In recent years, dietary fibre is getting a lot more attention within the field of human nutrition. And you may have wondered if this has any relevance to your dog’s diet and health. Often protein is the first macronutrient a discerning owner might look at when choosing a dog food. The protein source (i.e. meat) forms part of the principal display panel on dog food packaging. And with canine obesity an increasing cause of concern many owners may also look for a diet with a lower fat content. Although dietary fibre may not be the first thing you look at on a pet food label, it is an important macronutrient. Continue reading to find out more about its importance when feeding your dog.
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What is fibre?
Dietary fibre is an indigestible complex carbohydrate found in plants such as wholegrain cereals, vegetables, legumes and fruits. It is most commonly categorised into two subtypes; soluble and insoluble fibre. However, research has shown that many plants contain a mixture of these types of fibre and qualities such as the viscosity or fermentability are also considered important characteristics.
Soluble fibre:
Soluble fibre can be dissolved in water. Examples include pectins and gums which are polysaccharides found in fruits and vegetables. Some soluble fibres are viscous, this means that when mixed with water they form a gel in the bowel. The effect of this is a thickening of the faecal matter causing a slower gut transit time. Because viscous fibres add water, they can also soften stool.
Insoluble fibre:
Insoluble fibres, as the name suggests do not dissolve in or absorb water. Examples include cellulose and lignin which are polymers found in plants. Sometimes insoluble fibres get disregarded as “fillers” in dog food. But insoluble fibre does have its place in your dog’s diet, these undigested fibres pass through the digestive system adding bulk to the stool and stimulating gut motility.
What is the microbiome and how is this linked with fibre?
You may well have heard terms such as “microbiome”, “prebiotics” and “good bacteria” – current buzzwords relating to human health. The gut microbiome is made up of trillions of bacteria and other micro-organisms living within the bowel. Some of these microbes are beneficial to health, these beneficial or good bacteria can help digestion and absorption of some vitamins as well as improve immunity.
Prebiotics are fermentable fibres meaning that they are broken down (fermented) by gut bacteria rather than the digestive system. This fermentation process releases short chain fatty acids (SCFAs). These SCFAs provide energy to feed the good bacteria and to nourish the colonocytes (intestinal epithelial cells / bowel lining).
In humans research has shown that one particular SCFA, butyrate, provides 60-70% of the energy for colonocytes. A healthy bowel lining is important because it is thought that a “leaky bowel” may allow pathogens and toxins in the bowel to enter the bloodstream. An increased fibre intake increases the amount of these beneficial SCFAs, they are thought to have other health benefits too. For example SCFAs lower the pH of the bowel further promoting the growth of good bacteria and warding off pathogens such as E. coli and Salmonella. One study found that dogs with chronic enteropathy (i.e. diarrhoea) had lower levels of SCFAs than healthy dogs.
Fructo-Oligo-Saccharides (FOS) and Mannan-Oligo-Saccharides (MOS), Inulin and yeast are prebiotics which you may see on a pet food label. Resistant starch (found in cereals and legumes) is a type of fibre with both soluble and insoluble characteristics that works like a fermentable fibre.
What does fibre do for dogs’ health?
fibre is an integral component for a healthy digestive system and it is also thought to have a myriad of health benefits in people. Although further research is needed into the health benefits of fibre in our pets, it may be especially beneficial for dogs that have the following conditions:
Irregular bowel motions.
Do you find that your dog frequently has soft stools that you can’t pick up or do they seem to be straining when passing faeces? The right levels of fibre in the diet can regulate bowel motions and may help manage (or even prevent) both constipation or diarrhoea. If you are concerned about your pet’s gastrointestinal health it’s best to have a chat with your vet as sometimes gastrointestinal symptoms are due to underlying medical conditions or parasites; it’s also important to remember that in dogs too much fibre can be an issue as well as too little.
Anal sac disease.
There is no definitive scientific research that fibre alone can prevent or cure anal sac disease in dogs. However, there seems to be much anecdotal evidence and it’s widely thought that an increase in dietary fibre can help. A reasoning is that a normal stool pattern, as well as the pressure of a firmer stool can aid the natural emptying of a dog’s anal glands during defecation. If your dog regularly “scoots” their bottom across the ground or needs to have their anal glands expressed, increasing the fibre in their diet might help.
Obesity:
Has your vet or a friend ever commented that your dog might be overweight? A survey in 2022 found that as much as 50% of the UK dog population could be overweight. But help is at hand! Many veterinary nurses run weight clinics in practice. They can help you calculate if you are feeding your dog the correct amount to meet their nutritional needs or if a different diet might help and offer top tips on weight management.
When the amount of your dogs’ normal food is reduced with the aim of combating obesity they may feel hungrier, which can increase begging behaviour and the amount of other important nutrients is also reduced. Research has shown that a diet higher in fibre content, can increase satiety (a feeling of fullness) by increasing bulk within the intestines and slowing gut transit time. A higher fibre content along with an optimal protein content is often used in weight control diets.
Diabetes:
If your dog has been diagnosed with diabetes your vet or nurse will have discussed feeding with you. A diet higher in insoluble fibre is often recommended (usually alongside a lower fat content) as part of the dietary advice because research has shown that this can improve glycaemic control. The higher fibre content means there is a slower or more controlled release of sugar into the blood stream. If your pet is diabetic, it’s very important to discuss any dietary changes with your vet first as this may affect the insulin dose required.
How do I know I’m feeding my dog the correct amount of fibre?
There is still debate about what is the ideal amount of fibre to feed a dog. This is because although fibre may not be considered an essential nutrient it does provide a lot of benefits as discussed; research is ongoing and more information will become available in time.
Complete, commercial dog foods will have carefully balanced amounts of nutrients such as protein, fat and also fibre. The crude fibre percentage on a pet food label only accounts for the insoluble fibre rather than the total dietary fibre. The ingredients list may show a more extensive list of fibre sources. Although often the specific amounts of individual ingredients aren’t shown; so it can be difficult to know exactly how much fibre a pet food contains.
Too little fibre can cause irregular bowel problems in dogs. However, too much fibre can also cause constipation (especially if your dog isn’t drinking enough), diarrhoea or irregular bowel movements as well as flatulence and unintentional weight loss. The optimum amount of fibre will differ from dog to dog.
As a responsible dog owner, you’re probably picking up and disposing of your dog’s poo daily. And despite this not being the nicest part of dog ownership it’s actually very helpful to monitor gut health. Dog faecal (poo) charts show what a dog poo should look like – click here to access the Purina poo chart. Is your dog’s poo normal?
There are several diseases or illnesses which can cause bowel problems. So always check any abnormalities with your vet if you are concerned. If your dog’s faeces don’t look normal or they have one of the health conditions mentioned above its best to get in touch with your vet to discuss their health and nutrition.
On a final note…
Dietary fibre has been shown to have health benefits for dogs. However, every dog is different and will have different responses to fibre intake. Research into dietary fibre is ongoing for humans as well as animals. If your dog has a normal poo, is of a healthy bodyweight, doesn’t seem to be frequently hungry and has good energy levels it’s likely that their current diet including the fibre content suits them well.
If you do decide to change your dog’s diet, it’s best to do this over a span of 5-7 days slowly increasing the percentage of the new food. Several fibre supplements specifically for dogs are also available. If you decide to supplement your dogs diet with plant based foods do take care and remember that some foods we can eat are toxic to dogs. As always, if you have any concerns about your dog’s health, make an appointment with your vet.
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