I am sorry Casey has this trouble.
It is most likely an allergic response.
Dip an orange pekoe teabag in warm water. Apply it to the teary eye several times a day. The tanic acid in the tea will sooth and heal.
Casey can also 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).
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