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.

Evaluation of serum and seminal plasma markers in the diagnosis of canine prostatic disorders.

Serum and seminal plasma concentrations or activities of acid phosphatase (AP), prostate specific antigen (PSA), and canine prostate specific esterase (CPSE) were measured in normal dogs, dogs with benign prostatic hyperplasia (BPH), dogs with bacterial prostatitis, and dogs with prostatic carcinoma to determine if these assays would be of value in differentiating dogs with prostatic carcinoma from normal dogs, and dogs with other prostatic disorders. In addition, tissue sections of prostatic adenocarcinomas were stained with antiprostatic AP, anti-CPSE, and anti-PSA antibodies to determine if these would be suitable immunohistochemical markers of prostatic carcinoma. Prostate-specific antigen was not detected in canine serum or seminal plasma. Serum and seminal AP activities did not differ significantly between normal dogs and those with prostatic diseases, or among dogs with different prostatic disorders. Serum CPSE activities were significantly higher in dogs with BPH than in normal dogs. Mean serum CPSE activities in dogs with BPH, bacterial prostatitis, and prostatic carcinoma were not significantly different from each other. Slight to moderate immunohistochemical staining of canine prostatic adenocarcinomas was noted for prostatic AP and PSA; most tumors did not stain for CPSE. These results show that proteins of prostatic origin appear in the serum of dogs as a result of prostatic pathology, especially BPH. Canine prostatic adenocarcinoma does not appear to be associated with significant increases in CPSE or AP activities, possibly because of down-regulation of these enzymes by prostatic carcinoma cells. It is also possible that failure to detect significant differences resulted from limited statistical power for some groups and pairwise analyses because of the small number of dogs evaluated.

Comparison of radiographic and necropsy findings of lung lesions in calves after challenge exposure with Pasteurella multocida.

OBJECTIVES: To test suitability of radiographic evaluation of lung lesions as a substitute for lung lesion scores derived by examination at necropsy in challenge-exposure models of bovine pneumonia. ANIMALS: 10 calves selected by body weight from 20 multiple-source male Holstein calves approximately 1 to 2 months old enrolled in a Pasteurella multocida challenge-exposure study. PROCEDURE: Calves were paired on the basis of weight and randomly assigned within pairs to vaccine or control (saline solution) group. By use of deep tracheal cannulation, calves were challenge exposed with a culture of virulent P multocida, observed for 10 days, euthanatized, and necropsied, and the lungs were scored for pneumonic lesions. Radiographic views of the lung fields of the calves were taken before challenge exposure and before necropsy and were evaluated for alveolar disease by a veterinary radiologist. Lung lesion scores were compared with radiographic evaluations. RESULTS: There was a strong and significant correlation (R2 = 0.91, P < 0.001) between results of the evaluation of postchallenge-exposure radiographs and necropsy results. There also was also strong and significant correlation (R2 = 0.90, P < 0.001) between evaluation of the prechallenge-exposure radiographs and necropsy results. CONCLUSIONS: Radiographic evaluation of lung lesions correlates well with lung lesions found at necropsy. The findings emphasize the need for caution in interpreting the results of challenge-exposure studies of bovine respiratory tract disease in which small numbers of calves are studied.

Effect of multiple excretory urograms on glomerular filtration of normal dogs: a preliminary report.

Study was made of the effect of a triiodinated radiopaque contrast agent, sodium iothalamate on glomerular filtration of ten normal dogs given the dosages commonly recommended for diagnostic studies--200, 400, and 800 mg of iodine/0.45 kg of body weight administered at 2- to 6-day intervals. Renal function was evaluated by determination of serum urea nitrogen and serum creatinine concentrations and endogenous creatinine clearance immediately before each urogram and at 2 to 5 days after the last urogram. Although no significant changes in serum urea nitrogen or creatinine concentrations were identified, a statistically significant reduction in endogenous creatinine clearance following urography was identified when the data from all the dogs were evaluated as a group. However, only 3 of the 10 dogs had successively decreasing values on serial evaluations of endogenous creatinine clearances and an additional 2 animals had final endogenous creatinine clearances further than 1 SD below the preinjection (base line) mean for that animal. Serial renal function studies will be required in dogs given a single dose of the radiopaque contrast to determine the reversibility of the decreased endogenous creatinine clearance and the significance of the decreased creatinine clearances when compared with those values in control dogs (not given radiopaque contrast medium). In addition, these studies may reveal whether the incidence, degree, and duration of reduced glomerular filtration are related to the dose rate of radiopaque contrast agent and are statistically significant were greater numbers of dogs given single and multiple doses of radiopaque contrast agent under laboratory conditions.

