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.