I was a vet tech for a while. I always had EXTREMELY good PFTs (FVC 120%, FEV1 121%) for years. While I worked as a vet tech, I contracted a new strain of PA that was resistant to a lot of stuff (Amikacin, Tobramycin, etc.) that resulted a MASSIVE exacerbation (FVC 70%, FEV1 41%). Doctor put me on a month of Merapenem, Fortaz, Cefepime and Vancomycin along with inhaled Tobi and then another month of Levoquin and Doxycycline. I still never fully recovered. Right now, my FVC is around 102% and my FEV1 is mid 80's. Luckily, the resistant strain of PA was eradicated and hasn't shown up again a year and a half later.
Staph (including MRSA), PA and several other CF pathogens (including Aspergillus fungi) are very common animal pathogens. We would always find PA, Staph and usually yeast when we'd do ear swabs. There isn't a doubt in my mind that this is where I got the nasty strain that ruined my lungs. It's okay to own a pet, but it's a different matter all together to be around dozens or hundreds of sick animals for a prolonged period of time.