MAGNETIC RESONANCE IMAGING FINDINGS ASSOCIATED WITH LATERAL CEREBRAL VENTRICULOMEGALY IN ENGLISH BULLDOGS

Multiple congenital or developmental anomalies associated with the central nervous system have been reported in English Bulldogs. The purpose of this retrospective study was to identify and describe the prevalence and MRI characteristics of these anomalies and their association with presence and degree of cerebral ventriculomegaly. Magnetic resonance imaging studies of 50 English Bulldogs were evaluated. Forty‐eight dogs had some degree of cerebral ventriculomegaly, 27 of which had an otherwise normal brain. Presence of lateral ventriculomegaly was not significantly associated with presence of another intracranial lesion. Appearance of the septum pellucidum was variable, ranging from intact to incomplete or completely absent. The corpus callosum was subjectively thinned in all but three dogs, two of which had normal lateral ventricles. Fusion of the rostral colliculi was not found in any dog. A persistent craniopharyngeal canal was identified in one dog. Aqueductal stenosis caused by fusion of the rostral colliculi was not identified in any dog. Findings indicated that cerebral ventriculomegaly is a common finding in English Bulldogs with or without other intracranial lesions, aqueductal stenosis caused by fusion of the rostral colliculi is unlikely to be a common etiology leading to obstructive hydrocephalus, and a large craniopharyngeal canal is a rare finding that has unknown clinical significance at this time.     

Third degree atrioventricular block following non-penetrating chest trauma in a dog

A two-year-old mixed breed dog was referred to the University of Florida Veterinary Medical Teaching Hospital for the management of post traumatic ventricular arrhythmias. Electrocardiography revealed third degree atrioventricular (AV) block. An echocardiogram demonstrated an echogenic, pedunculated mass arising from the caudoventral aspect of the atrial septum. The mass was believed to represent a haematoma or a thrombus associated with trauma to this region of the atrial septum. The patient was managed conservatively; third degree AV block was still pre- sent five days after trauma. The owner of the dog refused specific therapy of the arrhythmia. The patient was discharged and, unfortunately, lost to follow-up. Third degree AV block has not previously been reported following accidental, blunt thoracic trauma in the dog.     

Cardiac trauma and third degree AV block in a dog following a road accident

A nine-and-a-half-year-old dog was referred for investigation of bradycardia after being hit by a car. Electrocardiography revealed a third degree atrioventricular (AV) block. The dog died during a syncopal attack. Post mortem examination revealed an atrial septal tear with haemorrhage and myocardial degeneration affecting the AV bundle.     

Third degree atrioventricular block and sudden death secondary to acute myocarditis in a dog

Third degree atrioventricular (AV) block in dogs is thought to be most frequently characterized by non-specific fibrotic changes in the AV node. However, it may occur secondary to an undiagnosed inflammatory process. We report a case of third degree AV block in a dog, secondary to acute lymphocytic-plasmacytic myocarditis that resulted in sudden death. This dog had cardiac troponin I levels of 44.65 ng/mL (normal <0.11 ng/mL). The serum cardiac troponin I level was five times higher than any other AV block patient measured in our laboratory, and was also substantially higher than in dogs with chronic valve disease or dilated cardiomyopathy. The severe myocardial necrosis observed at necropsy correlated with the degree of cardiac troponin I elevation. This report suggests that measurement of cardiac troponin I may be an indicated test before pacemaker implantation in dogs with third degree AV block.     

Suspected lily-of-the-valley (Convallaria majalis) toxicosis in a dog

Objective: To describe successful treatment of third-degree atrioventricular (AV) block using temporary noninvasive transthoracic pacing and placement of a permanent transvenous pacemaker in a case of suspected lily-of-the-valley ( Convallaria majalis ) intoxication in a dog.
Case summary: A 2-year-old neutered male Beagle weighing 17.8 kg was presented to the emergency service for treatment of bradycardia, vomiting, and lethargy. An electrocardiogram revealed third-degree AV block that was nonresponsive to atropine. Ten hours after admission, the dog became obtunded. Treatment initially consisted of temporary noninvasive transthoracic pacing and eventually placement of a permanent transvenous pacemaker. The initial history did not suggest that the dog had access to any known cardiotoxins. However, C. majalis , which contains cardiac glycosides, was identified within the dog's environment and the dog's serum did contain digoxin or an immunologically cross-reactive compound.
New or unique information provided: This is the first reported successful management of C. majalis toxicosis in a dog. Temporary noninvasive transthoracic pacing was used in the management of this case as a safe and effective bridge to permanent pacemaker implantation.     

