There are many types of worms and some show no real signs until they get so bad that it becomes a major problem. She really should be tested for heartworms as those can be deadly but show no signs until it's too late. Even people can have worms (most commonly roundworms) and not even know it but it can definitely cause malnutrition. Getting all the proper tests, vaccines, heartworm preventative, flea/tick preventative, and so on can really run high when you are taking good care of their health. Tasha and Tommy's vet bill for all of that in February ran me $400, but it's certainly worth it to keep them healthy and safe. That's why I couldn't afford to add another dog right now!