Page 679 - Small Animal Internal Medicine, 6th Edition

CHAPTER 38 Clinical Manifestations of Urinary Disorders 651

BOX 38.1
VetBooks.ir Causes of Hematuria

Urinary Tract Origin (Kidneys, Ureters, Bladder, Urethra)
• Trauma
• Traumatic collection (e.g., catheterization,
cystocentesis)
• Renal biopsy
• Blunt trauma (e.g., automobile accident)
• Urolithiasis
• Neoplasia
• Inflammatory disease
• Urinary tract infection
• Feline idiopathic cystitis, urethritis (idiopathic feline
lower urinary tract disease)
• Chemically induced inflammation (e.g.,
cyclophosphamide-induced cystitis) FIG 38.2
• Polypoid cystitis Capillaria plica ovum in the urine sediment of a cat (100×).
• Proliferative urethritis (granulomatous urethritis)
• Parasites
• Dioctophyma renale bladder neoplasia than in dogs with renal neoplasia. Often,
• Capillaria plica dogs with renal neoplasia present with nonspecific signs,
• Coagulopathy such as weight loss and poor appetite. When hematuria is
• Intoxication by vitamin K antagonists associated with coagulopathies, other signs such as epistaxis,
• Coagulation factor deficiencies
• Disseminated intravascular coagulation melena, bruising, and prolonged bleeding from venipunc-
• Thrombocytopenia ture sites are also likely to be present.
• Renal infarction The first step in the diagnostic evaluation of an animal
• Renal pelvic hematoma with hematuria is assessment of a properly collected urine
• Vascular malformation sample by urinalysis and urine culture to rule out bacterial
• Renal telangiectasia (Welsh Corgi) urinary tract infection. The presence of increased numbers
• Idiopathic renal hematuria of white blood cells in the urine sediment (i.e., pyuria) indi-
• Polycystic kidney disease cates an inflammatory process and increases the suspicion of
bacterial urinary tract infection. Identification of hematuria
Genital Tract Contamination (E.G., Prostate, Prepuce,
Vagina) in a voided urine sample but not in a sample collected by
• Estrus cystocentesis suggests the urethra or genital tract as the
• Subinvolution of placental sites source of bleeding. Abnormal transitional epithelial cells
• Inflammatory, neoplastic, and traumatic lesions of the observed in urine sediment stained with Wright-Giemsa
genital tract increases the suspicion of transitional cell carcinoma.
However, this diagnosis should always be based on histo-
pathologic findings in tissue biopsy samples collected during
urethrocystoscopy or by a catheter-assisted (aspiration)
idiopathic cystitis in a cat with a previous history of the approach because irritation and inflammation can result in
disease. This erroneous conclusion (and ongoing diagnostic dysplastic changes in epithelial cells observed on routine
evaluation) can sometimes be avoided by simply comparing cytologic evaluation. Anemia associated with blood loss is
the results of a voided urine sample with those observed in uncommon in patients with hematuria and is mainly seen in
the sample obtained by cystocentesis. dogs with benign renal hematuria (see later). Hematuria is
During the history, it is crucial to determine whether not a common presentation for patients with coagulopathies,
dysuria (see later) is associated with hematuria. If present, but if the cause of hematuria remains obscure after routine
signs of dysuria (e.g., pollakiuria, stranguria) suggest involve- clinical diagnostic evaluation, which includes urinalysis,
ment of the lower urinary tract (i.e., bladder, urethra), complete blood count, serum biochemical profile, and diag-
whereas painless hematuria suggests upper urinary tract nostic imaging studies, coagulation tests and a platelet count
involvement. If hematuria is present, ask the owner about its may be indicated. Ova are observed in the urine sediment of
timing. Blood at the beginning of urination may indicate a animals with urinary tract parasites (Fig. 38.2). Plain abdom-
disease process in the urethra or genital tract. Blood at the inal radiographs are useful to identify radiopaque calculi
end of urination or throughout urination may signify a (e.g., struvite, oxalate). A double-contrast cystogram, posi-
problem in the bladder or upper urinary tract (kidneys or tive contrast urethrogram, or excretory urogram may be
ureters). Hematuria is more common in dogs with urinary necessary to identify radiolucent calculi and investigate