The disease is usually non-fatal in adult animals, not highly contagious, and most often contracted by ingesting the infective oocysts in raw meat. Cats do not exhibit clinical signs, but pass the oocysts in their feces, posing a danger to other animals and people through contaminated soil or litter. Toxoplasmosis has become common in many species of wildlife, and is more serious in young animals. Several elements and chemicals may produce toxicological symptoms mimicking rabies. Lead poisoning not only has a toxic effect on red blood cells and hemoglobin, but produces marked neurologic signs such as blindness, tremors, and convulsions.
Intoxication is more common around dump sites for old motors, vehicles, lubricants, and paints.
Mercury poisoning targets nervous tissue, producing blindness, ataxia, abnormal reflexes and paresis. Poisoning usually occurs when mercury-containing fungicides are used on seed grains and distributed or spilled above ground. The sweet taste attracts animals and ingestion results in neurologic signs and death. Rabies should, however, always be included in the differential diagnosis of suspected CNS toxicoses. The bacterium Listeria monocytogenes is currently emerging as a cause of foodborne illnesses reported in the United States.