Click the Arrow to Access the Table of Contents Links • Guide Updated January, 2022
Chronological Age vs Physiological Age
Presently, there are no different nutrition guidelines set in place when it comes to feeding aging dogs than those in place for younger adult dogs despite there being a good amount of peer-reviewed scientific and anecdotal evidence documented about the fact that aging dogs do have changes that can be supported nutritionally. We should in fact, despite there not being a standard to follow, feed aging dogs differently than we feed adult dogs in their prime years of life.
The chronological age vs physiological age chart is a helpful tool to use as a reference for determining what phase of adulthood your dog is in.
This chart is based on breed class size averages so there are plenty of dogs out there who surpass their breed’s average lifespan expectations. You want to make nutrition and functional support adjustments as your dog ages so that yours is one who surpasses average expectations and makes many memories with you for years to come.
As you can see, the smaller a dog is, the longer the dog’s predicted lifespan is. Smaller dogs do not age (physiologically) as fast as larger dogs. You’ll notice that extra-large breed dogs reach their older years sooner. Extra-large breed dogs are puppies the longest and spend fewer years in “their prime” before reaching their golden years than small, medium, and large breeds. Now that isn’t to say that big dogs begin acting like seniors when they are a few years old in chronological age; many big dogs remain playful as puppies for many years.
Use the chart to establish when your breed typically reaches different phases of adulthood.
The Natural Wear Down of an Aging Dog
Aging dogs are susceptible to ailments and illnesses as a natural part of the aging process. They can experience skeletal issues such as osteoarthritis and/or spondylosis; as well as internal organ issues such as kidney disease, liver disease, heart disease, and a decrease in pancreatic function. There can be muscle condition and body score changes, and unfortunately, also environmental cancers. Proactive steps can be taken nutritionally to support the inevitable aging process. A diet and support protocol formulated for the aging dog’s particular needs is a better fit than commercially premade products during the later years of life.
Annual blood work, x-rays, ultrasounds, and possibly other diagnostic scans should begin occurring annually once a dog reaches the first year of what is deemed “their senior years” and increase to twice a year as the dog continues to age. These frequent proactive tests allow an owner to catch system failures and diseases quickly so they can have a better chance at treating and managing whatever the situation is that their aging dog is encountering.
Signs of Aging
- Wear and tear on the teeth (chips, weakened enamel, weak teeth, plaque stains)
- Joint stiffness
- Spondylosis (spinal condition)
- Slowing of activity level
- Changes in body condition score with increased weight when no increase of calories has occurred
- Change in body condition score with weight loss when no nutritional changes have taken place
- Changes in muscle condition score with lean muscle mass loss
- Restlessness during the night hours due to discomfort
- Loss of bodily function control such as incontinence
- Hearing loss
- Vision-related issues
- Changes in skin texture, age spots may be present
- Change in coat texture and/or luster
- Changes in the olfactory system (sense of smell and scent tracking abilities)
- Change in taste buds
- Lumps, cysts, and tumors
- Graying of the fur under the chin, around the muzzle, eyes, chest, and/or paws
- Digestive issues such as acid reflux, constipation, and or loose stool
- Cognitive decline
- Internal organ issues
- Non-typical blood work or other lab panels and scans
Aging Dog Energy Requirements (Calories)
As a dog ages, the changes in their metabolic function can affect their energy requirements. Usually, aging dogs require fewer calories as they get older but sometimes a dog can need more calories than they did in the younger years of their life.
Often, right around the time the chronological vs physiological age chart states a dog is entering its senior years is when an owner will notice their dog needs/desires to eat less. This is a normal metabolic slowdown and often there has been a decline in activity level. This is not a constant that happens with every aging dog, it is dog dependent so always feed the dog in front of you based on that dog and not make calorie reductions unless there are indicators that it is needed.
Making Changes to Your Aging Dog’s Energy Factor (EF)
Calorie Reductions: Because we feed the dog and not the paper, if you find that you need to reduce the number of calories your aging dog eats and it has been eating at an EF of 160, you do not want to drop it to an EF of 95 overnight simply because an age chart or calorie chart say that aging dogs are assigned an EF of 95 or lower. That can cause a system shock for the dog.
