Ultrasonographic evaluation of the adrenal glands was performed in 10 dogs with pituitary-dependent hyperadreno-corticism (PDH) and in 10 age-and weight-matched healthy control dogs. Thickness, shape, and echogenicity were determined for each adrenal gland. Adrenal thickness in dogs with PDH (median, 10 mm-left; 8.5 mm-right) was significantly greater than thickness in control dogs (median, 6 mm-left; 6 mm-right). Other ultrasonographic characteristics associated with PDH included bilaterally symmetrical adrenomegaly and maintenance of normal adrenal shape. Adrenal echogenicity was homogeneous and less than that yperadrenocorticism is a common canine endocrinopa

Cavernous sinus syndrome (CSS) is characterized by deficits in more than one of the cranial nerves (CN) that traverse the cavernous sinus at the base of the cranial vault: CN 111 (oculomotor), IV (trochlear), VI (abducens), and the first two branches of CN V (trigeminal). Records from 4 dogs and 8 cats with CSS diagnosed over a 14-year period were reviewed. The most common clinical signs were ophthalmoparesis or ophthalmoplegia, mydriasis with no direct or consensual pupillary light reflexes, ptosis, decreased corneal sensation, and decreased retractor oculi reflex. All cats had initial signs referable to a left CSS lesion (one had bilateral CSS), whereas in all dogs the lesions were localized to the right cavernous sinus. Median ages at diagnosis were 9 and 10 years of age for dogs and cats, respectively. Cerebel lomedullary cisternae cerebrospinal fluid analysis in 6 aniavernous sinus syndrome (CSS) is a recognized syn-C drome in people characterized by variable impairment of multiple cranial nerves (CN) including the oculomotor (III), trochlear (IV), abducens (VI), and the first two branches of the trigeminal nerve (CN V)." The cavernous sinus is a paired venous sinus that lies on each side of the floor in the middle cranial fossa and runs from the orbital fissure to the petro-occipital canal! CN 111, IV, VI, and the ophthalmic branch of V exit the skull through the orbital fissure on their way to innervation of the muscles of the eye.4 The maxillary branch of CN V passes in the dura mater of the lateral wall of the cavernous sinus and exits through the round f~r a m e n .~ This intimate association of CN 111, IV, VI, and the ophthalmic and maxillary branches of CN V is the reason for multiple cranial nerve deficits due to inflammatory or mass lesions in this area.In people, CSS is associated with several disease processes. Neoplasia accounted for approximately 70% of the cases in one study.5 Other causes include infectious and noninfectious inflammatory:,' v a~c u l a r ?~,~ and traumatic lesions.' Only sporadic individual cases of CSS have been described in animals . *-' * This retrospective study describes CSS in 4 dogs and 8 cats. The purpose of this article is to familiarize the clinician with the common clinical signs, diagnostic tests, clinical outcome, and review of applicable neuro-ophthalmology associated with CSS in these species. Materials and Methods Criteria for EnrollmentMedical records from The Ohio State University Veterinary Teaching Hospital were reviewed for all small animals diagnosed with CSS from 1979 to 1993. The criterion for a diagnosis of CSS was a deficit in more than one cranial nerve closely associated with the cavernous sinus: CN 111, IV, VI, and the maxillary and ophthalmic branches of CN V. Diagnostic EvaluationThe diagnostic evaluation of each animal varied. All animals had complete physical, ophthalmologic, and neurological examinations. Serological, biochemical, and hematologic evaluation performed on one or more animals included CBC, serum chemistry profile, feline Provoca...

Muscle potassium content and supplementation with potassium gluconate were evaluated in normokalemic cats with chronic renal failure (CRF). Affected cats received standard medical therapy for renal failure and either placebo (sodium gluconate) or potassium gluconate. At the beginning of the study and after 6 months of supplementation, glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were estimated using 3H-inulin and '4C-tetraethylammonium bromide (TEA) clearances. Muscle potassium content was determined in biopsy specimens using atomic absorption spectroscopy. Muscle biopsy samples obtained from cats with CRF before treatment had significantly lower muscle potassium content than did those from normal control cats. Over the 6-month period of supplementation, muscle ats with chronic renal failure (CRF) are presented to C veterinarians for evaluation of chronic weight loss, anorexia, polyuria, polydipsia, and vomiting. In retrospective studies, hypokalemia occurred in 20% t o 30% of cats with CRF,'.' and CRF was the most common disease association in a survey of cats with hypokalemia.' Potassium is predominantly an intracellular cation, and approximately 95% of total body potassium resides in the skeletal muscles. Consequently, serum potassium concentration may not reflect total body potassium status, especially in the early stages of potassium depletion. The purposes of this study were to compare muscle potassium content in normokalemic cats with CRF and in normal control cats, and to determine whether supplementation of normokalemic cats with CRF using potassium gluconate would have beneficial effects over a 6-month period. Materials and Methods Criteria for Inclusion in the StudyClient-owned cats with spontaneously occurring CRF were eligible for entry in the study if the following criteria were met: (1) From the Departments of Veterinary Clinical Sciences (Theisen, DiBurtoh, Chew, Btlffingtonj and Veterinary Biosciences (Rudin) clinical evidence of small, irregular kidneys based on abdominal palpation, routine abdominal radiography, or abdominal ultrasonography; (2) serum creatinine concentration (SCr) of 2.0 to 7.0 mg/dL; (3) normal serum potassium concentration (>3.4 mEq/L); and (4) absence of urinary tract infection based on bacterial culture of urine obtained by cystocentesis. Informed consent of the owners was obtained, and cats were required to be available for study over a 6-month period. Renal biopsy specimens were not obtained from cats with CRF in an attempt to facilitate enrollment of client-owned cats in the study. Based on these criteria, 12 cats were enrolled over a 2-year period. Control cats for muscle potassium content determinations consisted of 13 middle-aged experimental cats (7 males, 6 females), determined to be normal based on physical examination, serum chemistry, and renal histopathology.