I Have A Question Regarding Fluconazole 340 Mg. This Is

I have a question regarding fluconazole 340 mg. This is not for a human, but for our Golden Retriever, 5 yrs old, suffering from diagnosis of Valley Fever. He has been taking this med for about one (1) full week, one tablet every 12 hours. It make him very lethargic with no appetite. Within the last two days I have noticed blood on his bedding. Examined him and could find to evidence of any type of external injury. Checked hind-end and no evidence of blood. It was hard to determine if he is vomiting the blood but it is the only conclusion I came determine. Is this possible that the above mentioned medication is the cause and should I stop treating him with this. I wanted to ask a physician vs a vet as the vets I have spoken to are unsure as they state they base it on human results and truly only guess on canine.