A Great Dane should not be fed an EF of 95 so that is another example of feeding the dog in front of you and not fitting the dog into a chart. Use the chart as a tool and apply the EFs that work for your dog.
The best approach for a 160 EF eating dog who needs a caloric reduction would be to do a gradual decrease from 160 EF to 140 EF to 130 EF to 120 EF, and so on and so forth as needed.
Many aging dogs who spent most of their life eating what is deemed to be more common energy factors with EFs of 110 and 105 may begin to hold a bit more weight at those common energy factors than they used to and would benefit from being reduced to 95 or 90 and in some cases as the dog grows older, even 85 or 70. This is again, something that is very individual to the dog at hand.
A gradual reduction of EF by EF is the approach to take, moving the EF number down every two weeks until the calories are sitting at the sweet spot for that particular dog. How will you know exactly what the sweet spot is for the dog at hand? The scale, body condition, and muscle condition scores will tell you.
Important Recaps: As an owner on your own, never drop an aging dog’s EF more than one EF at a time. Remember to always allow a two-week time frame for each adjustment before making a further reduction.
Caloric Increases: Some dogs need more calories as they age to keep weight on their bodies. If this is the case with your aging dog then you would want to consider increasing the EF you use when situating your dog’s calories.
If your dog has been eating at an EF of 95 but you notice they are looking thin and/or their muscle tone isn’t as great as it was, you can increase to an EF of 105 or even start with 100. The 100 EF is not on the Energy Factor Key here in the guide but this is what is referred to as an “in-between energy factor.” You can use an in-between EF if you feel like the next EF that is generally used might be too high for your dog. What you can do is use a 100 EF for two weeks and then assess your dog’s body condition score, their muscle condition score, and their current weight. If you find that using an EF of 100 worked well then you can either keep it there or if you would like to add a bit more weight then you can increase to an EF of 105 and then assess again at the end of two weeks.
You do not want to increase your aging dog’s energy factor by more than one EF at a time because it can cause bloat. You want to conservatively increase the volume of food being fed so your dog can adjust and digest well.
Macro-digestibility is important so you want to make sure you are using lean proteins and good fats in your dog’s diet. Macro distribution should have a good balance going across the protein, fat, and carb %s. Just increasing fat can create issues for your dog so addressing the EF you are using by moving it upwards to the next energy factor and then ensuring your macros are balanced in a way that works for your dog is the way you want to go about it.
If the diet your dog eats works well in terms of digestibility but they need to gain weight, then make calorie changes before making diet content changes.
Critical Recap Note: Bloat can lead to serious life complications so be sure you do not increase your dog’s EF more than one EF at a time.
Recap Note: Not all aging dogs will need a significant drop in their energy requirements.
Macronutrient Digestibility & Macro Distribution
As the efficiency of the pancreas and liver naturally begin to decline, a dog may begin to have difficulties digesting protein and/or fat. This difficulty can show itself in a few ways: Mucus in the stool, loose stool, audible stomach gurgling, foul-smelling breath, and/or vomiting. If your aging dog is dealing with any of these descriptors, a change to their diet macronutrients is probably needed. Additionally, digestive enzymes can become helpful for a dog to be given at this point.
- Macros for Aging Dogs
If an aging dog is experiencing any or a combination of the above-outlined age-related digestive issues, take a look at the diet’s macronutrient % levels on a caloric basis to assess where your dog’s macro %s are situated. Often you will find the diet is higher in fat than the dog can tolerate at that point in life.
Begin with reducing the fat and increasing the protein by making changes to the types of proteins and cuts of those proteins that you feed. Using quality proteins can help feed an aging dog’s muscles and combat muscle mass loss. At the same time, if fiber is not present in the dog’s diet, bring in the fiber.
Underweight or Muscle Deterioration in Aging Dogs
Some aging dogs become underweight and experience loss of lean muscle mass. This is called Sarcopenia, often referred to as muscle wasting.
