Topography
The body and apex extend cranially along the abdominal floor depending on how full it is. Unlike the dog's, the feline bladder is abdominal even when empty and its neck is relatively long. The ureters arrive on the dorsal surface and open at the trigone.
Urethra
- Male: after a long preprostatic urethra it passes through the small prostate, runs along the pelvic floor and, beyond the bulbourethral glands, continues as the penile urethra, the narrowest part. This is where urethral plugs and stones lodge.
- Female: shorter and wider; it opens on the floor of the vestibule.
Clinical relevance
- Feline idiopathic cystitis: the most common cause of lower urinary tract disease in young and middle-aged cats; linked to stress and indoor life. It causes pollakiuria, stranguria, haematuria and urination outside the litter box.
- Urethral obstruction: a typical emergency of male cats, caused by matrix-crystalline plugs, stones or urethral spasm. It produces hyperkalaemia, bradycardia and azotaemia; it is relieved by catheterisation and, if it recurs, by perineal urethrostomy.
- Urolithiasis: struvite and calcium oxalate stones are the most common. Feline struvite is usually sterile and can be dissolved by diet; oxalate cannot.
- Cystocentesis: the feline bladder is easy to palpate and immobilise, which makes ultrasound-guided or blind puncture straightforward.
- Sacrocaudal luxation: tail-pull injuries damage the pelvic and pudendal nerves and cause bladder atony; the prognosis worsens if perineal sensation and anal tone are absent.
3D model
Segmentation from the CT of a cat (pixelbeaker model), simplified and registered to the atlas skeleton.