Border Collie (age 18mths) with dry deep cough and occasional sick with it (mostly bile). Treated at vets as urine infection and now chest infections (2). Antibiotics work for about 5 days and then coughing, lethargy starts again (even when still on medication). Temp has been high 105 & 106 in last two visits to vet. Had procedure where samples taken (for cell growth) but first part of test stated insufficient sample to test. Losing confidence with vet as today we seem to be back to square one and have a very unhappy sad dog. Has no appetite. Any suggestions?