Experienced and professional animal trainer provide their insights in answering this question :
A. Black stool usually means bleeding in the gastrointestinal tract (unless the dog was fed large amount of food containing blood). You should take your dog to your vets as this symptom can be due to one of serious diseases like blood clotting disorder, stomach or intestinal ulceration, intoxication.

How to Identify Common Pet Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced pet care professionals :

Known as melena, black stool can result from a range of things including cancer, foreign bodies, parasites, and viral or bacterial pathogens, Dr. Spangler adds. As such, black dog poop warrants a call to your veterinarian.
How can I treat my dog`s black stool at home? If your dog has black poop but is still acting normal (a.k.a. no vomiting, healthy-looking gums, etc.), you can reverse his stool appearance by feeding him bland yet high-quality, human-grade food.
Various infectious agents can cause black diarrhea in dogs. Common culprits include bacteria, parasites, viruses, and fungi. All of these pathogens can cause severe bleeding either in the stomach or intestines. In both cases, the outcome is the same – bloody diarrhea.
Melena 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.
Black dog poop can be caused by a number of issues, including, indigestion, parasites, internal bleeding, bacterial infections, pancreatitis, or toxic indigestion. Seek veterinarian advice when you dog has black poop because it could result in a severe problem if left untreated.
The biggest concern with black dog poop is that it may indicate digested blood coming from somewhere in the body. If your dog`s stool is black and tarry or sticky, he should be evaluated by a veterinarian right away as this is a serious symptom–called melena.
Melena is a dark, sticky, tarry stool, almost jelly-like. This blood has been digested or swallowed, indicating a problem in the upper digestive tract. You can check whether your dog`s stool contains this kind of blood by wiping it on a paper towel to see if the color is reddish.
Symptoms that may be seen with melena vary depending on the amount of blood loss and the source of bleeding. Significant blood loss can lead to symptoms of low blood volume, anemia, or shock, such as weakness, shortness of breath, pale skin, clamminess, dizziness, confusion, and tachycardia or a fast heart rate.
When should you worry about black stool? If your black stool looks tarry or sticky and has a strong smell, it might be melena. Melena means you`re bleeding somewhere inside. Internal bleeding is always serious, especially when you can`t tell if it`s stopped.
Melena usually means bleeding from this location. It takes 50 ml or more of blood in the stomach to turn stools black. One to two liters of blood administered orally will cause bloody or tarry stools for up to 5 days, the first such stool usually appearing within 4 to 20 hours after ingestion.
Melena can sometimes go away on its own, but there are other times when it may need medical attention. For example, if the Melena is caused by a minor irritation in the digestive tract, such as a small tear in the lining of the stomach or esophagus, it may heal on its own within a few days to a week.
Black stool may be from dark foods and drinks (beets and dark beer), supplements like iron, or a sign of bleeding in the upper GI tract. If stool is black and has a bad odor, it is likely a sign of bleeding, from a peptic ulcer, gastritis, inflammation, colon polyps, or colon cancer.
Do I need to visit the vet? Loose runny poo with jelly like blood: this may be colitis (inflammation of the lower part of the bowel) – it should resolve in a couple of days, but some cases need treatment, so contact your vet if your dog is unwell or the symptoms persist or are severe.
People with diabetes may experience frequent diarrhea — loose, watery stools that happen at least three times a day. You may have fecal incontinence as well, especially at night. Diarrhea can also be due to metformin, a diabetes medication.
Sometimes, blood in your dog`s stool is nothing to be worried about, and it`s the result of a simple problem that will get better on its own in just a few days. However, in other instances, there may be a much more severe underlying problem that needs to be addressed.
Melena in Dog`s Stool

If the blood in your dog`s stool is darker, sticky, and tar-like then it`s Melena. Melena is the blood that has either been swallowed or digested which points to issues in your pet`s upper digestive tract, esophagus, stomach, or upper small intestines such as parasites, and liver cancer.

