Thoracoscopic-assisted lung lobectomy in the dog: report of two cases

The benefits and application of thoracoscopy with selective ventilation, as an adjunct to thoracotomy, in facilitating pleural exploration and lung lobectomy in two dogs are presented. Similar thoracoscopic-assisted procedures are commonly used in human patients because there is better exposure and they are technically less demanding than thoracoscopy alone, while causing less postoperative morbidity than conventional thoracotomy. There are no previous reports of thoracoscopic-assisted surgery in the veterinary literature. In the cases described, thoracoscopic-assisted mini-thoracotomy was an effective, minimally-invasive approach for ipsilateral hemithorax exploration and lung lobectomy.     

Thoracoscopic foreign body removal and right middle lung lobectomy to treat pyothorax in a dog

A three-year-old, 30-kg, spayed female German wirehaired pointer was presented for coughing, pyrexia and lethargy. Thoracic radiographs showed mild right-sided pleural effusion, moderate pneumothorax and a pulmonary lesion in the right middle or caudal lung lobe. A diagnosis of pyothorax was established by fine needle aspiration of the pleural effusion. Thoracoscopic exploration was performed using one-lung ventilation. A vegetal foreign body (grass awn) and an abscess were observed in the distal part of the right middle lung lobe. The foreign body was removed and a right middle lung lobectomy was performed, both thoracoscopically. No complications were noted. The dog was discharged 48 hours after surgery, and no recurrence of the clinical signs was observed during the follow-up time period (three years and three months). Thoracoscopy is a minimally invasive alternative to thoracotomy to explore and successfully treat some non-chronic pyothoraces in dogs, including lesions affecting the right middle lung lobe.     

An aspirin-prednisolone combination to modify postadulticide lung disease in heartworm-infected dogs

A combination of aspirin and prednisolone was used in an attempt to modify the pulmonary disease produced by thiacetarsamide treatment of heartworm-infected dogs. Results of 6 heartworm-infected dogs treated with prednisolone (1 mg/kg, daily for 4 weeks) and aspirin (10 mg/kg, daily for 4 weeks) after thiacetarsamide treatment were compared with previously published results of 3 groups of dogs (6 dogs/group). One of these 3 groups was a nontreated control group, another was treated with prednisolone, and the 3rd was treated with aspirin. All dogs, each with 9 adult heartworms transplanted, were treated with a 2-day, twice-a-day treatment of thiacetarsamide (1 mg/kg) 4 weeks after the transplant. Thoracic radiographs were taken before and at 1, 2, and 3 weeks after thiacetarsamide treatment to evaluate lung disease. Pulmonary arteriography was performed before and 3.5 weeks after thiacetarsamide treatment to evaluate pulmonary blood flow. After treatment, radiographs of the aspirin-prednisolone group were similar to radiographs of the prednisolone group, both with a marked attenuation of the parenchymal disease, as compared with the non-treated group. Addition of aspirin to prednisolone prevented the blood flow obstruction and intraluminal filling defects that were present in the groups not receiving aspirin. Sixteen of 54 transplanted heartworms survived thiacetarsamide treatment in both prednisolone-treated groups, in contrast to complete elimination of heartworms in the nontreated group. Aspirin may be considered for treatment of any heartworm-infected dog that does not have hemotypsis, but postthiacetarsamide use of prednisolone should be restricted to the dog that develops severe lung disease after the heartworms have been killed.     

Accidental entrapment of an endo-bronchial blocker tip by a surgical stapler during selective ventilation for lung lobectomy in a dog

OBJECTIVE: To describe the use of an endobronchial blocker (EBB) and to perform selective ventilation during pulmonary lobe resection via thoracotomy in a dog and report its accidental stapling in the resection site. STUDY DESIGN: Clinical case report. ANIMAL: One female dog with a suspected abscess or neoplasia of the right caudal pulmonary lobe. METHODS: One-lung ventilation was performed using a wire-guided EBB to seal the contaminated parenchyma and facilitate surgical access. The affected lung parenchyma was resected and the resection site was closed with staples. RESULTS: Lobar resection was performed successfully, but the loop of the EBB guide wire was inadvertently entrapped in the staple line of the lobectomy. Staples were removed to release the wire loop, and the resulting air leak caused loss of ventilation control until the parenchyma was re-sealed. CONCLUSIONS: We recommend removing the wire guide associate with the EBB after successful lung separation to avoid accidents that could have life-threatening consequences if not recognized. CLINICAL RELEVANCE: One-lung ventilation is useful to isolate healthy parenchyma from diseased parenchyma during lobectomy. Anesthesiologists and surgeons need to be aware of the potential complications associated with use of EBB.     

Eosinophilic leukaemoid reaction in a dog

A haematological disorder in a dog characterised by a massive leucocytosis, mainly composed of eosinophils and their precursors is reported here. The normal composition of cells in the bone marrow was displaced in favour of the eosinophils and their precursors. No apparent cause for the pronounced eosinophilia could be determined by clinical, haematological, clinical-chemical, radiological or pathological examinations. A diagnosis of eosinophilic leukaemoid reaction was suggested as the criteria for the diagnosis of eosinophilic leukaemia in the dog but this was not firmly established.     

