• Cat leftover in a small amount of water: pure and purifying, but mildly disliked when other suitable water exists.
• Donkey leftover: pure in itself, but its capacity to purify is doubtful; if it is the only water available, Wudu and Tayammum are both performed.
• Mule leftover: The supplied commentary specifies the doubtful ruling for a mule whose mother is a female donkey, not a mare.
This distinction is important: “disliked” and “doubtful in purifying capacity” are not the same legal category.