My Dog's Poop Starts Solid Then Goes Soft



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The color, consistency and other properties of a dog's stool can tell us a lot about their state of health. If a dog's poop starts solid then turns runny, it indicates they are affected by small intestine diarrhea. This type of diarrhea in dogs can be caused by various pathologies or infections. Such diseases can seriously affect their nutritional status and health by interfering with the proper absorption of nutrients from their diet. If the underlying cause of small intestine diarrhea is not controlled, our dog will get progressively worse.
If you see that my dog's poop starts solid then goes soft, it is important to find the correct cause so that it can be treated effectively AnimalWised explains these causes of small intestine diarrhea and what treatment might be available.
Why a dog's stool is hard then runny
As stated in the introduction, when a dog's poop starts solid and then turns soft, it is an indication of small intestine diarrhea. Having feces of two such contrasting consistencies can be confusing for guardians. Normal dog stool should be firm, but moist and with a slight odor. Dogs with a high-fiber diet should have more voluminous stools.
Changes in consistency of the dog's stool are usually down to the absorption of water in the intestine. Poor ability to absorb water is known as malabsorption. Certain pathologies can alter the osmolarity (concentration of solute) and reduce the capacity of water absorption resulting in diarrhea. This can be contrasted with pathologies causing high water absorption, in turn causing the stool to become dry and hard. This results in constipation as it is difficult for the feces to pass.
If the dog has diarrhea, it can explain why your dog defecates more than usual. The excess water leads to fluidity of the feces, making it easier for it to pass through the intestines. Volume and consistency of the stool can also be affected. In general, diarrhea in dogs can be classified as small intestine and large intestine diarrhea.
Characteristics of small intestine diarrhea
Small bowel diarrhea is characterized by:
- Rarely is tenesmus (difficulty) and urge to defecate seen
- Daily frequency of defecation 2-3 times higher than normal
- Increased volume
- There is usually no mucus
- There is usually no fresh blood, but can be digested blood (melena)
- Vomiting can occur
- Weight loss
Characteristics of large intestine diarrhea
In large intestine diarrhea appears:
- Tenesmus
- Daily frequency of defecation greater than 3 times normal rate
- Urgency to defecate
- Presence of mucus
- Presence of fresh blood
- Vomiting and weight loss are rare
Take a look at our article on the types of diarrhea in dogs to know more about less common forms of gastrointestinal disease.
Causes of solid poop which goes soft
When small intestine diarrhea in dogs causes a dog to have firm stool followed by loose stool, it is a symptom of disease. This disease is one which affects the gastrointestinal tract, but there are various causes which can lead this to happen:
- Infectious enteritis (caused by various bacteria and intestinal parasites including Campylobacter, Giardia, Histoplasma and Phycomycosis)
- Bacterial overgrowth
- Kidney disease
- Liver disease
- Hypoadrenocorticism (Addison's disease)
- Food hypersensitivity
- Exocrine pancreatic insufficiency
- Inflammatory bowel disease (IBD)
- Protein-losing enteropathy
- Intestinal obstruction
- Intestinal intussusception
- Foreign bodies in the intestine
- Intestinal tumors (lymphosarcoma, adenocarcinoma, fibrosarcoma, leiomyoma)
- Hemorrhagic gastroenteritis.
- Lymphangiectasia
- Rectal polyps
- Change of diet
Large intestine diarrhea occurs when there is disturbance or diseases from the large intestine, such as:
- Parasitic or bacterial infections
- Inflammatory bowel disease
- Perineal disease
- Irritable bowel syndrome
- Neoplasms (lymphosarcoma)
- Colonic histoplasmosis

