My dog won't eat, losing weight, and has black tarry poop. Poisoning?
I am very sorry to hear that Max is experiencing this issue, I am sure it is unsettling. From what you are describing, tar dirrhoea, you are probably observing fresh blood in it. it sounds as though Max has colitis, or inflammation of the last portion of the large intestines.
There are several causes of colitis in dogs, ranging from bacterial infections, parasite infestations, IBD, or ingestion of contaminated food. So it is possible he ate a toxin or poison as well.
Since you have noticed such episodes for a four day period and Max is not eating I would advise a trip to the veterinarian as soon as you can. Continue to monitor Max at home until then and Provide a bland diet of boiled boneless chicken breast and white rice and plenty of fresh water.
If the episodes continue, if Max becomes depressed, passes large amount of blood, vomits, or seems very uncomfortable take Max to see his vet immediately.
I hope this answer was helpful and more importantly that Max feels better soon. Warmest regards to you both.
Updated on September 23rd, 2025