Temporary transvenous cardiac pacing in a dog with diltiazem intoxication

Objective: This case report presents the clinical findings of a dog with diltiazem intoxication and the utilization of temporary transvenous pacing for management of high‐grade second‐degree atrioventricular (AV) block with associated bradycardia and hypotension. Case summary: A nine‐year‐old spayed female Basset Hound, who ingested between 95 and 109 mg/kg of sustained‐release diltiazem exhibited clinical signs of cardiac arrhythmias, bradycardia, hypotension, mental depression and gastrointestinal (GI) upset. Bradycardia was present initially, then was followed by high‐grade second‐degree AV block with ventricular escape. Traditional medications to treat calcium channel blocker (CCB) intoxication, including atropine, calcium gluconate, dopamine and glucagon were initially successful in managing the cardiac rhythm disturbances and hypotension. Twenty‐two hours post‐ingestion, however, the dog became refractory to these medications following sedation for GI decontamination and a temporary transvenous pacemaker was placed. The dog was paced for 19 hours. Transvenous pacing effectively increased heart rate, which increased blood pressure into an acceptable range. The dog was successfully discharged from the hospital following treatment. New or unique information provided: The use of a temporary pacemaker should be considered an acceptable treatment for bradycardia, AV block and hypotension associated with CCB intoxication when conventional medical therapy fails.     

Transvenous pacemaker placement in a dog with atrioventricular block and persistent left cranial vena cava

The case reported herein describes the placement of a permanent transvenous pacemaker in an older dog with a previously undiagnosed persistent left cranial vena cava (PLCVC) and recent onset symptomatic third-degree atrioventricular (AV) block. On presentation the dog was found to have atrial flutter and third-degree AV block and echocardiography demonstrated evidence of chronic valvular disease and pulmonary arterial hypertension. The persistent left cranial vena cava was discovered via angiography when difficulties were encountered with pacemaker placement. Successful right ventricular pacing necessitated passage of the lead through the coronary sinus. The attendant complications in pacemaker placement in the presence of a PLCVC are well-described in man but, to the authors' knowledge, have not been described in companion animals.     

Surgical management of 2 different presentations of ear canal atresia in dogs

A 6-year-old French spaniel and a 14-month-old German shepherd dog were diagnosed with ear canal atresia. Based on presentation, computed tomography, and auditory function evaluation, the first dog underwent excision of the horizontal ear canal and bulla curettage, and the second underwent re-anastomosis of the vertical canal to the external meatus. Both dogs had successful outcomes.     

Trifoliate left atrioventricular valve with and without intact septal structures in four dogs: echocardiographic findings and surgical repair

Trifoliate left atrioventricular (AV) valve with common atrioventricular junction is considered part of the spectrum of atrioventricular septal defect. This valve morphology is typically associated with defects in the AV septum resulting in communication at the atrial or ventricular level, but has also been described as an isolated defect in the setting of a common AV junction without AV septal defect. Trifoliate left AV valve exhibits a line of apposition between the bridging leaflets that is directed toward the inlet interventricular septum, distinguishing it from isolated mitral valve cleft in which the orientation of the bridging leaflets are toward the left ventricular outflow tract. The echocardiographic findings of four dogs with trifoliate left AV valve are described; two with intact septal structures and two with large ostium primum defects. Three dogs underwent open surgical repair using different approaches depending on the presence or absence of a septal defect. One of these underwent concurrent surgical repair for right AV valve dysplasia. One dog with intact septal structures underwent interventional closure of a concurrent patent ductus arteriosus. Current terminology associated with trileaflet left AV valve malformations is reviewed.     

