Feline lower urinary tract disease
Encyclopedia
Feline lower urinary tract disease (FLUTD) is a broad term that is used to cover a number of conditions associated with the feline
lower urinary tract
. It may present as any of a variety of problems such as, inflammation of the bladder
(cystitis
) or urethra
, formation of urinary crystals/stones
in the bladder (crystalluria
/urolithiasis
), and partial or total obstruction of the urethra. The latter condition is also known as plugged-penis syndrome and blocked cat syndrome. Complete urethral obstruction is fatal if left untreated.
FLUTD is a common disease in adult cats, affecting from 0.5% to 1% of the population. FLUTD affects cats of both sexes, but tends to be more dangerous in males because they are more susceptible to blockages due to their longer, narrower urethrae. Urinary tract disorders have a high rate of recurrence, and some cats seem to be more susceptible to urinary problems than others.
The older term, Feline urologic syndrome (FUS) was renamed to discourage the perception that the clinical signs seen represent one disease with one cause.http://www.marvistavet.com/html/body_feline_lower_urinary_tract_dis.html
and struvite
(magnesium ammonium phosphate) uroliths. The majority of uroliths are located in the urinary bladder, but can also form in the kidneys, ureters and urethra. Many studies have concluded magnesium
in the diet as a primary cause of struvite urolithiasis in cats. However, researchers have found that urine pH
is a more important contributing factor. Urine that is acidic helps to dissolve struvite uroliths and also provides a less favourable environment for its formation.
Commercial feline diets now limit the amount of magnesium and add acidifiers in the food to increase urine acidity, thereby reducing the likelihood of struvite formation. The decrease of struvite uroliths coincides with an increase in oxalate uroliths, low magnesium levels and urine pH both being a factor in calcium oxalate formation.http://www.veterinarypartner.com/Content.plx?P=A&A=1741http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/130617.htm Oxalate uroliths are not dissolvable in cat urine and have to be removed surgically, barring those small enough to pass out the urinary tract.
Less common forms of uroliths includes ammonium urate, uric acid, calcium phosphate, and cystine uroliths.http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/130617.htm
(mucus or blood cells) can form a urethral plug and cause a complete blockage of the urethra. Inflammation of the bladder wall can cause the protein matrix to "leak" from the wall. Even without crystal formation, a thick protein matrix may cause urethral obstruction by itself.http://www.fabcats.org/owners/flutd/info.html Renal failure
and uremia
will follow within 36–48 hours of complete urethral obstruction. The time from complete obstruction until death may be less than 72 hours.http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/130615.htm
FLUTD cases or Feline Idiopathic Cystitis(FIC).
The disorder may be caused by a combination of these factors. For example, a diet of dry food which is high in magnesium
or other minerals and high in pH
, combined with inadequate intake of water may lead to favorable conditions for precipitating buildup in the lower urinary tract. However, these factors affect individual cats differently. Most cats tolerate normal dry diets with no urinary problems.
(pollakiuria), prolonged squatting and straining during attempts to urinate (dysuria
), small amounts of urine voided in each attempt, blood in the urine (hematuria
) and urinating outside of the litter box. Owners with outdoor cats may not be able to observe the symptoms associated with litter box use and should watch for unusual behavioral changes.
A cat experiencing a urethral obstruction behaves similarly to any other cat with FLUTD. However, as time passes, the bladder fills up with urine and cause painful bladder distension. Kidney failure and uremia
will follow within hours. The cat becomes increasingly distressed, and may howl or cry out in pain. The male cat may constantly lick at his penis and the penis may be protruded. The cat may seek seclusion, stop eating and drinking, begin to vomit, and become lethargic and eventually comatose as toxins accumulate in the bloodstream.
Urethral obstruction is a serious medical emergency which will lead to death if not treated in time. Any cat suspected of suffering from this condition should be seen immediately by a veterinarian.
might be used to drain the bladder. Intravenous fluids are given to treat uremia. Antibiotics and a special diet may be prescribed. Diets low in magnesium and urine acidifiers may be helpful. Cats susceptible to repeated attacks of this disorder may require surgery, such as the removal of the penis (Urethrostomy
) to prevent its blockage.