Some of the signs of parvovirus include lethargy; loss of appetite; abdominal pain and bloating; fever or low body temperature (hypothermia); vomiting; and severe, often bloody, diarrhea. Persistent vomiting and diarrhea can cause rapid dehydration, and damage to the intestines and immune system can cause septic shock.
Stress is a common cause of bloody diarrhea in dogs. Stress can be caused by many different things, including changes in routine, travel, boarding, or even moving to a new home.
Hookworms attach to the intestinal wall, and heavy parasite loads can lead to potentially fatal anemia as well as ulceration at the feeding sites. It leads to a dark, bloody stool called melena, which occurs when the digested blood passes through the gastrointestinal tract.
Black, tarry stool typically indicates the presence of an acute condition in the upper GI tract. After the bleeding has stopped, stool may continue to appear black and tarry for several days.
Black or tarry stools may be due to bleeding in the upper part of the GI (gastrointestinal) tract, such as the esophagus, stomach, or the first part of the small intestine. In this case, blood is darker because it gets digested on its way through the GI tract.
Foods that cause dark stools are beetroots, dark chocolates, blueberries, blackberries, etc., It is normal if you get black stools after eating these foods. It does not need medical treatment as it will resolve on its own. However, if the cause does not seem to be food, it is a medical emergency.
Late-stage symptoms

In the later stages of cirrhosis, you may vomit blood or have tarry, black stools. This is because blood can`t flow through the liver properly, which causes an increase in blood pressure in the vein that carries blood from the gut to the liver (portal vein).

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Q. Which common foods are poisonous to pets?
ANSWER : A. That’s a great question. As responsible pet owners we need to be aware of food items that can be harmful to our canine or feline companions. Here are some of the most common foods proven to cause illness in our animals at home:

Chocolate: A favorite and irresistible treat amongst most humans, chocolate is considered toxic to dogs. In very small amounts it is usually not a huge issue, but with larger volumes and with darker chocolates pet owners should be concerned. Chocolate contains methylxanthine theobromine, which is similar to caffeine. Chocolate ingestion can cause vomiting, diarrhea, hyperactivity, issues with normal heartbeats, seizures, and in some severe cases, death. It is best to keep your favorite chocolate treats in a good hiding spot and out of reach of your dog or cat.

Grapes and raisins: Dogs should not consume grapes and raisins because of the risk of acute kidney failure. Most dogs experiencing grape or raisin toxicity will begin to have vomiting and/or diarrhea within 6-12 hours of ingestion. Other abnormal clinical signs include lethargy, abdominal pain, dehydration, and tremors. Kidney failure develops within 24-72 hours of the initial ingestion. There are some dogs that do not experience these devastating side effects. It is best to contact your veterinarian or veterinary emergency facility if you believe your pet has ingested grapes or raisins.

Garlic and onions: We often forget that our meals contain these two popular ingredients and will allow our furry companions a few bites or licks. Onion and garlic both can cause a type of poisoning that results in damage to red blood cells, making them more likely to rupture. They can also cause stomach upset and mouth irritation. Look for pale gums, increased breathing or drooling or any vomiting or diarrhea.

Bread dough: Unbaked bread dough is considered poisonous to our pets. The bread dough, when ingested, expands in the stomach because of the warm and moist environment. This can lead to a bloated or even twisted stomach. In addition yeast is often added to our baking products to help get bread to rise, and when this yeast is fermented it produces both carbon dioxide and alcohol. The alcohol produced can be absorbed into the bloodstream and causes dangerous drops in blood sugar, blood pressure and body temperature. Common clinical signs include vomiting or retching, distension of the stomach, weakness and collapse.

Macadamia nuts: Ingestion of these nuts are not proven to be fatal in dogs but can cause them to experience uncomfortable clinical sings, including fever, joint stiffness, vomiting, tremors and difficulty walking, especially in their hind legs. Often your pet will start to feel better after about 48 hours, but supportive veterinary care (such as pain medication) may help ease their discomfort.

Xylitol: The most common ingredient used in sugar-free gum is xylitol, which is a non-caloric sweetener. It is also found in some oral rinses, toothpastes and vitamins. Xylitol and dogs do not mix – it can cause a dangerous drop in blood sugars levels. Dogs will often display signs of disorientation, black tarry stool, tremors and seizures. If severe enough some dogs have developed liver failure. Keep your gum away from your canine companion.

