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  • Author or Editor: Richard M. DeBowes x
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Summary

Biaxial palmar digital neurectomy of all limbs was performed on 6 mixed-breed castrated adult male horses, using a standard guillotine method. Using a Teflon catheter, 20 mg (2 ml) of sodium hyaluronate (group 1), 2 ml of phosphate-buffered saline solution (group 2), or catheter placement with no infusion (group 3) was applied to 4 (group 1) or 2 (groups 2 and 3) of 8 incisions/horse. Treatments were administered after closure of the neurectomy incision, and the catheter was removed. Horses were evaluated daily for 1 week, then weekly over a 9- week period for evidence of lameness, swelling, and ultrasonographic changes. On week 9, horses were euthanatized and neurectomy sites were removed en bloc for histologic evaluation of axonal regrowth, inflammation, and fibrosis. Neither lameness nor sign of painful neuroma was observed clinically in any of the horses. Neurectomy eliminated cutaneous heel sensation in all limbs for the duration of the study. Swelling was evident at all neurectomy sites. There were no significant differences between treatment sites for measurement of pastern circumference or ultrasonographic evaluation of incisional swelling. Foci of ultrasonographic hyperechogenicity increased over time, but there was no significant difference in hyperechogenicity between treatment groups. Histologic evidence of neuroma formation was observed at all sites. Morphometric assessment of neuroma cross-sectional areas revealed no significant difference between the groups, as did subjective histologic assessment of neuroma density and fibrous tissue content. We conclude that there are no clinical, ultrasonographic, or histologic effects on neuroma formation and fibrosis at sites of palmar digital neurectomy associated with a single perineural administration of sodium hyaluronate or phosphate-buffered saline solution.

Free access
in American Journal of Veterinary Research

Abstract

Objective

To evaluate the frequency and sites of communication among the antebrachiocarpal, middle carpal, and carpometacarpal joints in cattle.

Animals

137 limbs were obtained from 72 fresh bovine cadavers submitted for necropsy because of problems unrelated to the carpus.

Procedure

1 of the 3 injection sites was randomly assigned to both carpi of each ox, and a mixture of latex and barium sulfate was injected into the joint. Communication between 2 or more joints was determined by the presence of latex and contrast material in a joint adjacent to the injected joint by examination of frozen sections, positive-contrast arthrography, and fluoroscopy.

Results

Communication existed among the 3 joints in 18 specimens (13.1%). The middle carpal joint and the carpometacarpal joint always communicated. The antebrachiocarpal joint communicated with the middle carpal joint between the ulnar and intermediate carpal bones. The middle carpal and carpometacarpal joints always communicated between the fourth and fused second and third carpal bones. In a few specimens, additional sites of communication were identified at the palmar aspect of the fourth carpal bone and the fused second and third carpal bones.

Conclusions and Clinical Relevance

Individual anatomic variation of the carpus in cattle should be considered when diagnostic or treatment protocols are established. (Am J Vet Res 1997;58:7–10)

Free access
in American Journal of Veterinary Research

Abstract

Objective

To evaluate the frequency of communication between the lateral and medial femorotibial joints and the femoropatellar joint in cattle.

Design

1 of 3 injection sites was randomly assigned to each ox.

Animais

102 limbs were obtained from 55 fresh bovine cadavers presented for necropsy with problems unrelated to the stifle.

Procedure

The joints were injected with a mixture of latex and barium sulfate. Communication between 2 or more joints was determined by the presence of latex and contrast material in a joint adjacent to the injected joint by examining frozen sections and positive-contrast arthrography.

Results

Communication between the 3 joints was present in 58 (56.9%) limbs. The femoropatellar and the medial femorotibial joints always communicated. Thirteen of 38 (34.2%) specimens injected in the lateral femorotibial joint did not communicate with the 2 other joints. The femoropatellar joint communicated with the lateral and medial femorotibial joints on the distal abaxial aspect of the trochlear ridge.

Conclusion

Individual anatomic variation of the stifle in cattle should be considered when diagnostic or treatment protocols are established.

