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To describe the use of skin-fold advancement flaps for covering large skin defects in dogs and cats.Clinical study.Eight client-owned animals: 6 dogs and 2 cats.Six dogs and 2 cats underwent reconstruction of soft-tissue wounds resulting from traumatic, neoplastic, or infectious lesions. Skin-fold flaps were created by division of the medial and lateral attachment to the proximal limb or the dorsal and ventral attachment to the trunk, enabling closure of adjacent defects on the trunk or proximal limb, respectively.Skin-fold flaps proved effective for closing defects in all animals. Necrosis of a portion of the flap occurred in 2 dogs due to technical errors, but the resultant defects remained amenable to primary closure. All wounds ultimately healed primarily, without major complications.The skin-fold advancement flap is a versatile technique that lends itself to use in a variety of locations, depending on which attachments are divided. The clinical results are comparable with those reported for axial pattern and subdermal plexus flaps.

To determine the prevalence of intraoperative hemorrhage in a consecutive series of dogs undergoing patent ductus arteriosus (PDA) ligation at a veterinary teaching hospital, and to describe strategies to reduce the risk of ductus perforation and deal with hemorrhage when it occurs.Retrospective clinical study.Sixty-four dogs.The records of all dogs undergoing PDA ligation at the University Veterinary Center, Sydney between May 1989 and February 1998 were reviewed and the prevalence and nature of complications identified.Serious hemorrhage occurred in 4 of 64 dogs (6.25 %) that underwent PDA ligation. In all cases, hemorrhage resulted from perforation of the craniomedial aspect of the ductus while attempting to expose the tips of the dissecting forceps. Hemorrhage was controlled in 3 dogs by clamping the main pulmonary artery, digital compression of the descending aorta, and completion of ductus ligation during an approximately 5-minute period of circulatory arrest. The remaining dog exsanguinated during an unsuccessful attempt to locate, clamp, and ligate the bleeding point. The mortality rate for PDA ligation was 1 of 64 dogs (1.6 %).The technique described in this report permits simple ligation of a range of different ductus morphologies in dogs of varying breeds, weights, and ages. In the event of serious hemorrhage, prompt ventricular outflow occlusion and ductus ligation followed by rapid whole blood transfusion is life saving in most cases.

Little is known about myocardial cryoablation at normothermia and the effect of cryoprobe head size and duration of freeze on final lesion volume. In the present study, cryolesions were created with a carbon dioxide cryoprobe with two head sizes (cylindrical head 6 mm diameter and large circular head 18 mm diameter) in the normothermic canine heart during cardiopulmonary bypass. The duration of freeze (exposure time) varied from 2 to 3 or 4 minutes and the effects on immediate and chronic lesion size were evaluated. Lesions produced by epicardial exposures were compared with intramyocardial lesions created by placing the cylindrical head in a 6 mm stab incision. A minimum of four lesions were created in each dog. Lesion size was evaluated at 0 minutes (iceball) and 24 hours (two dogs), 7 days (one dog), or 4 weeks (five dogs). Iceball diameter was approximately 5 mm larger than chronic lesion diameter regardless of bead size or exposure time. Prolongation of exposure time from 2 to 3 minutes resulted in significant increases in the volume of epicardial lesions (cylindrical head: 280 ± 100 mm3versus 740 ± 200 mm3, p = 0.001; circular head: 1200 ± 100 mm3versus 2300 ± 500 mm3, p = 0.007) because of increases in diameter and depth. No further increase in lesion size was observed when exposure time was prolonged from 3 to 4 minutes. A 3-minute intramyocardial exposure with the cylindrical head placed in a stab incision enabled production of transmural lesions (16 ± 2 mm deep). Two and 4 weeks postoperatively, dogs underwent electrophysiologic study from the right and left ventricular apices. No animals had inducible ventricular tachycardia despite the heterogeneous configuration of the multiple cryolesions. In conclusion, it is possible to produce rapid and predictable ablation of clinically useful volumes of myocardium during normothermic bypass with the use of currently available equipment. Under these conditions, an exposure time of 3 minutes is optimal for a liquid carbon dioxide cryoprobe. Cryolesions should be overlapped by at least 2.5 mm to produce continuous areas of ablation. Multiple cryolesions do not form a chronic substrate for ventricular tachycardia.

The inducibility and reproducibility of ventricular tachycardia were evaluated in 97 dogs after myocardial infarction produced by single stage coronary artery ligation. Arrhythmia induction was performed with use of an endocardial electrode catheter positioned at the right ventricular apex before each study. An aggressive protocol of programmed stimulation was used, employing up to seven extrastimuli and three attempts at arrhythmia induction in each study. Electrophysiologic study was performed in individual dogs at the following times after infarction: 1) 7.7 ± 0.3 and 15 ± 0.2 days (34 consecutive dogs); 2) 14 ± 0.6 and 26 ± 1.7 days (24 selected dogs); 3) 19 ± 2 and 43 ± 3 days (12 selected dogs); 4) 36 ± 2 and 60 ± 6 days (8 selected dogs); and 5) 59 ± 12 and 130 ± 10 days (3 selected dogs).

To determine the most effective and reliable method for progressive attenuation of single extrahepatic portosystemic shunts in dogs.The effects of the four treatments on femoral vein diameter and histology were compared with controls.Fourteen healthy adult dogs.Twenty-eight canine femoral veins were subjected to sham surgery (4), partial attenuation using silk (5), cellophane banding (6), ameroid constrictor implantation (5), and intravascular thrombogenic coils (8). Changes in vein diameter were evaluated at weekly intervals using venography. After 6 weeks, the dogs were humanely euthanatized, and histopathology was performed on the femoral veins.Only cellophane and ameroid constrictors produced progressive and permanent vein attenuation. Ameroid constrictors produced complete occlusion within 14 days in four of five veins and by 21 days in the fifth vein. Cellophane banding produced slow progressive (but not complete) attenuation in five of six veins. Complete occlusion was demonstrated in four of eight veins after thrombogenic coil implantation; however, recanalization occurred in all but one dog. Perivascular silk did not produce significant progressive attenuation.Ameroid constrictors produced rapid occlusion of femoral veins. Cellophane banding resulted in slower attenuation. Thrombogenic coils produced attenuation, but this was not sustained in many cases. Silk did not promote ongoing attenuation.Both ameroid constrictor implantation and cellophane banding show promise for progressive attenuation of single extrahepatic portosystemic shunts in dogs. Because rapid occlusion was seen with ameroid constrictors, however, cellophane banding maybe a safer technique in animals with increased hepatic vascular resistance. Further evaluation of both treatments in clinical cases is warranted.