In the summer of 2004, Aardvark and several of our other dogs were diagnosed with Tick Fever.  At that time, his platelet count was low, which is typical of Tick Fever.  All the dogs were treated with Doxycycline for roughly one year (Tick Fever can be rather stubborn).

When we rechecked Aardvark's bloodwork in the late summer of 2005, his platelet count was alarmingly low - - to the point that he would have been spontaneously hemorrhaging if the count had dropped abruptly rather than gradually.  The Tick Fever, however, was apparently gone.  We tested him for several illnesses, including Babesiosis, which is a disease caused by a blood-borne parasite.  Those tests were negative.

In the meantime, his vet started him on prednisone.  His next recheck showed that his platelet count had increased quite a bit in response to that medication, making a condition called Immune Mediated Thrombocytopenia the most likely cause of his problems.  In this condition, the immune system decides the platelets are an invading protein and destroys them faster than the body can make them.  It is possible that his immune system overreacted to the Tick Fever, but any number of things could have triggered it.

We'll be checking his platelet count every month for a while and adjusting his prednisone dose to the lowest effective level.  Odds are, he'll need to stay on medication for the rest of his life.  Interestingly, through all this, he has not had any symptoms at all.  If we hadn't rechecked him for Tick Fever, we wouldn't have known he had a problem.

June 2009 Update:
We took Aardvark off prednisone in February of 2009 and will have his bloodwork checked every few months to see whether everything is OK.  The hope is that he has managed to get over this illness and can remain medication-free.