COMPARISON OF UPPER GASTROINTESTINAL RADIOGRAPHIC FINDINGS TO HISTOPATHOLOGIC OBSERVATIONS: A RETROSPECTIVE STUDY OF 41 DOGS AND CATS WITH SUSPECTED SMALL BOWEL INFILTRATIVE DISEASE (1985 to 1990)

It was the intent of this study to define which, if any, radiographic observations corresponded with specific causes of diffuse infiltrative small bowel disease and if radiographic findings could differentiate inflammatory disease from neoplastic disease and either of them from normal. Bowel spasticity, luminal narrowing, and thumbprinting tend to indicate the presence of tumor more often than inflammatory disease. Increased bowel gas in cats and barium adhesion in dogs and cats suggest that a component of enteritis is present. Decreased bowel gas in dogs is more often associated with obstructive disease, but is not helpful in differentiating diffuse inflammatory disease from diffuse neoplastic disease. While several observations that can foster differentiation of neoplastic from inflammatory disease were found, this study also indicated that the UGI lacks a high degree of predictive value other than to indicate the presence of infiltrative small bowel disease.     

TECHNETIUM-99M AND IODINE-131 THYROID SCINTIGRAPHY IN NORMAL AND RADIOTHYROIDECTOMIZED COCKATIELS (NYMPHICUS HOLLANDICUS)

Thyroid scintigraphy using sodium ^99mTechnetium pertechnetate (⁹⁹TcO₄-) was performed in normal and radiothyroidectomized cockatiels ( Nymphicus hollandicus ). ¹³¹I scintigraphy was performed in the course of ablating the thyroid glands. The thyroid glands in normal birds were clearly visualized, but were not individually resolvable. Thyroid glands were not visualized in thyroid-ablated birds. With ^99mTcO₄ scans, thyroid (or other region of interest)/body count density ratios were used for comparisons of normal and thyroid-ablated birds. Normal ^99mTcO₄- thyroid/body ratios (mean +/− SD) for the dorsal and lateral views were 1.83 +/− 0.31 and 1.70 +/− 0.34 respectively. Pertechnetate thyroid/body count density ratios decreased (to 0.93 -/−0.14 and 0.88 +/− 0.12 for dorsal and lateral views respectively) after thyroid ablation, while crop/body ratios increased. ^99mTcO₄- thyroid scintigraphy, therefore, was capable of detecting hypofunctional thyroid abnormalities in ¹³¹I radiothyroidectomized cockatiels.     

In Vitro Loss of Tensile Strength and Elasticity of Five Absorbable Suture Materials in Sterile and Infected Canine Urine

The loss of breaking strength and elasticity of five absorbable suture materials (polydioxanone [PDS-II], polyglycolic acid [PGA], polyglactin 910 [PG-910], polyglyconate [GTMC], and chromic gut) after in vitro incubation in sterile, Escherichia coli- and Proteus mirab/tfs-inoculated canine urine was studied. Biomechanical testing, in a controlled environment, was performed during the 28-day study period. Polydioxanone and chromic gut retained greater than 90% of their original strengths after 28 days of incubation in sterile urine and 87% of original strengths in E. co//-inoculated urine. Polyglyconate retained 24% and 18% of original strength, respectively, after incubation in sterile and E. co/i-inoculated urine for 28 days. Polyglycolic acid and PG-910 retained less than 30% of original strength in sterile urine and only 7% in E. co/i-inoculated urine after 21 days of incubation. In P. m/rabi/is-inoculated urine, loss of tensile strength and elongation was significant for all suture materials. Polyglycolic acid and PG-910 lost all strength after 24 hours of incubation. Polydioxanone lost all strength after 7 days of incubation, whereas GTMC retained 19% at day 7. Chromic gut retained 78% at day 7 and 16% after 21 days of incubation, however, the absence of normal phagocytic destruction of chromic gut in this in vitro study may have artificially elevated these values. In sterile urine with chemically modified pH, loss of strength and elongation was greater in alkaline urine than in neutral or acidic urine for all types of suture materials.     

