black stool

Question
My 14mo old bulldog has had black tarry stool for 2+ weeks now. The vet
put
him on Metronidaxole 500mg last Monday for 4 days but it didn't help. He
has had 2 stool samples taken into the vet and they both came out negative
(one last Monday and one this past Saturday). He vomited yesterday after a
walk. He didn't want to eat much this morning, but eventually did. He's still
real active and happy. He's on biweekly alergy shots. We are waiting for the
vet to call us back today, for further direction. Should we get blood work,
urinalasis, xrays? I've been reading way too much on the internet about the
worst case scenarios. Please let me know your thoughts. I'm very worried!

Answer
Yes, you need blood work immediately and an xray wouldn't hurt either. He could have a puncture or rupture bleeding into his stomach. I don't know why your vet would put him on Metro without a finding in the stool samples. If you don't get answers I suggest you seek out a second opinion asap.