I have encountered several different cases where my feline patients with anemia suddenly showed high levels of PCV. For example, one patient with IMHA whose PCV was around 30% suddenly increased to about 40%; however, after a week without any change in the treatment regimen, its PCV had again dropped (stabilized) to the 30s.
Cases like these usually happened when the cats were very agitated, which made it difficult for me to reassess the PCV levels shortly after to double-check these findings. However, the hematocrit levels were the same with numbers obtained from the IDEXX machine.
I cannot disregard the possibility of these findings being just artifacts, but is it possible that agitated animals show increased levels of PCV?