Complex sentence: Understanding the digestive system of a domestic cat is very important for pet owners; if a pet owner understands how the different parts work together, then if a problem occurs they could potentially help the cat's situation even before taking it to a vet.
Split into simpler sentences: Understanding the digestive system of a domestic cat is very important for pet owners. If a pet owner understands how the different parts work together then if a problem occurs they could potentially help the cat's situation even before taking it to a vet.