Aseel disease looks like what they call coccidiosis in those countries. Based on your symptoms description, it doesn't really sound like that. Without a necropsy there are so many things it could be. Lymphoid leukosis can cause similar symptoms. And the symptoms of Marek's can also vary. With chickens it can sometimes be very hard to narrow it down as different things can present with very similar symptoms. And since Marek's, and some other virus's really weaken a birds immune system, they may actually get sick with something else, like a respiratory disease, and unless testing is done at necropsy, you might not know that Marek's was the ultimate underlying cause. Some birds die and the reason is easily identified, with a informal home necropsy, like some reproductive problems and cancers. I would always recommend that if someone loses a bird and suspects it may be Marek's and has not had it confirmed in the flock before, then have a necropsy done. That way you know going forward whether it is or isn't. Anytime a death is a complete mystery and it could be something that could affect the rest of the flock, then a necropsy can either give you important information going forward, or give you peace of mind.
**Edit: wanted to add this link with more info:
https://www.birdhealth.com.au/mareks-disease
**Edit: wanted to add this link with more info:
https://www.birdhealth.com.au/mareks-disease
