Page 900 - Small Animal Clinical Nutrition 5th Edition

932 Small Animal Clinical Nutrition

VetBooks.ir Table 46-7. Clinical and diagnostic findings associated with the most common feline uroliths.* Purine (urate)
Parameters
Struvite
Calcium oxalate
Breed predisposition
Chartreux
British shorthair
Domestic longhair Burmese Siamese
Domestic shorthair Exotic shorthair
Foreign shorthair Foreign shorthair
Himalayan Havana brown
Manx Himalayan
Oriental shorthair Persian
Ragdoll Ragdoll
Siamese Scottish fold
Domestic shorthair
Gender predisposition Female >male Male >female Neutered >intact
Neutered >intact
Common age (years) Younger (<7 years) Middle-aged to older Young (if associated with
(>7 years) portosystemic shunt)
Serum biochemistries Normal Hypercalcemia Normal (idiopathic)
Acidemia (decreased TCO ) Evidence of hepatic disease
2
(low urea nitrogen,
increased ammonia)
Urinary pH** Slightly acidic (>6.5) or alkaline Acidic to neutral Acidic to neutral
Bacteria Usually sterile Usually sterile Usually sterile
Occasionally associated with May be present in cats with May be present in cats with
urease-producing bacteria infection secondary to infection secondary to
uroliths uroliths
Typical crystals Colorless, coffin-lid prisms, Monohydrate–oval, Spherical, tan in color
sometimes shaped like squares dumbbell shaped May be green/brown
Dihydrate-squares with Thorn apple appearance
diagonal lines
Radiopacity 1+ to 4+ 3+ to 4+ 0 to 2+
Radiographic appearance Rough or smooth, round or Rough or smooth, usually Smooth, occasionally irregular
faceted, sometimes disk-shaped small, occasionally jackstone
shaped

*Adapted from Osborne CA, Kruger JM, Lulich JP, et al. Disorders of the feline lower urinary tract. In: Osborne CA, Finco DR, eds. Canine
and Feline Nephrology and Urology. Baltimore, MD: Williams & Wilkins 1995; 651.
**Concomitant infection with urease-producing bacteria may cause alkaline urine in cats with uroliths.

b
pH meters have become available and are more accurate for
Table 46-8. Possible risk factors for urinary tract infection in cats. measuring urinary pH than reagent strips (Heuter et al, 1998;
Raskin et al, 2002; Johnson et al, 2007). These instruments
Age (≥10 years)
Female gender can be used in veterinary hospitals or by pet owners at home.
Urinary tract procedures A study in cats revealed that portable pH meters were more
Urethral catheterization
Perineal urethrostomy accurate than pH paper or reagent test strips for measuring
Urolithiasis urinary pH in healthy cats (Raskin et al, 2002). Another study
Systemic diseases of hospitalized dogs compared hand-held pH meters, pH pa-
Chronic kidney disease
Hyperthyroidism per and reagent strips with a bench top pH meter, considered
Diabetes mellitus the gold standard for measuring pH. Results revealed that pH
paper and reagent strips had poor to moderate agreement
with the reference method, whereas, hand-held pH meters
roughly from 5.0 (orange) to 9.0 (blue). According to most had nearly perfect agreement (Johnson et al, 2007). Based on
manufacturers, pH values measured with indicator paper are these studies, a portable or bench top pH meter should be
only accurate to within 0.5 pH units. For best results, indicator used when accurate urinary pH measurements are crucial for
squares on reagent strips should be compared with the manu- diagnosis or treatment.
facturer’s color standards in well-illuminated areas, as directed
by product instructions. Urine reagent strips may be used to Urine Culture
estimate pH for routine urinalysis; however, they should not be Urine culture should be done in all cats with lower urinary tract
relied on when accurate pH measurements are needed for diag- signs or in asymptomatic cats when there is increased risk of
nosis, prevention and management of disease (Johnson et al, UTI (Table 46-8). Quantitative bacterial culture of urine col-
2007). lected by cystocentesis is the gold standard for diagnosis of
Relatively inexpensive microprocessor-based, pocket-sized UTI. For most accurate results, urine should be cultured with-