Melena in Birds
Melena is the presence of digested blood in the fecal component of the droppings. In birds, the droppings are composed of three elements: feces, urates and urine. The droppings are stored in the cloaca, the common emptying chamber for the gastrointestinal, urinary and reproductive tract. Feces are produced in the intestinal tract and are normally light green or brown in color. Urine and urates are produced in the kidneys. Usually, birds only produce a very small volume of liquid urine, and the majority of the waste from the kidneys is in the form of semi-solid, white/beige urates.
Melena usually appears as green-black, tarry stool. The feces may be firm or liquid in consistency (diarrhea). In most cases melena is caused by bleeding in the upper gastrointestinal tract. Occasionally, however, melena may be seen when blood is ingested.
There are many causes of melena in birds. A few of the more common causes include:
- Gastrointestinal foreign bodies
- Gastrointestinal cancer
- Bacterial infections
- Gastrointestinal ulcers
If your bird occasionally has a few droppings that are dark green or black in appearance but has no other symptoms, the color change may be caused by the diet. For example, birds fed a colored commercial pelleted diet sometimes pick out and eat only green colored pellets. This will give the feces a temporary green color. Other dietary pigments may have a similar effect. If, however, the color change is persistent (lasts more than a day), recurrent (returns frequently) or other symptoms occur, medical attention is needed.
What to Watch For
- Ruffled feathers
- Tucking the head under the wing
- Loss of appetite
- Vomiting or regurgitation
- Fresh blood in the feces
Your veterinarian will recommend specific diagnostic tests depending on how severe the melena is and what other symptoms are present. Birds with melena usually have serious disease requiring extensive diagnostic testing.
A complete history is extremely helpful in reaching a diagnosis. Be able to answer the following questions:
- When did the melena began?
- Have the droppings changed in consistency or color?
- Does your bird chew on toys or other objects?
- What type of diet does your bird eat?
- Is there any potential exposure to other birds?
Diagnostic tests your veterinarian may recommend include:
- A thorough physical examination
- A fecal occult blood test
- Sampling the feces or cloaca for bacterial culture and cytology
- A complete blood count (CBC) and serum biochemistry panel
- Blood tests or other samples for Chlamydiosis (Psittacosis)
- Radiography (X-Rays)
Treatment for melena may include any combination of the following:
- Hospitalization for fluid administration and injectable medications
- Surgical or endoscopic removal of foreign bodies
- Dietary change or forced-feeding
- Antibiotics or antifungal medications
- Medications to protect the intestinal tract
- Medications to alter the motility of the intestinal tract
Home Care and Prevention
If only one or two of the droppings appear melenic and the bird has no other symptoms, return the bird to his usual diet, without fruits, vegetables or colored pellets for 24 hours. Be sure that plenty of fresh water is available and that the bird is drinking.
Use only paper (no litter of any type) on the cage bottom, and change the paper daily so that you can monitor the droppings. If droppings do not return to normal within 24 hours, or any other symptoms develop, contact your veterinarian.
After being treated by your veterinarian, be sure to give all medication as directed, for as long as directed, even after the symptoms appear to be gone. Watch for a change in the droppings, and report any changes or lack of improvement to your veterinarian.
Melena is the presence of digested blood in the feces, and usually occurs as a result of bleeding in the gastrointestinal tract, including the crop, esophagus, proventriculus, ventriculus or small intestine. Occasionally, melena occurs as a result of blood being ingested. For example this might occur if blood from the nose or mouth were swallowed.
Melena should be differentiated from fresh blood in the feces, which is bright red, and usually comes from the colon or the cloaca (common emptying and storage chamber for the intestinal, urinary and reproductive tract). The color of the feces can also change due to alterations in the diet, and may be mistaken for melena. For example, if birds are fed heavily pigmented foods, such as berries, tomato products or colored pellets, the stool may turn the color of the food. If the stool ever appears to be a very dark green-black color, and has a shiny consistency, your veterinarian should be notified immediately, since this is likely to be caused by digested blood.
Anorexia, weight loss, crop stasis, vomiting or regurgitation often accompany melena. Feces may be a normal or loose consistency.
There are many causes of melena in birds. In most cases, bleeding within the gastrointestinal tract is reason for serious concern. There are many contagious diseases which cause melena, so it is important to inform your veterinarian of any potential contact – direct or indirect – with other birds. Possible causes of melena in birds include:
- Foreign bodies. Ingested foreign objects cause irritation and ulceration of the gastrointestinal lining, and are therefore a common cause of melena. Psittacine birds have powerful beaks, and a strong instinct to chew. Common foreign bodies include string toys, bark or wood shavings, and pieces of rubber toys.
- Toxins. Heavy metals, plants and cigarettes are commonly ingested. Most plants and cigarettes cause melena by irritating the intestinal tract. Heavy metal toxicity, caused by ingestion of objects containing lead or zinc, is one of the most common diseases seen in pet birds. Not all birds with heavy metal toxicosis have melena, and most have other symptoms, especially neurologic signs.
