Evaluation of the use of intranasal atipamezole to reverse the sedative effects of xylazine in dogs.

OBJECTIVE: To assess the ability of intranasal atipamezole to reverse sedative effects of xylazine in dogs. DESIGN: Prospective proof-of-concept study. SETTING: University research laboratory. ANIMAL: Six healthy, staff-owned dogs. INTERVENTIONS: Dogs were sedated with 1.1 mg/kg of xylazine intravenously. The sedation score of each dog was recorded every 5 minutes until they achieved a sedation score of >13/21 for 3 readings. Once achieved, 0.3 mg/kg of atipamezole was administered intranasally using a mucosal atomization device. Sedation scores continued to be recorded every 5 minutes until successful reversal was achieved (<4/21). MEASUREMENTS AND MAIN RESULTS: Average times to standing and normal wakefulness after administration of intranasal atipamezole were 6 minutes, 30 seconds and 7 minutes, 20 seconds, respectively. CONCLUSIONS: Intranasal atipamezole successfully reversed the sedation effects of xylazine. The findings of this study provide justification for future controlled prospective studies into the potential use of intranasal atipamezole in a variety of settings including exposure to xylazine in operational canines as well as bioavailability studies for optimal dosing.

Respiratory distress in small animals: Pathophysiology and clinical approach.

BACKGROUND: Respiratory distress is a common reason for animals to present to the emergency room. An understanding of respiratory physiology is helpful to facilitate accurate localization of the patient's source of respiratory distress. This knowledge will aid implementation of more appropriate therapies. PHYSIOLOGY/PATHOPHYSIOLOGY SUMMARY: Respiratory distress can occur secondary to lesions at any location of the respiratory system. Diseases affecting different portions of the respiratory track (eg, upper airway, lower airways, parenchymal, or the pleural space) lead to distinguishing clinical signs as the patient's respiratory physiology is affected differently. CLINICAL IMPORTANCE: Respiratory distress can be life-threatening if it is not recognized and addressed in a timely matter. Prompt recognition of unique clinical signs may aid the clinician's ability to localize the disease process and implement targeted therapies. KEY POINTS: Diseases affecting different portions of the respiratory track (eg, upper airway, lower airways, parenchymal, or the pleural space) lead to distinguishing clinical signs as the patient's respiratory physiology is affected differently. Recognition of respiratory patterns allows clinicians to correlate clinical signs to the most likely affected region of the respiratory tract. Ideally, alveolar gas (ventilation) and blood flow (perfusion) are equally matched. However, even a normal lung does not have ideal ventilation/perfusion (V/Q) matching. There are a variety of conditions that lead to decreased lung compliance, from pathology of the pulmonary parenchyma (eg, pulmonary edema, alveolar infiltrates such as pneumonia or contusions, or pulmonary fibrosis), pleural space disease (eg, pneumothorax or pleural effusion), abdominal distension, or the inability to expand the rib cage (eg, pain, thoracic wall injury, constricting thoracic bandages). The five classic causes of hypoxemia include low FiO2 , diffusion impairment, hypoventilation, shunt, and V/Q mismatch. Being prepared to rapidly induce anesthesia and intubate dyspneic animals with upper airway obstruction may be required alleviate the risk of respiratory arrest.

Performing an upper airway examination in dogs.

BACKGROUND: Increased airway resistance due to upper airway obstruction is a common cause of respiratory distress. An upper airway exam is an inexpensive and quick diagnostic procedure that can serve to localize a disease process, confirm a definitive diagnosis, and offer therapeutic benefits. DESCRIPTION: The upper airway examination consists of an external evaluation of the head and neck as well as a sedated examination of the oral cavity, the pharyngeal cavity, larynx, and nasal passages. SUMMARY: An upper airway examination should be performed in patients with increased inspiratory effort or increased upper respiratory noise (eg, stertor or stridor). A complete, sedated upper airway examination should be considered for patients with clinical signs of upper airway disease for which a cause is not obvious from the physical examination. KEY POINTS: Indications for an upper airway examination include sneezing, nasal discharge or epistaxis, reduced or absent nasal airflow, change in phonation, inspiratory difficulty, and audible respiratory sounds. Upper airway examination helps localize pathological processes and allows the clinician to confirm or exclude several differential diagnoses. Pre-oxygenation of the patient for 3-5 minutes prior to sedation will help increase the amount of time available before hypoxemia occurs, should complications arise. Upon completion of the upper airway examination, it is important to monitor the patient carefully and ensure a safe recovery. Careful planning to ensure the availability of necessary equipment and preparation of the team to react during and after the airway examination will minimize the risks of examination to patients with upper airway disease.

Successful non-invasive management of iatrogenic splenic injury associated with a peritoneal dialysis catheter in a dog.

An 11-month-old, intact female Labrador retriever was presented with oligoanuric acute kidney injury and overhydration after grape ingestion. Percutaneous placement of a 12G × 30 cm Mila chest tube was done as an emergency temporary peritoneal dialysis catheter. Although no serious immediate complications were noted, an iatrogenic splenic injury had occurred. The catheter was used for peritoneal dialysis and urine output and hydration status improved over time. When the dialysis catheter was removed 3 d later, a synthetic hemostatic matrix, Surgiflo, was deposited through the catheter. No complications were noted. The dog recovered uneventfully and was doing well with normal kidney function. Key clinical message: To the authors' knowledge, this report represents the first description of non-invasive management of iatrogenic splenic injury secondary to percutaneous peritoneal dialysis catheter placement in a dog.

