Keeping Up With the Dachshunds (Big Book Edition) Understanding Differential Equations. Keeping Up With the Dachshunds (Big Book Edition) by Carla Fitzgerald is a delightful read where keeping up is RUFF! Jet the dog discovers this in a hilarious parody that will tickle the funny bones of both young readers and adults alike. Jet only has three biscuits and a joke to tell. Despite her attempts to keep up with the Dachshunds, she realises that these simple offerings are more than enough to forge a genuine friendship. This heartwarming story is a reminder of the true value of friendship and being yourself. Perfect for a light hearted read with a meaningful message.