Oculocardiac reflex induced by zygomatic arch fracture in a crossbreed dog

A 3-year-old crossbreed male dog was presented with a history of blunt facial trauma. Skull radiographs showed right zygomatic arch fracture. An electrocardiogram revealed bradycardia, first-degree atrioventricular block and QT prolongation. Standard biochemical profile including electrolytes was normal. Atropine response test (0.04 mg/kg intravenously) restored normal sinus rhythm at a rate of 140 bpm with normal QT and PR intervals. This observation is consistent with oculocardiac reflex secondary to zygomatic arch fracture.     

Surgical salvage from comminuted metatarsal fracture using a weight-bearing pin-putty apparatus in a dog

Comminuted metatarsal fractures in a dog were treated using intramedullary pins externally connected and stabilized by epoxy resin putty and application of a fibreglass cast. Two weeks later the cast was removed. After further 2 weeks application of a Robert-Jones bandage the dog could stand and walk with the pin-putty apparatus in position. The pin-putty apparatus was removed 3 months postoperatively, and the dog resumed normal activity. This fixation method could be an easy, economical and effective alternative treatment for managing comminuted fractures of the metatarsal and possibly metacarpal bones in selected cases.     

Ultrasonographic and radiographic assessment of uncomplicated secondary fracture healing of long bones in dogs and cats

OBJECTIVES: To evaluate the use of ultrasonography (US) to detect bone healing in uncomplicated diaphyseal fractures of dogs and cats, and to compare these observations with detection of healing by radiography (RG). STUDY DESIGN: Clinical study. ANIMALS: Dogs (33) and cats (11). METHODS: RG and brightness mode US were used to follow uncomplicated secondary fracture healing. Fractures were examined at admission and then every 2-4 weeks until healed or implant removal. Temporal differences in definitive detection of healed fracture by imaging technique were examined by species, patient age, bone, and fracture type. RESULTS: US images obtained during uncomplicated secondary fracture healing were consistent with images of fracture healing described in humans. Mean time to US diagnosis of a healed fracture (mean 46 days) was significantly shorter than by RG (mean 66 days). Mean time until diagnosis of a healed fracture (US and RG) did not differ significantly between open and closed treatment. Patients 36 months (n=11), but there was no significant difference between the latter 2 groups. Diagnosis of a healed simple fracture by US was significantly quicker than for a comminuted fracture (P<.05), but no difference was noted when using RG. CONCLUSIONS: US can be used to evaluate secondary fracture healing in biologically treated fractures in dogs and cats. US permits detection of a healed fracture earlier than RG. CLINICAL RELEVANCE: Earlier diagnosis of a healed fracture by US can prevent unnecessarily long limb immobilization and allow earlier dynamization.     

Bilateral correction of metatarsal rotation in a dog using circular external skeletal fixation

An 8-month-old castrated male Saint Bernard was evaluated for bilateral hind limb lameness. Lameness was ascribed to bilateral metatarsal rotational abnormalities on the basis of the physical examination and radiographic evaluations. Staged, bilateral deformity correction and tarsometatarsal arthrodeses were performed using circular external skeletal fixators. The dog's gait improved following surgery and the fixators were removed 3 (left hind paw) and 4 (right hind paw) months following surgery. Twenty months after the initial surgery, the owner reported that the dog was walking well without apparent lameness. Previous reports suggest that metatarsal rotation is untreatable; however, our results suggest that surgical correction of this deformity can substantially improve limb function in dogs affected with metatarsal rotation.     

Exophthalmos secondary to zygomatic adenocarcinoma in a dog.

An 8-year-old Labrador Retriever developed unilateral exophthalmos over a 1-year period. Contrast radiography, surgical exploration, and histologic examination revealed the cause to be an adenocarcinoma arising from the zygomatic salivary gland or duct.     

