External-beam Co-60 radiotherapy for canine nasal tumors: a comparison of survival by treatment protocol.

A retrospective analysis of survival times in dogs with intranasal tumors was performed comparing those treated using hypofractionated or full course Co-60 radiotherapy protocols alone or with surgical adjuvant therapy and those receiving no radiation treatment. One hundred thirty-nine dogs presented to the University of Minnesota Veterinary Medical Center for treatment of histologically-confirmed nasal neoplasia between July 1983 and October 2001 met the criteria for review. Statistically analyzed parameters included age at diagnosis, tumor histologic classification, fractionation schedule (number of treatments, and number of treatment days/week) (classified as hypofractionated if 2 or less treatments/week); calculated minimum tumor dose/fraction; calculated total minimum tumor dose (classified as hypofractionated if less than 37 Gy in six or fewer fractions); number of radiotherapy portals, a treatment gap of more than 7 days in a full course (3-5 treatments/week, 3-3.5 week treatment time) radiotherapy protocol, the influence of eye shields on survival following single portal DV fields, the survey radiographic extent of the disease, and the presence or absence of cytoreductive surgery. There was a significant relationship only between protocols using 3 or more treatments/week and at least 37 Gy cumulative minimum tumor dose and survival. However, there was no significant relationship between either total minimum tumor dose or dose/fraction and survival and there were no significant relationships between survival and any of the other variables analyzed including tumor histologic type.

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.

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.

Endotracheal tube displacement during cervical manipulation in the dog.

A retrospective study was performed to identify positional changes of endotracheal tubes (ETT) during cervical spine radiography in 153 dogs. Three neck positions were identified: traction, hyperextension, and flexion. A properly placed ETT was defined as having the caudal tip of the tube located between the caudal half of the fourth cervical (C) vertebra (C4) and the caudal half of C7. In the traction position, before neck flexion and extension, the caudal tip of 13% of ETT were located caudal to C7, and one tube was in the endobronchial position at the seventh thoracic (T) vertebra (T7). In the hyperextended position, 60% of ETT moved cranially. The average distance moved was 0.6 vertebral spaces. In the flexed position, all ETT moved caudally. The average distance moved was 3.5 vertebral spaces, with 81.8% of ETT located caudal to C7 and seven tubes in endobronchial positions. Endotracheal tube occlusion caused by kinking at the atlanto-occipital joint was seen in four dogs during flexion of the neck. Based on this study, ETT position should be monitored during cervical manipulation.

Ultrasonography of the kidney and prostate gland. Has gray-scale ultrasonography replaced contrast radiography?

Beginning in the late 1970s with the first reports of two-dimensional, gray-scale ultrasonography used to image small-animal abdominal organs, the question of whether to use contrast radiographic or ultrasonographic techniques for urogenital assessment has become increasingly important. In the last five to seven years, the volume of veterinary literature on ultrasonographic imaging equals or exceeds that on contrast radiographic imaging of the small-animal urogenital tract. While the advantages of ultrasonographic over contrast radiographic imaging are obvious for some situations (eg, renal failure or paraprostatic cyst), no overviews critically comparing these techniques have been published to our knowledge. With the increasing availability of ultrasonographic equipment in private veterinary practice, choices between these imaging techniques must be made. Imaging the kidney and the prostate gland are discussed because both techniques are applicable to these organs. Our intent was to determine which of these techniques would be appropriate for the common clinical conditions. This article addresses the advantages and disadvantages of both techniques for renal and prostatic imaging. The perspective provided is based on ten years of clinical experience with both techniques by each of the authors. Clinical scenarios and specific diseases are discussed and the consensus of the authors on the procedure(s) of choice for these situations are described.

Diagnostic imaging of the male canine reproductive organs. Methods and limitations.

Survey radiographic, contrast radiographic, and ultrasonographic techniques for evaluation of the male canine reproductive organs are reviewed. The applications and limitations of these technique as they apply to reproductive diseases involving the prostate gland and testicles are illustrated.

Intracranial lesions in dogs with hemangiosarcoma.