Thoracoscopic lung lobectomy for treatment of lung tumors in dogs

OBJECTIVE: To report use of thoracoscopic lung lobectomy (TLL) for treatment of lung tumors (LT) in dogs. STUDY DESIGN: Retrospective study. ANIMALS: Nine dogs. METHODS: Dogs that had TLL for tumor removal were included. Using general anesthesia and 1-lung ventilation, TLL was performed using a 30-60 mm endoscopic gastrointestinal anastomosis stapler. If the visual field was obscured, lobe resection was completed via thoracotomy. RESULTS: Metastatic and primary LT were resected by thoracoscopic lobectomy in 9 dogs (6 male, 3 female; mean (+/-SD) weight, 29+/-7 kg; mean age, 10.7+/-1.9 years). Six dogs had a solitary mass and 3 dogs had 2 masses within a single lobe. The left caudal lobe was removed in 3 dogs. In 5 dogs, TLL was used alone whereas conversion to thoracotomy was required in 4 dogs because of poor visibility. There were 7 metastatic LT and 2 primary LT. Mean duration of thoracoscopic surgery was 108.8+/-30.3 minutes compared with 150.75+/-55.4 minutes in dogs requiring conversion to thoracotomy. Mean hospitalization was 3.1+/-1.3 days. CONCLUSION: Provided the visual field is not obscured, TLL can be performed effectively in dogs. CLINICAL RELEVANCE: Dogs with metastatic or primary LTs should be considered for TLL, particularly for small masses positioned away from the hilus in the left caudal lung lobe.     

Effects of treatment with ticlopidine in heartworm-negative, heartworm-infected, and embolized heartworm-infected dogs.

Ticlopidine hydrochloride was evaluated for its effectiveness in inhibiting platelet aggregation and serotonin release in 5 laboratory Beagles before and after heartworm implantation with 7 adult Dirofilaria immitis, and after embolization with 7 dead heartworms to mimic what happens after heartworm adulticide treatment. Five other laboratory Beagles, similarly implanted and embolized with heartworms, were used as nonmedicated controls. During the heartworm-negative stage, the dosage of ticlopidine that inhibited adenosine diphosphate (ADP)-induced platelet aggregation in 5 dogs by at least 50% after 5 days of treatment was 62 mg/kg of body weight once a day. In the same dogs implanted with 7 adult heartworms 21 days previously, mean (+/- SD) ticlopidine dosage required to obtain similar results was 71 (+/- 13) mg/kg given once daily. During the 21 days after dead heartworms were implanted in heartworm-infected dogs, mean ticlopidine dosage was 108 (+/- 35) mg/kg (range, 62 to 150 mg/kg). Ticlopidine treatment was associated with increased platelet numbers in all 5 dogs during the heartworm-negative stage and in 4 of 5 dogs during the heartworm implantation and heartworm embolization stages. Mean platelet volume tended to decrease as platelet numbers increased. At necropsy, gross and histologic pulmonary lesions were less severe in ticlopidine-treated dogs than in nonmedicated control dogs.     

Torsion of a lung lobe in the dog

A 3-year-old Whippet in severe respiratory distress was found to have an extensive pleural effusion associated with a 180^o torsion of the cardiac lobe of the right lung. The possible cause of torsion and diagnostic indications of this lesion are discussed.     

Hypertrophic osteopathy in a dog with a chronic lung abscess

A 2-year-old dog was examined because of gradual lameness of all 4 limbs and weight loss. Hypertrophic osteopathy was diagnosed. Radiography revealed a mass in the caudal lobe of the right lung. At necropsy, the mass was determined to be a chronic abscess. Corynebacterium pyogenes was cultured from the lesion. Although hypertrophic osteopathy in dogs is commonly associated with a thoracic lesion, most often neoplastic, the chronic lung abscess in this dog might have been formed as a result of a paralaryngeal abscess that was treated 3 months before the onset of the lameness.     

Enhanced platelet reactivity in heartworm-infected dogs

Platelet number, mean platelet volume, and platelet function were evaluated in 34 clinically normal dogs and 28 heartworm-infected (HWI) dogs. Mean platelet numbers for dogs of the HWI group was not significantly lower than those for dogs of the control group (214,000 vs 254,000 cells/microliter); however, 6 (21%) HWI dogs had platelet numbers less than 150,000/microliter, compared with only 2 (6%) heartworm-negative dogs. The mean platelet volume was not significantly different (7.8 vs 7.7 fl) between the 2 groups of dogs. Mean platelet aggregation responses to intermediate and low concentrations of collagen (3.0 and 1.5 micrograms) and to high, intermediate, and low concentrations of ADP (25, 10, and 5 microM) were greater in dogs of the HWI group. Mean platelet 14C-serotonin release was also greater in HWI dogs in response to high concentration of ADP (25 microM) and to intermediate concentration of collagen (3.0 micrograms).