Prise en charge non invasive réussie de lésions spléniques iatrogènes associées à un cathéter de dialyse péritonéale chez un chien. Une femelle Labrador retriever intacte âgée de 11 mois a été présentée avec une lésion rénale aiguë oligoanurique et une surhydratation après ingestion de raisin. La mise en place percutanée d'un drain thoracique Mila de 12G × 30 cm a été réalisée en tant que cathéter de dialyse péritonéale temporaire d'urgence. Bien qu'aucune complication immédiate grave n'ait été notée, une lésion splénique iatrogène s'était produite. Le cathéter a été utilisé pour la dialyse péritonéale et le débit urinaire et l'état d'hydratation se sont améliorés au fil du temps. Lorsque le cathéter de dialyse a été retiré 3 jours plus tard, une matrice hémostatique synthétique Surgiflo a été déposée via le cathéter. Aucune complication n'a été notée. Le chien a récupéré sans incident et se portait bien avec une fonction rénale normale.Message clinique clé:À la connaissance des auteurs, ce rapport représente la première description de la gestion non invasive de lésions spléniques iatrogènes secondaires à la pose d'un cathéter de dialyse péritonéale percutanée chez un chien.(Traduit par Dr Serge Messier).

Paroxysmal atrial fibrillation in a dog that was presented for neck wounds.

A 12-year-old spayed female German shorthaired pointer dog sustained extensive bite wounds around the neck. At presentation, atrial fibrillation was identified with a rapid ventricular response rate of 300 beats per minute (bpm). The ventricular response rate rapidly decreased to 130 bpm following administration of hydromorphone and oxygen. Based on the rate, antiarrhythmic therapy was not initiated. The heart rhythm converted back to sinus rhythm by the time of the first recheck evaluation 2 days later, and the dog remained in sinus rhythm at all subsequent evaluations. With the resolution of the arrhythmia, paroxysmal atrial fibrillation was suspected. The underlying etiology of the arrhythmia was not determined; however, imbalances in autonomic tone associated with trauma and/or direct trauma to the heart were hypothesized. Key clinical message: This report indicates a possible role of imbalances in autonomic tone due to trauma in the development of paroxysmal atrial fibrillation and suggests that it should be a differential diagnostic consideration in patients with atrial fibrillation following trauma. Primary treatment of atrial fibrillation may not be needed in these cases if the ventricular response rate is not rapid, or if there is spontaneous conversion to sinus rhythm.

Fibrillation atriale paroxysmique chez un chien présenté avec des blessures au cou. Une femelle braque allemand stérilisée âgée de 12 ans a subi des blessures extensives de morsure autour du cou. À la présentation, une fibrillation atriale fut identifiée avec un rythme de réponse ventriculaire rapide de 300 battements par minute (bpm). Le rythme de réponse ventriculaire diminua à 130 bpm à la suite de l'administration d'hydromorphone et d'oxygène. Sur la base du rythme aucune thérapie antiarythmique ne fut initiée. Le rythme cardiaque était retourné au rythme sinusal lors de la première réévaluation 2 jours plus tard, et le chien est demeuré en rythme sinusal à toutes les évaluations subséquentes. Avec la résolution de l'arythmie, une fibrillation atriale paroxysmique fut suspectée. L'étiologie sous-jacente de l'arythmie ne fut pas déterminée; toutefois, des débalancements du tonus autonome associés avec un trauma et/ou un trauma directement au coeur furent émis comme hypothèses.Message clinique clé:Ce rapport mentionne un rôle possible de débalancements du tonus autonome dus à un trauma lors du développement de fibrillation atriale paroxysmique et suggère que cela devrait être un diagnostic différentiel à considérer chez les patients avec fibrillation atriale à la suite d'un trauma. Le traitement initial de la fibrillation atriale pourrait ne pas être nécessaire dans ces cas si le rythme de la réponse ventriculaire n'est pas rapide ou s'il y a une conversion spontanée au rythme sinusal.(Traduit par Dr Serge Messier).

Concurrent renal amyloidosis and thymoma resulting in a fatal ventricular thrombus in a dog.

Thymoma-associated nephropathies have been reported in people but not in dogs. In this report, we describe a dog with thymoma and concurrent renal amyloidosis. A 7-year-old castrated male Weimaraner was presented for progressive anorexia, lethargy, and tachypnea. The dog was diagnosed with azotemia, marked proteinuria, and a thymoma that was surgically removed. Postoperatively, the dog developed a large left ventricular thrombus and was euthanized. Necropsy confirmed the presence of a left ventricular thrombus and histopathology revealed renal amyloidosis. We speculate that the renal amyloidosis occurred secondary to the thymoma, with amyloidosis in turn leading to nephrotic syndrome, hypercoagulability, and ventricular thrombosis. This case illustrates the potential for thymoma-associated nephropathies to occur in dogs and that dogs suspected to have thymoma should have a urinalysis and urine protein creatinine ratio performed as part of the pre-surgical database.