Chronic Otitis Externa and Otitis Media Treated by Total Ear Canal Ablation and Ventral Bulla Osteotomy in Thirteen Dogs

Ventral bulla osteotomy was combined with total ear canal ablation for the treatment of chronic otitis externa and otitis media in 13 dogs (14 ears) that had been refractory to medical and surgical treatments. Resolution of disease occurred in 11 dogs (12 ears). One dog with unilateral disease underwent a second operation before achieving a good result. One dog was euthanatized for persistent unilateral disease after three surgical procedures. The recurrence of disease in these two dogs (15%) was associated with remnants of ear canal integument within the osseous horizontal canal or tympanic bulla. Facial paralysis occurred in four dogs (31%) and there were no complications in eight dogs (62%). This technique shows no advantage over lateral bulla osteotomy combined with total ear canal ablation for the treatment of chronic otitis externa and otitis media.     

Primary anastomosis of segmental external auditory canal atresia in one dog

This report describes a case of canine segmental external auditory canal atresia (EACA). The dog was managed medically with non-steroidal anti-inflammatory drugs until clinical deterioration, at which time a novel and successful end-to-end anastomosis surgical repair was performed. At the 30 day postoperative re-examination, the dog was clinically well and otoscopy confirmed that there was no evidence of auditory canal stenosis. The patient remained free of ongoing issues 20 months after the surgery. End-to-end anastomosis should be considered for treatment of developmental segmental EACA in the canine.     

Traumatic tympanic bulla fracture

A Pekingese dog was presented for evaluation of head trauma with ventral head and neck swelling, puncture wounds, palpable mandibular fractures, and loss of menace, severe miosis, and loss of palpebral reflex of the right eye. Computed tomography confirmed multiple mandibular and zygomatic fractures, a right ear canal avulsion, and a complete right tympanic bulla fracture with ventral displacement. The tympanic bulla fracture was managed conservatively. Topical lubrication and antibiotic ointment was prescribed for the right eye. A subtotal hemimandibulectomy was performed to address the mandibular fractures. A temporary oesophagostomy feeding tube was placed. No short‐term complications developed as a result of the fractured bulla and avulsed ear canal being left in situ, and no complications were reported 18 months after the injury. To the authors’ knowledge this is the first report of a traumatic tympanic bulla fracture in the dog.     

Combined spinal-epidural anesthesia in a dog

OBJECTIVE: To report use of combined spinal epidural anesthesia for tail resection and surgical exploration of the pelvic canal and the perineal-pararectal area in a dog. ANIMAL: A 4-month-old, 13 kg male Collie dog. METHODS: Under inhalant anesthesia, an epidural catheter was threaded through a Tuohy needle at L5-L6. Then using a Whitacre spinal needle bupivacaine and fentanyl were administered in the subarachnoid space at L6-L7 level. Fifteen minutes later, morphine was administered epidurally. Bupivacaine and morphine were administered epidurally 4 hours after the subarachnoid injection. RESULTS: No cardiorespiratory response to surgical stimulation was observed. Postoperative analgesia was satisfactory, and the catheter was removed 30 hours later. No complications or neurologic sequelae occurred before discharge or were noted 10 days later. CONCLUSION: Combined spinal-epidural anesthesia provided excellent intraoperative anesthesia and perioperative analgesia in a dog undergoing surgery involving the pelvic canal. CLINICAL RELEVANCE: Combined spinal-epidural anesthesia can be performed in dogs, and its use should be considered in major surgeries caudal to the diaphragm, as the epidural catheter allows cranial extension of the block, providing excellent intraoperative anesthesia and perioperative analgesia.     

Separation of the Auricular and Annular Ear Cartilages: Surgical Repair Technique and Clinical Use in Dogs and Cats

Objective— To report a surgical technique for primary repair of separation of the annular and auricular cartilages of the ear and long-term outcome.
Study Design— Case series.
Animals— Cats (3) and dogs (2) with ear canal separation.
Methods— Medical records (1998–2007) of dogs and cats with ear canal separation were reviewed. Long-term outcome was obtained by telephone interview of owners or referring veterinarians.
Results— Three cats and 1 dog had ear canal separation after being hit by a car; there was no history of trauma in 1 dog. Successful repair was achieved by a caudal approach to the ear canal, identifying and debriding separated cartilage edges and using primary repair. A patent ear canal was confirmed in all animals by otoscopy 4–12 weeks later and by ear canalography in 3 animals. Long-term outcome was excellent with no reported complications 10–90 months later (median 24 months).
Conclusions— Both acute and chronic separation between the annular and auricular cartilages, in the absence of middle ear disease, can be successfully treated using primary repair via a caudal approach to the ear canal, with excellent long-term outcome.
Clinical Relevance— Primary repair should be considered in animals with separation of the annular and auricular cartilages.     

