By Michelle van Lienden, DVM

For the past 10 years, I have worked as a veterinarian for Lions Foundation of Canada Dog Guides. This charitable organization breeds and trains dogs to assist Canadians with disabilities. Each year, approximately 300 pups are born at its breeding facility. Once these dogs are old enough to leave their mothers, they are placed in a loving home with a foster family. These volunteers help our organization by providing the caring environment and basic training necessary for the puppies to learn, grow, thrive, and, ultimately, become confident, adult dogs.

Young adult dogs start their official training at the Dog Guides campus in Oakville, Ont., when they are between 14 and 18 months old. The foundation has seven canine training programs:

• Vision
• Hearing
• Seizure Response
• Service
• Autism Assistance
• Diabetic Alert
• Facility Support

After graduation, the trained dogs are placed all over Canada and go on to do many amazing things. These remarkable canines are loyal companions that change lives for the better. They provide people with disabilities the opportunity to become more independent, and provide support and safety for both children and adults.

Unfortunately, however, canine diarrhea is a common problem—especially for young puppies. Indeed, about 40 per cent of puppies at Dog Guides experience diarrhea, with it most often occurring when the dogs are between the age of eight weeks and six months. My position, as a veterinarian with the organization, allows me to provide care for many puppies. Further, I am able to follow long-term treatment responses—not just for individual dogs, but for the foundation’s canine population. Subsequently, over the years, my approach and treatment plans for diarrhea have evolved and improved.

Antibiotics

Diarrhea in puppies can be very frustrating, and can result in sleep deprivation for pet owners, as well as young pups. Cleaning dirty carpets and washing soiled bedding is not a pleasant task for anyone. What’s more, prolonged diarrhea can lead to weight loss and dehydration. In some cases, can even be life threatening.

Traditionally, veterinary common practice is to prescribe antibiotics for diarrhea. This is especially true in cases when the condition does not respond within three to five days to a “bland homemade” or a “prescription gastrointestinal” diet and “routine fecal analysis” is negative.

While antibiotics such as Metronidazole and Tylosin have anti-inflammatory properties and can result in improvement of clinical signs,¹ evidence supporting the routine use of antimicrobial therapy for treatment of acute diarrhea is lacking, as recent studies have shown this therapy does not consistently lead to quicker recovery compared to probiotics or symptomatic treatment.^2,3

Further, antimicrobial therapy has long-term effects on the gastrointestinal (GI) microbiota of dogs.³ Anecdotally, many pups in the Dog Guides organization will relapse shortly after finishing the course of antibiotics or when they are switched back to a regular puppy diet. Additionally, after analyzing my medical records, I found that dogs receiving multiple or longer courses of antibiotics to control diarrhea during their first year of life were often not able to tolerate a regular commercial diet when they reached adulthood. These dogs would typically receive a diagnosis of chronic enteropathy (CE) and, as such, were no longer suitable for our training programs. Some dogs even progressed to develop serious and life-threatening complications of CE, such as sepsis, motility disorders, and malabsorption.

After realizing the long-term results on our dogs’ health and educating myself on microbiome research, I decided to take a completely different approach to managing diarrhea in my patients. Under the guidance of Jan Suchodolski, MedVet, DrVetMed, PhD, AGAF, DACVM, of Texas A&M University, I have introduced a multi-modal microbiome-friendly approach for all of my diarrhea cases, which has reduced my use of antibiotics to a small fraction of what it used to be. I now, only occasionally, will use a short course of antibiotics for refractory cases, but the vast majority of diarrhea cases are managed with a combination of prescription diets, psyllium husk, probiotics, and fecal microbiota transplants (FMTs).

Since switching to this new microbiome-friendly approach, I have noticed significant improvement in the overall health of our dog population. Almost all of the canines at Dog Guides are now able to tolerate a regular commercial diet by the time they reach adulthood and we have not seen any more dogs with serious CE-related complications. Of course, this is based on clinical observation, and future randomized clinical trials are needed to evaluate the effect of antibiotic-use on progression of CE. Other factors (i.e. improved genetics of our breeding program, availability of new pharmaceutical products) likely also play a role in this overall improvement; however, I have found there is no good reason to continue use of antibiotics as a first-line approach for diarrhea. Antimicrobial resistance (AMR) is a growing and significant threat to public health that is compromising our ability to treat infections effectively.⁴ It is critical veterinarians be part of the solution and do everything they can to reduce unnecessary antibiotic use.

