A Multimodal Treatment Approach to Canine Acute Diarrhoea

Canine acute diarrhoea is a very common condition that normally resolves without veterinary treatment, meaning that cases are often presented to veterinary teams due to owner concerns or difficulty managing symptoms. Diarrhoea lasting less than two weeks is generally defined as acute¹.

Symptomatic treatment of acute diarrhoea

Most uncomplicated cases of diarrhoea normally resolve within one to five days and, while most cases are self-limiting, it can often be beneficial to consider symptomatic treatment to help to alleviate symptoms and aid recovery.

Gut conditioners

Gut conditioners are products that contain a variety of beneficial ingredients to support the digestive system, including:

• Probiotics

Studies have shown that probiotic use can be associated with equally fast recovery from acute diarrhoea in comparison to antibiotic treatment, meaning that antibiotic treatment is often unnecessary^2,3.

Products containing microbial cultures can be used to recolonise the gut with beneficial bacteria. This is beneficial because diarrhoea can result in disruption of the microbiome. Probiotic cultures can lead to increased mucus levels in the gastrointestinal tract and are also able to exert a protective effect on the intestinal epithelial barrier, as well as having a positive effect on the immune system. Probiotics may help to suppress the growth of potentially pathogenic bacteria through competition for exclusion sites and nutrients within the gastrointestinal tract. Some probiotics will also produce organic acids that inhibit the growth of harmful bacteria⁴.

• Adsorptive agents

These agents include activated charcoal which is derived from wood, coconut, peat or pecan shells. The material is then treated in a way that results in the formation of many large pores to increase the overall surface area of the product. This enables charcoal to work effectively to adsorb bacterial enterotoxins and endotoxins which can form part of the causal mechanism in some types of diarrhoea⁵. Montmorillonite is a naturally occurring tri-lamellar clay which provides superior coverage in addition to having adsorptive properties.

• Electrolytes

Electrolytes will inevitably be lost during gut disturbances, so it is important to provide patients with a balanced blend of electrolytes to compensate appropriately and encourage fluid intake to return to more normal levels. These electrolyte ingredients will often include sodium chloride and propionate as well as potassium and magnesium chlorides, as these have important functions in the body, meaning replacement after loss is an important element of restoring homeostasis during recovery.

• Ingredients for energy

Ingredients including dextrose and sorbitol are both sources of immediately available energy for the patient. These ingredients work by providing an energy source for healthy intestinal cells, as well as supporting the gut flora, enabling it to thrive. They also act as a co-transporter to maintain and support electrolyte and fluid uptake during digestive disturbances.

Gut supplements

Certain high-quality supplements are available to use in canines experiencing gastrointestinal upset in order to help maintain normal gut motility and general health. These products contain probiotics and electrolytes, discussed above, in addition to:

• Prebiotics

Prebiotic ingredients are non-digestible and work to stimulate activity and growth of bacteria in the digestive tract by acting as a nutrient source. This helps to maintain a healthy and balanced microbiota, resulting in beneficial effects for the patient. Fermentation of prebiotics by the gut bacteria also produces short-chain fatty acids which are the preferred energy source for intestinal cells⁶.

• Vitamins

Gut supplement products often contain a complex source of vitamins including vitamins A, B, C, E, K and PP, to maintain the normal feed converting ability of the gut to absorb and bind nutrients present in the diet. This in turn aids recovery by encouraging a normal appetite and supporting general patient health and activity levels.

Additional symptomatic treatments

As well as gut conditioners and supplements, there are a variety of other symptomatic treatment options that veterinary clinicians will consider for cases of canine acute diarrhoea including:

