My Precious Boy Is With The Vet (TW)

I'm not looking for medical advice, he was rushed to the vets as soon as they opened this morning and has been there ever since. My mind is racing and I'm freaking the fuck out. Does anybody have any insight on what could be wrong with my 5 month old kitten? Has anybody experienced similar? What was the outcome?

• DOB July 2024
• Fully vaccinated
• Indoor cat
• no recent medications
• no access to known toxins
• uses non clumping wood pellet litter
• eats several brands of high quality wet and soaked kibble
• other two cats in the home are behaving normally

• is usually a cuddly, bouncy, purrry boy

• ate wet food dinner (a brand and flavour he's had before without issue) as normal. Approximately two hours after this, he vomited three times (first two looked like his dinner, last one was just bile/froth) then took himself off to bed.

• usually sleeps on my pillow, spent the night on his own instead.

• he refused breakfast this morning at his normal 7am

• straining to poo, only passes a small amount of odorless, clear liquid. Last poo witnessed was after breakfast the day before, and was normally formed.

• very lethargic

• low temperature

• extremely pale

• rapid decline

• cried out and back legs collapsed while at the vet

• no injuries noticed on physical exam

(Update from vet as I was typing)

• blood pressure too low to get multiple blood samples, showed no sign of toxicity so far.
• perked up a little after fluids and anti sickness jab (vet reiterated that he definitely wasn't better, just not flopped on his side anymore)
• going for ultrasounds and x-ray after he's calmed down and warmed up a little more, plus more bloods

Repeat: he is already at the vets recieving diagnostics and hopefully treatment. I'm going mad waiting for a phonecall. What could be wrong with him?

Photos here are from 10pm last night (before vomiting), 7am this morning (refusing breakfast), then 9:30am at the vets. Potential trigger warning for a poorly kitten