Huge lump on cats neck

Question
We have a little boy cat, who is just over a year old. A couple of days ago, he developed a lump on the side/front of his neck. At first, he was not bothered by it, but today it is very large, and his breathing is slightly laboured, he has lost a lot of weight although he is eating and drinking quite normally. He sleeps a lot more than he used to and is a lot more slow when walking/laying down/anything he does. We booked a vet appointment however the earliest they can see him is tomorrow morning, and I am extremely worried that he won't last that long. The lump is now larger than a golf ball and though he is not too distressed when you touch it, occasionally he lets out a sad meow when you do. He also has his third eyelids out all the time, and he does not seem to be as selective as he was when deciding where to sleep.

I am extremely worried, and any help or advice before tomorrow morning would be very appreciated.

Thank you.

Answer
Well it sounds as if he has a massive abscess on this neck and it's getting ready to rupture pus all over the place. He is going to be down with this as it's a huge pocket of dead white blood cells trying to fight off an infection. He may have been bit by another cat.

If he wasn't a year old I would say to rush him to an emergency vet but since he is, and he IS eating and drinking, he should be fine until tomorrow morning. I wouldn't be surprised however, if the abscess ruptures before that.

If it's soft on one spot, or looks more blueish there, that's where it will rupture.
Even if it does overnight, you need to have the vet see him so that they can clean it out, and give him antibiotics to kill the bacteria from the inside out. Otherwise, it CAN come back, so it's important that you do that.

His breathing might be laboured because it's pushing a little against his windpipe. But if he is eating and drinking it should be okay.

If you want to help it rupture sooner, lay some warm washrags on it and that can help it break open. Getting the massive amount of pus out is the key here, so if you are squeamish at all, better let someone else do this. (warning: some of them smell as bad as the pus looks. Some don't smell at all.)

Get all the pus out once it ruptures by gently pressing on the edges of it and clean it off a few times with warm water but do not put anything on it. Nothing, not even a wrap.

Leave it open and it will be fine till the vet sees him.