Experienced and professional animal trainer provide their insights in answering this question :
A. You need to see your vet or emergency vet as soon as possible. Black coloured faeces can indicate bleeding in the stomach or high in the intestinal tract which is potentially very serious. My other big concern is dehydration as it has been going on for several days.

How to Identify Common Pet Problems ?

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When the colon becomes inflamed, it attempts to up its defences by producing even more of the normal mucus. So you will often find that your dog`s poo has a slimy consistency, or even looks like jelly. Since the walls of the colon are very sensitive to any insult, they can bleed quite easily.
If an otherwise healthy, adult dog with mild gastroenteritis signs is bright and is drinking at least their usual volume (even if they`re temporarily off their food) and you can`t see fresh blood or anything resembling coffee grounds in their vomit or diarrhoea, they`ll often recover within 24 to 48 hours with …
Most dogs with gastroenteritis will have intermittent episodes of vomiting and diarrhea. The vomit may contain foamy, yellowish bile, especially after emptying the stomach. Many owners observe dry heaving or gagging after their dog eats or drinks.
Pets that have chronic soft stool or chronic full-blown diarrhea should definitely be examined by a veterinarian, even if they are otherwise behaving normally. In these cases, there is likely an underlying problem that`s causing the diarrhea. This is especially true with older pets.
Answer From Elizabeth Rajan, M.D. A small amount of mucus in stool is usually nothing to worry about. Stool normally contains a small amount of mucus — a jellylike substance that your intestines make to keep the lining of your colon moist and lubricated.
Diarrhea that looks like mucus or contains a larger amount of mucus may signal an underlying inflammatory condition, such as a food intolerance, gastrointestinal infection, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), or hemorrhoids.
Luckily, with prompt and correct treatment, gastroenteritis in dogs can clear up within a few days to a week. However, if it doesn`t seem to be going worse or you notice blood in their stool, take them back to the vet as soon as possible for further treatment.
You`ll also want to have your dog examined by a veterinarian if diarrhea lasts for more than two days or if he or she has other symptoms along with the diarrhea. Dehydration and a host of other complications associated with diarrhea can occur quickly.
Most commonly, the cause of dog diarrhea is related to what your dog eats. Eating things like garbage or spoiled food can cause stomach upset, as can consuming poisonous substances or plants. Food intolerances and allergies can also cause diarrhea in dogs.
Most cases of gastroenteritis resolve with supportive care, either at home in very mild cases or in the hospital in more serious cases. Recovery time usually is within a few days but sometimes can last a week or more.
Chronic diarrhea is a severe condition in dogs. If you find that your dog has been suffering from diarrhea for more than twenty-four hours, you must take your pup to see the veterinarian. Due to water loss in the stool, dehydration is dangerous for your dog, so do not hesitate to take them.
Contact your vet right away if your pup is experiencing repeated episodes of diarrhea or chronic diarrhea. If your dog is showing other symptoms as well as diarrhea they should be seen by a vet as soon as possible.
Yellow stool by itself does not lead to complications, but the underlying cause of it might. Yellow stool may indicate a malabsorption disorder caused by a parasite, illness, or disease. Malabsorption of fat can lead to an increased fat content in stools, which can be pale, large, foul-smelling, and loose.
Mucus in stool caused by dietary changes

After changing to a high-carbohydrate (bread, pasta, rice) diet, stool consistency also immediately changes. If a large amount of mucus persists for several days, there is often another underlying cause.

You may also feel the urge to have a bowel movement, but only pass mucus or a very small amount of stool. It`s a common symptom of irritable bowel syndrome (IBS), but infections, including sexually transmitted infections (STIs) and other conditions, can also cause it.
Possible causes of white strings in poop

Intestinal parasites – Parasites such as tapeworms, pinworms, and roundworms can cause white string-like structures to appear in your stool. These parasites often enter the body through contaminated food or water.

Some infections, food allergies and intolerances, digestive tract problems, abdominal surgery, and long-term use of medicines can cause chronic diarrhea. Some infections from bacteria and parasites that cause diarrhea do not go away quickly without treatment.
When should I take my dog to the vet for vomiting and diarrhea? If their symptoms haven`t improved within 12-24 hours you should bring them to the vet. You should bring them sooner if they`re displaying other symptoms such as; severe tummy pain, not drinking, lethargy or if there is blood in the vomit or feces.
Canine influenza is a viral infection that primarily affects dogs, but can sicken cats, too. Currently, two strains have been identified in the United States: H3N8 and H3N2.
When signs of parvo start showing, the stool gets more watery, becoming brownish to black diarrhea with traces of blood. After signs of parvo start to show and diarrhea gets bloody and smelly, it`s a race against time because most dog fatalities happen within 2 to 3 days after the symptoms.
My dog has diarrhea, What should I do? Fast your dog for 24 hours. Only water is permitted. After the 24 hour fast, begin feeding a combination of boiled white meat chicken (with all the skin and fat removed and the water poured off) and boiled long grain white rice.
Bland, starchy, low-fiber foods like those included in the BRAT diet (bananas, bananas, rice, applesauce, toast) are binding, which can bulk stool and help you get rid of diarrhea fast. You can also try probiotics, glutamine supplements, or home remedies like herbal teas and rice water.
Recovery of Gastroenteritis in Dogs

If the symptoms do not clear after a few days, or if your dog develops additional signs, return to the veterinarian immediately. Otherwise, the gastroenteritis should clear on its own, and no further examinations will be necessary.

