Pets can bring joy and companionship, as well as financial worries, loss and logistical challenges.Dann Tardif/Stone via Getty Images Emily Hemendinger, University of Colorado Anschutz Medical Campus Owning a pet can be a roller coaster. There are the highs, like when your dog greets you with a full-body wiggle when you return home, or when your cat purrs loudly as you cuddle next to one another. Then there are the lows, like stressful trips to urgent care, waking up to that unpleasant vomiting noise, or making the difficult choice to say goodbye because of medical problems or even intractable…