My cat with very dark diarrhea

My dad saw my cat steal and eat food from the garbage, this is probably the cause, but we don't know what exactly she could eat. After giving her vitamins and something else, she got better. The vet said that the worsening of the condition will remain and that it is due to her age (like 16 years old), he did not do any examination other than touching her and feeling the inflammation that decreased over time, but the diarrhea keep going. The appearance of the cat's fur is a bit deteriorated and his mood too, although it's not that bad I'm afraid it could get worse over time if left untreated, I'm worried about her diarrhea, which by the way looks like petroleum. Any information or advice you can give me? Do you know what is probably wrong with her?

Hello - Black tarry stool (it is hard to appreciate the colour from the picture - you say this looks like petroleum) is a specific symptom, called melena.  Melena is a sign that the patient is bleeding into their gastrointestinal tract (food-tube), high enough up that the blood is being partly-digested by the gut as it passes along.  Melena can signify cancer or some other cause of  serious ulceration to the guts or stomach (perhaps a foreign body or severe worm infestation).  We also see it in coagulopathies, where the blood no longer clots appropriately so the blood vessels discharge into the gut, for example in liver disease or rat-poison overdose or other clotting disorders.  Often, we will try to find out what is causing it - a foreign body or clotting disorder, for example, might be treated.  I wonder whether your vet has their suspicions already?  Good questions for them, would be 'could this be Melena?'   'What do you think could be causing it?' and 'How do you feel about the prognosis?'  and 'What options are available in this case?'

Hello Liz, thanks for your reply! Today I took my cat to the vet and asked him about the black tarry stools (I forgot to mention melena), he told me that the cause is due to an affected gut flora, he is not worried about this and told me there is not much we can do, humans and dogs have yogurts to counteract this (I understand that he refers to regeneration), cats don't. He gave her a liver protective injection because yesterday she vomited, and today he felt her liver swollen. Cold water and no food for the rest of the day. Is he right or should I seek help from someone else? What do you think? Any advice will be appreciated!

Hi - it sounds as though you'd really like more discussion of this case and as though you do not trust your vet.  I cannot tell whether that is melena or not from  a picture and furthermore am not allowed to give you a second opinion - it is outside the scope of this website.  However, it in my experience it is very stressful when owners and vets are not on the same page and I am a strong advocate of second opinions.  If your vet is wrong, which happens sometimes, you need to know.  If your vet is right, you also need to know in order that you can trust them in future.  As a vet, when owners talk about black, tarry faeces I always get worried - but i am in no poaition to pass judgement on a pet I havent seen that is not my case.  I hope that this helps.