Cats with chronic
feline lower urinary tract disease caused by struvite crystals or oxalate crystals can be treated with a life-long diet of a prescription wet or dry food which minimizes the content of the building blocks of the crystals. These foods will be prescribed by vets if needed and will replace all other food to ensure a healthy urinary tract. Even after treatment, cats need to be checked regularly for urinary problems as the crystals can return.
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
lower urinary tract
Urinary system
The urinary system is the organ system that produces, stores, and eliminates urine. In humans it includes two kidneys, two ureters, the bladder and the urethra.-Kidney:...
. It may present as any of a variety of problems such as, inflammation of the bladder
Urinary bladder
The urinary bladder is the organ that collects urine excreted by the kidneys before disposal by urination. A hollow muscular, and distensible organ, the bladder sits on the pelvic floor...
(cystitis
Cystitis
Cystitis is a term that refers to urinary bladder inflammation that results from any one of a number of distinct syndromes. It is most commonly caused by a bacterial infection in which case it is referred to as a urinary tract infection.-Signs and symptoms:...
) or urethra
Urethra
In anatomy, the urethra is a tube that connects the urinary bladder to the genitals for the removal of fluids out of the body. In males, the urethra travels through the penis, and carries semen as well as urine...
, formation of urinary crystals/stones
Bladder stone (animal)
Bladder stones or uroliths are a common occurrence in animals, especially in domestic animals such as dogs and cats. Occurrence in other species, including tortoises, have been reported as well. The stones form in the urinary bladder in varying size and numbers secondary to infection, dietary...
in the bladder (crystalluria
Crystalluria
Crystalluria refers to crystals found in the urine when performing a urine test. Crystalluria is considered as one of the side effects of sulphonamides.-Clinical significance:It can be an indication of urolithiasis.It can be associated with cysteinuria....
/urolithiasis
Urolithiasis
A bladder stone is a solid concretion or crystal aggregation found in the urinary bladder...
), and partial or total obstruction of the urethra. The latter condition is also known as plugged-penis syndrome and blocked cat syndrome. Complete urethral obstruction is fatal if left untreated.
FLUTD is a common disease in adult cats, affecting from 0.5% to 1% of the population. FLUTD affects cats of both sexes, but tends to be more dangerous in males because they are more susceptible to blockages due to their longer, narrower urethrae. Urinary tract disorders have a high rate of recurrence, and some cats seem to be more susceptible to urinary problems than others.
The older term, Feline urologic syndrome (FUS) was renamed to discourage the perception that the clinical signs seen represent one disease with one cause.http://www.marvistavet.com/html/body_feline_lower_urinary_tract_dis.html
Uroliths
Approximately 15-20% of FLUTD cases are caused by uroliths, with the most common form being calcium oxalateCalcium oxalate
Calcium oxalate is a chemical compound that forms needle-shaped crystals, known in plants as raphides. A major constituent of human kidney stones, the chemical is also found in beerstone, a scale that forms on containers used in breweries...
and struvite
Struvite
Struvite is a phosphate mineral with formula: NH4MgPO4·6H2O. Struvite crystallizes in the orthorhombic system as white to yellowish or brownish-white pyramidal crystals or in platey mica-like forms. It is a soft mineral with Mohs hardness of 1.5 to 2 and has a low specific gravity of 1.7...
(magnesium ammonium phosphate) uroliths. The majority of uroliths are located in the urinary bladder, but can also form in the kidneys, ureters and urethra. Many studies have concluded magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
in the diet as a primary cause of struvite urolithiasis in cats. However, researchers have found that urine pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
is a more important contributing factor. Urine that is acidic helps to dissolve struvite uroliths and also provides a less favourable environment for its formation.
