Page 904 - Small Animal Clinical Nutrition 5th Edition

936 Small Animal Clinical Nutrition

ation]) were significantly younger than cats with calcium
VetBooks.ir oxalate uroliths (7.5 ± 3.42 years) (Lekcharoensuk et al, 2000).
Cats four years of age and older but younger than seven years
had the highest risk of developing struvite uroliths. Cats older
than seven years, but younger than 10 years, had the highest
risk of developing calcium oxalate uroliths.

BREED
Several breeds of cats have increased risk for lower urinary
tract disorders; however, there is so much overlap that it is dif-
ficult to draw meaningful conclusions (Tables 46-7 and 46-
10) (Thumchai et al, 1996; Lekcharoensuk et al, 2000;
Cannon et al, 2007). In one study, Persian, Himalayan and
manx cats had increased risk for lower urinary tract diseases in
general, whereas Siamese cats had decreased risk (Lek-
charoensuk et al, 2001). Breeds with increased risk of devel-
oping urocystoliths were Persian, Himalayan and Russian
Figure 46-8. Relationship between urolith mineral type and age in
cats. Note that struvite urolithiasis occurs more frequently in blue (Lekcharoensuk et al, 2001). No breed predilection was
younger cats, whereas calcium oxalate urolithiasis occurs more fre- observed for urethral obstruction (Lekcharoensuk et al, 2001).
quently in older cats. Breeds reported to have decreased risk for struvite uroliths
include Burmese, Persian, Himalayan, Rex, Abyssinian,
Russian blue, Birman, Siamese and mixed-breed cats (Thum-
ple, it is likely that feeding a therapeutic renal food is associ- chai et al, 1996; Lekcharoensuk et al, 2000). However,
ated with (i.e., is a risk factor for) chronic kidney disease; Siamese cats were reported to have significantly more struvite
however, this does not mean it causes kidney disease. Finally, uroliths than other breeds in another study (Cannon et al,
individual cats in a population are rarely exposed to a single 2007). Birman, Abyssinian, Siamese and mixed-breed cats
risk factor; it is likely that FIC is a multifactorial disease and had significantly lower risk of developing calcium oxalate
effects of interaction between multiple risk factors are chal- uroliths in one study (Lekcharoensuk et al, 2000). Persian cats
lenging to evaluate (Willeburg, 1984). had significantly fewer urate uroliths than other breeds in
another study (Cannon et al, 2007).
Patient Characteristics
Patient factors that may affect risk for various types of FLUTD GENDER
include age, breed, gender, neuter status, body condition and Neutered males and females had increased risk of lower uri-
miscellaneous factors. nary tract diseases overall and intact females had decreased risk
in one epidemiologic study (Lekcharoensuk et al, 2001). Male
AGE cats are at increased risk for calcium oxalate uroliths, whereas
Review of data from the Veterinary Medical Database females are at greater risk for struvite uroliths (Thumchai et al,
(1980-1990) revealed that lower urinary tract disease is most 1996; Lekcharoensuk et al, 2000; Houston et al, 2003; Cannon
prevalent in cats between one and 10 years of age (Bartges, et al, 2007). In one study, however, there was no gender
1997). Another study using information from the same data- predilection for cats with calcium oxalate uroliths (Kirk et al,
base (1980-1997) revealed that cats between four and seven 1995). Neutered cats are reported to have increased risk for
years of age had the highest risk of lower urinary disease in gen- both struvite and calcium oxalate uroliths compared with sexu-
eral (Lekcharoensuk et al, 2001). Cats between four and 10 ally intact cats (Lekcharoensuk et al, 2000). Neutered males are
years of age had increased risk for urocystolithiasis, urethral at increased risk for urethral obstruction (Lekcharoensuk et al,
obstructions and FIC, whereas, cats older than 10 years were at 2001). UTI is more common in female than male cats (Bailiff
increased risk for UTI and neoplasia (Lekcharoensuk et al, et al, 2006; Lekcharoensuk et al, 2001).
2001). Compared with younger to middle-aged cats, UTI is
more commonly diagnosed in older cats (Lees, 1984; Bartges, BODY CONDITION
1997; Lekcharoensuk et al, 2001). In one study of cats with Being overweight or obese has been a risk factor for lower
lower urinary tract disease that were 10 years of age and older, urinary tract diseases in older and more recent studies (Walker
63% had UTI (46% had UTI only and 17% had UTI com- et al, 1977; Cameron et al, 2004; Willeburg, 1984). Overweight
bined with uroliths) (Bartges, 1997). cats (defined as ≥6.8 kg) had increased risk for lower urinary
In general, cats with struvite uroliths tend to be younger and tract diseases when compared with cats weighing less than 6.8
those with calcium oxalate uroliths older (Figure 46-8) (Thum- kg (Lekcharoensuk et al, 2001). In a study of more than 8,000
chai et al, 1996; Cannon et al, 2007). In one study, cats with cats in the U.S., nearly 29% were overweight, which was asso-
struvite uroliths (5.75 ± 3.12 years [mean age ± standard devi- ciated with urinary tract disease (Lund et al, 2005).