Black Cat Poop: Treatment & Causes

If you’ve noticed that your cat’s faeces seem to look black, there’s a fairly good chance that your pet has some health issue, likely relating to their upper digestive tract. 

Is Black Cat Poop Normal?

The short answer to this question is no. 

Black stools are usually a sign of melena, which is a medical term describing the presence of blood in a cat’s poop. 


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There can be two types of blood that are seen in a pet’s faeces. 

Classic red blood remnants usually suggest a lesion in the cat’s large intestine toward the rectum. 

Black stools are typically an indication of blood that comes from the upper intestine as it has time to degrade and turn a darker colour. 

black cat poop

So, if you see that your cat is passing black stools, the best piece of advice that we can give you is to take them to the veterinary clinic. 

Black cat poop should not be something that you notice in the litter box day in and day out. 

It can be a sign that your cat ate something that has led to an intestinal lesion, with the lining becoming scratched or even punctured. 

cat at vet

Black and tarry stools can also be an indication of a severe parasitic infestation, where the population of worms is so large that they produce damage to the intestinal lining. 

But until you take your pet to the vet, there is no way of knowing for sure what is causing the melena that your cat is experiencing. 

Interestingly in some cases worms can also cause your cat’s poop to turn white.

How To Treat Black Poop In Cats

When you take your pet to the animal hospital for the first time, and you inform the veterinarian that they are passing black stools, the vet will then try to find the source of the bleeding. 

This will usually involve diagnostic techniques such as a complete blood count, blood chemistry, urinalysis, and more. 

Imaging diagnostic techniques like an ultrasound or an X-ray can prove to be very valuable in this situation. 

x-ray of a cat's bowels

For example, ultrasonography can show whether there is something wrong with your cat’s internal organs, and the bleeding might be stemming from them. 

An X-ray, on the other hand, especially one performed with contrast substances that can be either administered orally or rectally, can reveal the presence of a foreign body. 

X-rays can also show the exact ‘leak’ from the intestine if there is one, meaning in the event of a puncture. 

Cats are not as likely to develop anaemia due to blood loss as easily as people can. 

Unless there’s a severe blood loss happening, the cat will be stabilised at the veterinary clinic until the exact cause of the melena is discovered. 

Treating black cat poop at home is definitely not recommended in this case. 

Even if your pet has a long history of digestive issues perhaps triggered by various foods or by diet changes, where they experience diarrhoea and vomiting somewhat regularly, melena is not normal. 

There’s also the possibility of an endoscopy being performed under anaesthesia, which can reveal the exact location of the bleeding and the foreign body. 

In some cases, endoscopy can also be utilised for treating black cat poop, in the sense that it can dislodge the foreign body or, depending on the endoscope head, could actually stop the bleeding from the inside. 

Black Cat Poop Treatment

Until an accurate and clear diagnosis, the vet will use fluid therapy to try to compensate for the blood loss. 

There are other medications that can be administered intravenously to your cat, such as vitamin K and other adjuvants in this sense. 

vitamin K

The vet will ensure that they do not give your cat too high doses of such medications because they can cause additional problems, such as coaguli and imbalances in the bloodstream. 

Depending on your pet’s health status, they may need to be hospitalised for a couple of days so that they can be given medications at the clinic on a regular basis. 

They may also need to receive transfusions from other patients. 

If the cat is otherwise healthy and behaving normally, they have a fairly good chance of receiving the appropriate treatment and getting back to normal in less than a week. 

What Causes Black Cat Poop?

1. Foreign bodies 

Some cats develop pica, whether because they have vitamin and mineral deficiencies or because they may be suffering from behavioural complications. 

Stressed cats can ingest unnatural things such as wires, pieces of string, bits of their toys, and other foreign bodies. 

cat-in-a-paper-bag

Some of these can cause occlusions or obstructions, but if they are also sharp, they can effectively puncture the stomach or intestine lining. 

2. Ulcers 

Patients that develop ulcers in the gastrointestinal tract typically do so in the upper part of their digestive system. 

That means that the bleeding stems from a portion of the mucous membrane that can’t heal naturally.

If your cat has a gastric or gastroduodenal ulcer, by the time the blood reaches the lower part of their intestine, it will be oxidised and, therefore, cause melena. 

3. Digestive cancer 

Not all tumours cause faecal bleeding.

However, if there is a particularly large one that somehow gets damaged or produces a rupture in the intestinal lining, melena will be something that you, as a pet owner, will be able to notice. 

Cats that are known to have digestive tumours and are receiving treatment for them, but experience melena, should be seen by a vet as soon as possible.

4. Infectious diseases and parasites

Just like dogs, cats have a wide range of diseases that they can get from other animals.

Sometimes, gastrointestinal conditions can also be caused by you being a transmission vector where you bring dangerous microorganisms on your shoes when you come home. 

what causes spiral flea dirt

Some examples of infectious diseases that can cause melena, although sometimes along with diarrhoea, are the following:

  • Panleukopenia virus
  • Feline leukaemia virus
  • Feline coronavirus
  • Feline immunodeficiency virus
  • Fungal infections 
  • Isospora parasitic infestations
  • Cryptosporidium parvum 
  • Helicobacter spp.
  • Salmonella spp.
  • Campylobacter spp.
  • Clostridium spp. 

Infectious diseases could also cause your cat’s poop to turn green.

5. Rat poison

Some rodenticides are, in fact, anticoagulants as they contain Warfarin and other similar substances. 

And while they might do their job, they are also very dangerous for pets.

If cats accidentally ingest these rat poisons or if they happen to consume a rat or mouse that died because of this, they can experience internal haemorrhage too. 

Depending on the concentration and amount of rodenticide that they ingested, some cats will pass red bloody faeces or black stools. 

6. Trauma 

If your cat was hit by a car or involved in some other type of accident, you might notice black poop in their litter box. 

cat pooping in litter tray

Internal haemorrhage doesn’t necessarily involve the puncture of an organ from the outside of the body. 

Sometimes, trauma can be quite severe on the inside, even though there is minor bruising on the outside. 

Does Cat Poop Turn Black When It Dries?

Very rarely does cat poop turn black when it becomes fully dried up. 

In most cases, as it becomes even more dehydrated, the normal brown colour of cat poop might turn light brown to the point that it even becomes grey

Black poop, especially if it contains oxidised blood, will remain black for days on end. 

Black Smelly Cat Poop

Foul poop odours are almost always an indication that something is not right with your cat’s digestion. 

When combined with traces of blood such as melena, the possibility that your cat is not only experiencing bleeding in one of their digestive segments but has also developed an infection is very high. 

Black Cat Poop With Blood

The black itself means that there is blood in your cat’s faeces. 

But if there are also traces of fresher blood, such as bright red or red to brown, the bleeding could happen in several different parts of your cat’s intestine, including toward the rectum. 

Hard Black Cat Poop

Cats don’t normally pass soft stools. 

Almost always, their faeces are hard, so that’s something entirely normal. 

If the cat is constipated or dehydrated and they pass a hard stool which causes an anal fissure, for example, the blood will be red (fresh), not black. 

So, hard black cat poop still means that there could be bleeding in one of the upper segments of your pet’s digestive tract. 

Elderly Cat Black Stool

Seniors and kittens are the two categories of cats that require the most amount of care and attention. 

Their immune systems aren’t as good at putting up with the abuse of parasites, trauma, infectious diseases, or foreign bodies.

Elderly cats can pass black stools for the same reasons that we have already noted, but they might also be suffering from some type of cancer. 

So, in their case, veterinary assistance is necessary right away. 

Take your senior cat to the vet two or three times a year for check-ups, especially if they are older than 7.