When it is poison, it can be hard to convince people of that. Uremic breath, lingual ulcers, seizures, not urinating, hypocalcemia... Has your dog been around any cars? Was it acting drunk yesterday or the day before? Any anti-freeze? Any green-yellow puddles around? Any enemies? Are you sure that there is no anti-freeze around? No? Ok.
Finally get some urine and there are the crystals typical of EG toxicity. Oh, you have been working on your car. And the puppy ate the paper you used to soak up the anti-freeze. Well, if you had told me this, I could have saved you a metric ton of money at the outset.
Another case: bloody urine and bruising. Go through the questions, any aspirin? Any one on blood thinners? Any sago palm? History of liver failure? What about rat poison? Has anyone put any out? Are you sure? Are you really sure? Yes? Ok. Elevated PT, PTT and finally someone admits that the dog had bright green diarrhea a few days ago. Ok, now someone remembers that the pest guy brought around some packages last week.
Well, these two scenarios play out daily in the veterinary world. Very seldom is a pet actually poisoned on purpose. However, it does happen. We had a case in vet school where the owner told us point blank that her boyfriend poisoned the dog. It took some time and a store bought urine drug screen, but we found out she was telling the truth.
Two lab mixed sisters presented on the emergency service as a transfer from a day vet. Both were comatose and alternated being bradycardic and exhibiting tachycardia. The history was that the woman had broken up with her cheating beau. He happened to be a pharmacist. The dogs became suddenly, and similarly, ill and she thought that he might have poisoned them. It turned out that she was right. There was no source in the woman's house.
We treated both dogs with gastric lavage (flushing) and activated charcoal along with supportive care. One of the dogs did fine, but the other aspirated the charcoal and ended up dying. The police were called and the woman talked of bring charges. I am not sure that she did, but the thought of this person running around, giving out medications to humans skeeves me out.