Effects of sterilized micropulverized barium sulfate suspension and meglumine iothalamate solution on the genitourinary tract of healthy male dogs after retrograde urethrocystography.

A sufficient quantity of 30% w/v sterile barium sulfate suspension was infused into the caudal portions of urinary tracts of 12 young adult healthy male Beagles to induce vesicoureteral reflux. A control group of dogs was infused with a 7.5% solution of meglumine iothalamate. The dogs were radiographed at 1, 6, 13, and 29 days later. Three dogs from each group were euthanatized and necropsied (1 each) after radiography at each of these times. In some dogs, radiopacity in the prostate, urinary bladder, and renal pelvic diverticula due to barium persisted throughout the 30-day observation period. Opacity at or beyond 24 hours was not found in dogs infused with iothalamate. Light microscopy revealed barium either free or within macrophages in the submucosa of the bladder, in glandular and stromal areas of the prostate, and in the kidney. Renal barium was limited to pelvic diverticula (3 dogs), in a medullary tubule (1 dog), and in cortical tubules (2 dogs). Significant lesions attributable to barium were not seen in kidneys of dogs in the barium group. Iothalamate induced focal to multifocal inflammatory responses in some prostates; barium was phagocytosed by macrophages. Focal transient inflammatory and ulcerative lesions induced by bladder distention were observed in the bladder and urethral mucosa in both groups.

Dyschondroplasias, including osteochondrosis, in boars between 25 and 169 days of age: radiologic changes.

Boars in 6 different groups (between 25 and 169 days of age) were examined radiographically to determine the age of onset of lesions associated with the sites of endochondral ossification in limb bones. Although lesions were in histopathologic sections of physes from all groups of pigs, they were not found frequently in radiographs of live animals until boars were more than 100 days old. Microscopic lesions were infrequent in articular-epiphyseal (A-E) complexes of pigs less than 80 days old, and radiographic examination of live animals had limited value until animals were greater than 100 days old. Radiographs of slabs of bone were useful in the detection of physes with lesions in all age groups and A-E complexes with lesions in boars 100 days of age or older. So that the accuracy of radiographic examination of live animals for the diagnosis of dyschondroplasias could be evaluated, a comparison was made between the numbers of growth cartilages with lesions as determined by radiologic examination of live animals, radiographic examination of slabs of bone, and light microscopy (examination of tissue sections). Only 21% of the lesions associated with physes and 22% of the lesions associated with A-E complexes were detected in radiographs of bones of live pigs. The authors concluded that the latter method was inaccurate for the identification of dyschondroplastic foci. Identification of lesions by examination of radiographs of slabs of bone was only slightly more accurate, since 33% of physes and 23% of A-E complexes which had lesions were found. Potential errors in evaluation of radiographs were discussed.(ABSTRACT TRUNCATED AT 250 WORDS)

Maximum-distention retrograde urethrocystography in healthy male dogs: occurrence and radiographic appearance of urethroprostatic reflux.

Urethroprostatic reflux was found during retrograde urethrocystography in 21 of 24 mature healthy Beagles. Minimal parenchymal-positive contrast " blushes " near the urethra were identified, but no massive accumulations of contrast medium within the prostate were found. A particulate contrast medium, sterilized barium sulfate, was used in 12 of the dogs. After retrograde urethrocystography, the barium particles were found in the secretory (acinar) portion of the prostatic parenchyma, confirming that urethroprostatic reflux extended beyond the prostatic duct system that directly empties into the urethral lumen.

