I took our dog Jack ... ( he 's a long haired chihuahua ... very cute and very loved ) ... .. to the vet last week because he was coughing , I thought it was a cold or some minor thing that they could diagnose , treat and all would be well . It turns out that his big heart is too big and pressing against his esophagus , he also had fluid in his lungs , Jack is 8 . The vet gave me an antibiotic and a diuretic and asked us to come back in 10 days .
Question: Why is the narrator so worried about Jack ?
The answer to the above question:


Jack has an issue with his heart .