Pneumothorax secondary to Dirofilaria immitis infection in two cats.

Dirofilariasis was diagnosed in 2 cats with spontaneous pneumothorax. One cat had a 3-week history of a cough, and the other had an 11-month history of vomiting and tachypnea. Pneumothorax was managed in cats by thoracocentesis and supportive care. Diagnosis of dirofilariasis was made on the basis of heartworm antigen and antibody test results and radiographic findings. Clinical signs of heartworm infection improved after treatment with corticosteroids. Cats had good extended outcomes. Heartworm disease should be one of the differential diagnoses considered in cats with spontaneous pneumothorax.

Duplex doppler estimation of intrarenal pourcelot resistive index in dogs and cats with renal disease.

In human beings, intrarenal blood flow impedance, expressed as the resistive index (RI) and obtained by duplex Doppler ultrasonography, has been used to aid in diagnosis and prognosis of renal failure. Higher than normal values for RI were obtained in 3 of 4 dogs with acute tubular necrosis (ATN) and in 5 of 10 dogs with glomerulonephrosis (GN). Normalization of RI was observed in 2 dogs with ATN evaluated serially during treatment. Increased RI values were obtained in 9 of 10 cats with nonobstructive renal disease and in 2 of 5 cats with obstructive renal disease. Normalization of RI was observed in 3 cats with renal failure in which treatment was effective (1 with obstruction; 2 with nonobstructive disease). The magnitude of increase in RI did not correlate with the magnitude of concurrent renal dysfunction. These results suggest that duplex Doppler evaluation of intrarenal RI is more useful as an ancillary diagnostic technique in azotemic dogs with ATN than in those with GN and in azotemic dogs with nonobstructive than in those with obstructive disease.

Ultrasonographic features of intestinal adenocarcinoma in five cats.

Adenocarcinoma, followed by lymphosarcoma, are the most common feline intestinal neoplasms. Clinicopathological, survey radiographic, and ultrasonographic findings of five cats with intestinal adenocarcinoma are reported. An abdominal mass was palpable in all five cats, but the mass could be localized to bowel in only two cats. Radiographically an abdominal mass was detected in only one cat. Ultrasonographically there was a segmental intestinal mural mass in all five cats. The mass was characterized by circumferential bowel wall thickening with transmural loss of normal sonographic wall layers. In one cat, the circumferential symmetric hypoechoic bowel wall thickening was similar to that reported for segmental lymphoma. In the other four cats, the sonographic features of the thickened bowel wall were varied, being mixed echogenicity and asymmetric in 3 cats and mixed echogenicity and symmetric in one. The results of the present report suggest that sonographic observation of mixed echogenicity segmental intestinal wall thickening in the cat represents adenocarcinoma rather than lymphosarcoma, although other infiltrative diseases should be considered.

Acalculous cholecystitis in four canine cases: ultrasonographic findings and use of ultrasonographic-guided, percutaneous cholecystocentesis in diagnosis.

Canine cholecystitis is diagnosed infrequently. Clinical signs, physical examination findings, and clinicopathological abnormalities are nonspecific. Few reports exist of associated ultrasonographic findings which also are nonspecific for the disorder. Ultrasonographic-guided, percutaneous cholecystocentesis has been suggested for diagnostic confirmation. The present report further documents ultrasonographic findings associated with canine acalculous cholecystitis and demonstrates the utility of ultrasonographic-guided, percutaneous cholecystocentesis in confirmation of the diagnosis in a prospectively acquired clinical case series.

Canine gastric neoplasia: utility of ultrasonography in diagnosis.

The utility of ultrasonography in the diagnosis of canine gastric neoplasia was evaluated prospectively in a series of six cases subsequently confirmed as having adenocarcinoma by cytological or histological examination or both. Gastric neoplasia was associated with mural thickening with loss of normal wall sonographic layers and decreased or absent local motility. Sonographic findings were consistent with tumor localization obtained by other diagnostic methods employed. Ultrasonographic-guided, percutaneous, fine-needle aspirations biopsies were successful in two of the three cases in which they were performed. Ultrasonography appears useful in the diagnostic of canine gastric neoplasia.

Ultrasonographic-guided, percutaneous antegrade pyelography: technique and clinical application in the dog and cat.

Fluoroscopically guided, percutaneous antegrade pyelography in canine patients has been described previously in the veterinary literature. This report describes the technique with ultrasonographic guidance and its clinical application in the diagnosis of four cases (two dogs, two cats) of obstructive uropathy. The technique provided successful diagnosis of ureteral obstruction in all four cases. No complications were observed in three cases. In one feline case, ureteral obstruction with a blood clot occurred following the procedure; however, it could not be ascertained whether this event represented a complication of the technique.

Duplex Doppler estimation of resistive index in arcuate arteries of sedated, normal female dogs: implications for use in the diagnosis of renal failure.

The resistive index (RI), an ultrasonographic method of evaluating intrarenal resistance to blood flow, may be used to aid in diagnosis of renal failure. Values for arcuate artery RI, expressed as mean +/- two standard deviations, were obtained in clinically normal female dogs sedated with atropine, acepromazine maleate, diazepam, and ketamine hydrochloride. No statistically significant differences were noted between the values for the right kidney (0.33 to 0.57) versus the left kidney (0.32 to 0.56); however, the values were statistically significantly lower than values reported for nonsedated, normal dogs.

Diagnostic imaging strategies in small animal nephrology.