Maximum-distention retrograde urethrocystography in healthy male dogs: occurrence of vesicoureteral reflux.

Twenty-four healthy, mature male Beagles were examined radiographically for vesicoureteral reflux (VUR) by maximum-distention retrograde urethrocystography. Bilateral VUR was observed in 9 dogs and unilateral VUR was observed in 3 dogs. The VUR occurred when the bladder was full or nearly full when maximum bladder filling was defined by trigonal-prostatic urethral dilation. The refluxed contrast medium reached the renal pelves in all but 3 of the 21 affected ureters.

Feline renal ultrasonography: quantitative analyses of imaged anatomy.

Maximal kidney dimensions from serial ultrasonograms were measured in 10 healthy cats. Because clinical ultrasonographic examination is often performed in conjunction with excretory urography, the effect of radiographic contrast medium-induced diuresis on dimensional change also was evaluated. Although a slight, statistically significant increase in size was observed (compared with kidneys scanned without contrast medium), this increase could not be detected on the basis of visual image evaluation alone.

Renal ultrasonography in healthy cats.

Serial ultrasonographic examinations were performed on the kidneys of 10 healthy cats during normal hydration and after administration of contrast medium. Differences in the appearance of anatomic structures or in the echo intensity were not detected between kidneys during normal hydration and after contrast medium administration. The appearance of scanning images was influenced by mode, frequency, and focal range of the transducer, topography and mobility of the kidneys, and adequate sound conduction.

Effects of urinary bladder distention on location of the urinary bladder and urethra of healthy dogs and cats.

Evaluation of the anatomic location of the distended and empty urinary bladders and urethras of healthy adult male and female dogs and cats by retrograde urethrocystography revealed substantial variations. In 15 dogs in lateral recumbency with empty bladder lumens, the caudal portion of the urinary bladder was within the pelvic canal in 5 of 7 male and 5 of 8 female dogs. In female dogs examined in ventrodorsal recumbency, only 4 of 8 had the empty urinary bladders in part within the pelvic canal. After luminal distention, 3 of 7 male and 3 of 8 female dogs, while in lateral recumbency, had the urinary bladders in part intrapelvically. However, when female dogs were placed in ventrodorsal recumbency, only 1 of 7 urinary bladders was in part within the pelvis. The urinary bladders of 14 cats were consistently within the abdominal cavity, irrespective of whether the bladder lumen was distended or empty. Urethral flexures occurred in dogs with intrapelvic bladders that were distended or empty. Urethral flexures were not found in cats. The urethras of dogs and cats in lateral recumbency were generally closer to the floor of the pelvis after urinary bladder distention than when the bladder was empty. The urethra of the dogs and cats in ventrodorsal recumbency was to the left or right of or on the midsagittal plane, whether the urinary bladder was empty or distended. A greater degree of lateral displacement was encountered in ventrodorsal recumbency after urinary bladder distention.

Detailed ultrasonographic mapping of the pelvis in clinically normal horses and ponies.

OBJECTIVE: To map the equine pelvis using ultrasonography, validated by use of computed tomography (CT), magnetic resonance imaging (MRI), and measurements of frozen cadaver slices. ANIMALS: 6 ponies and 6 horses. PROCEDURE: Ultrasonographic examination of the pelvis was performed on 6 clinically normal ponies. Measurements were obtained for imaged structures. Computed tomography, MRI, and measurements of frozen sections were performed after death and used to verify measurements. Linear regression determined the degree of correlation between measurements obtained ultrasonographically and the other modalities. Six clinically normal horses were then examined by use of ultrasonography. For each structure measured mean, SD, and range were calculated. RESULTS: Data obtained from ponies revealed high correlations between ultrasonographic findings and those of CT, MRI, and frozen section measurements (r2 = 0.97, r2 = 0.99, and r2 = 0.99, respectively). Differences between structures measured on each side of the pelvis were not significant. Variation in size of structures was not associated with weight of horses. A correlation was not found between weight of horses and ponies and size of structure. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasonography can be used to accurately measure and evaluate the musculoskeletal structures of the pelvis of horses. The use of CT, MRI, and measurements of frozen sections provided a means of validating the ultrasonographic measurements. Reference range values determined in our study can be used to evaluate horses with suspected pelvic disease.