Symblepharon secondary to ophthalmomyiasis externa in a dog

A 4-month-old crossbred female dog presented with complaints of poor vision and odd appearance of the eyes. At the age of a month, the animal was found lying in a railway road in a very bad condition and was rescued from death. At that time, the patient was presented with severe bilateral ocular discharge, and from both eyes, dipterous fly larvae were extracted. The dog was given symptomatic treatment (deworming, topical and systemic antibiotics, nutritional support) but never regained a normal eye appearance. At the time of the initial presentation, it had severe vision impairment because of bilateral cicatricial symblepharon, total in the left eye and occupying 3/4 of the cornea in the right eye. Surgery was proposed to attempt a resolution. Superficial keratectomy was performed in both eyes. After a midline incision in the cornea, the conjunctiva was dissected away. The conjunctiva was apposed to and sutured to the limbus and secured in the upper and lower conjunctival fornix. Additionally, in the left eye, a lateral canthotomy and canthoplasty were performed to enlarge the size of the eyelid opening. The corneal epithelium healed without complications, the patient regained vision, and after 36 months of follow-up, no recurrences were observed. To the authors' knowledge, this is the first report of symblepharon secondary to ophthalmomyiasis externa in a dog.     

Modified lateral orbitotomy for vision-sparing excision of a zygomatic mucocele in a dog

A 1-year-old Shar Pei presented for recent-onset exophthalmos and right peri-ocular facial swelling. Physical examination revealed the facial mass was of soft-tissue consistency and nonpainful to the dog. Due to inability to retropulse the globe during ophthalmologic examination, it was suspected the mass had impinged into the orbit, resulting in rostral displacement of the globe. Anatomic location suggested the lesion was probably associated with the zygomatic salivary gland. Fine-needle aspiration and subsequent cytological evaluation of fluid extracted from the facial mass was consistent with a diagnosis of zygomatic mucocele. Computed tomography imaging confirmed a single fluid-filled mass was resulting in both the facial distention and the exophthalmos. A modified, lateral orbitotomy surgical approach was selected for excision of the lesion to provide ventral exposure to the orbit, while minimizing trauma to the globe and supporting structures. Histopathology of the excised lesion confirmed a diagnosis of zygomatic mucocele. This case demonstrates utilization of a modified lateral orbitotomy for effective surgical management of a zygomatic mucocele in a dog, with preservation of vision and absence of any significant postoperative complications.     

Imaging diagnosis--acquired pectus excavatum secondary to laryngeal paralysis in a dog

A 13-year-old neutered female Labrador retriever had inspiratory dyspnea secondary to bilateral laryngeal paralysis. Radiographically, there was pectus excavatum with a mediastinal shift to the right. Arytenoid lateralization was performed, relieving the upper respiratory obstruction, and the sternal deformity also resolved. Chronic upper respiratory obstruction should be considered in dogs with pectus excavatum. Furthermore, correction of upper respiratory obstruction has the potential to result in resolution of pectus excavatum.     

Retrobulbar respiratory epithelial orbital cyst in a dog: A case report

A 10-month-old female, neutered French Bulldog presented with a history of unilateral right-sided intermittent conjunctivitis and exophthalmos. The patient suffered blunt force trauma to the right eye after a tennis ball impact approximately five months prior to presentation. Examination identified the patient was visual with exophthalmos, lateral strabismus, conjunctival hyperaemia, episcleral congestion, and papilloedema. Magnetic resonance imaging and ultrasonography identified an approximately two centimeter diameter fluid-filled structure directly posterior to the globe leading to displacement of the optic nerve and distortion of the posterior globe wall. Centesis of the lesion demonstrated neutrophilic and macrophagic inflammation with evidence of prior hemorrhage. Within four weeks, the structure had re-filled to its original size and was subsequently excised in its entirety, via a lateral orbitotomy. Histopathologic findings indicated a non-keratinising orbital cyst, the lining of which was consistent with a respiratory epithelial cyst. Recurrence had not occurred seven months' post-surgery. To the author's knowledge, previous reports of retrobulbar respiratory epithelial cysts have not been documented in animals.     

Orbital cellulitis associated with Toxocara canis in a dog

Reports of Toxocara canis ocular larva migrans are uncommon in animals, with only a few cases reported. Most reports involve larval migration into the retina and choroid, with parasitic invasion of the orbit reported only in experimental studies. This is the first clinical case of Toxocara canis infection in the retrobulbar region of a 10-year-old, cross-bred male dog presenting with unilateral orbital cellulitis. Ophthalmic signs included protrusion of the nictitating membrane, chemosis, exophthalmos and hypertropia. The parasite was diagnosed by histologic and parasitologic examination of orbital tissues, which were removed during enucleation.     

Use of a semitendinosus myocutaneous flap for soft-tissue reconstruction of a grade IIIB open tibial fracture in a dog

OBJECTIVE: To describe the clinical use of a semitendinosus myocutaneous flap for soft-tissue reconstruction of a grade IIIB open tibial fracture. STUDY DESIGN: Case report. ANIMALS: A 5-year-old castrated male Labrador retriever with a grade IIIB open tibial fracture. METHODS: A myocutaneous flap was created by elevating the origin of the semitendinosus muscle and the associated overlying skin. The flap was rotated distally based on the distal vascular pedicle into a soft-tissue defect overlying the central and distal third of the tibia. RESULTS: The flap allowed one-stage reconstruction of a severe soft-tissue defect overlying denuded bone in a grade IIIB open tibial fracture. The muscular portion of the flap survived; however, there was necrosis of 3 cm of skin extending distally beyond the muscular portion of the flap. CONCLUSION: Distal rotation of the semitendinosus muscle and overlying skin can be used in the treatment of severe soft-tissue defects of the canine crus. CLINICAL RELEVANCE: Complex soft-tissue injuries to the canine crus can be treated with a myocutaneous flap as a reasonable alternative to other reconstructive techniques.     

Odontogenic parakeratinized cyst resulting in exophthalmos and palatine,maxillary, and zygomatic bone erosion in a dog

A novel case of a canine odontogenic parakeratinized cyst (COPC) that resulted in exophthalmos and palatine, maxillary, and zygomatic bone erosion in a 5‐year‐old Chihuahua dog is reported. Final diagnosis was aided by cross‐sectional imaging (magnetic resonance imaging and computed tomography) and confirmed with histologic examination of the cyst wall.     

Surgical correction of primary pneumothorax in a dog

Surgical repair of primary pneumothorax in a dog was performed by a median sternotomy and partial lung lobectomies using an automatic suturing device. A median sternotomy was performed since the location of the lesion was undetermined preoperatively. The automatic suturing device provided a quick, simple, and secure method of performing the partial lobectomies. Ruptured blebs and subpleural emphysema were present in the excised pulmonary tissue. Mechanical pleurodesis was also performed in an attempt to prevent recurrence. Large-gauge orthopedic wire was used to close the sternotomy in order to minimize postoperative complications. On follow-up evaluation 6 months later, the dog was normal.     

Surgical treatment of a double aortic arch in a dog

An 8-month-old spayed female Labrador retriever dog was evaluated for regurgitation 6 months after surgery for a suspected vascular ring anomaly. The dog had a history of regurgitation and slow development as a puppy. An initial left-sided exploratory thoracotomy was unsuccessful in identifying and treating a vascular ring anomaly. The dog was subsequently presented to the PennVet Emergency Service for regurgitation. Thoracic radiography showed cranial thoracic esophageal dilation and an esophageal foreign body that was then removed endoscopically. Subsequent computed tomographic (CT) angiography revealed a double aortic arch. A left 4th intercostal space thoracotomy was performed. The smaller left aortic arch and a left ligamentum arteriosum were ligated and transected. The dog recovered uneventfully and was healthy at the 1-month follow-up visit. This is the 5th reported successful surgical correction of a double aortic arch in a dog. Computed tomographic angiography was essential in diagnosis and surgical planning.Key clinical message:Although uncommon, double aortic arches can occur and present a diagnostic and surgical challenge when a persistent right aortic arch is suspected. Computed tomographic angiography provides an accurate preoperative diagnosis and allows for surgical planning.     

Surgical correction of congenital lobar emphysema in a dog

Massive lobar emphysema in the middle lobe of the right lung was observed in a dog brought to our clinic with sudden onset of tension pneumothorax, and lobectomy was performed to excise it. Pathological examination resulted in a diagnosis of congenital bronchiectasis associated with bronchial cartilage hypoplasia. Two cases of diagnosis and successful treatment of congenital lobar emphysema have been reported in dogs.