ANATOMY OF THE PORTAL AND HEPATIC VEINS OF THE DOG: A BASIS FOR SYSTEMATIC EVALUATION OF THE LIVER BY ULTRASONOGRAPHY

The objective of this study was to define, in detail, the anatomy of the portal and hepatic veins in the dog in order to establish a procedure for the systematic evaluation of the liver by ultrasonography. Anatomical details were obtained from the formalin fixed livers of ten dogs. The hepatic and portal veins were removed intact from these livers so that a detailed pattern of distribution could be established and the numbers of branches could be counted. Silastic casts were also made of the hepatic and portal veins of two livers, one in situ and one in which it had been removed. The former was to enable the relationship of the portal to the hepatic veins to be established as closely as possible within the animal and the other to provide a model of the distribution of each venous system within the liver. Contrast medium was infused into two other livers and radiographs taken to establish the relationship of each branch to each lobe. It was found that there was a consistent pattern of venous branching to each lobe of the liver in the dog with little variation between individual specimens. All liver lobes contained definite venous branches so that the left lateral and medial, quadrate, right medial and lateral, caudate and papillary veins could be distinguished in each venous system. We believe that an appreciation of this venous distribution will aid in the systematic evaluation of the liver during ultrasonography by enabling identification of each liver lobe. It should be of value for differentiating portal from hepatic veins and veins from dilated bile ducts.     

Mechanical Properties of Four Suture Patterns for Transected Equine Tendon Repair

Thirty-six superficial digital flexor tendons from nine fresh equine cadavers were transected and sutured with size 2 monofilament nylon. Nine tendons were repaired with each of four suture patterns: single-locking loop, double-locking loop, triple-locking loop, or three-loop pulley. The times required for application, tensile strengths, resistance to distraction (gap), and modes of failure were analyzed. The mean times required were: single-locking loop, 3 mins, 15 secs; double-locking loop, 4 mins, 15 secs; triple-locking loop, 10 mins, 50 secs; and three-loop pulley, 4 mins. The double-locking loop, triple-locking loop, and three-loop pulley suture patterns were stronger than the single-locking loop. The triple-locking loop and three-loop pulley patterns were close in strength and only the triple-locking loop was stronger than the double-locking loop. The three-loop pulley had the greatest resistance to gap formation and its mode of failure was different from the others. The three-locking loop suture patterns failed by suture breakage but the three-loop pulley failed first by suture pull-out and then by suture breakage.     

Comparison of Three Skin Preparation Techniques in the Dog Part 1: Experimental Trial

Premeasured, clipped areas of skin on both sides of 30 adult dogs were prepared with povidone-iodine (PI), chlorhexidine gluconate (CG) with a saline rinse, or 4% CG with a 70% isopropyl alcohol rinse. Skin bacteria were quantified with Replicating Organism Detection and Counting (RODAC) plates and cultured for identification before, immediately after, and 1 hour after skin preparation. The percentages of bacterial reduction immediately and at hour 1 and the percentages of negative cultures, cultures with more than five colony-forming units (CFUs), and skin reactions were analyzed by analysis of variance and chi-square. The percentage of reduction in skin bacteria for all techniques was significant and comparable with that reported in humans. There were no significant differences between PI and CG results except that acute contact dermatitis was observed more frequently after skin preparation with PI. The authors conclude that for similar application times, PI and 4% CG rinsed with saline or 70% isopropyl alcohol are equally effective for up to 1 hour in the preoperative skin preparation of dogs.     