The diagnostic imaging methods most readily available to the private practitioner are survey radiography, radiographic contrast procedures, and ultrasonography. Nuclear medicine imaging techniques are available at referral centers. The advantages and disadvantages of these methods as well as the favored strategies of the authors in their utilization for the diagnosis of renal disorders in the cat and dog are discussed.

Estimation of arcuate artery resistive index as a diagnostic tool for aminoglycoside-induced acute renal failure in dogs.

OBJECTIVE: To determine the potential clinical usefulness of duplex Doppler estimation of arcuate artery resistive index (a measure of intrarenal blood flow impedance) for diagnosis of aminoglycoside-induced nephrotoxicosis. ANIMALS: 30 adult, female, mixed-breed dogs, allotted to 3 groups of 10 dogs each as: toxic dosage of gentamicin, therapeutic dosage of gentamicin, and saline solution sham equivalent in volume to that of the toxic dosage of gentamicin. PROCEDURE: After baseline screening to establish normalcy (serum biochemical analysis, endogenous creatinine clearance determination, urinalysis, urine protein-to-creatinine ratio, urine culture, gray-scale sonography, and percutaneous ultrasound-guided renal biopsy), results of arcuate artery resistive index determination were compared with serum creatinine and urine specific gravity values on a Monday-Wednesday-Friday data collection schedule for 10 days. Endogenous creatinine clearance determination, ultrasound-guided renal biopsy, and urine culture were repeated at the end of data collection in all 3 groups. RESULTS: Significant differences in resistive index measurements were not observed, despite clinicopathologic and renal biopsy results compatible with severe acute tubular necrosis in dogs of the toxic dosage group. CONCLUSIONS: Duplex Doppler sonography of arcuate artery blood flow impedance, expressed as the resistive index, appears to have poor clinical usefulness as a diagnostic tool in this disorder. CLINICAL RELEVANCE: Normal arcuate artery resistive index values obtained in dogs for which aminoglycoside-induced nephrotoxicosis is suspected do not exclude the disorder. If abnormal arcuate artery resistive index values are obtained for such dogs, further evaluation for nephropathies other than aminoglycoside-induced nephrotoxicosis may be considered.

Gray-scale sonographic characterization of aminoglycoside-induced nephrotoxicosis in a canine model.

RATIONALE AND OBJECTIVES: The diagnostic usefulness of gray-scale sonography was evaluated in a canine model of aminoglycoside-induced nephrotoxicosis. METHODS: Sonography was performed before and during the onset and progression of nephrotoxicosis induced by administration of a toxic dosage of gentamicin. Subjective visualization of increased renal cortex echogenicity (IRCE) was objectified with digital image analysis methods. Results of both subjective and objective evaluation were correlated with clinicopathologic tests and renal cortex biopsy obtained concurrently. RESULTS: Subjective visualization of IRCE was associated with significant nephrotoxicosis and was superior to serum creatinine elevation in nephrotoxicity detection. Objective detection of IRCE improved nephrotoxicity detection sensitivity to that of increased urine enzymuria. CONCLUSIONS: Based on the above results, subjective visualization of IRCE in patients with aminoglycoside-induced nephrotoxicity may occur before azotemia and is suggestive of significant renal dysfunction; application of digital image analysis methods may lead to earlier sonographic recognition of nephrotoxicity.

Evaluation of urine gamma-glutamyl transpeptidase-to-creatinine ratio as a diagnostic tool in an experimental model of aminoglycoside-induced acute renal failure in the dog.

The potential diagnostic utility of the urine gamma-glutamyl transpeptidase (GGT)-to-creatinine ratio was evaluated in an experimental canine model of aminoglycoside-induced nephrotoxicity. A therapeutic dosage of gentamicin resulted in a twofold increase in the mean urine GGT-to-creatinine ratio that was not associated with clinically significant nephrotoxicity. In dogs each given a nephrotoxic dosage of gentamicin, an increase in mean urine GGT-to-creatinine ratios approximately three times baseline values preceded clinically significant abnormalities in serum creatinine, urine specific gravity, and urine protein-to-creatinine ratio. The urine GGT-to-creatinine ratio appears superior as an early indicator of aminoglycoside-induced nephrotoxicity. Further studies in canine clinical cases are warranted.

Duplex Doppler estimation of Pourcelot resistive index in arcuate arteries of sedated normal cats.

Renal failure is an important cause of morbidity and mortality in feline patients. In human patients, intrarenal blood flow values obtained with duplex Doppler ultrasonography have been used to aid in the diagnosis and prognosis of renal failure. The purpose of this report is to present values for resistance to intrarenal blood flow in normal cats, derived by duplex Doppler ultrasonography. Ten mature clinically healthy conditioned domestic shorthaired cats were screened for normal renal anatomy and function by CBC, serum biochemical profile, urinalysis, urine protein/creatinine ratio, endogenous creatinine clearance, and renal B-mode ultrasonography; and for normal systemic blood pressure with Doppler pressure cuff measurement. Subsequently, the cats were sedated with ketamine hydrochloride, and values for mean intrarenal (arcuate artery) resistance to blood flow were determined by duplex Doppler ultrasonography, and expressed as the Pourcelot resistive index, a ratio of systolic to diastolic flow commonly used in duplex Doppler sonography in human patients. After duplex Doppler sonographic examination, histological normalcy of the kidneys was verified by evaluation of ultrasound-guided percutaneous renal biopsy. Based on the obtained resistive indices, 95% confidence intervals for normal values were calculated as follows: left kidney, 0.52 to 0.60; right kidney, 0.55 to 0.63. No statistically significant difference was noted between the values obtained for the right versus the left kidney.