I've still never forgotten the story of Sheeba, a sheltie who presented to me about one year ago. She was about 3 years old, in great health previously, but had been lethargic and having increasing difficulty breathing for the last 1-2 days. Her breathing was labored, and her gums were pale. She had no history of trauma, and they did not witness her ingesting anything recently. No other symptoms had been noted, including no vomiting, diarrhea, or anything else unusual.
Immediately, a triage physical exam was performed. Auscultation of her lungs suggested fluid in her chest cavity, or pleural effusion. Pleural effusion is a build up of fluid between the surface of the lungs, and the body wall; typically there is only a very slight amount of fluid in this space which serves to lubricate the lungs as they move to and fro during the motion of breathing.
Oxygen was provided and a minimum database was collected to rule out causes of her symptoms. (For those not familiar with medicine, a minimum database typically includes the quick, in-house, rapid testing that provides the attending with critical information to help make diagnostic and treatment decisions). An IV catheter was placed. Initial testing indicated blood loss was occurring, and in conjunction with her symptoms, the most likely location was her chest cavity. Radiographs confirmed a severe amount of fluid within her chest.
Additional tests were performed to attempt to determine why Sheeba had been bleeding into her chest; in a young patient without a history of trauma, the most treatable (and arguably most common) cause of this is exposure to anticoagulant rat bait. Testing, called PT (prothrombin time) and PTT (partial thromboplastin time), were performed, and both were severely elevated, indicating a deficiency in the clotting factors necessary to maintain hemostasis. After talking to the family about her symptoms, signs, and test results, they remembered that rat bait was indeed placed under their house last week, and she was able to access this location. Rat bait toxicity was our most likely culprit.