FELINE LOWER URINARY TRACT DISEASE - (FLUTD)
FLUTD
(formerly called Feline Urological Syndrome – FUS) is a term used to describe a wide range of lower urinary tract disorders characterised by clinical symptoms such as bloodstained urine, increased frequency or difficulty of urination, urination in inappropriate places and inability to urinate due to urethral obstruction.
CAUSE
FLUTD has multiple causes. Cats with FLUTD can be divided into two main groups- those with urinary tract inflammation associated with the formation of urinary crystals or stones (mineral related causes), and those cats that have urinary tract inflammation in the absence of urinary crystals or stones (non-mineral causes).
NON-MINERAL CAUSES
A large proportion of cats with non-mineral related FLUTD are classified as IDIOPATHIC. Idiopathic is a term used to describe a condition of unknown cause! There is some thought that idiopathic FLUTD relates to damage to the normal protective layer (glycoaminoglycan layers – GAG’s) of the bladder lining and bears some similarity to interstitial cystitis in women. In these idiopathic cases, where other causes have been ruled out, the cat may benefit from treatment with drugs aimed at protecting the bladder GAG layer.
Other non-mineral causes include bacterial infection, fungal infection (rare) and tumours (also rare). There is also some evidence that viral infections can cause FLUTD.
It is also thought that in some cats this condition is stress induced.
MINERAL RELATED CAUSES
Cats are able to highly concentrate their urine, which leads to urine that supersaturated with many mineral. At supersaturation concentrations, these minerals can precipitate out to form crystals. These crystals vary from microscopic in size, to crystals coagulated in a mucoid gel to form a plug, to stones from 1mm up to 40mm or more in diameter. The most common crystal type is struvite followed by oxalate crystals. Bacterial infection of the bladder secondary to crystal formation is common and in male cats, who have a much longer, narrower urethra, there is a risk of life-threatening urethral obstruction.
DIAGNOSIS
The clinical signs that accompany FLUTD are quite characteristic. Initial tests to determine the likely cause and best management plan include a physical examination of the cat, plus a urine analysis. The urine analysis looks at parameters such as red and white blood cell content, protein content, urine Ph and also the presence or absence of crystals. Armed with this initial information, it may be necessary to x-ray the bladder. The initial x-ray is to check for the presence of large stones in the bladder. Sometimes, special contrast x-rays are needed. In addition, an ultrasound of the bladder may be recommended to check for stones that don’t show up on x-ray and to also examine the wall of the bladder for growths and nodules. In some cases, a urine sample may need to be obtained by needle puncture of the bladder via the abdominal wall, to be cultured at an external laboratory and check for evidence of bacterial infection in the bladder.
FACTORS THAT INCREASE THE RISK OF FLUTD
All breeds can suffer from FLUTD, but Persian cats are at higher risk. There is no difference in incidence between males and females, though females generally do not suffer from urethral obstruction due to their wider, shorter urethra. Inactive and overweight cats are at higher risk, as are cats that use a litter tray or have restricted access to outdoors. Cats who may delay urination due to soiled litter trays, multi-cat households competing for litter tray use, or cats under threat from feral or neighbouring cats are also at higher risk. There has also been a higher incidence noted during cold and/or rainy weather (due to cats being reluctant to leave the comfort of a warm lounge for an inhospitable yard ?!). Cats who are stressed are also likely to suffer from this condition as mentioned previously.
TREATMENT
Treatment is dependent upon the individual case. Complete urethral obstruction is a medical emergency and, if left untreated, is rapidly fatal. Treatment involves catheterisation and fluid therapy and usually requires at least a few days in hospital.
Long term treatment may involve a dietary change to restrict mineral intake and acidify the urine. Antibiotics are used if there is bacterial involvement. Large stones need to be surgically removed from the bladder. Anti-inflammatories are sometimes used to reduce bladder irritation. Drugs that help protect the bladder GAG layer, or that exert an anti-inflammatory effect within the bladder may also be used. Male cats that have repeated obstructive episodes may require preventative surgery.