摘要:

Experimental total ear canal ablation with lateral tympanic bulla osteotomy (TECA‐LBO) was performed in 13 normal dogs to evaluate healing and retention of brain stem auditory evoked potentials (BSAEP) after surgery. Healing was evaluated by gross and microscopic examination of the surgery sites after 1 (n = 2), 4 (n = 8), 5 (n = 1), and 6 (n = 1) weeks. One dog was eliminated from the study. Brain stem auditory evoked potentials were measured using an air‐conducted sound stimulus before and after surgery and before killing. Two dogs had nearly complete obliteration of the tympanic cavity by immature fibrous connective tissue. Eight dogs responded to surgery by either complete or partial re‐formation of the tympanic cavity. Retention of the tympanic membrane in three dogs promoted re‐formation of the tympanic cavity and blind epithelialized pockets in the surgery site with accumulation of keratinized debris. Granulation tissue formation and extensive proliferation of new bone on the internal surface of the tympanic bulla was seen in 10 dogs. Proliferative bone completely obliterated the tympanic cavity in two of these dogs. Eleven of 13 dogs had no detectable air‐conducted BSAEP after surgery. There was no change in BSAEP measurements before killing compared with postoperative measurements in any dog. Two dogs with retained tympanic membranes had measurable BSAEP after surgery. This study shows that healing after TECA‐LBO may be highly variable. Retention of the tympanic membrane and small osteotomies appeared to promote reformation of tympanic cavities and prevent ingrowth of granulation tissue. New bone proliferation was frequently observed in response to curettage of the epithelium lining the tympanic bulla. Hearing, as determined by BSAEP measurements, was lost except when the tympanic membrane and ossicles were retained. Retained tympanic membranes promoted accumulation of keratinized cellular debris that could become a nidus for infection or late abscessation in some dogs. These results indicate that resection of as much of the lateral and ventral tympanic bulla as possible and removal of the tympanic membrane may provide consistently improved results aft

ISSN:0161-3499    

DOI:10.1111/j.1532-950X.1995.tb01285.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Ventral tympanic bulla osteotomy was performed in 13 normal dogs to evaluate healing and retention of brain stem auditory evoked potentials (BSAEP). Healing was evaluated by gross and microscopic examination of the middle ears after 1 (n = 2), 4 (n = 8), 5 (n = 1), and 6 (n = 1) weeks. One dog was eliminated from the study. Brain stem auditory evoked potentials were measured using an air‐conducted sound stimulus before and after surgery and before killing. Nine of 12 dogs re‐formed the tympanic bulla by formation of fibrous connective tissue lined with cuboidal epithelium in the osteotomy site. Four of the nine dogs had a reduced tympanic bulla volume (estimated 20% to 40% volume reduction) caused by soft tissue ingrowth through the osteotomy. Nine of 12 dogs had proliferation of subperiosteal new bone from the inner surface of the tympanic bulla that varied in severity. Three of these nine dogs had nearly complete obliteration of the tympanic cavity by proliferating subperiosteal new bone. Eight dogs had nodules of granulation tissue containing new bone and mineralization diffusely distributed on the surfaces of the middle ear. The measured BSAEP sensitivity before killing was equivalent to preoperative levels in 11 dogs. The remaining dog had no change in auditory sensitivity after surgery but had a markedly reduced BSAEP detection threshold before killing. This appeared to be attributable to mechanical impingement on the ossicles and tympanic membrane by proliferating bone within the tympanic cavity. This study showed that after ventral tympanic bulla osteotomy the tympanic bulla rapidly re‐forms with no deleterious effect on hearing in most dogs treated. However, the internal surfaces of the middle ear appear to be sensitive to surgical trauma, and extensive new bone proliferation is easily induced. This response may be extreme, resulting in middle ear obliteration and reduced auditory sensit

ISSN:0161-3499    

DOI:10.1111/j.1532-950X.1995.tb01286.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Long‐Term Fate and Effects of Exercise on Sternal Cartilage Autografts Used for Repair of Large Osteochondral Defects in Horses by Howard RD, Mcllwraith CW, Trotter GW, Powers BE, McFadden PR, Harwood FL, Amiel

ISSN:0161-3499    

DOI:10.1111/j.1532-950X.1995.tb01287.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Dual‐energy x‐ray absorptiometry was used to measure bone mineral density of four regions in healed femora of nine dogs after fracture fixation with a leg‐lengthening plate. Six to 85 months (mean, 46 months) after surgery, the bone mineral density of healed femora was not significantly different from the contralateral uninjured femora (P>.05; power = 0.8 at Δ= 15%). Radio‐lucencies around the proximal screws, apparently associated with screw loosening, were seen on radiographic views of the healed femora of three dogs. In one of these dogs, one screw in the proximal metaphysis had broken. Force‐plate analysis of gait was also performed on dogs at the time of bone mineral density measurement. Peak vertical force was decreased in the pelvic limb with the healed fracture compared with the contralateral unoperated limb (P<0.05). Clinically apparent lameness in three dogs did not appear to be associated with altered bone mineral density and may have been caused by hip osteoarthritis, a nondisplaced hairline diaphyseal fracture, and screw loosening in conjunction with extensive post‐traumatic soft t