Symptoms of small intestine diarrhea in the dog
When diarrhea occurs in the small intestine, hard poop followed by runny stool us not the only clinical sign. Along with this major symptom, we may also see:
- Lack of growth in puppies
- Weight loss
- Anorexia
- Gurgling noises from belly area
- Flatulence
- Abdominal discomfort
- Ascites
- Edema
- Melena (digested blood)
- Dehydration
- Malabsorption
- Poor digestion
- Nutritional deficiencies
- Loss of coat shine and quality
- Vomiting
- Increased frequency of defecation
- Fever
- Lethargy
Generally, when a dog is affected by small intestine diarrhea, it is worse than when they have large intestine diarrhea. This is because the latter does not affect their appetite as much. Although they have a problem absorbing nutrients, they do not lose as much weight. Dogs can have diarrhea of both the small and large intestine, something which may be caused by parasites, IBD, lymphosarcoma or intestinal histoplasmosis.
The symptoms will also give us a clue as to what other problems may be present:
- Weight loss: a lack of nutrients and weight loss indicates intestinal malabsorption due to the various pathologies named above. If the malabsorption continues over time it can lead to chronic diarrhea.
- Vomiting and pain: vomiting and abdominal pain indicate intestinal inflammation or obstruction.
- Blood in the stool: blood in the stool indicates inflammatory, erosive or ulcerative diseases of the intestine.
- Infectious enteritis: when diarrhea is due to infectious enteritis, fresh blood and abdominal pain are usually seen in addition to vomiting and small bowel diarrhea.
- Pica and coprophagia: in cases of exocrine pancreatic insufficiency and chronic intestinal diseases, pica and coprophagia (i.e. eating inorganic material and feces, respectively) can be observed. Pica can be observed when the dog repetitively eats abnormal objects or even if they lick metal. Polyphagia (excessive appetite) is also common in exocrine pancreatic insufficiency.
- Anorexia and inappetence: anorexia and inappetence (loss of appetite) usually occur with tumors, inflammations or obstructive processes of the intestine.
- Edema and ascites: edema and ascites are due to an enteropathy (loss of protein).
Diagnosis of small intestine diarrhea in dogs
The diagnosis should include numerous tests to make a differential diagnosis. This is important due to the high number of potential diseases which cause a dog's poop to start solid and then go soft. A veterinarian will likely start with a hemogram and a blood chemistry to assess whether there is:
- Anemia from blood loss
- Low leukocytes which indicate an infection
- Low lymphocytes which indicate lymphangiectasia
- Azotemia (occurs with kidney disease)
- Alteration in liver enzymes (in liver disease)
- Eosinophilia (increased eosinophils) in parasitosis, hypoadrenocorticism or eosinophilic enteritis
- TLI (Trypsin-Like Immunoreactivity) less than 2.5 µg/L indicates exocrine pancreatic insufficiency
- If there is a deficiency of vitamin B12 (alteration in the jejunum) or folate (alteration in the ileum)
In addition, the following tests may be performed in cases of diarrhea:
- Stool culture: if there is a suspicion of bacterial infection, a culture of the dog's stool should be taken and tested to see if it proliferates.
- Parasitological tests: looking for parasites, parasitological tests are carried out, such as flotation of the feces, to search the parasite eggs under a microscope.
- Abdominal ultrasound: if tumors, obstructions, foreign bodies or inflammatory bowel disease are suspected, an abdominal ultrasound should be performed to look for characteristic changes. These tests are particularly important if the dog's belly is hard.
- Biopsy: if after performing the ultrasound both inflammatory bowel disease and intestinal tumor are suspected, a sample should be taken by biopsy and sent to the laboratory so that they can indicate what it is by histopathology.
- Hypoallergenic diet: in cases indicative of an adverse reaction to food, a hypoallergenic or novel protein diet should be given and then return to the previous diet and see if the symptoms return. If this occurs, it confirms the diagnosis.

Treatment of small intestine diarrhea in dogs
Once the diagnosis of why the dog defecates hard and then soft stools has been established, symptomatic and specific therapy should be applied.
Symptomatic treatment
Symptomatic therapy is based on correcting nutritional and electrolyte imbalances with fluid therapy. Rectifying potassium levels is especially important.
Antidiarrheal drugs may be used to stop diarrhea, but they should not be used in case of infectious diarrhea. This is because these microorganisms need to be expelled. In these cases, the necessary antibiotics, antiparasitics or antifungals will be used, as appropriate.
Specific treatment
Depending on which disease causes this symptomatology in dogs, a different specific or medical treatment will be used:
- Chemotherapy: in case of intestinal tumors, chemotherapy for dogs and/or surgical resection should be used.
- Diet and medications: in inflammatory bowel disease, a combination of diet, metronidazole and immunosuppressants such as prednisone, azathioprine or cyclosporine should be used depending on the severity.
- Vitamins: in the case of vitamin B12 or folate deficiencies, they should be supplemented.
- Surgery: obstructions, intussusceptions or presence of foreign bodies may require surgical intervention.
- Disease treatment: if there is kidney, liver or hypoadrenocorticism disease, specific treatment for the disease in question should be performed.
- Enzymes: if exocrine pancreatic insufficiency is diagnosed, pancreatic enzymes and a digestible diet should be administered.
This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.
If you want to read similar articles to My Dog's Poop Starts Solid Then Goes Soft, we recommend you visit our Other health problems category.
- Veterinary Portal. (2018). Chronic diarrhea. Available at: https://www.portalveterinaria.com/animales-de-compania/articulos/16845/diarrea-cronica.html
- Hall, E. J., Simpson, J. W., & Williams, D. A. (2009). Manual of Gastroenterology in Small Animals, 2nd Edition. BSAVA, Ediciones S.