Hello I am Dr. Joey. Thanks for trusting me to help you and your pet today. I am a licensed veterinarian with over 16 years of experience. I look forward to working with you.
I am sorry to hear your cat is experiencing this and on a holiday weekend. Unfortunately, his symptoms are vague and do not point to one particular problem. You ask about toxicity and it is possible but unlikely because toxicities that would lead only to not eating and increased water intake would lead to rapid decline within a day or two such as antifreeze toxicity or eating a certain plant. So, I doubt this is toxicity but if you are worried or have a high suspicion for toxicity then this is a medical emergency and he needs to be examined today.
Instead his symptoms make me worry about other issues such as he may have an infection (such as developing abscess) with fever, organ issue (liver, kidney), urinary tract infection (kidney, bladder), foreign object ingestion, and the list continues.
At this point after 3 days of not improving (perhaps worsening) he is going to need to be seen by a veterinarian. If you feel he is "worse" today than yesterday then taking him to be seen on emergency is your best option. If you are suspicious of toxicity (you know there was something put outside maliciously or something he got into) then have him seen today. Otherwise, there is no miracle home remedy for these vague signs other than continuing to offer him a buffet of his favorite foods to tempt him and keeping the water fresh and close.
I am at a point I need to know what questions you have. I hope that the information I provided has been helpful.
Please let me know if for any reason you need further clarification, have more questions, or were expecting a different type of answer.
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