Commercial feline diets now limit the amount of magnesium and add acidifiers in the food to increase urine acidity, thereby reducing the likelihood of struvite formation. The decrease of struvite uroliths coincides with an increase in oxalate uroliths, low magnesium levels and urine pH both being a factor in calcium oxalate formation.http://www.veterinarypartner.com/Content.plx?P=A&A=1741http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/130617.htm Oxalate uroliths are not dissolvable in cat urine and have to be removed surgically, barring those small enough to pass out the urinary tract.
Less common forms of uroliths includes ammonium urate, uric acid, calcium phosphate, and cystine uroliths.http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/130617.htm
Urethral obstruction
A combination of crystal precipitates(most typically struvite uroliths) and protein matrixMatrix (biology)
In biology, matrix is the material between animal or plant cells, in which more specialized structures are embedded, and a specific part of the mitochondrion that is the site of oxidation of organic molecules. The internal structure of connective tissues is an extracellular matrix...
(mucus or blood cells) can form a urethral plug and cause a complete blockage of the urethra. Inflammation of the bladder wall can cause the protein matrix to "leak" from the wall. Even without crystal formation, a thick protein matrix may cause urethral obstruction by itself.http://www.fabcats.org/owners/flutd/info.html Renal failure
Renal failure
Renal failure or kidney failure describes a medical condition in which the kidneys fail to adequately filter toxins and waste products from the blood...
and uremia
Uremia
Uremia or uraemia is a term used to loosely describe the illness accompanying kidney failure , in particular the nitrogenous waste products associated with the failure of this organ....
will follow within 36–48 hours of complete urethral obstruction. The time from complete obstruction until death may be less than 72 hours.http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/130615.htm
Infectious causes
Bacterial infection is a very rare cause of FLUTD, accounting for 1-5% of cats.Others
Other conditions that can contribute to this disease include physical trauma, tumors of the urinary tract, intentional urinary retention (a common behavior seen in cats not given a suitable place to void (e.g. no litterbox or dirty litterbox)), congenital abnormalities and neurological problems. In about 60% of cases, the cause is never discovered. These are classified as idiopathicIdiopathic
Idiopathic is an adjective used primarily in medicine meaning arising spontaneously or from an obscure or unknown cause. From Greek ἴδιος, idios + πάθος, pathos , it means approximately "a disease of its own kind". It is technically a term from nosology, the classification of disease...
FLUTD cases or Feline Idiopathic Cystitis(FIC).
Risk factors
- Age: Uncommon in cats younger than 1 year of age. Most commonly occurs in cats within the 2 to 5 age group.
- Sex: Male and neutered male cats are at greater risk for urethral obstruction than females because their urethra is longer and narrower.http://www.vet.cornell.edu/fhc/resources/brochure/urinary.html Nonobstructive FLUTD occur equally in males and females.
- Neutering: as above
- Dehydration:
- Diet: Dry food
- Obesity:
The disorder may be caused by a combination of these factors. For example, a diet of dry food which is high in magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
or other minerals and high in pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
, combined with inadequate intake of water may lead to favorable conditions for precipitating buildup in the lower urinary tract. However, these factors affect individual cats differently. Most cats tolerate normal dry diets with no urinary problems.
Symptoms
Regardless of cause, there is a common set of symptoms, which includes frequent trips to the litter boxLitter box
A litter box, sometimes called a sandbox, sand box, litter tray, litter pan, dirt box, catbox, or cat box, is an indoor feces and urine disposal box for cats that are permitted free roam of a home but who cannot or do not always go outside...
(pollakiuria), prolonged squatting and straining during attempts to urinate (dysuria
Dysuria
In medicine, specifically urology, dysuria refers to painful urination.Difficult urination is also sometimes described as dysuria.It is one of a constellation of irritative bladder symptoms, which includes urinary frequency and haematuria....
), small amounts of urine voided in each attempt, blood in the urine (hematuria
Hematuria
In medicine, hematuria, or haematuria, is the presence of red blood cells in the urine. It may be idiopathic and/or benign, or it can be a sign that there is a kidney stone or a tumor in the urinary tract , ranging from trivial to lethal...
) and urinating outside of the litter box. Owners with outdoor cats may not be able to observe the symptoms associated with litter box use and should watch for unusual behavioral changes.
