Hello & welcome, I am Dr. B, a licensed veterinarian and I would like to help you with your wee one today.
There wasn't any bones in the chicken,he can keep water down,he's got Diarrhea
If the vomiting does subside by that point, then tempt Bobby with a small volume (a tablespoon worth to start) of a light/easily digestible diet. Examples of this would be boiled chicken, boiled white fish, scrambled eggs (made with water and not milk), meat baby food (do avoid the ones with garlic powder in the ingredients) or there are also veterinary prescription diets that can be used in cases of gastroenteritis (ie Hill’s I/D or Royal Canin’s sensitivity). Now if he can keep the small amount, he can have a bit more after 30 minutes. And as he keeps it down, he can have a bit more and so on. The aim of an easily digestible diet is that they tend to be easier for the compromised gut to digest and absorb. And even if an infectious agent is wrecking havoc on their GI, this will give the gut the ability to gain as much nutrition as possible. Furthermore, if we can aid the gut in taking up more of the nutrients they are ingesting, we will also see less diarrhea as a side effect.
While doing this, do keep an eye on his water intake as profuse vomiting can quickly dehydrate a cat (and dehydration will make them feel worse and complicate their situation.) Further to this, do keep an eye on his water intake and hydration status. To check his hydration status to make sure he is not becoming dehydrated there are a few things we can test. One is whether the eyes appear sunken, if the gums are tacky instead of wet/moist, and whether they have a "skin tent" when you lift the skin. To see how to check these parameters for dehydration, you can find a wee video on this HERE. (They use a big dog but it makes it easier to see and the principle is just the same). If you check these and are already seeing signs of dehydration, then that would be a red flag that you'd want to have him seen by his vet before this becomes an additional issue for him (to avoid it getting to a stage where he has to be hospitalized for IV fluids).
That said, if his hydration is adequate at the moment and you are concerned that he is becoming dehydrated, you can try an encourage him to drink but offering fresh water or even low-sodium chicken broth. Since he is vomiting, syringe feeding of fluids is contraindicated since we don't want to cause further vomiting.
Even if we can settle the vomiting by resting Bobby's stomach, we do have to be concerned about associated nausea, as that can make getting them to eat difficult. There are a number of antacids that are available over the counter and pet friendly. I would advise only treating with one, but the two I tend to recommend are Pepcid (More info/Dose) or Zantac (More Info/Dose) .We tend to give these 30 minutes before offering food to give it time to be absorbed.
Now as long as he can settle, isn't constantly vomiting while you rest his stomach, and doesn't have belly pain then I'd advise you to try the above with him. If you initiate these treatments and do not see improvement over the next 12-24 hours (we don't want to let it go too long since Bobby is a young lad) or he has any further violent vomiting episodes then that would be our cue to follow up with his vet so that they can make sure there is nothing sinister afoot. As well, the vet will be able to cover him with antibiotics against bacterial gastroenteritis and anti-vomiting medication via injection. As long as Salmonella (which the raw chicken doe make a concern) is not a suspect, the vet can also dispense cat safe anti-diarrheal medication (ie Kaolin, Protexin, etc) to help settle his stomach and get him back on track as quick as possible.
Finally, just to note in case you were keen to have him seen today, some veterinary practices in our country have Sunday office hours. As well, I wanted to mention that most veterinary practices here do have contingency plans for emergency care for their patients even when they are not open. Therefore, it is worth ringing the practice. If they are open, you can get him seen today. If they aren't, then they will likely have a message to direct you on how to contact their out of hours service. And if you don't have a vet you can find one local to you, you can check you can check the RCVS Register (HERE) to find your local Vets Now (LINK) who are open all nights/weekends. In any case, if you wanted to get him checked or if he did deteriorate or have belly pain then there are options to have him seen today too.
I hope this information is helpful.
If you need any additional information, do not hesitate to ask!
All the best,