Forget about dry food for the time being.
Wet food contains 60% water so he will not drink as much as he would if he ate dry food.
Between his dental issues and cough/cold he will do much better on wet food.
He may have a sore throat and difficulty smelling well.
Rub a drop of honey into his gums. It will raise his blood sugar and sooth his throat. Repeat every 4 hours.
Drain the water from a can of people tuna into a bowl and see if he will lap that up for hydration.
You can also add a tablespoon of warm water to a can of food.
For sneezing, he can have an antihistamine:
Any of these are also acceptable:
Benadryl at a dose of 1/2 of a 25 mg tablet given twice daily or
Chlorpheniramine at a dose of 2-4 mg twice a day or
Claritin (Loratadine) at a dose of 2.5-5 mg/cat or
Zyrtec (cetirizine) 5 mg once or twice a day
It is important to ensure that the formulations used contain ONLY the antihistamine and are not combination products (e.g. Claritin-D contains pseudoephedrine, which could cause very significant adverse effects in a cat).
Please let me know how he is doing.
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