6 weeks.  With chemotherapy most cats will go into “remission” for a period of time, and the average survival time is 6 months.  Occasionally, cats may survive longer than a year.

Traditionally, osteoarthritis (which is commonly just called arthritis) has been somewhat neglected in cats.  This may be partly because cats show the signs of arthritis differently to dogs, and it is not always obvious to owners.  However, it has been estimated that 70-90% of older cats have signs of arthritis on x-ray, while up to a third of all cats show clinical signs of arthritis.

Arthritis may be seen in all breeds of cat, and those predisposed to hip dysplasia and patellar luxation may have a higher risk of developing arthritis secondary to these conditions.  The Burmese cat seems to be particularly predisposed to developing osteoarthritis of the elbows, and at a relatively early age.  Manx cats with partial tails are very prone to painful arthritis of the tail, as the vertebrae of these stumpy tails are abnormally formed.

Arthritis results in pain in affected joints, and generally a restricted range of movement for the joint/s.  Cats with osteoarthritis will often show an increased tendency to sleep, and a reduction in activity.  Often owners will assume this is just associated with “getting old”.  Cats also tend to be reluctant to jump, and may also be less willing to climb in and out of the litter tray, and so appear to lose their litter box training. 

Where the arthritis is associated with the hip joints, there may be obvious muscle wasting over the pelvic area and in the hind limbs, and the cat may limp.  The hip area may be painful to touch, and an affected cat may resent patting of the area.  This may also be true with arthritis of the spine, with owners thinking that their older cat is getting “grumpy” in her old age.  Arthritis associated with the elbows, such as is often seen in Burmese cats, may cause the cat to walk with the elbows held out from the chest somewhat.  A cat may be less willing to jump down than she is to jump up.

Your vet will diagnose arthritis by examining and manipulating the joints, and by taking x-rays to rule out any other causes of pain (e.g. trauma, tumours etc).  Treatment is multifactorial, and may involve medication with joint supplements and an antiinflammatory that is safe for long term use in cats, provided blood tests show no other underlying disease.  It will also be necessary to adjust the home environment to make it easier for your cat to move around easily, such as ensuring that food, water and bedding is low and accessible, that ramps are installed where needed for your cat to access safe places and furniture, and that litter is easy to access (e.g. low sided litter box, or ramp to litter box).

The photo shows a cat swimming.  Swimming is a non weight-bearing exercise that can help dogs as well as cats that have arthritis in one or more joints of the limbs.  Cats can be trained to enjoy swimming - you should consult with your veterinary physiotherapist for more information.