Sarcopenia is the loss of lean body mass in an otherwise healthy aging dog. This happens when a dog’s protein requirement changes due to a protein synthesis decrease in an older dog. Sometimes a dog’s protein needs increase upwards of 50% more than the dog required during the prime years of its life.
Essential Fatty Acids
It is important to make sure essential fatty acids are being fed in adequate amounts via bioavailable ingredients.
Hemp seed oil and wheat germ oil both provide linoleic acid (LA).
Oily fish like sardines, salmon, and mackerel are excellent sources of EPA + DHA which are important for combating skeletal inflammation, gut inflammation, and cancers.
It has been found that when omega-3 is increased, the production of O3 eicosanoids increases; these are anti-inflammatory. So it’s best to keep the Omega 6:Omega 3 ratio in your aging dog’s diet at less than 4:1.
If your aging dog is having trouble with digesting fish you can reach for a marine sourced oil instead, like a fish or calamari oil. These come in capsules and drops for easy feeding.
Vitamin D3 & Aging Dogs
This vitamin is an essential fat-soluble vitamin & its functions are intricately involved with normal calcium & phosphorus homeostasis in the body. At the site of the intestine, vitamin D3 stimulates the synthesis of calcium-binding protein, which is needed for efficient absorption of dietary calcium & phosphorus. It is important to make sure an aging dog is being fed adequate amounts of vitamin D3.
Sardine, mackerel, and salmon are three examples of oily fish that are excellent sources of the essential nutrient vitamin D3. These are the easiest foods to feed that will provide adequate D3 (and bring powerful Omega 3 at the same time).
Many vitamins cannot be stored as is the case with many trace minerals. It is very important to ensure that an aging dog is being given all of the essential micronutrients it needs daily. Aging dogs often have an increased frequency of urination and therefore water-soluble nutrients are lost more quickly than when the dog was in its prime years.
Taurine is not an essential dietary amino acid for dogs that is currently required to be added to the bowl. However, while taurine is one of the most abundant free amino acids in mammals, some dog breeds are known to be at higher risk for insufficient endogenous taurine synthesis and are predisposed to cardiac issues. Dietary supplementation may be called for, even when there is currently no minimum amount currently set by canine nutrition guidelines.
The recommended amount for taurine supplementation is 500 mg per 40 lbs / 18.14 kg of dog’s body weight. The amount a therapeutic aging dog may need might be different based on the dog.
Boosting the B Vitamins
Gut-related health issues like malabsorption or lack of probiotics (bacterias and yeast) can affect a dog’s ability to adequately use B vitamins. Excessive urination due to an ailment or medication can also impact B vitamins. It is important to make sure that these vitamins are being boosted if your dog is dealing with a health issue that can decrease the absorption of B vitamins. These vitamins are water-soluble and they do not store in the body so if they are not being adequately absorbed from the diet itself then boosting can help get more into the dog’s body. You can boost via snacks or as part of a daily support protocol.
B Vitamins to pay most attention to:
Vitamin B1- Thiamine: Lean pork, beef, liver, & beef heart
Vitamin B2- Riboflavin: Beef kidney, beef liver, chicken liver, beef heart, pork heart, hen eggs, salmon, and spinach
Vitamin B7- Biotin: Organ meats, egg yolk, many fresh vegetables (this is one that is easy to boost using a Biotin powder and it will not affect the daily calories or other nutrients in a negative way).
A Quick Note About B7-Biotin
Dogs are capable of endogenous microbial synthesis for this one but if a dog is dealing with a health situation that affects B7 (biotin) or is being fed a diet low in biotin or high in antimicrobials (yogurt, turmeric/curcumin, and heavy amounts of various herbs present in the diet are some examples) or if a dog is taking antibiotics that impact microbial synthesis, boosting this vitamin is called for.
Additionally, in 1989, a clinical study on the effect of biotin on skin conditions in dogs published findings of a 91% success rate in the treatment of 119 domestic dogs.
Anecdotally, I have found that boosting Biotin as part of skin + coat support protocols in the diets of dogs of various breeds has shown to contribute to a marked reduction in dryness and itching and improvement of the coat.
