Presumptive necrotising fasciitis with concurrent pyothorax in a 9‐month‐old Great Dane

Abstract A 9‐month‐old, entire, male Great Dane presented with rapid multi‐limb swelling, pyrexia and diarrhea following initial treatment for presumed gastroenteritis. Diagnostic evaluation revealed septic pleuropneumonia concurrent with rapidly progressive soft tissue infection affecting three limbs. Full clinical evaluation, including chest radiographs, point‐of‐care ultrasound and fine‐needle aspiration with cytology, was consistent with presumptive necrotising fasciitis with concurrent pyothorax. This was later confirmed to be secondary to β‐haemolytic Streptococcus species on antemortem blood and wound cultures. The clinical presentation suggested streptococcal toxic shock syndrome with multi‐system involvement. Despite intensive medical management, including broad‐spectrum antimicrobials and aggressive supportive care, the patient deteriorated rapidly due to multi‐limb involvement precluding surgical intervention and was humanely euthanased. To the author's knowledge, this represents the first documented case of necrotising fasciitis occurring simultaneously with pyothorax in a dog.