Clinical Relevance

The lateral femorotibial joint should be treated separately because it does not consistently communicate with the femoropatellar or medial femorotibial joint. (Am J Vet Res 1996;57:798–802)

Free access
in American Journal of Veterinary Research

Abstract

Objective

To evaluate the frequency and sites of communication between the lateral and medial synovial sacs of the metatarsophalangeal or metacarpophalangeal joints in cattle.

Animals

188 limbs were obtained from 55 fresh bovine cadavers submitted for necropsy because of problems unrelated to the fetlocks.

Procedure

In each ox, lateral or medial synovial sacs of each fetlock were randomly assigned. Joints were injected with a mixture of latex and barium sulfate. Communication between 2 joints was determined by presence of latex and contrast material in a joint adjacent to the injected joint by examining frozen sections and use of positive-contrast arthrography.

Results

Communication between the 2 synovial sacs existed in 186 of 188 (98.9%) specimens. The communication site between lateral and medial synovial sacs was located at the level of the proximal sesamoid bones, between the distal aspect of the interdigital band of the axial branch of the interosseus muscle and the metacarpal or metatarsal bone.

Conclusions and Clinical Relevance

Although communication between the lateral and medial synovial sacs did not exist in 2 specimens, the fetlock in cattle can be treated as 1 compartment. (Am J Vet Res 1997;58:710–712)

Free access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate clinical effects of immobilization followed by remobilization and exercise on the metacarpophalangeal joint (MPJ) in horses.

Animals—5 healthy horses.

Procedure—After lameness, radiographic, and force plate examinations to determine musculoskeletal health, 1 forelimb of each horse was immobilized in a fiberglass cast for 7 weeks, followed by cast removal and increasing amounts of exercise, beginning with hand-walking and ending with treadmill exercise. Lameness examination, arthrocentesis of both MPJ, single-emulsion radiographic examination, nuclear scintigraphic examination, ground-reaction force-plate analysis, and computed tomographic examination were done at various times during the study.

Results—All horses were lame in the immobilized MPJ after cast removal; lameness improved slightly with exercise. Force plate analysis revealed a significant difference in peak forces between immobilized and contralateral limbs 2 weeks after cast removal. Range of motion of the immobilized MPJ was significantly decreased, and joint circumference was significantly increased, compared with baseline values, during the exercise period. Osteopenia was subjectively detected in the immobilized limbs. Significant increase in the uptake of radionucleotide within bones of the immobilized MPJ after cast removal and at the end of the study were detected. Loss of mineral opacity, increased vascular channels in the subchondral bone, and thickening within the soft tissues of the immobilized MPJ were detected.

Conclusions and Clinical Relevance—Results indicate that 8 weeks of enforced exercise after 7 weeks of joint immobilization did not restore joint function or values for various joint measurements determined prior to immobilization. (Am J Vet Res 2002;63:282–288)

Full access
in American Journal of Veterinary Research

Summary

Effects of 2 drugs commonly used for chemical restraint of cattle were evaluated for their effect on laryngeal and pharyngeal anatomy, function, and response to stimuli. Eighteen adult Jersey cows, free of respiratory tract disease, were studied. Cows were assigned at random to 1 of 3 treatment groups. Endoscopic evaluations were performed before and at a predetermined time interval after administration of each drug. Responses to stimuli were evaluated by stimulating 7 preselected sites (epiglottis, left and right arytenoid cartilages, left and right vocal folds, and left and right dorsolateral pharyngeal walls) with a closed, transendoscopic biopsy probe. Xylazine HCl (0.05 mg/kg of body weight, IV) was administered to group-1 cows (n = 6), and endoscopy was repeated 5 minutes after administration of the drug. Xylazine (0.07 mg/kg, IV) was administered to group-2 cows (n = 6), and endoscopy was repeated 5 minutes after administration of the drug. Acepromazine maleate (0.035 mg/kg, IV) was administered to group-3 cows (n = 6), and endoscopy was repeated 10 minutes after administration of the drug. Responses to stimuli were scored as brisk (0), moderate (1), slow (2), and absent (3). Scores for responses to stimuli were compared, using the Wilcoxon signed-rank test for data within groups, and a general linear models procedure, using the Kruskal-Wallis test between groups. Interobserver agreement rates were generated for each group. A value of P< 0.05 was considered significant.

