Am I correct I thinking black tarry stools, like us humans is a bad sign need to call vet,?
Took my lab down this morning as been up straining with spluttery diarrhea  with flecks of blood all night, vet said she not got a temperature,tummy not sore, just give kaolin n rice n agg ,welll she threw up the food about a hour later, and ten mins ago she just produced the second lot of black poop,so I’m straight back on phone to vets, currently waiting a call bck
But
Monday she was in the vets all day with fine needle biopsy/aspiration near her anus, and she not been right since,but mainly just normal diarrhoea, I m thinking one of two things,picked a nasty bug up whilst at vets like parvo, she had her last jab just over two years ago as even vets say now three years regime is ok now,
Or has one of the needles punctured something inside her, she had 12: of which I can only see a couple visible,
I know I. Prob being neurotic but ...
Thanks

Black stools quite often mean blood in them & yes vets is first port of call

Almost Black solid poop is what I see when feeding a diet high in highly digestible animal protein something I am hapoy to see.

If fed raw tripe then it may be blackish green.

For me yellow poo is a sign if poor digestion/upset.

I am similar brainless but given op dog has had very recent fna in the anus I would be talking to the vet just for reassurance

Vets ran bloods n examined poop, n have given her omprimzole and sucralfate tablet, as everthyelse was clear
Back to vets to review sat morning
Cross fingers