1. Introduction

There are many types of dog food in the world, ranging from differences in flavours to differences in textures to differences in processing. We all want the best for our dogs, and we don’t just want our dogs to eat their food, but to enjoy it as well. However, getting misled by marketing and buzzwords can be dangerous in the long term for your pet. This article is a short guide on what kind of pet foods there are, and how to select a good pet food for your dog to ensure the best long term health for your pet. Each dog is unique and has different circumstances, and there are many variables playing into what you determine is best for both your dog and yourself as a pet owner.

2. What nutrients are important in pet food?
Food in general consists of macronutrients such as protein, fat and carbohydrates, and micronutrients, such as antioxidants, vitamins, and minerals. There may also be additives such as stabilizers, thickening agents, and preservatives. Each nutrient has its function, and getting too much or too little of a certain nutrient can be detrimental to your dog’s health.

Protein sources for dog food are generally animal-based, ranging from farmed animal sources such as beef, chicken or lamb, seafood-based sources such as bony fish like tuna, salmon or whitefish or exotic meat sources such as kangaroo or venison. There are new sources of protein that are under research right now such as vegan or vegetarian sources like legumes and eggs, and also insect-based sources in a bid to make pet food production more sustainable. Protein is a source of amino acids, which are important building blocks for cellular processes and products. For example, most biological hormones such as insulin are made from amino acids that have been metabolized from dietary protein! Some amino acids are able to be synthesized by the body, however there are some which are essential and need to be supplied via the food.

Fat can come from either animal sources or vegetable sources. Fat helps to make the pet food more tasty, and provides a good source of energy for dogs. For working dogs or sports dogs, their diets are usually quite high in fat to be able to provide enough calories for the dog to do its job safely without losing weight or condition. Fats are also a source of essential fatty acids such as omega-3s and 6s, which are essential to maintain function of the body (eg the health of hair and skin, and immune function).

Carbohydrates are important for multiple functions - firstly they provide a good source of digestible energy in the form of starches, and also complex carbohydrates provide both soluble and insoluble fibre. Dogs are omnivorous creatures and genetically distinct from their wolf cousins, and thus are able to utilize plant starches and grains as a healthy source of energy. Fibre is important for the function and health of the gut microbiome - peep us if you are interested in an article on that! Insoluble fibers are unable to be digested by the gut, and are used to maintain healthy gut transit time, whereas soluble fibers are used to feed the good bacteria in the gut microbiome to ensure healthy digestive systems.

Micronutrients are basically nutrients that are required in very small amounts. There are various types of vitamins that are important in the body (too many to list!) - but essentially there are water soluble vitamins and fat soluble vitamins. Vitamins are often used for cellular processes and most need to be supplied via the diet. Minerals are usually biologically active metals that are required by the body to do its job - for example, the oxygen-carrying molecule in blood is called haemoglobin, and it is made from iron.

There are also other additives that are not necessarily needed by the body to survive - this doesn’t mean that they are bad per se (especially in the amounts that they’re present in), but that the body doesn’t actually digest it and use it for maintaining health. Instead they are often used to either prolong shelf life of the food and make it easier to store, or to make the taste or texture of the food more palatable.

3. What kind of pet food is there?
There are so many kinds of pet foods out there! They don’t just differ in flavours but also in textures and types. There are pros and cons to each, and it’s important to analyse and see what fits best for your dog.

Kibbles - kibbles are dry biscuits that are typically either extruded or cut. This type of pet food often has a long shelf life per unit (up to 8-12 weeks) and easiest storage conditions. They are convenient to feed as well. However, not all brands are created equally (see below to point 4), as some kibble products may not be complete and balanced. They are also prone to rancidity if not stored in the right conditions, and may not be palatable to fussy dogs.

Cans - canned food typically has a long shelf life due to its preservation and processing. It has a high moisture content and is easily stored. Canned food is usually very palatable as most dogs like to eat moist textured food, but conversely it is the type of food which has the most processing and usually preservatives inside.

Semi-moist - this type of food has a medium level of moisture. Typically it comes in a processed dried form, either by freeze drying or dehydrating at a low temperature. This type of food needs to be stored at the proper conditions, and usually needs to be refrigerated. If stored improperly, especially raw-based semi moist diets, it can become contaminated with bacteria. It also comes at a high cost, but is usually very palatable and digestible for dogs.

Freshly prepared - these diets are freshly cooked/prepared and packaged into single servings. When it comes to palatability, these diets are often the most palatable to our dogs. They often need to be stored in the freezer and cannot be purchased in bulk as the home freezer does not have the storage conditions for storing long term (eg more than a month). unfortunately, not many companies in Singapore employ the properly credentialed individuals to make the recipes for their products, and use a lot of marketing and buzzwords in order to get people to buy their food, and often this results in not properly balanced diets, which can cause health concerns in the long run. Chuku’s Kitchen consults with a board-certified vet nutritionist based in Canada to formulate their recipes (learn more in point 4).

