Diarrhoea in dogs and puppies

There are occasions when both dogs and puppies may get a bout of diarrhoea. For puppies especially in very young animals, this can present a problem and should the condition be prolonged, possibly lead to veterinary hospitalisation and treatment.Most times when the vet is presented with a dog that has persistent diarrhoea, they have to make some clinical decisions and assessments about the case.To best treat diarrhoea it is important to know the cause in the first place and whether it is part of another underlying disease. Because of this diarrhoea is classified as a primary intestinal disease or secondary diarrhoea (which means the dog has diarrhoea as a result of another more prevalent disease). These are points that the veterinary team need to establish and as such will take a full history from the owner to aid diagnosis.

Primary intestinal diarrhoea

It is important to find out whether the diarrhoea originates from the small or large bowel, and there are several indicators that can be used to determine this:

• Weight loss - if the problem is with the small bowel then weight loss may be present; there is rarely weight loss of the dog, if the condition originates from the large bowel.
• Faecal volume - the volume the dog passes will increase if the condition is with the small bowel, but will reduce if it is the large bowel.
• Faecal blood - many dog owners might see blood in the dogs faeces, if the blood is fresh this indicates a condition within the large bowel. If the faecal material is dark (like old blood may be present) then the problem normally lies within the small bowel.

Causes of primary intestinal diarrhoeas

There are many causes of diarrhoea in dogs and some do resolve with a short treatment of a kaolin based medication, from the vets. Some causes of diarrhoea however need further treatment, they include:

• Viral and bacterial infections.
• Hookworm infections.
• Whipworm infections.
• Giardiasis - an intestinal infection caused by a parasite organism.
• Tumours.

Sometimes owners may be told their dog has colitis, which is a common cause of diarrhoea (but not in cats). This is the inflammation of the colon (the large intestine) and can be a serious condition, which requires veterinary treatment. It is not always known what causes colitis in dogs but several factors could be:

• Bacterial infections - especially campylobacter and salmonella (both bacterial infections normally associated with food poisoning and ones that can be passed to humans).
• Parasitic infections with whipworms.
• Food hypersensitivity reactions.
• Colitis can also be secondary to cancer of the colon.

The vet also might diagnose a condition called inflammatory bowel disease (IBD). This is a condition that causes diarrhoea, resulting in malabsorption (difficulty in absorbing) nutrients in the intestines. The signs of IBD in dogs include visible weight loss, persistent diarrhoea and at times always being hungry.

Secondary diarrhoeas

Dogs sometimes have more prevalent diseases and the diarrhoea is of a secondary importance. The diseases that can also cause diarrhoea include:

• Addison's disease - a hormonal disorder in dogs.
• A build-up of toxins in the blood due to renal failure.
• Liver disease.
• Hyperthyroidism

Maldigestion (the total lack of digestive enzymes) caused by pancreatic disease is another factor to why a dog could have secondary diarrhoea. This is relatively common in dogs and the condition is known as exocrine pancreatic insufficiency (EPI).

Diagnosis of primary intestinal diarrhoeas

A veterinary surgeon may decide to diagnose prolonged diarrhoea by calling on the services of a laboratory specialising in animal samples. The vet may ask the owner to collect a faecal sample for analysis. Although this is not a nice job for the owner, it is an important step in diagnosing and treating the animal.The vet might ask the laboratory to use the faecal sample to test for:

• Undigested food components - especially the fat and starch content.
• Parasites.
• Bacteriology - especially for salmonella and campylobacter.

The vet also may want to use an endoscope (a small camera that can be passed into the animal) and take a biopsy of tissue.

Treatment for primary intestinal diarrhoeas

The general treatment for diarrhoea may be carried out in the home, by the owner. In some cases, especially with very young puppies or dogs that have severe diarrhoea, the dog may be hospitalised in the veterinary centre for full nursing care. If infection is suspected and the owner feels unable to cope, or they have a young family hospitalisation will normally take place. The treatment the dog or puppy may undergo includes:

• Nil by mouth for 24 - 48 hours (this gives the digestive system a rest!)
• Fluid therapy - this could mean maintaining fluids via a bowl of water containing extra salts and minerals, or in severe cases the placement of a drip. Both will help prevent the animal from becoming dehydrated.
• Antibiotics - if the animal is found to be carrying an infection such as salmonella or campylobacter, then antibiotics will be given as treatment. It is rare to use this medication if a bacterial infection has not been confirmed.
• Diet - once the dog has been starved for 24 - 48 hours, small amounts of low-fat veterinary diets can be offered. After the diarrhoea has subsided completely then the animal can slowly return to its normal diet. In some cases where the dog has a history of diarrhoea, the vet might recommend the specialised veterinary diet for the rest of the dog's life.

Treatment for inflammatory bowel disease (IBD) and colitis is slightly different from the above. Because of the very nature of these diseases treatment should include:

• Diet - the dog should be fed only hypoallergenic diets that contain a single protein and are gluten-free.
• Medication - the dogs should be given anti-inflammatory drugs to calm down the digestive system and relieve pain. Because of extra bacteria in the digestive system occasionally antibiotics are given.

If you are at all worried about your dog or puppy having diarrhoea and they seem very unwell and lethargic, you should contact your vet as a matter of urgency.