Xylazine profoundly changed laryngeal sensitivity and function at both dosages. The corniculate processes of the arytenoid cartilages were observed to be in a markedly adducted position after sedation.

Response to stimuli was significantly (P = 0.03) slower than normal after sedation, using both dosages. Displacement of the soft palate dorsal to the epiglottis was persistent in 50% of the cows after stimulation tests subsequent to sedation with xylazine. Acepromazine had a mild effect on laryngeal sensitivity and function. The corniculate processes of the arytenoid cartilages were observed in paramedian position after sedation. Acepromazine did not significantly affect responses to stimuli. Effects of sedation on responses to stimuli were not significantly different for groups 1 and 2. However, effects for group 3 were significantly different from those for groups 1 and 2 (P = 0.006 and 0.004, respectively).

Endoscopic evaluation of the proximal portion of the respiratory tract of cattle should be performed without sedation, when possible. If sedation is required to facilitate restraint for endoscopy, acepromazine maleate is recommended over xylazine on the basis of results of this study.

Free access
in American Journal of Veterinary Research

Summary

Endoscopy of the nasopharynx, pharynx, and larynx was performed in each of 25 adult Jersey cows, age and body weight of which ranged from 2 to 6 years and 300 to 365 kg, respectively. The endoscopic appearance of normal anatomic structures of the proximal portion of the airway were described. Observations specific to female dairy cattle were: the nasal septum, which tapered caudodorsally in the distal third of the nasal passage; the ability to observe both ethmoturbinates from the same viewing side; presence of a pharyngeal septum; the nasopharyngeal opening of the auditory tubes dorsolateral to the pharyngeal septum; and the appearance of the larynx — a triangular epiglottis with round borders and prominent corniculate process of the arytenoid cartilages. Tracheoscopy was performed in 13 cows. Of 11 cows for which the soft palate could be observed immediately after withdrawing the endoscope, 7 had dorsal displacement of the soft palate.

Free access
in American Journal of Veterinary Research

Abstract

Objectives

To purify and characterize pepsinogens in equine gastric mucosa.

Sample Population

Stomachs collected from 2 healthy horses at necropsy.

Procedure

After collection, stomachs were placed immediately in ice before storage at −48 C. After slow thawing, the mucosa was scraped off while the tissue was immersed in 0.1 M potassium phosphate (pH 7.4) at 4 C, then was homogenized. The filtered extract was subjected to anion-exchange chromatography. Fractions that were found to contain pepsin or pepsinogen were further chromatographed. Individual fractions were tested for pepsinogen or pepsin content by monitoring proteolytic activity at pH 2 and 3, respectively. Fractions from all columns were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to confirm molecular weight of pepsinogens and pepsin.

Results

Two pepsinogens and at least 1 pepsin were purified from equine gastric mucosa.

Conclusions

On the basis of molecular mass, equine gastric mucosa contains 2 pepsinogens.

Clinical Relevance

Results of this study will enable future development of an ELISA or radioimmunoassay for use in the diagnosis of equine gastric ulceration. (Am J Vet Res 1999;60:114–118)

Free access
in American Journal of Veterinary Research

Summary

The medical records of 20 horses admitted to the veterinary medical center with a diagnosis of brachygnathia over a 10-year period (1979 to 1989) were reviewed. The study included 18 foals and 2 adult horses. Males were affected 5.7 times more frequently than females. The amount of disparity between the mandible and premaxilla varied between 0.75 and 3 cm. Sixteen foals were treated surgically with the temporary application of premaxillary tension band devices. Thirteen of the 16 surgical cases were available for follow-up evaluation. All of the surgically treated animals had improved incisive occlusion, and 6 foals had complete resolution of the deformity with corrections ranging from 0.75 to 2.5 cm. Complete correction of the malocclusion was more likely to occur if foals were treated when they were ≤ 6 months old. The average amount of correction achieved in foals treated when they were ≤ 6 months old was 1.5 cm. (range, 0.75 to 2.5 cm). Foals treated, when they were 7 to 12 months old, had an average of 0.6 cm of reduction in the malocclusion (range, 0.25 to 1 cm). Implant failure was the most common complication and occurred in 9 of the 13 foals treated surgically.

Free access
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association