Hen with suspected gape worm? Help needed

[Caitlin_hens]

Hi all, I think my mother hen has gape worm. She is gasping, raising her neck, holding her beak open, making gurgling raspy sounds, wheezing etc. I’m sure it could be gape worm and have been feeding the flock with flubenvet treated pellets for a few days. She is eating them quite well. But I wonder if anyone knows how long treatment can take and if it works for hens with severe symptoms like this? I’m anxious to wait the full 7 day treatment period and now I’m worried I was too late to treat them! I’m very fond of her so thank you in advance for your support

 

[Caitlin_hens]

PS she’s just been having a drink out of her water bowl and she’s just puked up the water and some pellets she ate a few minutes ago

 

[Caitlin_hens]

And finally a video of this helps