Homecooked - many pet owners would like to prepare their own pet food for their dogs. However, this method is the easiest way to make an unbalanced diet, and without a proper formulated recipe, can result in an unbalanced diet in the long term (see point 5).

4. How do I know that my dog’s food is complete and balanced?
Firstly, there are a few legal guidelines that a pet food needs to meet (depending on country) in order to call itself complete and balanced. Unfortunately, Singapore does not have its own legislation and thus, any local pet food company can call its products complete and balanced without actually being as such without legal repercussions. The main 2 guidelines that are important to note for purchasing a pet food are AAFCO and FEDIAF. AAFCO is an Organisation based in America that publishes a set of nutritional guidelines that pet food needs to meet in order to label itself as complete in America. They dictate how much of what nutrient is required in each life stage of dogs and cats, and publish any Limits if an excess of a nutrient can be harmful (especially important for vitamins and minerals). FEDIAF is the equivalent for mainland Europe and UK. Chuku’s Kitchen meets and exceeds both AAFCO and FEDIAF standards.

Secondly, the qualifications of the person who formulates the recipe for your pet food is important. The term “nutritionist” is not protected legally, and neither are any certificates in pet food manufacturing. This means that any rando could take a 2 week online course in nutrition, run by any institution, and call themselves a certified nutritionist. This is very important especially if you want to purchase a fresh diet for your dog! A properly qualified person should at least have a masters level education in animal nutrition, if not a PhD in companion animal nutrition and best-case a veterinarian who specialises in nutrition such as a vet with a PhD in companion animal nutrition or a board certified veterinary nutritionist. Only the term vet nutritionist is protected, and only vets who have undergone an approved residency in clinical nutrition, published relevant research and also sat and passed the board exam, can be called board certified vet nutritionists. There are 2 boards - a European board, of which the diplomate will have the credential of ECVCN, and an American board, of which the diplomate will have the credential of ACVIM (Nutrition) or DACVN.

WSAVA nutrition guidelines - these are the gold-standard when it comes to choosing a balanced dog food. The WSAVA is a nonprofit organization made of small animal veterinarians, and in particular, they have a nutrition committee made of PhD and board certified veterinary nutritionists. These folks have come up with a set of guidelines for pet food manufacturers to follow. However, following the guidelines is usually only possible for large scale manufacturers, so companies which produce kibble and caned food. As of now, only 3 companies (Royal canin, hills and purina) meet the WSAVA guidelines internationally, and 2 more meet them conditionally (IAMS and eukanuba). There are many other big name companies out there who have not been able to fully meet the guidelines, and hopefully with more consumer push, they will make the necessary changes!

5. What happens if I feed my dog food that is not balanced?
There are several types of diseases that can occur with unbalanced diets. If caught quickly enough, they can be corrected and treated for. However, if they are not treated in time, there can be irreversible changes, and some diseases may even be fatal. I will highlight a couple of diseases today, but there are so many that it’s hard to make an exhaustive list!

Nutritional secondary hyperparathyroidism, or aka metabolic bone disease, is caused by a nutritional imbalance of calcium:phosphorus ratios and often vitamin D is also implicated. Because of the imbalanced ratio of the minerals calcium and phosphorus, the bones become extremely soft and brittle, and this can result in pathological fractures. This is more commonly seen in puppies fed an unbalanced diet, however any age of dog may be affected.

Obesity is another extremely common disease of nutritional imbalance, most often in the energy-providing nutrients such as fat and carbohydrates. Obesity is a complex condition that could warrant an entire post of its own, but the long story short is - over feeding and reduced energy usage. In the Singapore context, pets often do not get as much exercise as they need, and pet owners often use food and treats as a way to connect with their dogs. There can be multiple factors that cause a dog to become obese - dogs may overeat due to boredom, or May be fed high fat and high energy treats such as human food scraps, or simply not get enough exercise, and also may be eating a diet that has insufficient dietary fiber. Not only does obesity exacerbate certain health conditions such as osteoarthritis and pancreatitis for example, but the body fat itself can create new health problems eg putting stress on the heart and causing an increased potential for heart disease.

Recently there has also been a lot of news about a disease known as nutritional dilated cardiomyopathy. Historically, this disease has more commonly been seen in dogs that have not been fed a balanced and complete diet. However, recently it has become more common with dogs that have been fed with diets that are grain free and high in peas, legumes and potatoes, with exotic meat proteins and made by boutique companies (otherwise known as BEG diets). Research is still ongoing as to why there is a link between grain free diets and nutritional DCM, but no conclusive results have been shown.

6. Conclusion
As pet owners we always want to do the best for our dogs, and we want our dogs to live happy and healthy lives. It’s always important to talk to your vet about the diet that your dog is eating, whether it’s appropriate for your dog and whether it’s properly balanced. There are pros and cons to every kind of diet, but the minimum conditions must be met. Remember that the health and wellbeing of your dog always comes first and foremost!

References:

https://www.purina.com/articles/dog/health/nutrition/dog-nutrition-basics

Samantha Ho, Final Year Student at the University of Edinburgh.