Diets and probiotics

Poor digestibility of diet and overfeeding are both significant factors that can contribute to diarrhea.⁵ When a puppy first presents with diarrhea, it is important to do a physical exam and take a good patient history.

Consider:

• Is the puppy overweight or underweight?
• Has daily feeding recently increased?
• Is food (including treats) measured consistently with a feeding cup?
• What is the quality of the diet? Is it suitable for puppies?
• Does the puppy eat rawhide, bones, sticks, or human foods?

Gastrointestinal veterinary prescription diets are helpful for the initial management of diarrhea because they are bland and easy to digest. It makes sense to try the response to a GI diet for three to five days in combination with some probiotics. The puppy should not receive any treats or other food during this period. If there is a quick response to a GI prescription diet, I will usually continue this for at least 10 days before gradually transitioning back to regular puppy food.

In cases where a puppy relapses once regular food is re-introduced, the dog should be fed the GI diet for a longer period (i.e. six to eight weeks) before an attempt to switch back is made. Some dogs require a prescription diet until they are six to 10 months old, but are then able to tolerate a regular commercial adult diet.

Hypoallergenic prescription diets have an even higher digestibility when compared to GI diets. If a puppy does not respond to a GI diet in combination with other treatments, a hypoallergenic diet suitable for growing animals can be tried as a next step. When diarrhea resolves on hypoallergenic diet, a dog is sometimes falsely presumed to have a food allergy; however, in the absence of skin disease, this is unlikely to be the case. Once the puppy has improved on hypoallergenic diet and stool has been normal for a period of six to eight weeks, a transition to GI diet or regular puppy food with a common source of protein (i.e. chicken, lamb, or beef) can be attempted.

Fibre

The addition of fibre to diet can help to bulk stool by binding water. Psyllium husk is an excellent source of high-quality fibre that stimulates peristalsis and slows transit time.

Fibre is metabolized by the microbiome into short-chain fatty acids. Short-chain fatty acids are an energy source for colonocytes and decrease pathogen growth.⁶ Plain psyllium husk or Metamucil without sweetener/sugar can be given at 0.25 to 0.5 gram/kg two or three times a day with food. It is recommended to start at the lower end of the dose range and gradually increase the amount until a response is observed. Psyllium can be mixed with food. If added to kibble, it should be soaked in warm water for about 10 to 15 minutes before it is fed.

For dogs over the age of six months, psyllium husk is often successful in treatment of intermittent or chronic diarrhea without the need for a diet change. In my experience, puppies younger than six months respond best to a diet change alone or diet change in combination with psyllium husk.

FMT

Fecal microbiota transplantation (FMT) is the administration of a solution of fecal matter from a healthy donor dog to the recipient via an enema. FMT can be used on a routine basis for diarrhea that relapses or is refractory to initial treatment with diet and fibre. Fresh fecal material is collected from a healthy donor dog that, ideally, has never experienced diarrhea and has not received antibiotics for at least six months. Dogs which are fed raw diets or receive medications other than routine parasite prevention are not suitable as donors.

Donors are, ideally, not too young (i.e. not younger than a year) or too old. Donor feces should be sent for routine fecal analysis to ensure there are no parasites that can be transferred to the recipient.

Ideally, the suitability of a donor is checked by determining the dysbiosis index (DI). This is a quantitative PCR-based assay that can be used to assess the canine microbiome in individual patients (see “The scoop on fecal microbiota transplantation”).

FMT syringes are prepared from fresh feces and can be stored in a fridge for three to four days or in a freezer for about six months. Donor feces are placed on a scale, and 1 to 1.25 ml of saline per gram of feces is added and mixed. It is recommended to filter the mixture through a tea strainer to remove any larger particles. If emptying the syringes completely is difficult, more saline can be added, but it is best to make the mixture as concentrated as possible. Young puppies should receive 1 to 2 grams of donor feces per kilogram of body weight; adult dogs with chronic GI disease require 5 grams per kilogram.