Evaluation of the morphologic characteristics and prevalence of canine urocystoliths from a regional urolith center.

OBJECTIVE: To determine whether morphology of single-mineral urocystoliths and age, sex, or breed data could be applied to facilitate radiographic and clinical urocystolith mineral type prediction, respectively, in dogs. SAMPLE POPULATION: Database of 2,041 dogs with pure mineral composition urocystoliths. PROCEDURE: All uroliths were characterized according to geologic descriptive terminology and by breed, sex, and age of dog at time of sample submission. Summary statistics were used to compare features with specific mineral types. Observed trends were analyzed for statistical relevance between observed and expected frequencies for age, sex, color, size, shape, and surface, using the null hypothesis that differences by urocystolith mineral type did not exist. On the basis of expected breed occurrence derived by equations, the null hypothesis that urocystolith occurrence paralleled canine breed popularity was tested. RESULTS: Urocystoliths > 10 mm in any dimension were > 92% likely to be magnesium ammonium phosphate hexahydrate (MAP). Smooth, blunt-edged or faceted, and pyramidal urocystoliths were usually MAP. Jackstone shapes were almost always silica. Botryoidal (grape-like clusters) urocystoliths were likely to be oxalates. Breeds with high relative likelihood of urocystoliths included: English Bulldog, Pekingese, Pug, Welsh Corgi, and West Highland White Terrier. Breeds with low relative likelihood of urocystolith production included: German Shepherd Dog, Shar-Pei, and German Shorthaired Pointer. About 94% of urocystoliths produced in females or spayed females were MAP, whereas males and neutered males produced a greater assortment. CONCLUSIONS AND CLINICAL RELEVANCE: For pure mineral composition urocystoliths, trends in mineral type among breeds and between sexes can be exploited clinically in the diagnosis and management of urolith-related disease. Size and shape, used in conjunction with age, breed, and sex, can facilitate pure urocystolith mineral type prediction.

Normal canine excretory urogram: effects of dose, time, and individual dog variation.

Ten healthy, young, adult mongrel dogs were given sodium iothalamate at dose levels of 200, 400, and 800 mg of iodine/0.45 kg of body weight on separate occasions by rapid IV injection; urinary bladders of the dogs were empty before injections were begun. Seven of the ten dogs were given an additional dose of sodium iothalamate (400 mg of iodine/0.45 kg) with the bladder partially distended with sterilized saline solution. Ventrodorsal abdominal radiographs were obtained immediately and at 5, 10, 20, 40, 60, and 120 minutes after injection of contrast medium. The kidneys, renal pelves, pelvic diverticula, and ureters were evaluated for radiographic density (radiopacity). The lengths and widths of the kidneys, pelves, and diverticula and the width of the ureters were determined, and those measurements were standardized by dividing the values by the corresponding length of the second lumbar vertebral body. From these evaluations, it was determined that postinjection radiographs should be obtained immediately and at 5, 20, and 40 minutes. The optimal dose of contrast medium was 400 mg of iodine/0.45 kg of body weight. It was also determined that the dose of contrast medium, as well as the time of postinjection radiography, significantly influenced many of the measurements (both linear and density) in the excretory urogram of normal dogs. Values for the measurements of the urinary structures based on the results of the present study are also presented.

Orthovoltage radiation of normal canine nasal passages: assessment of depth dose.

