Welcome! Thanks for asking your question. My name is***** am a licensed veterinarian and I will be assisting you today.
Friend, though elevated liver enzymes and increase water consumption can be seen with cushing's disease this can also occur with: Tumors (primary within the liver or secondary), hepatitis, infections, etc. to name a few causes. If she the cushing's test was negative the next step is discussing with your vet about doing an abdominal ultrasound to take a closer look at the liver and all abdominal organs. If possible they can also do a liver biopsy.
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No friend, the symptoms you are describing are not the result of the meds you mentioned.
If this was my dog I would try to get it done as soon as possible, I would not wait 2 months.
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