A radiopaque marker was injected, using needles of various lengths, into the cervical musculature, the lumbar epaxial musculature, and the cranial and caudal muscular masses of the thighs of anesthetized dogs. After this procedure, the dogs were euthanatized and deep-frozen. The bodies were then sectioned, and the slices were radiographed to determine the fate of the injected material. Material that was injected into the neck or caudal region of the thigh was determined to be located in the muscle bellies or dispensed throughout the intermuscular fascial sheaths. In contrast, material injected into the lumbar area and cranial region of the thigh was located entirely in the muscle bellies. It was concluded that the best sites for injection in dogs are the lumbar epaxial musculature or the quadriceps femoris muscle when IM administration is imperative.

Areas of skin vascularized by large axial vessels potentially suitable for microvascular anastomosis were investigated in 10 horse cadavers. Eleven such areas were dissected, and the skin over the flank region vascularized by the deep circumflex iliac artery was most suitable. The anatomy of this area was further defined, using angiography and latex injection studies on 10 cadavers.

The hepatobiliary dynamics of a 99mTc-labeled derivative of iminodiacetate were investigated in 29 healthy dogs. A 2-compartment model proved to be adequate to describe the hepatic time-activity curve. Model-derived variables for the hepatic accumulation and the biliary excretion and transport were used as a reference for evaluation of a number of commonly used measurements directly derived from hepatic and bilary time-activity curves (graphic variables). The difference between t50(ex) and t95(ex), representing the moments when 50 and 95%, respectively, of the maximal count rate during the hepatic excretory phase were measured, proved to be an adequate graphic variable to quantitate biliary excretion. The use of other graphic variables to quantitate hepatobiliary functions seemed unjustified.

The vascular patterns to pelvic limb muscles were studied in 6 dogs (12 limbs) to identify muscles most suitable for transposition in the treatment of large wounds. Gross dissection of injected specimens and angiography were used to identify the vascular pedicles. The vascular pedicles to several muscles were generally consistent, and any variations would not interfere with most muscle transfers. The cranial part of the sartorius, gracillis, semitendinosus, and rectus femoris muscles were identified as suitable candidates for transfer. The caudal part of the sartorius, cranial tibial, and long digital extensor muscles have segmentalized vascular patterns that would limit its arc of rotation.

Twelve horses, with acute laminitis (primarily in the forefeet) at 12 hours after intragastric dosing with an aqueous extract of black walnut (Juglans nigra) heartwood, were studied. The distribution of perfusion of blood to the foot and to outlined regions within the foot was quantified, using gamma scintigraphy of regionally 99mTC. labeled macroaggregated albumin, before and 12 hours after extract administration. Horses 1 to 3 were not studied further. Perfusion was quantified again for horses 4 to 12 at 84 hours after extract administration. At the onset of acute laminitis, horses 7 to 12 were administered a single dose of prazosin (0.025 mg/kg of body weight, IV) immediately after scintigraphy of the right forelimb and before scintigraphy of the left forelimb. When compared with baseline images, perfusion to the forefoot of horses after the development of acute laminitis was quantitatively decreased vs perfusion to the entire distal portion of the forelimb. Also with the onset of laminitis, perfusion also decreased to the dorsal laminar and coronary corium regions vs the distal portion of the forelimb. The acute laminitis-associated deficit in perfusion to the dorsal lamina was greater in magnitude than the deficit in perfusion to either the coronary corium or the entire forefoot. Equivalent deficits in the distribution of perfusion were not detected in forelimbs from horses with acute laminitis and which had been treated with prazosin. When compared with baseline images, perfusion to the dorsal lamina was increased in relation to perfusion to the distal portion of the limb at postdosing hour 84. Prazosin treatment did not influence that increase in perfusion to the dorsal lamina.

X-ray-computed tomography (CT), nephrotomography, and ultrasonography were performed in 10 clinically healthy dogs (weighing 14 to 33 kg) to visualize the adrenal glands. In all 10 dogs, CT enabled visualization of both adrenal glands. Cross-sectional diameter was measured accurately. The size and shape of CT sections of the adrenal glands varied widely because of individual differences in the actual size and shape of the adrenal glands and because of their position in the plane of the CT scans. In 5 dogs, nephrotomography enabled visualization of 1 or both adrenal glands as oblong craniocaudal-directed densities in the craniodorsal portion of the abdomen. In 7 dogs, transverse ultrasonography enabled visualization of 1 or both adrenal glands as round or oval hypoechoic structures in the surrounding hyperechoic fat.