• Nutritional management: allowing for the normalisation of intestinal motility and function. This also includes changes in diet or exclusion trials if dietary intolerance is suspected, and close monitoring by the owner if owners believe dietary indiscretion may have occurred through scavenging.
• Intravenous fluid therapy: to address more severe dehydration.
• Endoparasiticide treatment: either as a precaution or because a parasitic infestation is suspected or diagnosed.
• Opioids and other forms of pain relief: if there is significant abdominal discomfort, consider a pain relief option which is suitable for patients with gastrointestinal disturbances (NSAIDs should generally be avoided). It is worth noting that some opioids can prolong intestinal transit time and increase fluid absorption, thereby reducing symptoms.
• Gastroprotectants: medications including ranitidine and omeprazole can act to protect the gastrointestinal tract by inhibiting acid secretion, these drugs can be useful in cases with suspected gastrointestinal ulceration i.e. cases with melaena or haematemesis; however, these should not be used in uncomplicated gastroenteritis⁶.
• Anti-emetics: can be administered as needed but should be avoided in cases of suspected gastrointestinal obstruction. Commonly used anti-emetics, such as maropitant, are thought to be most helpful in cases with concurrent vomiting. However, where nausea is one of the main clinical signs in the absence of vomiting, drugs such as ondansetron may have a more profound anti-nausea affect.⁷

Acute diarrhoea and antibiotics

Using antibiotics to treat cases of acute diarrhoea is a frequently debated topic within the veterinary profession. Prescribing antibiotics unnecessarily can be problematic for several reasons as it can ultimately contribute to bacterial resistance, may cause intestinal microbiota imbalances and consequent disruption in gut health and the antibiotics themselves can result in adverse effects on the patient⁸.

In cases where it is not always possible to carry out faecal testing (e.g. due to financial restrictions) some clinicians will decide that clinical symptoms of both pyrexia and haemorrhagic diarrhoea are an adequate reason for antimicrobial treatment as these clinical signs often indicate damage to the intestinal epithelium which can result in an increased risk of septicaemia. However, in uncomplicated cases of acute diarrhoea, antibiotic treatment is not generally recommended. Ultimately, this is down to the discretion of each clinician.

Multi-modal approach to acute diarrhoea

As with many other conditions, a multi-modal approach to management of acute diarrhoea in canines is often beneficial for the patient as it means that treatment plans can be individually tailored according to each case, resulting in improved outcomes overall. Treatment regimes can also be created according to owner preferences, as many owners will favour certain management options based on their own lifestyle or desire to treat the condition (as many cases of acute diarrhoea are self-limiting). By creating a multi-modal treatment plan that is well-suited to the owner and patient, this has positive effects in increasing owner compliance.

1. Chandler M., The chronically diarrhoeic dog. In Practice, 24, 18–27, 2002 , https://www.researchgate.net/p...
2. Langlois, D., Koenigshof, A. and Mani, R., Metronidazole treatment of acute diarrhea in dogs: A randomized double blinded placebo‐controlled clinical trial. Journal of Veterinary Internal Medicine, 34, 98-104, 2019, https://pubmed.ncbi.nlm.nih.go...;
3. Shmalberg, J., Montalbano, C., Morelli, G. and Buckley, G., A Randomized double blinded placebo-controlled clinical trial of a probiotic or metronidazole for acute canine diarrhea. Frontiers in Veterinary Science, 6, 163, 2019, https://pubmed.ncbi.nlm.nih.go...
4. Williams, I., The role of probiotics in veterinary medicine, In Focus, July 2011, https://www.veterinary-practice.com/article/the-role-of-probiotics-in-veterinary-medicine
5. Dowling P. M., Drugs used in treatment of diarrhea, Veterinary Clinical Pharmacology, March 2015, https://www.buddyandlola.co.uk...
6. Wortinger, A., Prebiotics and Probiotics for Dogs and Cats, Today’s Veterinary Nurse Intergrative/Alternative Medicine, Spring 2019, https://todaysveterinarynurse....
7. Kenward, H., Elliott, J., Lee and T., Pelligand, L., Anti-nausea effects and pharmacokinetics of ondansetron, maropitant and metoclopramide in a low-dose cisplatin model of nausea and vomiting in the dog: a blinded crossover study, BMC Veterinary Research, Article Number 24, 2017
8. Tauro, A., Beltran, E., Cherubini, G., Coelho, A., Wessmann, A., Driver, C. and Rusbridge, C., Metronidazole-induced neurotoxicity in 26 dogs. Australian Veterinary Journal, 96, 495-501, 2018, https://pubmed.ncbi.nlm.nih.go...