Treatment for Gastroenteritis in Dogs

Antibiotics, such as metronidazole. Anti-nausea and vomiting medications. Anti-diarrheal medications. Medications to prevent stomach ulcers.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Q. Changed dog’s food. Now throwing up and with diarrhea, what should I do?
ANSWER : A. Vomiting and diarrhea can occur if food is switched too quickly. Dogs generally need a slow changeover of foods over a period of a week or so to allow their guts and the gut bacteria to adjust. If there has only been one vomiting and diarrhea episode, removing the food for a few hours then feeding a bland diet of boiled chicken and plain rice can help soothe the stomach. You should then return to his old food and begin a gradual changeover of foods starting with 3 days of 75 old/25 new, 3 days of 50/50 and then 3 days of 25old/75 new. However if the vomiting and diarrhea symptoms do not improve, it may indicate something else causing his digestive distress and an appointment should be made with your local vet.

Q. My 4 year Maltese has had diarrhea for about 3 days. Now he is vomiting and the stool appears to be dark and slimy. He has no appetite.
ANSWER : A. You need to see your vet or emergency vet as soon as possible. Black coloured faeces can indicate bleeding in the stomach or high in the intestinal tract which is potentially very serious. My other big concern is dehydration as it has been going on for several days.

Q. My dog has suffered from diarrhea with vomit and bloody stools for about 3 months. Vet has given Metronidazole, but hasn’t been effective
ANSWER : A. Several things can cause a dog’s diarrhea, and chronic diarrhea can sometimes be hard to treat. However the most common causes of chronic diarrhea can be from food allergies to certain ingredients in the diet as well as a disruption in the gut bacteria. Metronidazole helps with chronic diarrhea in some cases if there is an underlying bacterial condition. Checking your dog’s food for common allergens such as wheat, corn or soy products may alert you to a problem as these can cause a lot of digestive issues in some dogs. Some dogs may also be allergic to more common protein types such as beef, lamb or even chicken, so finding a food with an alternate protein source can also help. Natural remedies to help clear up diarrhea can also include adding plain yogurt to meals to seed the gut with healthy bacteria, or adding pureed pumpkin to provide a fiber boost to firm up stools. However, if these things don’t help with the diarrhea, additional testing and treatment with your vet is best.

Read Full Q/A … : Causes of Blood in Dog Stool

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. Very thin stools for several weeks now..no change in appetite, diet or energy level?..eats prescription diet c/d due to UT crystals several years ago
ANSWER : A. It’s a little hard to get specific about recommendations for you as I don’t know whether this is a dog or a cat, however I’ll see if I can give you some ideas. You said “thin” stools…do you mean diarrhea, or ribbon-like stools? Diarrhea in cats and dogs can be caused by parasites, food allergies or sensitivities (I know he’s been on c/d for years but they can develop food allergies relatively suddenly), inflammatory bowel disease, bacterial or viral infections of the gut, and dietary indiscretion. If you mean the stools are thin like ribbon I’d be concerned about a rectal mass potentially changing the shape of the stool on the way out. Either way I would get this checked out.

Read Full Q/A … : DIT Weekly Q's Flashcards

Q. Nursing dog pups 13 days old has sudden onset of diarrhea and vomiting what can I do
ANSWER : A. You can try with holding food for 12 hours. Offer unflavored Pedialyte if she’ll drink. If she doesn’t vomit or have diarrhea for those 12 hours you can then offer small amounts of a bland diet such as boiled white meat chicken (25%) and boiled white rice (75%) without flavoring or fat added. Offer about 1/4 cup every 2 hours. If she continues to do well and has an appetite do this for 12 hours, then transition back to a normal diet slowly. If she continues to have vomiting or diarrhea I think it’s important that you seek veterinary care, since continual loss of fluid through vomiting and diarrhea while nursing is very dangerous to any dog, but especially to a very small dog like a chihuahua.

Q. I currently feed my 2 year 31 lb Beagle 1 1/2 cups of Eukanuba a day. I was thinking of changing his food, can you recommend something?
ANSWER : A. If you are looking for a higher end food to feed your Beagle, there are many available now in commercial pet stores. Many brands such as Blue Buffalo, Nutro Natural Choice and others offer holistic foods that tend to be more meat based than carbohydrate based. Some brands such as Royal Canin also offer foods that are specific to certain breeds. This means the products tend to have more digestible ingredients in them rather than fillers. They may also avoid some allergenic ingredients such as corn, wheat and soy products which can cause digestive issues in some dogs. However, Eukanuba, Science Diet and others are a good mid-grade brand and many dogs do very well on it.

If you do decide to switch your dog’s food, it should be done so gradually to avoid digestive upset. A routine of 9 days is best for switching over. This involves 3 days of 25% new/75% old, 3 days of 50/50 and 3 days of 25%old/75% new before finally feeding only the new food. Also be advised that depending on the ingredient changes, foods that have different grains or fewer grains in them may slightly change the consistency and size of your dog’s stool.

Q. Seven month old cat has watery diarrhea for five days. Asks perfectly normal. What can I give him to help with diarrhea ?
ANSWER : A. Anytime a pet has prolonged diarrhea, it is always a good idea to schedule a wellness check with your veterinarian. Bringing in a sample of your cat’s stool is also a good idea to check for any internal parasites or illnesses that may be causing it.

Diarrhea can be caused by a large number of things ranging from illness, internal parasites, digestive upset or even dietary issues. Ruling out any more serious issues first is best, then looking to others such as stress or diet is next. Cats can have issues with some grain products such as wheat, corn and soy, and can even have issues with dairy and fish products! (Cats are naturally lactose-intolerant). Changing the diet may help to firm up the stools.

For other additives, adding a probiotic such as Forti-flora from your vet, or a teaspoon of plain yogurt added to the food can help. Adding in a small amount of pureed pumpkin to the diet may also help as the added fiber can firm up the stool. However if the stool does not improve after a few days of treatment, a follow-up with your vet is best.