Nephrotomography and ultrasonography were used in 11 dogs with hyperadrenocorticism to assess the value of these techniques for the localization of biochemically diagnosed hyperfunctioning adrenocortical tumors. Both techniques enabled accurate localization of a unilateral adrenal mass in each of the dogs. Cross-sectional diameters of the masses ranged from 1 to 4 cm. In 1 dog, expansion of tumor into the caudal vena cava was revealed by caudal venacavography and ultrasonography. Mineralization in the tumor mass in 2 dogs was easily recognized by nephrotomography, but not by ultrasonography. Paracostal laparotomy confirmed the presence of an adrenocortical tumor in each dog, and expansion of tumor into the caudal vena cava in 1 dog. Cross-sectional diameters of the tumors ranged from 1.2 to 4.5 cm and corresponded well with cross-sectional measurements by nephrotomography and ultrasonography. It was concluded that nephrotomography and ultrasonography have similar diagnostic accuracies for the detection and localization of hyperfunctioning adrenocortical tumors.

To investigate whether arthrographic findings had any prognostic value with respect to treatment and outcome of bilateral osteochondrosis, shoulder arthrograms (n = 80) from 40 dogs with bilateral lesions were evaluated. Arthrography was performed, using 1.5 to 4 ml of a 25% solution of meglumine-sodium diatrizoate, with admixture of 0.2 mg of epinephrine. A shoulder with signs of pain and lameness was surgically treated. The contralateral shoulder was treated conservatively, and the final outcome was compared with the arthrographic findings. In 37 dogs, signs of lameness and pain were associated with a loose cartilage flap and, in 3, with a detached cartilage flap. In 2 dogs, admitted with bilateral lameness, a loose cartilage flap was detected in both shoulders. Of 12 dogs with a detectable loose cartilage flap in the contralateral shoulder joint, 6 became lame 2 to 4 months after initial surgical intervention and needed bilateral surgery. In the contralateral joint, development of thick articular cartilage over the subchondral defect or a detached cartilage flap lodged in the caudal pouch of the shoulder joint was a favorable prognostic sign. Such dogs had no signs of lameness on the contralateral side during a follow-up period that ranged from 1 to 7 years.

The vascular permeability of the ocular fundus, alterations in the coagulation system, and plasma concentrations of thromboxane B2 (TXB2) and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) were studied in dogs following intradermal inoculation with 5 x 10(5) TCID50 of Rickettsia rickettsii. Twenty-four to 48 hours after the onset of fever and rickettsemia, multifocal areas of retinal vasculitis were evident, which corresponded to areas of altered vascular permeability demonstrated by fluorescein angiography. The number and intensity of retinal vessels with sodium fluorescein leakage peaked during the second week after inoculation, and retinal vascular permeability remained altered during the third week of infection, well past the phase of clinical and clinicopathologic recovery. Development of retinal vasculitic foci was associated with thrombocytopenia, increased concentrations of circulating fibrinogen, and slight prolongation of activated partial thromboplastin time. Increased concentrations of fibrin/fibrinogen degradation products were detected in 4 of 9 dogs. Despite the degree of vascular endothelial damage evident on fluorescein angiographic and histologic studies in these dogs, plasma TXB2 and 6-keto-PGF1 alpha concentrations were not increased.

Measurements of liver size were made from radiographs of 16 clinically normal anesthetized dogs. Two measurements were made from each of 3 views: right and left lateral and ventrodorsal. Each measurement was correlated with liver weight and volume. Liver weight and volume were also correlated with both measurements from the same radiograph multiplied together. All measurements, with the exception of ventrodorsal depth, correlated significantly (P < 0.05) with liver weight and volume. The multiplication of the 2 measurements made from the right lateral radiograph correlated most highly with liver weight. These data were then compared with those from similar studies involving liver measurements obtained from nuclear scintigraphic and ultrasonographic scans on the same dogs. The radiographic measurements made from the right lateral view had the highest correlation with liver weight, followed by the nuclear scintigraphic measurements made from the same position.