A retrospective analysis of 85 dogs with hemangiosarcoma (HSA) that underwent complete necropsy, including gross examination of the brain, was conducted. Grossly identifiable intracranial lesions were present in 17 dogs. Twelve of 85 dogs (14.2%) had brain metastases. Four of 85 dogs (4.7%) had hemorrhagic lesions and/or ischemic necrosis without identifiable tumor. One dog had a primary central nervous system tumor. Signs of intracranial disease were present in six of 85 dogs (7.1%) with HSA; four had brain metastases and two had nonneoplastic lesions. Metastases had a propensity for cerebrum and gray matter. Dogs with brain metastases had more widely disseminated disease than dogs without brain metastases (P less than 0.001). Dogs with pulmonary metastases were at greater risk for developing brain metastases than dogs without pulmonary metastases (odds ratio = 8.31). Although thoracic radiography accurately identified ten of 12 dogs (83%) with pulmonary metastases, too few cases were available to assess the applicability/accuracy of thoracic radiography in predicting the presence or absence of brain metastases in dogs with malignancy and signs of intracranial disease.

Radiographic diagnosis of hereditary chondrodysplasia in newborn lambs.

Normal appearing Suffolk lambs affected with hereditary chondrodysplasia (HC) and normal appearing unaffected lambs were radiographed at birth, and at 2, 4, and 8 weeks of age. In affected lambs, lesions were seen consistently in the elbows, shoulders, sternum, and spine. Similar lesions were not identified in unaffected lambs. A malformed Corriedale lamb was radiographed to compare its lesions to those seen in HC. The Corriedale lamb had islands of ossification of the anconeal process similar to those identified in lambs with signs of HC at birth. The islands of ossification seen in the Corriedale lamb were fused by 2 months of age, whereas elbow lesions seen in lambs with HC increased in severity during the same period.

Applications of ultrasonography in the diagnosis of parenchymal kidney disease in cats: 24 cases (1981-1986).

Renal sonograms from 24 cats with confirmed parenchymal kidney disease and from 1 cat with radiographic and palpable evidence of renal enlargement (but without identifiable histologic abnormalities) were evaluated to describe the ultrasonographic appearance of feline renal diseases and to determine the role of ultrasonographic examination in the clinical evaluation of these cases. In all cats with radiographic evidence of abnormal renal size or contour and when poor intraabdominal radiographic contrast precluded visualization of the kidneys, ultrasonography provided complementary information pertaining to location (cortical/medullary), extent, and distribution (focal/multifocal/diffuse) of disease. Ultrasonography also characterized these lesions as cystic (cavitating) or solid. The echo patterns were most specific for renal cysts. Infiltrative diseases did not have consistent patterns. Multifocal hypoechoic nodules, diffuse cortical hyper-echogenicity, and normal-appearing parenchyma were identified. In these instances, however, ultrasonography did define the extent of disease and narrowed the spectrum of differential considerations.

Ultrasonographic evaluation of renal parenchymal diseases in dogs: 32 cases (1981-1986).

The medical records of 32 dogs with microscopically proven renal parenchymal disease were evaluated to characterize the associated ultrasonographic patterns and to assess the contribution of ultrasonography to the diagnosis and management in each case. Ultrasonography provided additional information on internal renal architecture in 18 dogs with radiographic evidence of structural abnormality. Ultrasonography determined the renal origin of 2 abdominal masses, defined the extent and distribution of neoplastic disease in 6 dogs, and identified kidneys not seen on survey radiographs or excretory urograms in 5 dogs because of decreased abdominal contrast or poor function. The ultrasonographic patterns were most specific for focal and multifocal or diffuse neoplasia. Ultrasonographic findings were least specific for diffuse parenchymal disease without architectural disruption such as glomerulo/interstitial nephritis, renal tubular necrosis, and nephrocalcinosis. In these cases, biopsy was recommended. Six interpretive errors were made. Four of these errors were related to the overestimation of renal pelvic and diverticular size because of confusion with medullary papilla. Two errors occurred in the diagnosis of renal lymphosarcoma, one of which was interpreted to be pyelonephritis. The other was an interpretive dilemma because of absence of hypoechoic multifocal nodules. Renal tubular necrosis was confirmed in this case.