Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to diagnose hookworms in dogs [title] Be on the lookout for diarrhea or vomiting. [step] A hookworm bites into the bowel wall, which can cause pain and stomach cramps. The dog is also likely to have diarrhea that is tinged with blood.

Ending1: Look for diarrhea that changes colors and thickens, especially when the dog eats frequently. [substeps] If the dog is vomiting a lot, it may indicate hookworms. Ending2: The feces may appear slightly pink, become yellow or look yellowish, and form thick bits. [substeps] Your dog might also salivate or have a greenish ball in its stomach, which can be a sign of hookworm. Ending3: [substeps] Also, if there is bleeding into the bowel, by the time the blood have passed along the gut it gives the feces a dark color. Some dogs may also vomit from hookworms, and this could contain blood as well. Ending4: To treat this it's a good idea to contact your vet. [title] Be on the look out for diarrhea.

Answer format: ending1/ending2/ending3/ending4