We determined the position, dimensions, and structure of the kidneys, ureters, bladder, and urethra of 62 female sheep by use of ultrasonography. A 5.0-MHz convex transducer was placed over the right flank to examine the kidneys, and a 5.0 MHz-linear transducer was used to examine the bladder and urethra transrectally. All examinations were performed on sheep in standing position. The left kidney was 7.1 to 8.9 cm long, 3.4 to 5.5 cm wide, and 3.3 to 4.7 cm deep. Diameter of the parenchyma and renal sinus of the left kidney ranged between 1.1 and 1.9 cm and 1.1 and 2.0 cm, respectively. Circumference of the medullary pyramids varied between 2.1 and 3.3 cm. Similar ultrasonographic measurements were obtained for the right kidney. The diameter of the bladder varied between 0.3 and 6.9 cm in 96.8% of the sheep. The diameter of the bladder could not be determined in 32% of the sheep because it was > 10 cm, and, therefore, was beyond the penetration depth of the scanner. The only part of the urethra that could be ultrasonographically visualized was the internal urethral orifice. It had diameter between 0.1 and 0.2 cm. The ureters could not be ultrasonographically visualized in any of the sheep examined. The urinary tract of 8 sheep was examined 10 times within 2 weeks to examine whether measurements were reproducible. The interassay variation coefficient determined ranged from 3.1 to 31.8%, although for most variables, it ranged between 5 and 11%. Measurements for the length and width of the kidneys had the smallest interassay variation coefficient, whereas values obtained for diameter of the bladder and urethra, as well as thickness of the bladder, had the largest. It was concluded that the ultrasonographic findings described in this study can be used as references for diagnosis of morphologic changes in the kidneys, bladder, and urethra of sheep.

Ultrasonography of the ovaries of 10 bitches was performed daily, using a 7.5-Mhz transducer with a built-in stand-off pad, from the onset of proestrus until the onset of metestrus. Ovarian size, shape, location, echogenicity, follicular development, and apparent ovulation were monitored. Blood samples were collected twice daily for luteinizing hormone determination and daily for progesterone determination. Vaginal smears were made daily for cytologic evaluation. Ultrasonograms were evaluated independent of hormonal and cytologic data, and the day of ovulation was noted. Initially, the ovaries were uniform and had an echogenicity that was equal to or slightly greater than that of the renal cortex. Follicles appeared as focal hypoechoic to anechoic rounded structures. Ovaries were easier to identify as follicular development progressed. Ovarian size increased with time. Apparent ovulation was characterized by a decrease in number of follicles seen from 1 day to the next, but 1 or more follicles remained in at least 1 ovary of 7 of 10 bitches. The ovaries had an oval shape that became rounded after ovulation. At some time after ovulation, all bitches had cystic (anechoic) structures indistinguishable from follicles. These structures increased in echogenicity and decreased in size with time and may have been follicles that did not ovulate, corpora hemorrhagica, fluid-filled corpora lutea, or cyctic luteinized follicles. Time of ovulation determined by ultrasonography paralleled that predicted on the basis of hormonal data in 9 of 10 bitches and with cytologic findings in all bitches.

Superficial digital flexor tendinitis was induced in each forelimb of 8 horses by injecting 4,000 U of collagenase into the midmetacarpal region of the tendon. In each horse, each tendon was treated 24 and 96 hours after the collagenase injection with sc injections of sodium hyaluronate (treated limbs) or an equal volume of 0.9% NaCl solution (control limbs). Exercise was restricted for the first 3 weeks of the study, and a controlled exercise program was instituted for the remainder of the study. Horses were evaluated clinically for lameness, tendon swelling, and midmetacarpal limb circumference. Ultrasonographic examinations were performed regularly (11 examinations/horse) throughout the study, and all horses were euthanatized 12 weeks after collagenase injections. Tendons from 4 horses were harvested for biomechanical testing, and samples were obtained from tendons from the remaining 4 horses for biochemical analysis of collagen. Samples were obtained from all tendons for microscopic evaluation. Significant differences between treated and control tendons were not noticed in any of the variables examined in live horses, although trends toward less lameness in treated limbs and toward better healing on ultrasonographic examination in control limbs were recorded. Significant differences were not noticed in biomechanical or biochemical evaluations, and the only significant (P < 0.05) microscopic finding was more severe inflammation in tendons from treated limbs. This study did not reveal significant benefits of treatment with sodium hyaluronate outside a synovial sheath on tendon repair in collagenase-induced tendinitis.