Exploration of a third degree atrioventricular block by standard echocardiography, tissue Doppler imaging, and treatment with a cardiac pacemaker in a German wire-haired pointer

A nine-year-old intact male Drathaar was evaluated for syncope and extreme weakness, and was found to have a third degree atrioventricular (AV) block. As there were no biochemic, serologic, organic (thoracic radiographs, abdominal echography, standard and tissue Doppler echocardiographies) and histologic (interventricular septum biopsy) anomalies, the dog was treated with a permanently implanted cardiac pacemaker.     

Aural cholesterol granuloma in a dog

A five-year-old female Irish setter was referred for surgery for a left-sided aural mass. The dog was generally well, but had signs of left-sided otalgia for one week. Biopsy identified the lesion as a cholesterol granuloma. The mass was removed three weeks later by a total canal ablation/lateral bulla osteotomy. The dog recovered from surgery without any complications. Ten months later, there was no evidence of recurrence. The purpose of this paper is to report the clinical and histopathological findings of this unusual form of granuloma which has not previously been reported in the canine ear.     

A canine case of otitis media examined and cured using a video otoscope

Otitis media of the left ear was diagnosed by video otoscopic examination in a 7-year-old, intact male Shih-tzu dog (weight, 5.1 kg), that also had three complex ceruminous adenomas and a Pseudomonas aeruginosa infection in the left ear canal. In such cases, total ear canal ablation is usually required. However, a complete cure was achieved in the present case without total ear canal ablation. The complex ceruminous adenomas were excised using a diode laser, and repeated cleansing of the tympanic cavity and ear canal was implemented using a video otoscope. As a result, the ear canal was closed in a U-form, and the otitis media was cured.     

Root surface temperature rise of mandibular first molar during root canal filling with high-temperature thermoplasticized Gutta-Percha in the dog

This in vitro study evaluated the temperature rise on the outer root surface of the mandibular first molar following root canal filling using the high-temperature, thermoplasticized, Gutta-Percha technique (HTTG) (BeeFill) in the dog. Twelve extracted dog mandibular first molars were used. After root canal preparation, the teeth were filled with thermoplasticized Gutta-Percha and root canal sealer. Temperature changes on the vestibular surfaces of the mesial and distal roots of mandibular first molars were measured using a thermal imaging camera. The results of this in vitro study showed that using HTTG to fill mandibular first molars in dogs produces a safe temperature rise on the root surface and, therefore, should not damage the periodontal ligament and/or surrounding tissues.     

Acute onset quadriparesis as a sequela to an oropharyngeal stick injury

A three-year-old male neutered crossbred dog was referred for investigation of acute onset quadriparesis, which had occurred following an oropharyngeal stick injury. Myelography revealed a right-sided extradural lesion overlying the C5/6 intervertebral disc space. A dorsolateral hemilaminectomy was performed at this site and two fragments of wood were removed from the vertebral canal adjacent to the spinal cord. The dog was ambulatory with right-sided forelimb monoparesis within a week of surgery and improved further following discharge. Three months following surgery, the dog was exercising freely with only mild right forelimb lameness.     

Atresia of the external acoustic meatus in a dog

Summary: A 3 year old, female great Dane with atresia of the right external ear canal had recurrent episodes of ear pain. Radiography revealed absence of air in the right external acoustic meatus, thickened bone of the right tympanic bulla and increased radiodensity of the chamber of the bulla. Total ear canal ablation and lateral bulla osteotomy were performed. The superficial portion of the external ear canal was absent and the deeper segment of the vertical ear canal began as a blunt ended cartilage tube. A patent lumen in the existent portion of the external ear canal and the tympanic bulla contained wax, hair and exfoliated squames. The tympanic membrane was not intact. No bacteria were cultured from the contents of the external and middle ear. The dog responded well to surgery and was free of pain 11 months later. Failure to surgically correct atresia of the ear canal in young dogs may allow the accumulation of cellular and sebaceous debris with subsequent involvement of the middle ear in an inflammatory response.