Long-term clinical outcomes following surgery for spontaneous pneumothorax caused by pulmonary blebs and bullae in dogs - a multicentre (AVSTS Research Cooperative) retrospective study

OBJECTIVES

To report the clinical characteristics and recurrence rate of spontaneous pneumothorax secondary to pulmonary blebs and bullae following surgical management in a large cohort of dogs. To explore potential risk factors for recurrence and describe outcome.

MATERIALS AND METHODS

Medical records were retrospectively reviewed for cases with spontaneous pneumothorax managed surgically between 2000 and 2017. Signalment, clinical presentation, diagnostic imaging, surgery, histopathology findings and patient outcomes were recorded. Follow-up was performed via patient records and telephone contact.

RESULTS

Records of 120 dogs with surgically treated pneumothorax were identified and reviewed, with 99 cases appropriate for exploratory statistical analysis. Median follow-up was 850 days (range: 9-5105 days). Two- and 5-year survival rates were 88.4% and 83.5%, respectively. There was recurrence in 14 of 99 dogs (14.1%) with adequate follow-up, with a median time to recurrence of 25 days (1-1719 days). Univariable Cox regression analysis suggested increased risk for recurrence in giant breeds (hazard ratio = 11.05, 95% confidence interval: 2.82-43.35) and with increasing bodyweight (HR = 1.04, 95% confidence interval: 1.00-1.09). Of 14 dogs with recurrence, six were euthanased, two died of causes related to pneumothorax and six underwent further treatment, of which five were resolved.

CLINICAL SIGNIFICANCE

Long-term survival for dogs with surgically managed spontaneous pneumothorax was good and associated with a low risk of recurrence. Giant breed dogs and increased bodyweight were the only variables identified as possible risk factors for recurrence. The outcome for dogs with recurrence undergoing a second intervention was also favourable.

Subcutaneous abscess caused by Clostridium perfringens and osteomyelitis in a dog

A case of a subcutaneous abscess caused by Clostridium perfringens infection in a five-month-old dog is reported in this study. Clinical examination, radiological findings and cytological analysis of abscess fluid were consistent with Clostridium induced disease. Treatment including drainage of the abscess and antibiotic therapy led to rapid clinical improvement. However, despite aggressive medical therapy and proper wound care, the deep soft tissue infection led to osteomyelitis with premature closure of the growth plates of the tibia and secondary bone shortening. Prolonged treatment with metronidazole and amoxicillin-clavulanic acid resulted in an excellent outcome with normal weight bearing.

Mycoplasma felis arthritis in two cats

This report describes the occurrence of non-weightbearing lameness caused by Mycoplasma felis monoarthritis in two, immunocompetent, European, shorthair adult cats with a suspected history of trauma. Clinical signs recurred after conservative treatment. The joints were treated surgically and M felis was identified as the causative agent for the monoarthritis. Medication with 10 mg/kg doxycycline twice daily was initiated according to susceptibility testing. One cat underwent further joint flushing after two weeks; both the cats recovered completely after eight and nine weeks, respectively. The findings suggest that M felis, in addition to being an agent associated with conjunctivitis in cats, is able to act as a pathogen in other tissues and cause arthritis even in immunocompetent cats.

Traumatic triceps tendon avulsion in a cat

Traumatic avulsion of the triceps tendon was diagnosed in a 15-month-old, male, neutered European shorthair cat. Diagnosis was established clinically by palpation of a transverse groove proximal to the olecranon and by radiography. The avulsed end of the tendon was surgically reapposed using a modified three-loop pulley suture and horizontal mattress sutures. Postoperatively, elbow flexion was limited for three weeks with the aid of a spica splint and by exercise restriction for six weeks. The cat showed no lameness after bandage removal up to the time of writing (seven months). Although rare, triceps tendon injuries can occur after a blunt trauma and should be included in the differential diagnosis of foreleg lameness in the cat. The modified three-loop pulley suture in combination with subsequent immobilisation of the limb with a splinted bandage resulted in a successful outcome in this cat with a triceps tendon avulsion.