Sunday, May 31, 2009

Blood in stool: Part 2 Digested Blood: Melena

Bloody stools in pets can be attributable to a variety of underlying causes. While red blood in small quantities, sometimes mixed with mucous, is fairly common, it is always best to consult your veterinarian to pursue a diagnosis.
There are two variations of this problem. hematochezia and melena. Hematochezia is the presence of bright red and fresh blood in the feces, while melena is the passage of dark, tary and black feces. Melena is actually the passage of old, digested blood from bleedings which have occurred higher up in the intestinal tract. The causes, diagnostics and treatments for hematochezia often differ from those for melena. In part 1 of this series we discussed hematochezia, today we will talk about melena.

In medical terms, melena or melaena refers to the black, "tarry" feces that are associated with gastrointestinal hemorrhage. The black color is caused by oxidation of the iron in hemoglobin during its passage through the ileum and colon. Melena is different from fresh blood in the stool (hematochezia). It may represent a severe, life threatening illness, and should not be ignored. It must especially be addressed if it persists or worsens.

Melena develops when bleeding occurs into the stomach or small intestines. The bleeding must be high in the intestinal tract in order for the blood to be digested and become discolored. In contrast, hematochezia or bleeding into the colon or rectum appears as fresh blood in the stool.

Melena usually indicates the presence of significant upper gastrointestinal disease, although occasionally other diseases, such as clotting disorders, ingestion of blood, etc. unrelated to the gastrointestinal tract may present with melena. The classic appearance of melena is black, shiny, sticky, foul smelling feces with a tarry consistency. Melena may be seen as the only clinical sign, although other systemic signs often accompany it. Ingestion of blood must be ruled out, including swallowing blood from the oral cavity or respiratory tract, and licking blood from a wound. A careful history and thorough physical examination of these patients is essential. The presence of melena generally warrants hospitalization, extensive diagnostic testing, and supportive care. It is best to determine the underlying cause and treat the specific problem.There are many potential causes for melena to include infectious agents, certain drugs, cancer, foreign bodies in the stomach or intestines, infiltrative and inflammatory gastrointestinal diseases, ingestion of blood, bleeing disorders or coagulopathies, metabolic and other diseases that cause gastrointestinal ulceration, perioperative hemorrhage, which is bleeding associated with surgery on the intestinal tract, gastrointestinal ischemia or lack of blood supply and as an uncommon cause, ingestion of heavy metals.To determine if your pet is suffering the disease, watch out for dark, almost black stools, diarrhea, vomiting, pale gums, other areas of bleeding or bruising on the body, weight loss, poor appetite and excessive drinking or urinating.

To diagnose melena, a thorough history and physical examination are often helpful in determining if melena is present and in suggesting an underlying cause. To determine the exact cause, an extensive battery of tests is often required to identify or isolate the specific cause. Such tests may include:

Complete blood count (CBC) to evaluate for the presence of infection, inflammation and anemia associated with some diseases that cause melena, a biochemical profile to rule out metabolic causes of melena and to evaluate electrolyte and protein levels, urinalysis to evaluate the kidneys, the hydration status of the patient and the presence of blood in the urine, fecal examination for parasites and fecal culture for bacteria, abdominal and chest X-rays to identify foreign objects or tumors and to evaluate for the presence of fluid/blood or metastasis/spread of tumor in the lungs, serology for certain infectious diseases, coagulation profile and platelet count to assess blood clotting, abdominal ultrasonography, upper gastrointestinal barium series, endoscopy, dietary recommendations vary depending on the cause; however, a bland diet that is easy to digest may be recommended.

Avoid all gastrointestinal irritants like corticosteroids and aspirin drugs. Drugs that block the production of stomach acid and coat the stomach may be recommended. In severe cases, hospitalization is warranted for intravenous fluid therapy, blood transfusions, and supportive care.As the above diagnostic tests are underway, your vet may start symptomatic therapy, especially if the problem is severe. The following nonspecific, symptomatic treatments may be applicable to some pets with melena. They may reduce the severity of symptoms and provide some relief to your pet. However, nonspecific therapy is not a substitute for definitive treatment of the underlying disease responsible for your pet's condition.

Temporarily discontinue all oral liquids and food, especially if the animal is also vomiting. This allows the GI tract to rest and may facilitate healing of the lining of the GI tract. Gradual reintroduction of small amounts of bland food may then be instituted if the clinical signs have subsided. Subcutaneous or intravenous fluid and electrolyte therapy may be necessary in some patients with melena to correct dehydration, acid base, and electrolyte abnormalities. Blood transfusions may be indicated in the patient that becomes anemic from the melena. Plasma transfusions and vitamin K therapy may be indicated in patients with coagulopathies. Drugs that decrease acid production by the stomach may expedite the resolution of melena, especially if it is secondary to gastrointestinal ulcers. Gastrointestinal protectants and adsorbents or bind harmful substances may be considered. Protectants containing bismuth should be avoided because they often turn the stools black and can make it difficult to determine whether the melena has resolved. In some cases surgical intervention is recommended, especially when a bleeding ulcer, gastrointestinal tumor, foreign body, or malpositioning of the stomach/intestines is diagnosed.

Most of this information I found in an article written by
Dr. Bari Spielman for the
While I am not a vet and you most certainly need to follow your vet’s advice, I personally would prefer an alternative treatment over the conventional “throw some hard core meds at the problem” solution. Natural remedies can be great alternatives. They are very effective and safe to use as well. Look out for homeopathic medications with powerful herbs. Apart from giving the right medications make dietary changes. Highly processed food affects your pet’s health badly. As a first line of defense, you may try giving your pet a bland diet that consists of rice as well as potatoes and substitute these foods for its regular food. The best solution is raw, unprocessed food and plenty of water to drink. And maybe you want o look for a vet fit in holistic animal care.

Note: Blood in stool: Part 1 Fresh Blood: Hematochezia


Anonymous said...

"I personally would prefer an alternative treatment over the conventional “throw some hard core meds at the problem” solution...."

This paragraph reveals that you have a complete lack of any medical knowledge. You are endangering the lives of those animals owned by people daft enough to follow any of your advice.

The Pet Food Examiner said...

I was thinking a while whether or not to approve your comment for publication. I concluded, why not. Your comment is totally out of place and you are taking a part of an entire sentence completely out of content. That exact same sentence you are criticizing also states:
"While I am not a vet and you most certainly need to follow your vet’s advice".
And the paragraph containing the comment also concludes with:
"maybe you want o look for a vet fit in holistic animal care."
Everything else in this paragraph is my personal opinion and in no way meant to speak against any medical science.
As is the entire blog, a place where pet owners including myself can not just tal about their experiences but also express an opinion.
The blog also is clearly identified as such, see Disclaimer at the bottom. It is not supposed to be or represent a library of medical advice.
In that spirit, can we keep comments factual. I don't mind criticism and can take a lot of it if it is justified. Your comment is not.
If that is because you had a negative experience related to this issue, then I am very sorry to hear that and would understand you seemingly over-reacting. Otherwise not.