Vitamin B9- Folate: Liver, kidney, dark green leafy vegetables, meats, fish
Dietary fiber is the edible parts of plants or analogous carbohydrates that are resistant to digestion & absorption in the small intestine & have complete or partial fermentation in the dog’s large intestine.
There are two general categories, based on their structure and what they do in a dog’s body.
- Soluble fibers are fermentable and viscous (some insoluble fibers are too) and slow things down in the digestive tract. Soluble fiber attracts water and forms a gel inside of the digestive system. Ex: Some fruits, vegetables, nuts, seeds, and psyllium.
- Insoluble fibers help to bulk up stool volume + improve motility. Ex: The skin of fruits and vegetables, some vegetables, and whole grains. Insoluble fiber is non-viscous, less fermentable, contains more water, and doesn’t form a gel.
Fiber plays a role in the optimal functioning of the gastrointestinal (GI) tract and is also a source of short-chain fatty acids for intestinal cells and can help with digestion & evacuation of the bowels and fiber also helps with maintaining the microbiome.
It is best to feed non-starchy carbs than starch-rich carbs to avoid nutrition absorption issues and yeast infection triggers.
Note: Too much plant matter or plant matter that is not prepared in the proper way are anti-nutrients. Too much fiber decreases nutrient digestion and also impacts the absorption of lipids, calcium, iron, and zinc.
Antioxidants and Aging Dogs
Antioxidants help protect your aging dog from oxidative damage caused by scavenging free radicals.
Vitamin E, beta-carotene, vitamin C, and selenium are all antioxidants that neutralize free radicals. While vitamin E and selenium are essential vitamins, beta-carotene specifically and vitamin C are not. There is usually adequate selenium in most raw and cooked diets but vitamin E is an antioxidant/essential nutrient that must be on purpose focused on. 123.5 IU per 1,000 kcal/ME is a good amount to shoot for on a daily basis.
Dogs are able to synthesize vitamin C (endogenously make their own) however, aging dogs can have a harder time with this as well as dogs who are ill, so boosting vitamin C is advised. This can be given as part of a joint support protocol since vitamin C is a component that helps increase the absorption of type II collagen and MSM, two ingredients that are powerful to use in a joint support protocol.
Phytonutrients (such as beta-carotene) found in colorful vegetables and fruits offer antioxidant support and can be given as part of the daily fiber component of meals.
Coenzyme Q10 has been found in lower levels in aging dogs. It is an antioxidant, cardiovascular, and immune system supporter and can help with neurological decline and/or disorders. CoQ10 has also been used to treat dental situations in dogs. It is most commonly used with aging dogs who deal with cardiovascular issues and cancers.
Hydration & Toxin Elimination
Aging dogs can sometimes experience a decrease in thirst which can affect their filtration organs and therefore impact their ability to eliminate toxins. An adult dog should take in 1 ml of water per 1 kcal. Raw-fed and cooked-fed dogs don’t always want to take in that much water “on purpose” and that is because their diet is high in moisture and therefore they are in fact taking in a good amount of water when they eat.
Medications can sometimes be diuretics and so it is important to replenish water being lost by the dog through frequent urination.
Hydration Tip: Include water as part of the meal. Make the dog’s meal into stew using regular water or you can add coconut water or bone broth (in a small amount) to increase palatability.
Calcium Provider Changes- Moving an Aging Dog Away from Daily Bones
Moving an aging dog to a calcium supplement for daily feeding and making raw meaty bones a recreational/brain and mood stimulant or removing them altogether is a good idea. Bone contains high phosphorus which can cause stress on internal organs. Since an aging dog’s organs have been through varying levels of taxation throughout its life, reducing phosphorus to reduce the load on the organs is something to consider. Seaweed calcium can often be a good choice because it is highly bioavailable and low on phosphorus. Additionally, it contains iodine which removes another ingredient (kelp) from needing to be used. It is important to check the amount of iodine present in the seaweed calcium you want to use to make sure you are keeping your dog’s iodine level at a good number. Another reason to move an aging dog away from daily raw meaty bones is their teeth. Teeth wear down over the years and become more vulnerable to cracks and breaks. If a dog isn’t chewing on bones daily, its chances of suffering from a cracked or broken tooth decrease.