ISSN:0161-3499    

DOI:10.1111/j.1532-950X.1995.tb01288.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Twenty‐six female beagles were used to evaluate the effects of intravenous and long‐term subcutaneous administration of cephalothin, cefazolin, and cefmetazole on platelet function and the coagulation cascade. Platelet aggregation in response to an adenosine diphosphate (ADP) agonist, bleeding time, platelet count, platelet size, prothrombin time (PT), and activated partial thromboplastin times (aPTT) were evaluated before and 90 minutes after two intravenous doses (22 mg/kg) of cephalothin, cefazolin, and cefmetazole given at 90‐minute intervals. Dogs given saline injections were used as controls. Platelet count, platelet size, PT, and aPTT were evaluated after 7 days of subcutaneous administration of saline, cefazolin, and cefmetazole (22 mg/kg every 8 hours). A significant decrease in platelet aggregation in response to ADP was detected 90 minutes after intravenous administration of cephalothin. Bleeding time was increased significantly 90 minutes after intravenous administration of cefmetazole. Platelet size was decreased significantly 24 hours after onset of the study in all animals, including controls. No significant changes in platelet count, platelet size, PT, or aPTT were detected after 7 days of subcutaneous administration. Cefazolin had no adverse effects on platelet aggregation in response to ADP, bleeding time, platelet count, platelet size, PT, or aPTT. Therefore, cefazolin should be considered as a perioperative antibiotic in dogs with conditions predisposing to hemostatic complica

ISSN:0161-3499    

DOI:10.1111/j.1532-950X.1995.tb01289.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Five Holstein calves and two foals with omphalophlebitis were treated by surgical marsupialization of the umbilical vein remnant because complete resection of the infected tract was not possible. The infected umbilical stalk was resected, and the umbilical vein remnant was marsupialized in a one‐stage procedure by suturing it into the abdominal wall lateral to the abdominal incision. Antimicrobial drugs were administered, and the marsupialized tract was irrigated until closure by second intention healing. Cellulitis associated with the marsupialization site occurred in two calves but resolved with antimicrobial therapy. Owners reported that, 9 to 60 months after surgery, there were no complications associated with the procedur

ISSN:0161-3499    

DOI:10.1111/j.1532-950X.1995.tb01290.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

W. ROBERT COOK, BVSc, FRCVSThe effect of left recurrent laryngeal neuropathy (LRLN) on the metabolic cost of locomotion (MCL) and peak aerobic power (V̇O2peak) was evaluated in four trained Thoroughbred racehorses. Oxygen consumption (V̇O2), carbon dioxide production (V̇CO2), venous lactate concentrations (LAC), and heart rate (HR) were measured during a treadmill exercise test (TET). Each horse performed the exercise test four times, alternating between normal upper airway function and reversibly induced LRLN. Subcutaneous infusion of 2% mepivicaine, a local anesthetic, into the region where the left recurrent laryngeal nerve passes caudal to the cricoid cartilage was used to induce LRLN. The induction of LRLN did not alter the relationship between V̇O2and treadmill speed at exercise intensities where V̇O2was less than V̇O2peak (<9 m/sec). However, a 15.3% reduction in V̇O2peak (Normal = 165.3 ± 3.4, LRLN = 140.0 ± 3.2 mL/kg/min ± SE,P<.001) occurred at higher treadmill speeds in horses with induced LRLN. A significant group (Normal v LRLN) by treadmill speed effect was found for LAC and R only at treadmill speeds where V̇O2=V̇O2peak. Peak lactate (LACpeak) did not change after the induction of LRLN. The relationship between HR and treadmill speed increased in horses with induced LRLN at exercise intensities where V̇O2

ISSN:0161-3499    

DOI:10.1111/j.1532-950X.1995.tb01291.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Six forelimb specimens from three adult horses had the fetlock joint fused by application of a dorsal plate and by a screw placed in lag fashion through the metacarpus to each proximal sesamoid bone. Five specimens were instrumented on the central dorsal surface of the plate with a single rosette strain gage, and the plate of the sixth specimen was instrumented with four longitudinally oriented single‐axis strain gages. The specimens were loaded axially in compression to 4,000 N in a cast (test 1), in a cast with a heel block (test 2), and uncast (test 3). The principal angle of strain in all specimens, in all tests, closely approximated the vertical axis at loads1,000 N than the cast specimens (P3,000 N, the principal angle in test 3 closely approximated the horizontal axis, indicating a change from tension to compression on the dorsal surface of the plate, whereas the principal angle of the cast specimens was unchanged. Specimens in a cast (tests 1 and 2) suffered less surface deformation than did uncast specimens (test 3). Therefore, the cast changed the direction and extent of bending at the point of fixation, and thereby decreased the deformation of the plate. This effect would lead to greater fatigue life of the implant in the cast specimens compared with the uncast specimen

ISSN:0161-3499    

DOI:10.1111/j.1532-950X.1995.tb01292.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Six fiberglass casting tapes were evaluated in bending, using an unstable fracture model. Cylindrical casts were constructed and evaluated in bending at 2, 3, and 24 hours after application. Scotchcast Plus (3M, St. Paul, MN), Vet Cast II (3M), and Zim‐Flex (Zimmer, Warsaw, IN) were significantly stronger than other materials at 2 hours; however, by 24 hours, casts constructed from Delta‐Lite (Johnson&Johnson Products, New Brunswick, NJ) were strongest. Delta‐Lite Conformable casts were significantly weaker at all

ISSN:0161-3499    

DOI:10.1111/j.1532-950X.1995.tb01293.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Ruptured bladder was diagnosed in a 90‐day‐old Thoroughbred colt that had suffered a open, comminuted tibial fracture 2 days earlier. The bladder rupture was identified by laparoscopic examination of the abdomen and was repaired using a laparoscopic stapling instrument. This technique provided good visualization and allowed repair of the rupture with minimal intervention. Ten months after surgery, the foal was admitted to a referral surgical practice because of colic and stanguria. A urinary calculus was removed from the penile urethra by urethrotomy. Laparoscopic repair of the bladder with nonabsorbable staples may be contraindicated because of possible urolith format

ISSN:0161-3499    

DOI:10.1111/j.1532-950X.1995.tb01294.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY