What Is Your Diagnosis?

Abstract

HistoryA 1-year-old sexually intact male mixed-breed dog was evaluated within an hour of being hit by an automobile. On physical examination, the rectal temperature was 38.5°C (101.2°F), the heart rate was 160 beats/min, and the respiratory rate was 60 breaths/min. Femoral pulses were weak and mucous membranes tacky. The dog was alert and responsive; both pupils were miotic, and conjunctival hemorrhage was detected in the right eye. Direct and indirect pupillary light reflexes were absent in the right eye. Several small lacerations were detected on the head, and a contusion was detected on the lateral side of the left stifle joint. The dog was nonambulatory and unable to move both hind limbs. Signs of deep pain were detected in all limbs. A catheter was placed in a lateral saphenous vein, and fentanyl (4.4 µg/kg [2 µg/lb], IV bolus) was administered. The dog also received standard treatment for shock. No abnormalities were detected on abdominal and thoracic radiographs. Fluids were administered IV and the dog received antimicrobials and analgesics during the night.The following morning, the dog had signs of cervical pain and held its head in a guarded position and slightly to the right. The dog was unable to move both hind limbs, and movement was decreased in both forelimbs. Radiographs of the skull and cervical portion of the vertebral column were obtained (Figure 1).Determine whether additional imaging studies are required, or make your diagnosis from Figure 1-then turn the page * C

Dorsal surgical stabilisation using tension bands for treatment of traumatic atlanto‐occipital instability in a cat

“…To the authors’ knowledge, traumatic AO luxation with survival has been reported in only eight dogs and one cat . The most common cause of dislocation is road traffic trauma, which was the cause in the case of the cat reported previously.…”

“…AO luxation usually results in significant neurological injury with non‐specific clinical signs. In previous reported cases, gait dysfunction was present: ataxia, hemiparesis, tetraparesis and tetraplegia . Spinal reflexes were always increased.…”

“…In previous reported cases, gait dysfunction was present: ataxia, 1 hemiparesis, 3 tetraparesis 2,4-6,9 and tetraplegia. 8 Spinal reflexes were always increased. Hypermetria has never been reported.…”

“…To the authors' knowledge, traumatic AO luxation with survival has been reported in only eight dogs and one cat. 1,2,[4][5][6]8,9 The most common cause of dislocation is road traffic trauma, which was the cause in the case of the cat reported previously. A study of 57 dog cadavers concluded that extreme hyperextension of the AO joint was the likely cause of AO dislocation.…”

Zygomatic arch-atlas wing stabilization in 5 dogs with atlanto-occipital dislocation

“…Atlanto-occipital luxation is a rare condition in dogs and cats, because of the means of stability that prevent dislocation. Luxation and subluxation can occur in dogs and cats following trauma [ 2 , 4 , 5 , 10 , 11 , 14 , 17 , 18 ]. The stability of the atlanto-occipital joint is attributable to the multiple, strong ligaments associated with it [ 18 ].…”