When performing FMT on puppies, I use 6- to 12-ml syringes and a soft red rubber feeding tube. The syringes are defrosted in lukewarm water for 15 to 20 minutes, and, from there, the FMT procedure itself is quick and very easy. Apply some lubricant and carefully insert the red rubber feeding tube as far as possible into the colon. The procedure is not painful, and it is not necessary to sedate the patient. To ensure the transplanted material stays in the colon for a sufficient period, make sure the FMT is not too watery and try to keep the puppy calm following the procedure.

For treatment of diarrhea, the FMT can be repeated once or twice as needed. The transplantation can also be given to an animal with formed stool to repair the microbiome after a course of antibiotics.

Compliance

In my experience, pet owners are well aware of the dangers of antibiotic resistance and, as such, are very receptive toward this novel approach to treatment of diarrhea.

It is important, however, to set expectations and let clients know that if there is no improvement after the initial visit, there are alternatives to ensure the puppy gets better. The puppy’s digestive system is still developing and has to adapt and go through many changes to be able to digest solid food. Some puppies are a bit slower than others, but, with the right type of support, they will eventually get there.

Research

Currently, Lions Foundation of Canada is collaborating with Ontario Veterinary College (OVC) on a research study led by Shauna Blois, DVM, DVSc., DACVIM-SAIM; Scott Weese, DVM, DVSc., DACVIM; and Allison Collier, DVM, DVSc. The study aims to evaluate fecal and skin microbiota community structure and diversity in growing dogs. We hypothesize dogs with alterations of the fecal and/or skin microbiota are predisposed to develop signs consistent with chronic enteropathy and/or acute diarrhea. It will be very exciting to see the results of this and other studies related to microbiome in the years to come.

Michelle van Lienden, DVM, is a 2001 graduate of the University of Ghent, Belgium. She has worked in general practice and emergency clinics in both the United Kingdom and Canada. In 2012, she joined Lions Foundation of Canada Dog Guides to provide on-site veterinary care for the breeding program, foster puppies, and dog guides in training.

This article has been reviewed by Drs. Jan Suchodolski (Texas A&M University) and Shauna Blois (OVC). Lions Foundation Canada provides dog guides at no cost to eligible Canadians from coast to coast. The Foundation relies on donations from individuals, service clubs, organizations, and corporations, and does not receive any government funding. To learn more, visit dogguides.com.

References

¹ Langlois DK, Koenigshof AM, Mani R, Metronidazole treatment of acute diarrhea in dogs: a randomized double blinded placebo-controlled clinical trial. Journal of Veterinary Internal Medicine. 2020 Jan; 34(1):98–104. https://pubmed.ncbi.nlm.nih.gov/31742807 

² Shmalberg J, Montalbano C, Morelli G, Buckley GJ. A randomized double blinded placebo-controlled clinical trial of a probiotic or metronidazole for acute canine diarrhea. Front Vet Sci. 2019 Jun 4; 6:163. https://pubmed.ncbi.nlm.nih.gov/31275948

³ Werner M, Suchodolski JS, Straubinger RK, Wolf G, Steiner JM, Lidbury JA, Neuerer F, Hartmann K, Unterer S. Effect of amoxicillin-clavulanic acid on clinical scores, intestinal microbiome, and amoxicillin-resistant Escherichia coli in dogs with uncomplicated acute diarrhea. J Vet Intern Med. 2020 May; 34(3):1166–1176. https://pubmed.ncbi.nlm.nih.gov/32324947

⁴ Maurizio F, Ranucci E, Romagnoli P, Giaccone V. Antimicrobial resistance: A global emerging threat to public health systems. Critical Reviews in Food Science and Nutrition. 2017 Sep 2; 57(13):2857–2876. https://pubmed.ncbi.nlm.nih.gov/26464037

⁵ Marks SL. Diarrhea. Canine and Feline Gastroenterology. 2013: 99–108. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7151799

⁶ Currò D. Current evidence on the therapeutic use of fiber in irritable bowel syndrome. Expert Review of Gastroenterology and Hepatology. 2022 May; 16(5):425–436. https://pubmed.ncbi.nlm.nih.gov/33908323