Avocados: Avocados are not actually poisonous to dogs or cats but as many veterinarians can tell you the avocado pits can cause a foreign body obstruction. Avocados contain persin, which is actually toxic to the majority of pet birds. The abnormal clinical signs associated with avocado ingestion in birds include, respiratory distress, inability to perch, liver and kidney failure and sudden death.

Go forth and enjoy your favorite foods, but keep in mind which foods you should avoid sharing with your furry family members. Whenever in doubt, contact your veterinarian for healthy and safe food suggestions.

Q. Whenever I take my dog on walks he always barks at people and others dogs in my neighborhood. What should I do to resolve the problem
ANSWER : A. The very first thing to do is to make sure your dog is getting sufficient physical and mental exercise every day. A tired dog is a good, happy dog and one who is less likely to bark from boredom or frustration. Depending on his breed, age, and health, your dog may require several long walks as well as a good game of chasing the ball and playing with some interactive toys.

Figure out what he gets out of barking and remove it. Don’t give your dog the opportunity to continue the barking behavior.

Ignore your dog’s barking for as long as it takes him to stop. That means don’t give him attention at all while he’s barking. Your attention only rewards him for being noisy. Don’t talk to, don’t touch, or even look at him. When he finally quiets, even to take a breath, reward him with a treat. To be successful with this method, you must wait as long as it takes for him to stop barking. Yelling at him is the equivalent of barking with him.

Get your dog accustomed to whatever causes him to bark. Start with whatever makes him bark at a distance. It must be far enough away that he doesn’t bark when he sees it. Feed him lots of good treats. Move the stimulus a little closer (perhaps as little as a few inches or a few feet to start) and feed treats. If the stimulus moves out of sight, stop giving your dog treats. You want your dog to learn that the appearance of the stimulus leads to good things.

Teach your dog the ‘quiet’ command. Oddly, the first step is to teach your dog to bark on command. Give your dog the command to “speak,” wait for him to bark two or three times, and then stick a tasty treat in front of his nose. When he stops barking to sniff the treat, praise him and give him the treat. Repeat until he starts barking as soon as you say “speak.” Once your dog can reliably bark on command, teach him the “quiet” command. In a calm environment with no distractions, tell him to “speak.” When he starts barking, say “quiet” and stick a treat in front of his nose. Praise him for being quiet and give him the treat.

As in all training, always end training on a good note, even if it is just for obeying something very simple, like the ‘sit’ command. If you dog regresses in training, go back to the last thing he did successfully and reinforce that before moving on again. Keep sessions short, 15-20 minutes max, and do this several times a day.

Q. My dog keep hacking like a cough or something in her throat, what can I do?
ANSWER : A. Hacking and coughing can be caused by a number of things ranging from foreign bodies such as twigs stuck in the mouth or throat, to infections or illnesses such as Bordetella or Kennel cough, common in dogs that frequent kennels, dog daycare or dog parks. In older dogs, heart and lung issues can also be indicated by a cough that does not go away.

If you think there may be a foreign object stuck in your dog’s throat, you can sweep a finger gently through the back of the mouth or throat if your dog will let you. If something feels stuck and is not easily moved by the finger, it is best to contact your vet to have the object safely removed. This usually requires sedation so that your dog does not become panicked or move, causing the object to become further stuck or cut the throat.

If your dog is showing other symptoms of illness in addition to the cough such as runny nose or eyes, fever, lethargy or changes in appetite, it may indicate a viral or bacterial illness such as kennel cough. These are usually treated with a cough medication in severe cases, plus rest and treatment of any additional symptoms until the condition improves. In bacterial causes, antibiotics may also be given to help your dog feel better.

If your dog has a constant cough that does not go away, or has had changes in ability to exercise, breathing, or appears to have swelling around the chest or abdomen, in may indicate a lung or heart issue. Your vet can thoroughly examine your dog for any signs of heart or lung problems and can then offer care as needed depending on the cause.

Q. How do I determine how much my overweight pet should weigh?
ANSWER : A. There are many tools to determine overweight and obesity levels in pets. A new tool, morphometric measurements and body fat index, are available to accurately determine a pet’s ideal weight; this will allow an accurate determination of the amount of food a pet should receive to achieve weight loss. Feeding the correct amount will lead to greater weight loss success.