Frozen heads of 9 clinically normal dogs were irradiated with orthovoltage x-rays. Surface doses and nasal cavity depth doses were measured, and the percentage of surface dose (depth dose) was calculated at random depths from the dorsal cutaneous surface in transverse planes through the medial and lateral canthi. Depth dose of 2 orthovoltage x-ray beams having half-value layers of 1.5 mm of Cu (96 keV) and 2.6 mm of Cu (134 keV) were compared with and found to resemble that reported in depth dose tables based on soft tissue equivalent material. Any differences (identified graphically) in depth dose, compared with that described using a uniform (soft tissue equivalent) phantom, were explained by the variations in tissue composition and the presence of air within the normal nasal and paranasal cavities.

Canine excretory urogram: correlation with base-line measurements.

Ten healthy, adult mongrel dogs were each given various dose levels of sodium iothalamate IV, and postinjection radiographs were made. Base-line plasma and urine osmolality, glomerular filtration rate, packed cell volume, plasma protein concentration, serum urea nitrogen concentration, serum creatinine concentration, and urine specific gravity were measured. The base-line values and the dose of contrast medium were compared statistically with linear and density measurements made from the post-injection radiographs. Base-line plasma osmolality was directly related to the pyelographic and nephrographic density. The dose of contrast medium directly influenced the kidney length, the kidney, pelvic, diverticular, and ureteral widths, and the renal and diverticular densities despite variations in base-line values within accepted limits.

Effects of intravesical hydrostatic pressure and volume on the distensibility of the canine prostatic portion of the urethra.

Positive-contrast retrograde urethrocystograms were obtained serially on 12 male dogs weighing 11.4 to 23.2 kg before, during, and after the injection of contrast medium until the urinary bladder neck and prostatic and membranous portions of the urethra remained open and distended as viewed by fluoroscopy. Correlations of intravesical volumes and pressures required to achieve maximum distension of the midprostatic portion of the urethra with body weight and surface area were not significant. Because of the variability in intravesical volumes and pressures encountered at maximum distension of the prostatic portion of the urethra, a dose of contrast material expressed relative to body weight or surface area could not be determined for consistently providing maximum distension of the prostatic portion of the urethra.

Use of gray-scale ultrasonography in the diagnosis of reproductive disease in the bitch: 18 cases (1981-1984).

Gray-scale ultrasonography was utilized in addition to radiography in the diagnosis of reproductive disease in 18 bitches. In 72% of the cases, ultrasonography was considered diagnostic because it revealed information on organ architecture, relationships of radiographically silhouetting soft tissue structures, and fetal viability that was unobtainable by radiography alone. In the remainder of the cases, ultrasonography was contributory to the diagnostic process by supporting the clinical and radiographic diagnoses. The benefits of ultrasonography are discussed, as is the ultrasonographic appearance of a variety of reproductive tract diseases.

Comparison of the effect of pneumonia detected during lifetime with pneumonia detected at slaughter on growth in swine.

Pneumonia in swine has been studied mainly at slaughter or necropsy. However, when performing slaughter or postmortem examinations, assessment of the true prevalence or lifetime extent of pneumonia is at best speculative. Radiography was used to evaluate lungs from pigs 21 to 150 days old. Follow-up slaughter examination was performed on pigs 180 days old. Individual percentage of pneumonia observed over the life of each pig and at slaughter were added to yield lifetime pneumonia scores. A significant (P = 0.0001) negative effect of lifetime pneumonia on growth rate was found. By comparison, slaughter examination proved to be a poor indicator of lifetime pneumonia; lesions were found to progress and regress dynamically throughout the life of pigs.

Gray-scale ultrasonography in the diagnosis of adrenal neoplasia in dogs: six cases (1981-1986).

In addition to survey abdominal radiography, 2-dimensional gray-scale ultrasonography was utilized as a non-invasive imaging mode in 6 dogs with adrenal neoplasia. Ultrasonography was a safe method of obtaining information about the organ of involvement, extra-adrenal extent of disease, vascular invasion or compression, and internal architecture of abdominal masses in the area of the adrenal gland. The data obtained ultrasonographically was determined to be useful in diagnosing adrenal neoplasia.