Diagnosing and treating haemothorax in dogs and cats

Causes and consequences of feline haemothorax: A retrospective case series

BACKGROUND

The objective of this study was to describe the causes of haemothorax in cats, patient presentation and outcome.

METHODS

This was a retrospective study based in a university teaching hospital. The electronic case records of cats presenting with a haemothorax between January 2005 and January 2023 were searched. Cases were categorised into 'trauma', 'neoplasia', 'coagulopathy' or 'other'. Signalment, physical examination, clinical pathology findings, concurrent injuries and diagnostic imaging findings were recorded. The median hospitalisation time was calculated, and survival to discharge was noted.

RESULTS

Twenty-five cats were eligible for inclusion. Twenty cases of haemothorax were traumatic in origin, two were neoplastic, two were 'other' and one was coagulopathic. Increased respiratory rate (n = 22) and effort (n = 20) were common, and most patients were anaemic at presentation (n = 16). Common concurrent injuries included pulmonary contusions (n = 15) and pneumothorax (n = 11). The median hospitalisation time for the trauma cats was 5 days (range 1‒15). Overall, 83.3% of the cases survived to discharge.

LIMITATIONS

The limitations of this study are related to its retrospective nature and the relatively small number of cats in the study population.

CONCLUSION

Haemothorax requiring a thoracocentesis in cats is rare, with trauma being the most likely cause. These patients tend to have concurrent injuries and require ongoing hospitalisation. Owners can be advised that the short-term outcome is generally favourable.

Presumptive spontaneous hemothorax associated to thymic involution in a dog with steroid responsive meningitis-arteritis (SRMA)

OBJECTIVE

To describe an unusual case of spontaneous hemothorax resulting from thymic involution in a dog with suspected acquired bleeding dyscrasia associated with steroid-responsive meningitis-arteritis (SRMA).

CASE DESCRIPTION

A 6-month-old spayed female Golden Retriever was referred due to the sudden onset of lethargy, fever (pyrexia), loss of appetite (anorexia), and moderate neck pain. These symptoms emerged six days after an ovariohysterectomy performed by the primary veterinarian. Upon admission, the patient exhibited pale mucous membranes, tachycardia (180 bpm), bilateral muffled heart sounds and tachypnea. Abdominal and thoracic point-of-care ultrasound (POCUS) were performed and revealed bilateral pleural effusion. Due to the patient's unstable condition, emergent thoracocentesis and transfusion of packed red blood cells was required. The initial work-up performed included a complete blood cell count (CBC), biochemistry profile, venous blood gas and coagulation panel (PT, APTT, fibrinogen). Pleural effusion analysis was compatible with hemothorax. Bloodwork was unremarkable including the initial coagulation panel. Further coagulation test was performed including buccal mucosal bleeding time, viscoelastic-based clot detection tests (TEG) and Von Willebrand factor antigen measurement. TEG revealed marked hyperfibrinolysis. Angiostrongylus vasorum and 4DX snap test were performed and yielded a negative result. Thoracic CT scan revealed the presence of a soft tissue-attenuating mass in the ventral mediastinum, thymic involution, and enlargement of the sternal and mediastinal lymph nodes. Therapy with tranexamic acid and corticosteroids at anti-inflammatory doses was initiated. Marked clinical improvement was observed within 24 hours, and after three days of hospitalization the patient was discharged. One month later, the dog was referred again for acute pyrexia, hyporexia, and neck pain which progressed to non-ambulatory tetraparesis. Neurological examination was compatible with C6-T2 lesion. MRI and cerebrospinal fluid analysis were performed and revealed a final diagnosis of steroid-responsive meningitis-arteritis (SRMA) with associated intramedullary hemorrhage. Corticosteroids were started again, and the patient showed a dramatic improvement over the next 24 hours. Three weeks after the diagnosis, the dog returned to a clinically normal state. The treatment was gradually tapered over the following months, guided by regular neurological and clinical examinations and CRP measurements, without any relapses.

NEW OR UNIQUE INFORMATION

To the best of the author's knowledge, this is the first documented case of a dog experiencing spontaneous hemothorax as a result of thymic hemorrhage/involution which, in the absence of other identifiable diseases, was attributed to a hyperfibrinolytic state induced by a severe inflammatory disease such as SRMA.

Non-coagulopathic hemothorax in a dog: A case report

An 8-year-old, female-spayed, Blue Heeler presented with suspected non-coagulopathic spontaneous, hemothorax with neoplasia as the most likely differential as coagulation parameters were normal and no obvious history of trauma was reported. Computed tomography scan was crucial for diagnosis of a traumatic partial vascular avulsion injury that was successfully managed supportively.