Sometimes a Cooked Diet is Called For
Sometimes an aging dog is more prone to infections due to a depressed immune system and/or gut issues. If an older dog experiences repeated bacterial infections, increased yeast infections, and/or other signs of immune system struggles; if a dog is on any immunosuppressant medications; or if an older dog has a condition that can affect their immune systems such as short bowel syndrome, recurring allergies, illness, or surgeries, then switching from a raw to a cooked diet can be a good idea.
Healthy dogs and dogs in their prime years have strong enough HCl (stomach acid) to handle the naturally heavy bacterial load of raw ingredients, however, it can be risky to feed an aging dog a raw diet as they are more susceptible to a depressed immune system.
Palatability Note: Some dogs prefer the taste of cooked food so if you have an aging dog who is being particularly finicky and not wanting to eat its raw meals anymore, a cooked diet may help manage that.
Guidance for Setting Nutrient Levels
Keep essential nutrients as close to adult maintenance recommended allowances (RA) as possible with the exception of any nutrients that you know that you need to elevate for the dog at hand. Remember these are things like EPA & DHA, Zinc, Vitamin E. Also remember that when you move zinc, you must pay attention to the copper amount as well.
Gut Support for Aging Dogs
Gut support is very important for aging dogs. Finding the right support protocol is dog dependent. For some, it can be a probiotic, for others, it’s fiber, for others it’s digestive enzyme support; and for some dogs, it is all of these. The best thing to do is address each issue one at a time so you can see if what you are doing to manage that issue helps with it and if it may also help with another gut-related issue at the same time.
- Soil-Based Organisms
A daily gut support protocol that includes soil-based organisms (SBO) is a good way to start. SBOs are spore formers which means they are housed in a protective shell that keeps them intact and protected against stomach acid and some antibiotics. The spores can safely travel through the GI system until they reach an environment they are meant to do their job in which are the large intestine & colon. This type of gut support is especially great for dogs who need gut support but deal with small intestinal bacterial overgrowth (SIBO). The organisms in this type of gut support do not populate the small intestine with bacteria.
- Digestive Enzymes
Enzyme deficiency can increase as a dog ages depending on its diet. This results in many related cofactors such as allergies, premature aging, low immunity, auto-immune & skin problems. The stomach starts breaking down proteins immediately. However, when proteins don’t break down properly, inflammation spikes & as a result, skin conditions can occur, like dry skin & itching. Digestive insufficiency sometimes shows up as a dog gets older. The dog as an ecosystem has to work harder, organs slow down & dogs become less efficient at processing food. A good enzyme supplement can help older dogs assimilate more nutrients. Enzymes should be given any time cooked or processed food is served to replace the natural enzymes destroyed by heat. Enzymes can be from animal, plant & microbial sources (fermented).
Animal sources usually come from the pancreas of animals such as cows & pigs. Pancreatin is pancreas-derived & contains amylase, lipase & protease covering carbohydrates, fats & proteins.
Ox Bile is a liver salt replacement that helps digest fats & oils for dogs having a hard time or lacking a gallbladder.
The two most popular plant enzymes are papain from papaya & bromelain from pineapple. Note: Warm dogs may not do well with pineapple-derived digestive enzymes. Papain (extracted from the papaya) helps digest proteins & supports the immune system as well as is an anti-inflammatory. Bromelain comes from pineapple breaking down proteins. It also helps bring down swelling & inflammation with an affinity towards the joints, ear, nose & throat.
Feeding aging dogs to support their phase of life gives them a better quality of life than a non-supported dog and can help extend your time with your best friend.
If you have a dog who is getting more seasoned in life, consider all of the topics discussed in this guide and see how you can best support your dog as they live out their golden years.
Diet Affects Nutrient Digestibility, Hematology, and Serum Chemistry of Senior and Weanling Dogs (2004) by K. S. Swanson, K. N. Kuzmuk, L. B. Schook, and G. C. Fahey, Jr. Department of Animal Sciences, University of Illinois, Urbana