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Summary

For 16 dogs with testicular neoplasia (n = 19 tumors), ultrasonography was performed to determine whether a correlation exists between ultrasonographic features of testicular tumors and cell type. The echogenicity of the tumors varied depending on the size of the tumor and whether the tumor had focal or diffuse distribution within the testis. The ultrasonographic characteristics of Sertoli cell tumors were variable, with no predominant pattern. This variation may be related to tumor size, because 6 of 7 Sertoli cell tumors were > 5 cm in diameter. Focal seminomas and interstitial cell tumors < 3 cm in diameter had hypoechoic texture. Focal seminomas and interstitial cell tumors > 3 cm in diameter had mixed echogenicity. Tumors of multiple cell types were > 5 cm in diameter and had mixed echogenicity. In valuable breeding dogs with a small (< 3 cm) focal intrascrotal lesion, testicular ultrasonography would be of benefit for localization of the mass to the testis or epididymis for subsequent biopsy. In dogs with intra-abdominal neoplastic testes, ultrasonography may be of benefit in determining intra-abdominal metastases and invasion of contiguous structures.

Free access
in Journal of the American Veterinary Medical Association

SUMMARY

The source of a previously described radiolucent crescent in the flexor cortex of the distal sesamoid (navicular) bone on the palmaro45°proximal-palmarodistal oblique (Pa45°Pr-PaDio) clinical radiographic projection was investigated in 48 forelimb navicular bones from 24 Thoroughbreds by use of high-detail radiography and x-ray computed tomography (ct). Twenty-five of these bones also were evaluated, using microradiography and histologic examinations. Of these 25 bones, 5 had been labeled in vivo with fluorochrome markers. Tetrachrome-stained 100-µm-thick nondecalcified sections of these 5 bones were examined, using epifluorescence microscopy.

A reinforcement line of compacted cancellous bone, parallel and several millimeters deep to the flexor cortex in the region of the flexor central eminence, was visualized by ct in 42 of 48 navicular bones and by microradiography in 23 of 25 navicular bones investigated. Variable degrees of compaction were observed in the cancellous bone between the flexor cortex and the reinforcement line. High-detail skyline radiographic projections and reconstructed ct images indicated a crescent-shaped lucency within the flexor central eminence of the flexor cortex in the bones in which the reinforcement line was identified, but the cancellous bone between the reinforcement line and the flexor cortex had not been compacted. The radiolucent crescent seen in the flexor central eminence of the navicular bone on the Pa45°Pr-PaDiO projection was not caused by the concave defect or synovial fossa of the flexor central eminence overlying the flexor cortex, as was described. The crescent-shaped lucency within the navicular bone flexor central eminence identified on clinical radiographs was associated with remodeling of cancellous bone within the medullary cavity of the navicular bone. It is hypothesized that remodeling of the cancellous bone is secondary to biomechanical stresses and strains placed on the navicular bone, although the clinical relevance of this finding was not determined during the study.

Free access
in American Journal of Veterinary Research

Summary

To determine the effects of long-term dietary protein restriction in cats with chronic renal failure (crf), 4 healthy adult cats and 7 cats with surgically induced crf were fed a high-protein (hp, 51.7% protein) diet and 4 healthy adult cats and 7 cats with surgically induced crf were fed a low-protein (lp, 27.6% protein) diet for 1 year.

Cats with induced crf that were fed the lp diet had reduced serum urea nitrogen concentrations, despite lower glomerular filtration rates, compared with cats with crf fed the hp diet. Despite five-sixths reduction in renal mass, reduced glomerular filtration rate, and azotemia, 13 of the 14 cats with induced crf retained the ability to concentrate urine and produced urine with a specific gravity > 1.035.

Cats fed the hp diet consumed significantly more calories than did cats fed the lp diet, presumably because the hp diet was more palatable. As a result of the lower caloric intake in cats fed the lp diet, these cats were protein and calorie restricted, compared with cats fed the hp diet. Cats fed the hp diet weighed significantly more than did cats fed the lp diet. Mean hematocrit and mean serum albumin concentration were significantly lower in control cats and in cats with crf fed the lp diet, compared with control cats and cats with crf fed the hp diet.

Hypokalemia developed in 4 of 7 cats with crf fed the hp diet (containing 0.3% potassium); hypokalemia did not develop in control cats fed the same diet or in cats with crf fed the lp diet containing 0.4% potassium. Excessive kaliuresis, hypomagnesemia, and metabolic acidosis did not appear to contribute to the hypokalemia. Subsequent supplementation of the hp diet with potassium gluconate prevented hypokalemia in cats with crf.

Free access
in American Journal of Veterinary Research

SUMMARY

The influence of induced chronic renal failure on 24- hour urinary excretion and fractional excretion of sodium and potassium was studied in cats. Induction of chronic renal failure significantly increased fractional excretion of potassium (P < 0.0001) and sodium (P < 0.05); however, 24-hour urinary excretion of sodium and potassium decreased slightly following induction of chronic renal failure.

Fractional excretion and 24-hour urinary excretion of sodium and potassium were compared by linear regression in clinically normal cats, cats with chronic renal failure, and clinically normal and affected cats combined. In clinically normal cats, linear regression revealed only moderate correlation between fractional excretion and 24- hour urinary excretion for sodium and potassium. Linear regression of these same relationships in cats with chronic renal failure, and in clinically normal cats and cats with chronic renal failure combined, indicated low correlation.

Fractional excretions of sodium and potassium were not reliable indicators of 24-hour urinary excretion of these electrolytes in cats with chronic renal failure or unknown glomerular filtration rate. Fractional excretion of potassium and sodium correlated only moderately with 24-hour urinary excretion in clinically normal cats.

