Dr House gives a lecture about diagnostic medicine and there's a case about a farmer allegedly getting bit by a snake. It turns out it was his dog who already had a history of biting and after admitting to it while he was dying Dr House told him they'd need to put the dog down because of it's history. The dog gave him flesh eating bacteria with the bite.
From 33 minutes 50 seconds to 35 minutes 10 seconds Dr House is disecting the dead pet cat of his current patient. The cat has already been dead for about a month and was exhumed by his assistants. The death of the cat itself isn't shown onscreen but it's discussed throughout the episode.