3 weeks of on and off fever of 106° with 24 hour hourly monitoring at animal hospital. X-rays showing fluid in his lungs. Blood platelet count still very low. Multiple blood tests and no tick born illness. They can not figure out what is wrong. Multiple antibiotics being used injected with no positive results. Any idea of what this can be from and what we can do, the doctor is now requesting we go to another specialist because he can not figure out what is wrong?