Free access
in American Journal of Veterinary Research

SUMMARY

Clinicopathologic manifestations of induced infection of the feline lower urinary tract with bovid herpesvirus-4 (bhv-4, strain FCAHV) were characterized in 6 conventionally reared adult cats (2 sexually intact males, 2 castrated males, and 2 females). Two additional control cats were exposed with noninfected cell culture control inoculum. Clinical and radiographic signs of lower urinary tract disease were not observed in exposed or control cats. Microscopic hematuria was detected in urine samples collected by cystocentesis from 4 of 6 exposed cats and 1 of 2 control cats. Results of culture of urine for bacteria, maycoplasmas, ureaplasmas, and viruses were consistently negative. Low titer of serum bhv-4 (strain FCAHV)- neutralizing antibodies was detected in 4 of 6 exposed cats, but not in controls.

Gross abnormalities of the urinary tract were not observed in any cat. Light microscopic examination of serial sections of the lower urinary tract revealed mild focal lymphoid cystitis in 2 of 6 exposed cats, one of which also had increased amounts of connective tissue and proliferation of blood vessels in the urinary bladder lamina propria. Ninety days after initial exposure, bhv-4 (strain FCAHV) was reisolated from explanted urinary bladder tissues of 5 of 6 exposed cats. Virus was not isolated from tissues of control cats.

It was concluded that bhv-4 (strain FCAHV) establishes persistent urinary tract infection in conventionally reared adult male and female cats. However, persistent bhv-4 infection in cats may remain clinically inapparent.

Free access
in American Journal of Veterinary Research

Summary

The clinicopathologic manifestations of bovid herpesvirus-4 (bhv-4; FCAHV strain)-induced infection of the lower portion of the urinary tract were characterized in 12 adult neutered male and 6 female specific-pathogen-free cats, and were compared with those in 12 neutered male control cats. Six neutered male and 6 female cats were given immunosuppressive doses of methylprednisolone acetate prior to inoculation of their urinary bladders with bhv-4. Six neutered male control cats were given immunosuppressive doses of methylprednisolone acetate prior to inoculation of their urinary bladders with uninfected tissue culture control inoculum. Six additional neutered male control cats were exposed only to uninfected tissue culture control inoculum. All cats were observed for 90 days following inoculation. Dysuria and gross hematuria were observed in only 1 bhv-4-exposed cat. Radiographic abnormalities of the lower portion of the urinary tract were not observed. Microscopic hematuria, crystalluria, and lipiduria were identified with similar frequency in bhv-4-exposed and control cats. Results of urine culturing for bacteria, mycoplasma, ureaplasma, and viruses were negative. Viruses were not isolated from blood leukocytes collected from exposed or control cats. Three to 6 weeks after inoculation, high concentrations of bhv-4 serum antibodies were detected in all exposed cats by an indirect fluorescent antibody test.

Light microscopic examination of the urinary tract revealed multifocal lymphoid cystitis in 2 bhv-4-exposed cats. Except for suppurative bronchitis in 1 bhv-4-exposed cat given glucocorticoids, morphologic differences in urinary and extraurinary tissues were not observed. In urinary bladder tissue collected 90 days after inoculation, bhv-4 was reisolated from urinary bladder explants of all but 1 exposed cat. Virus was also isolated from a kidney explant of 1 exposed male cat, and spleen cell cocultures of 1 exposed female cat given glucocorticoids.

Bovid herpesvirus-4 (FCAHV strain) caused persistent urinary tract infections in male and female specific-pathogen-free cats. Detection of occult bhv-4 infection required isolation of virus from tissues by explantation, or demonstration of specific bhv-4 antibodies by immunofluorescent techniques. Administration of glucocorticoids prior to inoculation did not enhance morbidity associated with bhv-4 urinary tract infection. Further investigations are needed to determine the pathogenic role of bhv-4 in noninduced feline lower urinary tract disease.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate and compare circulating concentrations of islet amyloid polypeptide (IAPP), insulin, and glucose in nondiabetic cats classified by body condition score (BCS) and in cats with naturally occurring diabetes mellitus.

Animals—109 (82 nondiabetic, 21 nonketoacidotic diabetic, and 6 ketoacidotic diabetic) cats.

Procedures—Cats were examined and BCSs were assessed on a scale of 1 to 9. After food was withheld for 12 hours, blood was collected and plasma concentrations of IAPP and serum concentrations of insulin and glucose were measured. Differences in these values were evaluated among nondiabetic cats grouped according to BCS and in diabetic cats grouped as ketoacidotic or nonketoacidotic on the basis of clinicopathologic findings. Correlations were determined among variables.

Results—In nondiabetic cats, BCS was significantly and positively correlated with circulating IAPP and insulin concentrations. Mean plasma IAPP concentrations were significantly different between cats with BCSs of 5 and 7, and mean serum insulin concentrations were significantly different between cats with BCSs of 5 and 8. Serum glucose concentrations were not significantly different among nondiabetic cats. Mean IAPP concentrations were similar between nonketoacidotic diabetic cats and nondiabetic cats with BCSs of 8 or 9. Mean IAPP concentrations were significantly reduced in ketoacidotic diabetic cats, compared with those of nondiabetic cats with BCSs of 6 through 8 and of nonketoacidotic diabetic cats.

Conclusions and Clinical Relevance—Results indicated that increased BCS (a measure of obesity) is associated with increased circulating concentrations of IAPP and insulin in nondiabetic cats.

Full access
in American Journal of Veterinary Research

Abstract

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 nephrotoxi-cosis may be considered. (Am J Vet Res 1996;57:1536–1544)

Free access
in American Journal of Veterinary Research