Hi, Candace - Fever of Unkown Origin (or Pyrexia of Unknown Origin) is in fact not common. The term is used to designate a chronic fever, with a certain number of differentials (cancers, chronic disease such as Lyme, and auto-immune diseases primarily), the diagnosis of which require more work than the common-or-garden fevers due to bite wounds, other trauma, GI disorders and so on. When a veterinarian uses or sees the term PUO, it gives everyone a heads-up that the condition is complicated and not obvious.
Short-lived undiagnosed fevers are in fact very common. They either clear up on their own, or respond to antibiotics. The reason most of these fevers are undiagnosed is because in the first instance, if there is no obvious wound or abscess present, and the animal is fairly bright (or if you are in a place where you can't run week-end blood-work), then a reasonable approach is to start antibiotics (geared towards the species of animal, and toward the body system most suspected of being the problem). If the animal gets better, well and good. If not, then further work-up and tests are clearly indicated.
I think you got lucky with your Airedale. Tara's response to you is perfect - Divina's case is very unusual and very complicated, and she and her team are doing a fabulous job.
---In equinecushings@..., <candace.costis@...> wrote :
I'll just throw in my two cents. My Airedale had FUO - fever of unknown origin. Apparently it is common.