There are many weight loss food options to help pets reach their ideal weight. Your veterinarian can help make a ideal weight recommendation. Here are some tips to help your dog lose weight in a healthy and safe way:

1. Diet: Providing a healthy and well balanced diet is essential to your pet’s overall health. Finding the right food for your dog can be a challenging process. For those overweight animals many commercial dog companies offer weight loss diets, but it is important to evaluate food labels for adequate nutritional content.

You want to ensure you are not missing other essential vitamin or mineral content. Volume of food is also important and the amount of food that works for one breed of dog may not be the same for another breed of dog. Portion control as opposed to free-choice feeding can help your dog to drop a few unnecessary pounds.

There are also prescription weight loss foods designed by veterinary nutritionists, such as Hill’s r/d (http://bit.ly/1AoENSd). Some pet owners find that home cooking is the best option for helping to provide a well-balanced and realistic diet plan. There are websites such as balanceit.com that offers recipes to fit your dog’s specific needs. Consulting with your veterinarian or a veterinary nutritionist to find the appropriate diet is a great way to help your dog be as healthy as possible.

2. Exercise: Another great tactic for weight loss for your dog is exercise. Whether this is through running, walking or playing with a favorite toy all of these are wonderful types of exercise to help keep your dog at a lean and healthy weight.

For those pet owners with busy schedules utilizing professional dog walking services or playtime through dog daycare services is another option. It has been shown that those pet owners that exercise regularly with their pets generally live a healthier lifestyle.

3. Physical therapy: As animals age pet owners offer encounter their favorite canine having more difficulty walking and have a dwindling desire to play with toys. Physical therapy, specifically hydrotherapy is a wonderful way to help older and arthritic animals gain more mobility and lose weight. Hydrotherapy has been proven to have several therapeutic effects on the body including, muscle strengthening, relief of swelling, decreased joint pain, less stiffness in limbs, improved circulation, weight loss, and increased tissue healing to name a few. For more information on the benefits of hydrotherapy:
http://bit.ly/1w1qqoy

4. Veterinary visit and blood work: Weight gain can also be related to underlying health concerns such as hypothyroidism or other endocrine disorders. Scheduling a veterinary evaluation and routine blood work can be another important component in increasing the longevity of your dog’s life. Conditions such as hypothyroidism that predispose dogs to gain weight can be treated with a daily medication to improve hormonal balance. If feel that your dog is unnecessarily overweight there can be an underlying health condition that needs to be addressed.

5. Healthy treats: Pet owners love the chance to reward their favorite canine companion with treats and most dogs jump at the chance to consume these delicious products. The problem is many treats, which can include commercial dog treats or table scrapes can add many unnecessary calories to your dog’s daily intake. Reading labels and making note of the calories in these treats is an important component of understanding your dog’s overall health. Treats should not exceed more than 10 percent of your pet’s daily calories. There are healthier treats that can be offered to your pet to keep calories lower yet provide a fuller sensation. A pet owner can add steamed or pureed vegetables, such as carrots, green beans or sweet potato to add more fiber and thus a fuller feeling for your dog.

Q. Rescued a dog almost two weeks ago, and now that her kennel cough is gone her personality shines!! No previous training, how should I start?
ANSWER : A. POST FOUR:

After your dog is familiar with the behavior you lured from scratch, and taught to your dog, you can start to use the “no-reward marker” I talked about. What you do is ask the dog to perform the behavior, and if the dog does not perform the behavior, you simply say your no-reward marker (choose one: eh-eh, hey, uh-oh, oops) show them the treat, put it behind your back, and BRIEFLY ignore your dog. Just turn your back for a second or two, before turning back to your dog and saying, “let’s try that again.” When you’re ready to start over with your dog, make sure you move around. If you are repeating the same cue while in the same position, while your dog is in the same position, you are likely to receive the same results. The more you move around, and start fresh, the better your chances are of having your dog listen to your cue the second time around. BIG rewards when they dog it successfully! Lots of praise and treats.

