Hi and thank you for your help!

Stinky is unfortunately not better - we have ruled out a set of allergies and lung parasites, but we will repeat this last test to be sure, as the sample sent to the lab was insufficient to be certain.
We are going today for a x-ray (for his lungs) and we will also sterilize him - as it is better for him to be put to sleep (anesthesia) only once for both. The xray might show if there is anything unusual in his lungs - but if nothing is found that could obturate his breathing, we will probably run a cardio test too - which means we need to bring Stinky to a specialized cardiologist.

Keeping you guys posted!

Thank you, everyone, for your support!