Myocardial perforation by a stick foreign body in a dog

Objective: To report a case of myocardial perforation by a stick foreign body in a dog. Case Summary: A 3‐year‐old castrated male Labrador Retriever was examined because of a puncture wound seen after an unsupervised run in the woods. The wound was suspected to penetrate into the thoracic cavity on the basis of physical exam and radiographs. Uniform ventricular premature complexes (VPCs) and junctional beats were noted on electrocardiogram (ECG). Thoracotomy was performed and a 6‐cm wooden stick was seen protruding from the right ventricle through the pericardium toward the sternum. The stick was removed while purse string sutures were tied around the resultant myocardial defect. Follow‐up echocardiography revealed intact intracardiac structures. VPCs were treated with lidocaine and resolved completely within 24 hours of presentation. New or Unique Information Provided: Thoracic trauma can result in myocardial injury; penetration into the myocardium represents a life‐threatening situation for the emergency clinician. Cardiac injury should be included in the differential diagnoses of penetrating thoracic foreign bodies.     

Pharmacokinetics of single-dose intravenous levetiracetam administration in normal dogs

Objective: To determine plasma pharmacokinetics of levetiracetam after a single intravenous dose (60 mg/kg) in normal dogs using a high‐performance liquid chromatography assay validated for canine plasma. Design: Pharmacokinetic study. Setting: A university‐based canine research facility. Animals: Six healthy adult dogs. Interventions: Intravenous drug administration, multiple blood sample procurement. Measurements and main results: There were no obvious adverse effects associated with the intravenous (IV) bolus administration of levetiracetam in any of the dogs. Plasma levetiracetam concentrations remained above or within the reported therapeutic range for humans (5–45 μg/mL) for all dogs, for all time periods evaluated. Mean and median (in parentheses) values for pharmacokinetic parameters included the following: maximum plasma concentration, 254 μg/mL (254 μg/mL); half‐life, 4.0 hours (4.0 hours); volume of distribution at steady state, 0.48 L/kg (0.48 L/kg); clearance, 1.4 mL/kg/min (1.5 mL/kg/min); and median residence time, 6.0 hours (6.0 hours). Conclusions: In normal dogs, a 60 mg/kg IV bolus dose of levetiracetam is well tolerated and achieves plasma drug concentrations within or above the therapeutic range reported for humans for at least 8 hours after administration. Based on the favorable pharmacokinetics and tolerability demonstrated for IV levetiracetam in this study, in addition to previously demonstrated efficacy of oral levetiracetam, IV levetiracetam may be a useful treatment option for emergency management of canine seizure activity.     

Ischemia–reperfusion injury pathophysiology, part I

Objective: To review the current scientific literature on ischemia–reperfusion (IR) injury in both human and veterinary medicine. To describe the normal antioxidant defense mechanisms, the pathophysiology of IR injury, and the role of neutrophils in IR injury. Data sources: Data sources include scientific reviews and original research publications in both human and veterinary medicine. Summary: IR injury is a complex pathophysiological process involving numerous pathways and body systems. Normal antioxidant defense mechanisms function to limit oxidative injury during times of health. Ischemia is the period that occurs before oxygenated blood is re‐introduced and the severity of injury has been shown to correlate with the magnitude and length of ischemia in dogs. During ischemia, there is a buildup of substances (i.e., xanthine oxidase, hypoxanthine, etc.) that, upon re‐introduction of oxygen, form reactive oxygen species (ROS). ROS, produced in large part upon reperfusion, can cause extensive damage to DNA, proteins, carbohydrates, and lipids. Although mammalian systems are endowed with abundant antioxidant defenses, the generation of large amounts of ROS can overwhelm these mechanisms leading to cell dysfunction and death. Neutrophils play a critical role in IR injury and may mediate the majority of mucosal and microvascular injury that occurs by releasing ROS and proteolytic enzymes. Although experimental studies have been carried out on cats, dogs, and horses there are few clinical studies on companion animals. Conclusions: The pathophysiology of IR injury is complex and involves damage by ROS to all biological membranes. Neutrophils play a major role in IR injury and initiate and propogate much of the damage. This article is intended as a review of the pathophysiology of IR injury.     

Hemorrhagic bile pleuritis and peritonitis secondary to traumatic common bile duct rupture,diaphragmatic tear,and rupture of the spleen in a dog

Objective– To describe the diagnosis and successful treatment of bile pleuritis and peritonitis secondary to traumatic rupture of the common bile duct and a diaphragmatic tear in a young dog. Case Summary– A 1‐year‐old German Shepherd dog was referred for evaluation of vomiting and icterus 4 days after being hit by a car. Thoracic radiographs, thoracic and abdominal ultrasonographic examinations, thoraco‐ and abdominocentesis, and positive contrast celiogram indicated hemorrhagic pleuritis and peritonitis, left dorsal diaphragmatic tear, and rupture and infarct of the spleen. Surgical exploration of the abdomen confirmed these findings in addition to a circumferential tear of the common bile duct, leading to a diagnosis of hemorrhagic bile pleuritis and peritonitis. Aerobic and anaerobic bacterial culture of the abdominal fluid yielded no growth. Surgical correction of the traumatic injuries was achieved via common bile duct anastomosis, cholecystojejunostomy, repair of the diaphragm, and splenectomy. The dog developed postoperative signs consistent with aspiration pneumonia but was successfully treated and discharged from the hospital. Clinical signs and laboratory abnormalities resolved and the dog was alive and healthy 8 months after discharge. New or Unique Information Provided– Bile pleuritis is rare in dogs and cats and is usually associated with penetrating, not blunt, abdominal trauma. Multiple organ injury in cases of traumatic bile duct rupture is uncommon; in this dog, rupture of the common bile duct was accompanied by rupture of the diaphragm and spleen.