Animal bites and scratches that break the skin deserve careful attention, even when they look small or harmless at first. The mouth of an animal carries bacteria, and when teeth or claws puncture the skin, those bacteria can be pushed deep into the tissue. Some wounds heal without complications, but others can become infected, require stitches, or lead to more serious problems if they aren’t treated properly.

Poisoning occurs when a substance interferes with the normal functioning of the human body after entering it through swallowing, inhalation, injection, or absorption through the skin. These substances may be natural or manufactured, mild or extremely toxic, but the result is the same: disruption of vital biological processes. The medical field dedicated to identifying poisons, understanding their effects, and managing exposure is known as toxicology .