Pneumorrhachis in a cat: case study and a literature review.

A three­year­old domestic shorthair cat was referred for treatment of pelvic limb paralysis. Imaging examinations revealed air in the spinal canal (pneumorrhachis). A right­sided hemilaminectomy was performed to decompress the spinal cord, which led to full resolution of the symptoms within four weeks after the procedure. To our knowledge, this is the first reported case of spontaneous pneumorrhachis in a cat. As there are no treatment standards, we would like to add to their creation. The available literature on pneumorrhachis has also been reviewed.

Encapsulated gas accumulation in the spinal canal: Pneumorrhachis in two dogs.

A 17-year-old mongrel dog and 12-year-old Shiba Inu dog presented with ataxia and paresis of the pelvic limbs, respectively. Gas accumulation within the spinal canal adjacent to the herniated disc was suspected in both cases. Since the gas remained accumulated for a prolonged period, hemilaminectomy was performed to decompress the spinal cord. The bulged external lamina of the dura matter was removed and histopathologically examined. Granulomatous inflammation and hyperplasia of fibrous connective tissues was noted, suggesting that the gas was encapsulated and the fibrous nodules made reabsorption difficult. Clinical signs resolved post-surgery. This is the first report describing histopathological features of pneumorrhachis in dogs. The accumulated gas was successfully removed by surgery. Postoperative course remained uneventful in both cases.

Postoperative symptomatic haematoma and pneumorrhachis in a dog with a thoracolumbar intervertebral disc extrusion.

CASE REPORT: A 6-year-old male neutered crossbreed dog presented with acute onset paraparesis and was diagnosed with an L1-L2 intervertebral disc extrusion. A right-sided T13-L2 hemilaminectomy was performed. However, the dog deteriorated and became paraplegic with marked thoracolumbar hyperaesthesia 48 h after surgery. A computed tomography scan of the thoracolumbar vertebral column revealed the presence of pneumorrhachis (PR) at the level of T13, possibly embedded in a haematoma, and causing marked spinal cord compression. Revision surgery confirmed the presence of a haematoma, which was removed. The dog gradually improved and was neurologically normal 6 weeks after surgery. CONCLUSION: Although PR is a rare condition, it may be considered a possible cause for early postoperative neurological deterioration in dogs undergoing decompressive spinal surgery. Surgical revision resulted in a good outcome in the presented case.

Ventricular pneumocephalus, cervical subarachnoid pneumorrhachis, and meningoencephalitis in a dog following rhinotomy for chronic fungal rhinitis.

CASE DESCRIPTION: A 5-year-old 35.8-kg (78.8-lb) neutered male Labrador Retriever was evaluated for chronic nasal discharge associated with a fungal infection. The dog had previously been prescribed antimicrobials and antifungal treatment, but owner compliance was lacking. CLINICAL FINDINGS: Bilateral mucopurulent nasal discharge, mild ulceration of the left nasal commissure, and hyperkeratosis of the dorsal nasal planum were present. Computed tomography revealed destruction of the intranasal structures, focal lysis of the cribriform plate, and invasion of a soft-tissue mass into the frontal cortex. Rhinoscopy revealed a large pale mass in the caudal aspect of the right nasal passage; a biopsy sample was consistent with Aspergillus sp on histologic evaluation. TREATMENT AND OUTCOME: Initial treatment included medical management with an antifungal agent. Approximately 3 months later, a large fungal granuloma in the right frontal sinus was removed and debridement was performed via dorsal rhinotomy. One month after surgery, the dog was evaluated for signs of cervical pain and altered mentation. An MRI and CSF analysis were performed; diagnoses of ventricular pneumocephalus, subarachnoid pneumorrhachis, and meningoencephalitis were made. Management included oxygen therapy and administration of antimicrobials, analgesics, and antifungal medications. On follow-up 9 months after initial evaluation, neurologic deficits were reportedly resolved, and the dog was doing well. CONCLUSIONS AND CLINICAL RELEVANCE: This report emphasizes the importance of prompt, appropriate treatment of fungal rhinitis in dogs. Although rare, pneumocephalus and pneumorrhachis should be included as differential diagnoses for neurologic signs following treatment for this condition. In this dog, the complications were not considered severe and improved over time with supportive care.