- Bacterial infection. Bacteria may invade the lining of the gastrointestinal tract, resulting in ulceration or hemorrhage. Bacterial infections may come from other birds, from an overgrowth of dangerous bacteria on dirty food or water bowls, or spoiled foods. Often, small amounts of potentially dangerous bacteria live in the intestinal tract without causing harm. This population of bacteria can overgrow and cause disease if the bird's immune system is not functioning properly, as may occur during times of stress. An overgrowth of harmful bacteria may also occur when antibiotics are used improperly.
- Viral infection. Several different avian viruses may cause melena. In most cases, melena will be only one of several symptoms.
- Neoplasia (cancer). Tumors in the intestinal tract occasionally hemorrhage.
- Cloacal papillomas. Papillomas are wart-like structures. They appear most commonly in the cloaca but may occur anywhere along the gastrointestinal tract. Papillomas are one of the most common causes of fresh blood in the feces, but may occasionally also cause melena. There is also a higher incidence of gastrointestinal tract cancer in birds with cloacal papillomas.
- Obstruction. Occasionally, an intestinal intussusception (telescoping of one part of the intestinal tract into another) may cause diarrhea and melena initially, then a lack of feces later in the course of disease.
- Metabolic disorders. Liver disease or renal disease can cause melena.
- Nasal or oropharyngeal hemorrhage. Blood from hemorrhaging tumors, irritation or infection in the nasal cavity, mouth or pharynx may be swallowed, resulting in melena.
A thorough history is extremely important in the diagnosis of diarrhea. Be prepared to answer the following questions:
- Is there fresh blood in the droppings?
- Has the diet changed?
- Is the bird still eating a normal amount of food?
- What are the birds chewing habits?
- Does he have access to metal objects or plants?
- Does the bird chew apart wood, rubber or string toys?
- Are any other symptoms, such as lethargy, diarrhea or vomiting present?
- Has the bird been exposed to other birds?
- How often is the cage, the food and water dishes cleaned, and how are they cleaned?
Your veterinarian will recommend specific diagnostic tests depending on other symptoms present and physical examination findings. Most birds with melena have a serious disease that requires extensive diagnostic testing. Any combination of the following may be recommended:
- Examination of the nasal cavities and mouth
- A fecal occult blood test, to differentiate blood in the feces from dietary pigments
- Sampling the crop, feces or cloaca for bacterial culture and cytology (looking at cell types for evidence of infection or inflammation)
- A complete blood count (CBC) to determine the number of circulating white blood cells and distinguish between infectious and non-infectious causes of melena
- A serum biochemistry panel to look for evidence of metabolic problems, such as diseases of the liver, kidney or pancreas
- Plasma protein electrophoresis to look at the types of proteins present in the circulation. For example, birds with chronic diseases, especially infectious or inflammatory diseases, produce antibodies, and an increase in one class of proteins (gammaglobulins) occurs. Birds with liver disease or severe intestinal disease usually have low concentrations of another class of protein (albumin).
- Blood tests that measure the amount of heavy metals, such as lead or zinc in circulation
- Radiography (X-Rays) to look for evidence of intestinal disease, size and density of the liver, kidneys or other organs.
- Contrast radiographs, such a barium studies, to look for tumors or foreign bodies, ulcerations or thickening of the lining of the intestinal tract. This test will also determine how quickly ingested material is moved through the intestinal tract.
- Fluoroscopy is a video or moving X-ray that is used to determine if the coordination of peristaltic waves is normal. It is useful in the diagnosis of foreign bodies, toxicity (lead or zinc) or viral diseases (proventricular dilatation disease).
- Abdominal ultrasound is only possible in birds with enlargement of the liver or fluid in the abdomen. It allows visualization of the intestinal tract for evidence intestinal wall thickening, gastrointestinal masses and foreign bodies. A specialist usually performs this test.
- Endoscopy is used to view the intestinal tract or body cavity directly. Samples can be collected for biopsy or culture. A specialist usually performs this test. Some foreign bodies may be removed this way.
- Exploratory laporotomy is a surgical procedure that is occasionally necessary to obtain segments of the intestinal tract for biopsy in order to determine the cause of melena.
Before a diagnosis is reached, treatment of the symptoms might be needed, especially if the problem is severe. The following treatments may be applicable to some, but not all birds with melena. These treatments may reduce the severity of symptoms, or provide relief for your bird. However, nonspecific therapy is not a substitute for definite treatment of the underlying disease responsible for your bird's condition.
- Birds with melena and other symptoms such as lethargy and anorexia usually require hospitalization and 24-hour care.
- Fluid therapy is often needed since birds can become dehydrated. Fluids may be given by an intravenous catheter, an interosseous catheter (into the bone marrow) or subcutaneously (under the skin). The route of administration will depend on the severity of the dehydration.
- Dietary change may be needed for birds that are still willing to eat. A low fat and easy to digest diet is recommended. Usually, food is not withheld from birds with melena. Birds have a very high metabolic rate and require a constant source of energy.
- Forced feeding of an easily digestible liquid food may be necessary in birds that refuse food. Your veterinarian may pass a tube into the bird's crop to deliver this food.
- Antibiotics or antifungal medications may be needed to treat or prevent an overgrowth of bacteria or yeast.
- Intestinal protectants such as sucralfate (Carafate®) and cimetidine (Tagamet®).
- Surgery or endoscopy to remove foreign bodies.
- Chelation with Calcium EDTA or other chelating agents to bind lead or zinc.