Disaster.  Took my dog out in the pet carrier for the first time this morning.  All went well for 40 minutes then the left rear wheel came off.  My dog has a steel pin in  one of her rear legs and is 11 years old, she can only walk short distances.  I am 80 and had to drag the carrier and my dog home.  I should be glad of your comments as I don't know what to do next.