Help! Chicken is weak, and he drinks water, but doesn't want to eat feed(crumbles).

[Luckybaby]

I think my chicken can't fully empty his crop for about 2 1/2 days about 5 days ago. The crop is filled with liquid, and it is not hard, so I think that he had a sour crop on that time. However, after that, water seems to enter the stomach at a normal rate. I only gave him water and or water mixed with vitamins since 3 days after the symptoms first appear, since he doesn't want to eat his feed. Today he still doesn't want eat the crumbles, and he can't stand up anymore. His poop's color is green with white creamy looking urine. I think the last time I saw a sign of digested feed on his poop was 4 days ago.

He has been inside his cage for about 7 days, before the first symptom appear. I think I overdosed dose him with fenbendazole( significantly more than 20mg/kg for 3 consecutive days) and the symptoms appear 3 days after the first does. What is the toxicity level of fenbendazole on chickens? What are the symptoms? I can't find any info about toxicity symptoms of fenbendazole overdose in chickens. What should I do?

 

[Hollywood Chickens]

Have you tried mashed cooked egg yolk or scrambled eggs? Yogurt could also help.