When to Be Concerned: Blood in Your Dog’s Stool Explained

Seeing your dog deal with a bout of diarrhea is concerning enough, but for many owners, discovering traces of blood in that diarrhea is a whole lot more alarming.

As a veterinarian, I understand how worrying it can be to discover bloody dog poop, even if your pet is acting fine otherwise.

So what do you do when your dog has diarrhea with blood but is acting normal? Is it time to panic, or is a bit of blood in your dog’s stool nothing to worry about?

Well, the answer is it depends…knowing what causes bloody diarrhea, even when your dog seems unaffected otherwise, could help you respond appropriately and promptly to such situations.

It’s perfectly understandable for owners to feel an instinctive surge of panic when they catch sight of blood in their dog’s poop, even if their pet remains seemingly unfazed.

While it isn’t ‘normal’ to find blood in your dog’s stool, it doesn’t always indicate the worst-case scenario. 

Rest assured that I’ve seen many cases where a dog stool containing a small amount of blood doesn’t need to raise immediate alarms. If the issue is confined to the gastrointestinal system, it generally doesn’t cause your dog to become unwell; the small amount of blood loss is often not enough to cause adverse symptoms. But that doesn’t mean it should be ignored.

If your dog is unwell, displaying any other symptoms, or has had blood in their stool for a prolonged period of time, then you should take them to see a veterinarian immediately. There are more sinister causes of bloody diarrhea in dogs that shouldn’t be ignored. 

It’s a common scenario I see in my practice as a vet: a happy, energetic dog suffering with a bit of blood in their stool. There can be a range of different causes of this, ranging from less severe to more concerning.

The most common causes of bloody stool in a dog that is acting fine are:

1. Dietary changes – A sudden change in diet can alter the delicate balance of beneficial bacteria in your dog’s gut that helps with digestion. This irritates the gastrointestinal tract, causing inflammation and potentially damaging the lining of the intestines. This can result in small amounts of blood in your dog’s stool. 
2. Dietary indiscretion or allergies – Dogs have a reputation for devouring anything within their reach. Ingesting foreign objects or spoiled food can injure or damage the intestinal lining, leading to blood in dog stool. Similarly, if your pet has a dog food allergy, that could result in bloody poop.
3. Parasitic infection – Parasitic infections, such as hookworms, whipworms, or coccidia, can cause a bloody stool due to the damage they inflict on the intestinal lining.
4. Constipation – When a dog is constipated, the hard and dry feces can cause small tears or fissures in the delicate tissues of the anus as your dog strains to try and poop. These tears can result in bleeding, which may be visible in the stool.
5. Anal gland disease – When a dog’s anal glands become blocked, infected, or inflamed, this can result in discomfort and pain when your dog poops, leading to straining and damage to the anus. This can result in blood in the stool.
6. Eating raw meat – Occasionally, dogs might eat raw meat containing blood, which then passes through their digestive system. This blood is typically partially digested, resulting in a darker, bloody appearance known as melena.

If your dog has blood in their stool, it is crucial to closely monitor their condition. If your dog shows any signs of deterioration or if the bloody poop persists for more than a few days, it is best to seek immediate veterinary advice.

In a dog’s stool, blood can appear in two distinct forms: bright red or dark black. This distinction is crucial as it helps identify the source and severity of bleeding within your dog’s digestive tract.

Hematochezia is a term used to describe the presence of fresh blood in a dog’s stool. The bright red appearance of the blood indicates that the bleeding has likely occurred in the lower digestive tract, most often in your dog’s large intestine or colon. 

When a dog has hematochezia, the blood is often mixed with the feces, giving it a reddish appearance. You may also see mucus or a slimy appearance on your dog’s stool. 

The causes of hematochezia can vary and may include conditions such as intestinal parasites, dietary indiscretion, inflammatory bowel disease, infections, rectal or anal injuries, or tumors. Although hematochezia doesn’t always indicate a severe health problem, ongoing or excessive bleeding requires veterinary attention immediately.

Melena refers to the presence of a dark, sticky, and tarry stool. It indicates bleeding in the upper digestive tract, usually the stomach or small intestine. When blood is digested or swallowed, it undergoes chemical changes, resulting in the characteristic dark appearance of melena. 

Unlike bright red blood seen in hematochezia, melena suggests that the bleeding occurred higher up in the gastrointestinal system. Melena can be caused by various conditions such as stomach ulcers, tumors, ingestion of foreign objects, or certain medications. Melena, combined with other signs like vomiting, decreased appetite, weakness, and lethargy, should be taken seriously.

However, there is a slight caveat: if a dog eats raw meat, the blood in the meat will be digested, also resulting in melena. Simply, changing from a raw meat diet, which I wouldn’t advocate for dogs anyway, can clear up the presence of melena in a dog’s stool.

Blood in dog stool can sometimes resolve itself without specific treatment, particularly when the cause is mild, such as in the case of dietary indiscretion.

However, it’s important not to wait too long for this issue to resolve itself. If your dog’s blood stools are due to something minor, then you’d expect the issue to clear up within 24-48 hours.

It’s essential not to presume your dog’s bloody stool will resolve on its own. If the bleeding is getting more frequent or severe, then it’s important to seek veterinary attention immediately.

While blood in your dog’s stool can sometimes be caused by something minor, it’s important to be aware that this is not always the case.

Seek veterinary advice immediately if your dog displays any of the following signs:

A few streaks of blood in your dog’s poop is one thing, but if their stools consist almost entirely of blood, then see the vet immediately. Look at the color; if their poop is redder than it is brown, then it’s time to be proactive. A lot of blood in your dog’s stool is always a cause for concern.

If the bloody dog poop persists for longer than 24-48 hours, it’s essential to take your dog to the vet as soon as possible. This could point towards a more severe underlying condition like hemorrhagic gastroenteritis or bacterial and viral infections, which require veterinary attention immediately.

Bloody stools accompanied by pale gums is more of a cause for concern. If the inside of your dog’s lips doesn’t seem the normal pink color, then this could indicate that your dog is anemic – likely caused by a significant loss of blood. This indicates a more severe underlying condition that requires urgent vet care for an accurate diagnosis and treatment plan.

If your dog suddenly loses their appetite in addition to their blood stool, it’s crucial to see the vet immediately. A lack of appetite in dogs can indicate an underlying condition that requires urgent attention.

Vomiting, in addition to bloody diarrhea, indicates a more severe underlying condition such as viral and bacterial infections, foreign body ingestion, toxins, or even cancer. Get your dog checked out immediately.

When it comes to blood in a dog’s poop, the presence of blood should never be ignored, even if your dog is acting normally. But whether bloody stools in dogs constitute an emergency depends on the specific circumstances and the context of the situation.

A young, otherwise healthy dog that has just a small amount of blood in their poop is not considered an emergency case. Monitor them carefully, and if they deteriorate in any way or the blood doesn’t clear up after 24-48 hours, then you should take them to see the vet. 

Blood in the stool of older or senior dogs should be approached with greater caution, even if they appear fine in themself initially. Older dogs are prone to more severe health conditions, so you should err on the side of caution in this case; take them to see the vet to rule out any underlying causes.