Diarrhoea in dogs

On the basis of the duration, severity and cause of the disease, diarrhoea in dogs could be divided into two categories - acute diarrhoea and chronic diarrhoea.

Acute diarrhoea appears suddenly in an otherwise healthy dog. It starts suddenly and tends to last anywhere from a couple of days to a couple of weeks. One must not worry too much if the diarrhoea persists for a day or two, but keep a closer eye on the dog in case other severe symptoms start to appear.

Acute diarrhoea mainly occurs due to damage that has occurred to the intestines. The things that could possibly go wrong with the intestines are:

• Any toxic infection present in the intestines, making them secrete too much stool
• Any ulceration in the intestines leading to increased intestinal exudation (water, blood) 
• Increased peristalsis (muscle contractions that keep the food moving) of the intestines

The reasons for damage to the intestines could be:

• Eating spoiled food or garbage
• Sudden changes in diet
• Drugs and toxins
• Ingesting foreign bodies (nonfood items) which may block the intestines
• Parasitic, viral, fungal and bacterial infections
• Pancreatitis (inflammation of the pancreas)
• Inflammatory bowel disorders like colitis and Crohn’s disease
• Stress
• Rickettsial (tick-transmitted disease)
• Addison’s disease (deficiency of adrenal gland hormones)
• Liver disease
• Kidney disease

Acute diarrhoea may present with symptoms like:

• More water in faeces than normal (softer or unformed faeces)
• May have an increased volume of faeces or frequency of defecation
• Faecal accidents
• Straining to defecate

You may need to take your dog to a vet if he/she presents with more severe symptoms like:

• Vomiting
• Blood or mucus in the faeces
• Anorexia (lack of appetite)
• Depression
• Abdominal pain
• Fever (rectal temperature greater than 103.5 F)
• Weakness

You can monitor most acute and sudden diarrhoea episodes in dogs at home. All you need to do is observe your dog during the time they have the loose and runny stools, so if things start getting worse you can provide proper information to your vet.

• You must make sure your pet drinks enough water to avoid dehydration in dogs. 
• You may also withhold food or solids for 12 hours to ensure that the gastrointestinal tract rests and heals on its own.
• You must give your dog a bland diet for a few days until (and after) the diarrhoeal episode ends. Gradually, you can add a small amount of boiled chicken to the rice and you can also add probiotic supplements to their meal after consulting your vet.
• You must avoid all medications or over-the-counter drugs until your vet prescribes them.
• If the sudden onset diarrhoea does not resolve within a day or two, or if the episodes are continual, consult the veterinarian without delay.

Chronic diarrhoea is a change in the frequency, consistency and size of the dog's faeces for more than three weeks. The diarrhoea could originate in the small or large intestine and can either be secretory (very watery) or osmotic (not watery).

Diseases in the small and large intestines that could lead to chronic diarrhoea are:

• Inflammatory bowel diseases like ulcerative colitis and Crohn’s disease
• Lymphangiectasia (protein-losing disease)
• Any viral or bacterial infection
• Parasitic infections like Giardia
• Cancer
• Partial blockage of the intestine
• Stomach or intestinal ulcers
• Noninflammatory causes

Sudden change in the diet or a low fibre diet could also lead to chronic diarrhoea in dogs. Also, dogs with dietary or gluten intolerance or an allergy tend to get diarrhoea more easily.

A dog suffering from pancreatic disease or liver disease tends to have poor digestion, thus it can also lead to chronic diarrhoea in them.

Dogs suffering from chronic diarrhoea can present with different symptoms depending upon the origin of the infection. Symptoms seen when the infection originates in the small intestine may include:

• Your dog may pass faeces 2-4 times per day 
• Unusually large volume of faeces
• Faeces look black and tarry 
• Gaseous sounds heard from the gut
• Weight loss in dogs
• Vomiting
• Very low appetite (due to poor digestion and absorption of food)

Symptoms seen when the infection originates in the large intestine may include:

• Your dog may pass faeces more than 4 times per day 
• Unusually smaller volume of faeces
• Bright red blood is seen in the faeces
• Mucous present in the faeces
• Your dog may strain a lot to defecate 
• Your dog might have pain while excreting
• Gaseous sounds heard from the gut

Treatment for chronic diarrhoea cannot be done at home. You must take your dog to a vet for the treatment, which usually depends on the underlying cause.  

If your dog is dehydrated, your veterinarian might give them intravenous fluid therapy.

Your veterinarian might de-worm your dog just in case parasites are responsible for the disease. 

If your dog’s illness is due to dietary intolerance or allergies, your veterinarian might prescribe a low-fat, easily-digestible diet for three to four weeks and follow-up to see if the diarrhoea has cleared up. 

In cases of large intestinal diarrhoea, a therapeutic course of treatment could be initiated with metronidazole for 5-10 days along with an addition of fibre to the diet.

Dogs with an obstruction or foreign bodies may require surgery to evaluate the intestine and remove foreign objects.