A cat experiencing a urethral obstruction behaves similarly to any other cat with FLUTD. However, as time passes, the bladder fills up with urine and cause painful bladder distension. Kidney failure and uremia
Uremia
Uremia or uraemia is a term used to loosely describe the illness accompanying kidney failure , in particular the nitrogenous waste products associated with the failure of this organ....
will follow within hours. The cat becomes increasingly distressed, and may howl or cry out in pain. The male cat may constantly lick at his penis and the penis may be protruded. The cat may seek seclusion, stop eating and drinking, begin to vomit, and become lethargic and eventually comatose as toxins accumulate in the bloodstream.
Urethral obstruction is a serious medical emergency which will lead to death if not treated in time. Any cat suspected of suffering from this condition should be seen immediately by a veterinarian.
Diagnosis
- Blood testBlood testA blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a needle, or via fingerprick....
- clinical signs - Per symptoms
- physical examinationPhysical examinationPhysical examination or clinical examination is the process by which a doctor investigates the body of a patient for signs of disease. It generally follows the taking of the medical history — an account of the symptoms as experienced by the patient...
- palpitations etc. - urinalysisUrinalysisA urinalysis , also known as Routine and Microscopy , is an array of tests performed on urine, and one of the most common methods of medical diagnosis...
- incl. use of cystocentesisCystocentesisCystocentesis is a veterinary procedure where a needle is placed into the urinary bladder through the abdomen of an animal and a sample of urine is removed. Diagnostic cystocentesis is used to prevent sample taken for urinalysis from being contaminated with bacteria, cells and debris from the lower... - Urine cultures for bacteriaBacteriaBacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
Treatment
A blocked urethra requires immediate veterinary attention. The plug must be removed from the penis and the bladder drained. Gentle mechanical manipulation of the penis may dislodge the blockage, or a catheterCatheter
In medicine, a catheter is a tube that can be inserted into a body cavity, duct, or vessel. Catheters thereby allow drainage, administration of fluids or gases, or access by surgical instruments. The process of inserting a catheter is catheterization...
might be used to drain the bladder. Intravenous fluids are given to treat uremia. Antibiotics and a special diet may be prescribed. Diets low in magnesium and urine acidifiers may be helpful. Cats susceptible to repeated attacks of this disorder may require surgery, such as the removal of the penis (Urethrostomy
Urethrostomy
Urethrostomy is a surgical procedure that creates a permanent opening in the urethra, commonly to remove obstructions to urine flow. The procedure is most often performed in male cats, where the opening is made in the perineum.-History:...
) to prevent its blockage.
Cats with chronic
Chronic (medicine)
A chronic disease is a disease or other human health condition that is persistent or long-lasting in nature. The term chronic is usually applied when the course of the disease lasts for more than three months. Common chronic diseases include asthma, cancer, diabetes and HIV/AIDS.In medicine, the...
feline lower urinary tract disease caused by struvite crystals or oxalate crystals can be treated with a life-long diet of a prescription wet or dry food which minimizes the content of the building blocks of the crystals. These foods will be prescribed by vets if needed and will replace all other food to ensure a healthy urinary tract. Even after treatment, cats need to be checked regularly for urinary problems as the crystals can return.
Further reading
Carlson, Delbert G. & Giffin, James M. Cat Owner's Home Veterinary Handbook. New York: Howell Book House, 1995.External links
- FLUTD from Veterinary Partner
- Urolithiasis: Overview & Feline Urolithiasis and FLUTD at the Merck Veterinary ManualMerck Veterinary ManualThe Merck Veterinary Manual is a reference manual of animal health care. It is published by Merck & Co., Inc. and Merial Limited. The Merck Veterinary Manual is available as a reference manual or as an online resource for veterinarians, veterinary students, and others involved in animal health...
- FLUTD Brochure by the American Association of Feline Practitioners and the Cornell Feline Health Center
- Feline lower urinary tract disease Feline Advisory Bureau
- Bladder Stones in Your Cat
- FLUTD (Felipedia.org)