In Vitro Assessment of the Equine Hoof Wall Strains in Flat Weight Bearing and After Heel Elevation

Horseshoeing is a common practice, but effects on the hoof wall are poorly understood. Strain gauges were used to document and compare hoof behavior in vitro during flat weight bearing and after artificial heel elevation. Ten front limbs of Thoroughbred race horses, shod with conventional flat shoes, were used. Eight strain gauges were symmetrically distributed around the toe, quarters, and heels. Each limb was mounted to a testing machine (Kratos K5002; Kratos Dynamômetros, Ltda., Cotia-SP-Brazil) and subjected to a load equivalent to 30% of the donor's body weight. Strains (μ) were acquired by means of a computerized system and the results compared using Friedman and Wilcoxon statistical tests. There was greater strain variation when the heels were elevated. Compression predominated during flat weight bearing, with a tendency to horizontal traction after heel elevation. The changes in strain caused by heel elevation were not always symmetrical. Elevation of the heels tensed the toe and the medial quarter horizontally, increased load at the posterior portion of the hoof capsule, and hindered its expansion.     

Radiographic aspects of exercise-induced pulmonary hemorrhage in racing horses

Abnormal pulmonary radiopacities were identified in 13 racing horses in which a diagnosis of exercise-induced pulmonary hemorrhage (EIPH) had been confirmed. The lesions were in the caudal lung lobe in all horses; seven were on the right and three on the left, and the laterality for three could not be determined. In ten horses the opacities, which were large and peripherally located, obliterated the thoracophrenic angle. They merged with the silhouette of the diaphragm and had a circular or ovoid surface directed toward the hilum. The intensity of opacification of the consolidated areas varied, and they often were not sharply marginated. Dorsal displacement of the pulmonary arteries was noted in the region of the radiopacity in seven horses. Varying volumes of pleural effusion were observed in nine horses. Serial radiographic examinations were performed in seven horses. The pulmonary radiopacities cleared within ten days in two horses. In the remaining five horses, gradual resolution, characterized by a reduction in lesion size with improved margination, occurred during several months. The central region of the radiopaque lesion commonly had a patchy appearance, suggesting cavitation. Normal pulmonary vascular and interstitial markings were evident following complete resolution of these lesions. The cause of these abnormal pulmonary opacities has not been determined. Pathologic-radiologic correlations will be required to improve understanding of the pathophysiology of EIPH in the racing horse.     

Dorsal Laminectomy in the Horse II. Evaluation in the Normal Horse

Subtotal dorsal cervical laminectomy was performed on nine normal horses to evaluate positioning, refine the surgical technique, and assess the immediate and long-term effects of this procedure in the horse. Funkquist type B laminectomies were performed at various levels from C3-C4 to C6-C7. Absorbable gelatin sponge or autogenous nuchal fat was placed over the exposed dura mater. Surgery times varied from 2 to 3 hours, and all horses recovered without complication. Rapid primary intention wound healing occurred, with two horses showing neck pain. All remained neurologically normal. The horses were euthanized 6 weeks, 3 months, or 6 months postoperatively. Myelograms performed just prior to euthanasia demonstrated normal or expanded dye column widths. Necropsy revealed that all surgical sites had healed well. The laminectomy membrane was soft and pliable and could be easily separated from the underlying dura mater when fat was used as interpositional material. When gelatin sponge was used, the laminectomy membrane was firmly bonded to the dura. Spinal cords at the level of laminectomy appeared normal and moved freely within the vertebral canal. Histological evaluation of the laminectomy sites and associated spinal cord revealed no abnormalities attributable to the surgery. It was concluded that dorsal cervical laminectomy can be performed in horses without untoward sequelae. The procedure may be useful for the treatment of equine cervical compressive myelopathies.     

Physiologic responses of feral horses to succinylcholine chloride immobilization

Five captive feral horses were immobilized at 72 hour intervals for 30 days by intramuscular administration of succinylcholine chloride (SCh) using a capture gun and dart system. The serum enzyme activities of creatine phosphokinase, glutamate-oxaloacetate transaminase, and lactate dehydrogenase and serum cortisol concentrations were monitored to assess the response to chemical immobilization in feral horses over time.Reference values for these parameters in feral horses were found to be in close agreement with those of normal, rested horses not in training. The results suggest that single, or infrequently repeated, use of succinylcholine-chloride by intramuscular administration to captive feral horses, or to otherwise unapproachable horses, could be efficiently and practically employed in field situations without major physiologic alterations and with minimal stress occurring in these horses.