My no-reward marker is “hey.” When my dog does something wrong I say, “hey” and she immediately understands that she needs to offer a different behavior. This is clear to her. I don’t have to say it in a mean way, I simply say, “hey” in a normal tone of voice and she understands what the word means.

Once you’ve built up that connection and communication with your new dog, you can work on all kinds of fun behaviors! I personally enjoy the more zen-like behaviors: https://www.youtube.com/watch?v=ruy9UMcuGh8

I like to teach my dog fun tricks that offer her a “job” to do of sorts like object retrieval: https://www.youtube.com/watch?v=I4iertZSva8

(object retrieval training completed; what it looks like: https://www.youtube.com/watch?v=jx0Dml28FGY)

Scent-games are fun too! Very confidence building. Hide a REALLY smelly treat in a box, and place that box in a line of boxes. Let your dog go in the room while saying something like “search!” or “find it!” and watch them hunt for that smelly treat! Lots of rewards when they find it!

Q. My dog licks his feet and legs and they are turning brown. He is a white dog. Can you help?
ANSWER : A. Licking the feet and legs can be caused by a number of things in dogs including allergies, illness or even stress behaviors. Allergies are the most common in dogs, with yeast infections coming in second. Allergies can cause the area to become red and itching, making your dog want to lick and chew on them. Over time, the area may become stained from saliva, especially in lighter or white-coated dogs. Yeast infections are also common between the toes, and may cause a smelly “corn chip” smell to appear near your dog’s feet. Again, dogs will attempt to lick and chew to relieve the itch. Keeping the feet clean and dry can help relieve both allergies and infections and pet wipes or a baby wipe of all paws when your dog comes in from outdoors may also help. Keeping your dog from licking the space with either dog booties or an Elizabethan collar is also good as it will prevent secondary infection and staining of the paws and legs. If your dog is determined to keep licking and keeping the feet clean and dry do not help, then your vet can help by providing a medication to treat any infection or provide relief of allergies.

Q. Healthy German Shepherd has extremely loose stools once a day. I added 2 spoonfuls of pumpkin puree that hasn’t helped. No diet changes. Any advice?
ANSWER : A. Loose stools can be caused by a number of factors, and the first step is always to bring a stool sample to your local veterinarian to check for anything. Fecal exams can check for common bacteria and parasites in the stool that may cause chronic diarrhea.

Diet problems can also play a factor in loose stool as well as chronic illness. Dogs can be allergic to many different ingredients in the diet, however grains such as corn, wheat and soy products can be the most problematic. Adding a probiotic supplement can sometimes help such as a scoop of plain yogurt ever meal, or commercial product from your vet.

Illnesses and metabolic disorders may also cause chronic loose stools. German Shepherds are prone to a disease called Exocrine Pancreatic Insufficiency which is a problem with the pancreas (the same organ that dysfunctions in diabetes- however that is ENDOCRINE function in that case) producing enough digestive enzymes. This causes stools that may be loose, discolored grey or yellow and appear very fatty in color. Shepherds can also be prone to chronic small intestine infections that cause loose stool as well. Luckily, treatment for these conditions often just involves adding a daily digestive enzyme supplement to the food, or daily anti-biotic designed specifically for chronic bowel issues.

Read Full Q/A … : Veterinarians

Q. My 9 month old Maltese-Shih eats his own feces. Is there anything i can give him to get him to stop?
ANSWER : A. Coprophagia (or eating stool) is very common in young dogs. Luckily, most dogs will outgrow this behavior as they age. There are several theories as to why dogs do this which range from mimicking the mother dog’s behavior of cleaning the den, nutrient deficiency, boredom or just plain enjoyment of it.

If your dog is eating his own, removing the feces as soon as he deposits them is best in preventing them from being eaten. Keeping your dog on a leash while he potties can also help to catch any stool before he finds it. If he is eating other stool as well, sweeping the area prior to letting him out to go potty can help you identify and remove any left-behind stool.

There is also a product called For-bid that is available to make stool distasteful to pets. This product is sprinkled over every meal for a period of a week. When your dog attempts to eat the stool formed from this product, it becomes distasteful and discourages him from doing so. Most dogs will stop after a week of use, but some may need a few reminders from time to time to completely stop the behavior.