Equine Post-anesthetic Lameness A Retrospective Study

The incidence of post-anesthetic lameness in 655 horses undergoing 733 anesthetic episodes over a 3 year period was 6.4%. Nineteen factors previously reported or proposed to play a role in the development of post-anesthetic lameness were evaluated statistically. Only hypotension and the duration of the anesthetic period were significant factors.     

DOPPLER MEASUREMENT OF SPLANCHNIC BLOOD FLOW DURING DIGESTION IN UNSEDATED NORMAL DOGS

The purpose of this study was to measure splanchnic blood flow during digestion in unsedated dogs by using duplex Doppler sonography. The study population consisted of 12 healthy dogs. Blood flow in the cranial mesenteric artery, the celiac artery, and the aorta was measured before a test meal and at 20, 60, and 90 minutes after eating. The following measurements were made or calculated: vessel diameter, peak systolic velocity, end diastolic velocity, mean velocity, resistive index, pulsatility index, and flow volume. There was a significant postprandial decrease in the resistive and pulsatility indices in both the cranial mesenteric (preprandial RI = 0.867, postprandial RI = 0.796, preprandial PI = 3.033, postprandial PI = 2.173) and the celiac (preprandial RI = 0.854, postprandial RI = 0.769, preprandial PI = 2.639, postprandial PI = 1.930) arteries. In both vessels the end diastolic velocity, the mean velocity, and the flow volume increased significantly postprandially. These changes occurred significantly earlier in the celiac artery than in the cranial mesenteric artery. The findings most likely correspond to postprandial splanchnic vasodilation. Doppler ultrasound provide a good methode of detecting changes in postprandial splanchnic blood flow in the dog.     

Radiographic Evaluation of the Anconeal Process in Skeletally Immature Dogs

Objective: To determine if a secondary center of ossification (SCO) of the anconeal process is present in skeletally immature dogs that do not develop an ununited anconeal process (UAP). Study Design: Case series. Animals: Dogs 77–154 days of age with conditions other than developmental disease of the elbow (n=78 dogs; total elbows=100). Methods: Mediolateral radiographic projections of the elbow were reviewed for presence or absence of a SCO of the anconeal process. Results: A SCO was radiographically evident in 16% of elbows from breeds that have been reported to be affected by UAP. The appearance of the SCO was different to an UAP fragment. None of the elbows with SCO of the anconeal process developed UAP. A SCO was not present in any small breed dogs. Conclusions: A SCO of the anconeal process is uncommon in medium and large breed dogs and the presence of a SCO does not indicate that UAP will develop. Clinical Relevance: Because radiographic diagnosis of a SCO of the anconeal process and UAP lesions have distinct appearances, an earlier diagnosis of UAP is possible.     

Negative Pressure Pulmonary Edema as a Post-Anesthetic Complication Associated With Upper Airway Obstruction in a Horse

An 8-year-old Trakehner mare developed fulminant pulmonary edema following suspected upper airway obstruction 50 minutes into an otherwise unremarkable anesthetic recovery after surgery for left cricoarytenoideus dorsalis muscle reinnervation and ventriculocordectomy. Establishing a patent airway by orotracheal reintubation and cardiopulmonary resuscitation attempts were unsuccessful. Gross, histological, and electron microscopic postmortem examination showed severe hemorrhagic pulmonary edema. Laryngeal swelling or hemorrhage were not evident, suggesting laryngospasm or functional airway collapse associated with the underlying left laryngeal paralysis, as a cause of the upper airway obstruction. Negative pressure pulmonary edema is rarely reported in the veterinary literature as a postanesthetic complication.     

Traumatic Flexor Tendon Injuries in 27 Cattle

Information for all cattle with a diagnosis of tendon injury entered into the Veterinary Medical Data Base (VMDB) was retrieved and selected medical records reviewed. The proportional morbidity rate for tendon disruption was 0.89 cattle/1,000 cattle admissions and 95 of 99 cattle survived. Female and dairy cattle had a greater risk of tendon disruption than male or beef cattle, respectively. Also, cattle 6 months to 7 years old had a greater risk than cattle younger than 6 months old. Complete medical records were examined for 27 cattle. Affected cattle were 2.5 ± 1.8 years old and weighed 593.6 ± 315.6 kg. Injuries were most commonly caused by accidents involving farm machinery (72%). Unilateral superficial digital flexor tendon injury occurred in 8 cattle (30%); multiple tendon injury occurred in the other 19 cattle (70%). A single limb was involved in 25 cattle, a rear limb was involved in 24 cattle, and an open wound was associated with the injury in 26 cattle. Wounds were identified most commonly at the mid (13 cattle) and proximal metatarsus (4 cattle). Treatment of tendon disruption included tenorrhaphy and casting (9 cattle), external coaptation, alone, (14 cattle), stall confinement, alone, (1 cow), and euthanasia or salvage (3 cattle). External coaptation was maintained for 74.4 ± 34.3 days, and total confinement period was 88.3 ± 59.5 days. Short-term complications included severe tendon laxity (one cow) and fatal septic peritonitis (one bull). Twenty-two of 24 cattle treated for tendon disruption survived. Follow-up information was available for 16 cattle; 14 cattle (87%) returned to productivity and 11 of 15 cattle with long-term follow-up (73%) were considered productive. Long-term complications included persistent lameness (56%) and persistent hyperextension of the digits (19%).     

Femoral Head Osteotomy in Horses and Cattle

Femoral head ostectomy was performed in six horses, three ponies, and four cattle for treatment of fractures of the femoral capital physis, coxofemoral luxation, fractured acetabulum, or severe degenerative joint disease. The procedures were performed via a cranial approach that did not involve osteotomy of the greater trochanter. A dorsal approach for femoral head ostectomy via osteotomy of the greater trochanter was evaluated in three healthy adult ponies. Three animals (2 ponies, 1 calf) were euthanatized within a month and one horse was euthanatized at year 2 due to postoperative complications. Nine animals were discharged to owners and six of them fulfilled their intended functions of breeding, milking, and being kept as companions. One horse was lost to follow-up and two horses died of causes unrelated to the surgery. All surviving animals had a residual lameness that was described by owners as mild to moderate. None of the horses were used as riding animals. The mean age and weight of 10 animals that regained weight-bearing locomotion was 3.1 months and 84 kg; for three unsuccessful cases it was 34 months and 174 kg. We concluded that femoral head ostectomy was a viable salvage procedure for large animals with capital femoral physeal fracture, chronic coxofemoral luxation, or acetabular fracture. Surgical prognosis appeared to be favorable in young cattle and fair in young horses or ponies weighing less than 100 kg. Osteotomy of the greater trochanter resulted in superior exposure of the intact coxofemoral joint and allowed easier, less traumatic surgical luxation of the joint to facilitate femoral head ostectomy.