Urethral pressure response to alpha-adrenergic agonist and antagonist drugs in anesthetized healthy male cats.

Urethral smooth muscle tone in response to treatment with phenylephrine, a selective alpha 1-adrenergic receptor agonist, and prazosin a selective alpha 1-adrenergic receptor antagonist, was evaluated in 12 anesthetized healthy adult sexually intact male cats. Intravenous administration of prazosin (20 to 30 micrograms/kg of body weight) decreased the average preprostatic and prostatic intraurethral pressure, compared with baseline and postphenylephrine (20 to 30 micrograms/kg) administration, values. Neither prazosin nor phenylephrine administration had an effect on functional urethral length.

Diffuse cerebral and leptomeningeal astrocytoma in dogs: MR features.

Magnetic resonance (MR) imaging has increased sensitivity in detection of nonenhancing brain tumors and may show the extent of CNS neoplasia with greater detail than CT. Magnetic resonance images of the canine brain were acquired in two dogs with diffuse leptomeningeal and cerebral low grade astrocytoma. Abnormalities were identified with MR imaging when CT and CSF analysis were noncontributory.