Hi again, and thanks for the additional and helpful information.
The swollen neck may be a sign of a thyroid problem, or an injury, but the fact that he may not be urinating for a while, is the most important symptom here. He may have a urinary blockage and this will cause the toxins in his body to back up into his bloodstream and cause him to be very ill.
I would suggest that you bring him to the vet immediately; if your vet is closed now, bring him to a vet ER center for evaluation and treatment. If he can't urinate (or defecate) because he's blocked, this is very dangerous to his health.
The dilated pupils may signify toxic ingestion or toxicity from the blockage, or he may have ingested something poisonous or a non-food item which is stuck or caused injury to his throat on it's way down. As you can see, there are so many possibilities, and all of them require immediate veterinary attention.
Please try to get him in to see a vet ASAP!
Keep me posted on how he's doing and what the vet tells you. Thanks! I hope he'll be fine!
Cher
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