Administration of progesterone in poly(d-,l-lactide) microspheres was used to maintain pregnancy in mares after luteolysis was induced by treatment with pros F2 alpha at day 14 of pregnancy. Mares were given vehicle only (control, n = 6) or 0.75 g (n = 7), 1.5 g (n = 8), or 2.25 g (n = 5) of microencapsulated progesterone at days 12 and 22 of pregnancy. Serum progesterone concentrations were determined daily, and pregnancy was evaluated by transrectal ultrasonography on alternate days. Significantly (P < 0.05) more mares given 1.5 or 2.25 g of progesterone (6 of 8 and 4 of 5 mares, respectively), but not those given 0.75 g (3 of 7 mares), maintained pregnancy through day 32, compared with control mares (O of 6). Progesterone concentrations decreased significantly (P < 0.025) in all groups after administration of prostaglandin F2 alpha at day 14, and significant (P < 0.05) effects of time and treatment on progesterone concentrations were found between days 12 and 22, and 22 and 32. Although treatment with 1.5-g and 2.25-g doses of microencapsulated progesterone improved maintenance of pregnancy, compared with that of vehicle-treated controls, administration of 2.25 g of microencapsulated progesterone appeared to be most efficacious in maintenance of pregnancy during the study interval.

The purpose of the study reported here was to get detailed information about the normal size and texture of the liver in sheep by means of ultrasonographic examinations. Structure, location, and shape of the liver, gallbladder, portal vein, and caudal vena cava were examined ultrasonographically in 100 sheep. Furthermore, 10 sheep were scanned 10 times within 2 weeks to determine reproducibility of findings. Examinations were performed on the right side of the abdomen in the seventh through twelfth intercostal spaces. In each intercostal space, the dimensions of the liver, and, if visible, the location and diameter of the caudal vena cava and portal vein were determined. The angle of the liver, and location and size of the gallbladder also were determined. Ultrasonographic measurements of liver size and location in healthy sheep can be used as references for changes in liver size attributable to illness.

The accuracy of ultrasonography in detection of feline hepatic lipidosis was studied retrospectively. The following ultrasonographic criteria were associated positively with severe hepatic lipidosis: the liver hyperechoic, compared with falciform fat; the liver isoechoic or hyperechoic, compared with omental fat; poor visualization of intrahepatic vessel borders; and increased attenuation of sound by the liver. In a group of 36 cats with clinically apparent hepatobiliary disease and in which liver biopsy was done, liver hyperechoic, compared with falciform fat, was the best criterion for diagnosis of severe hepatic lipidosis with 91% sensitivity, 100% specificity, and 100% positive predictive value.

A sample of testicular parenchymal tissue, approximately 2 X 7 X 7 mm, was aseptically removed from 1 testis in each of 9 stallions on day 0. Slight to moderate hemorrhage from the tunica albuginea was observed in 8 stallions, but bleeding from the parenchyma was detected in only 2 stallions. Stallions were castrated 27 days later. Normal development of granulation tissue was evident at the biopsy site, but hematomas were not observed. In situ measurement of the widths of the right and left testes, total scrotal width, and evaluation of testicular echogenicity during ultrasonography were variables used to monitor changes in the testicular parenchyma from 14 days before biopsy through 27 days after biopsy. The control testis was consistently larger than the biopsied testis, except for day 3. Ultrasonography revealed signs of a localized change in the parenchyma of the biopsied testis in 4 stallions, but each lesion decreased in size by day 27. Tissues removed during biopsy enabled an excellent appraisal of spermatogenesis at that time. Detailed examinations of seminiferous tubules in the testes were performed to assess for damage to testicular function. At castration, samples were taken from 6 sites in each testis. Quantitative histologic evaluations of testicular tissues revealed low numbers of spherical spermatids and pachytene spermatocytes in biopsied testes, compared with control testes. It was concluded that there was a transitory increase in degeneration of preleptotene spermatocytes and B spermatogonia at the time of biopsy. A mild inflammatory response at the biopsy site in some testes was evidenced by an increased number of leukocytes at the biopsy site and at a dorsal site. Because damage was minimal and appeared to be transitory, it was concluded that the open method of biopsy does not greatly alter the process of spermatogenesis or function of the testis in stallions.