The Nose has it!

The Nose has it

Gaining the edge: nutrition to sharpen sense of smell?

Those who work with their dogs already appreciate their extraordinary power of smell: it’s a foundational pillar of their partnership. The ultimate tool of the quietly confident gun dog picking up the faintest scent of a bird. But the serious enthusiast might now be questioning whether this ability is a fixed genetic trait, or something more dynamic that can be shaped and enhanced.

A growing body of scientific research suggests that the answer lies not just in breeding and training, but also in the most fundamental aspect of a dog’s life: its diet. The prevailing wisdom that a dog’s olfactory capacity is a fixed attribute is giving way to a new understanding: that this capacity can actually be modified – even enhanced – by nutrition.

For dogs who rely on their noses in the field, even small gains in scenting performance can make a critical difference. And the right fuel can help keep them sharp.

The science

Before we can appreciate how diet can influence olfaction, we need to understand the sheer biological complexity of a dog’s nose. We humans possess a relatively small number of specialised cells that detect odour molecules (olfactory receptor neurons, or ORNs). A dog, however, boasts hundreds of millions of these neurons, depending on the breed. This anatomical advantage is magnified by the structure of their nasal cavity, which contains intricately branched, scroll-like bones called turbinates. Branching dramatically increases the surface area for scent detection and analysis. Dogs with long snouts, particularly hunting and tracking dogs, often have more developed and numerous turbinates, correlating with their heightened sense of smell. (By way of comparison, humans have just a single scroll!)

The sniffing process is also a highly evolved and sophisticated system. The dog can separate inhaled air into two distinct streams: one for respiration and one for olfaction, with a specialised airflow that routes odours to the olfactory recess. This unique ability allows the dog to breathe and smell simultaneously, a key advantage in continuous scent tracking. The health of this super-sensitive olfactory network – neurons, supporting cells and neural pathways – can be influenced by a dog’s nutritional intake.

However, when a dog is under a significant heat load and must pant to cool down, its physiology changes, with the primary focus shifting from sniffing to thermoregulation. To cool down, a dog engages in heavy panting, which bypasses the intricate nasal airflow system. Instead of using their nose to pull in scent, the dog is now using its mouth and respiratory tract as a heat exchanger. Essentially, while panting is a fixed, involuntary response to heat, a dog’s physical fitness level and diet can influence the intensity and duration of work it can perform before that response is triggered. So, resilience and condition matter[1].

And then come the fatty acids

It may seem both revolutionary and intuitive that the very cells responsible for detecting scent are built from the nutrients a dog consumes.

Ever heard of phospholipids? They are the fundamental building blocks of cell membranes, including those in the nose. They help maintain the integrity and moisture of the nasal surface, and by extension its function. And they’re made of fatty acids. When a dog consumes fats, their digestion and absorption provide fatty acids that are incorporated into the fatty acid chains of phospholipids and used for their synthesis and repair – including those in the nasal, brain and nervous tissues.

Essentially, the membrane’s composition mirrors dietary intake. If more polyunsaturated fats (PUFAs) are eaten, more of them end up in the membranes. If mostly saturated or medium-chain fats are eaten, those get incorporated instead. Studies in dogs have shown that dietary fatty acids are incorporated into neuronal cell membranes, where they influence both the lipid composition and the functional properties of those membranes.

One of the clearest demonstrations of the link between fat and olfaction comes from a pivotal study involving 18 male English Pointers[2], which showed after meticulous testing that the type of fat – particularly the inclusion of PUFAs and the avoidance of high concentrations of medium-chain triglycerides (MCTs) – is an important consideration for the working dog’s diet.

That seems biologically logical: given the makeup of the membranes of olfactory sensory neurons, altering the dietary fat profile may influence their structure and function. The researchers were, in effect, changing the very building blocks of these critical cellular structures. The higher incorporation of PUFAs may have conferred a greater functionality on the cell membranes, improving odour detection and signal transmission to the brain.

This highlights how a specific nutritional choice can potentially have a direct impact on the microscopic architecture of a dog’s most valuable tool.

And although fats, currently the best-studied nutritional factor directly linked to olfaction in dogs, are crucial, they are only part of the picture. Several other micronutrients also underpin olfactory tissue and signalling. Some of them are even dual-purpose, contributing to gut health and influencing the power of smell at a ‘systems’ level too.

Zinc, for instance, is critical for maintaining the sense of smell because it supports the regeneration of receptor cells; it is found in abundance in meat, fish and seeds. The B-vitamins also matter: thiamine, niacin and pyridoxine all contribute to the enzymatic pathways and nerve conduction that help process odour signals. They are plentiful in liver, whole grains and yeast products. Copper and iron provide the means for oxygen transport and the synthesis of haem proteins and enzymes involved in olfaction, with rich dietary sources including red meat and organ meats.

Other nutrients are also crucial. Adequate levels of protein and amino acids are essential for the maintenance and repair of the olfactory sensory neurons.

Last, but not least: antioxidants. Olfactory neurons are particularly vulnerable to oxidative damage because of their constant exposure to inhaled particles and high metabolic turnover. Antioxidants in the diet (vitamin E, selenium, etc.) protect the delicate membranes of olfactory cells.

The Gut-Brain-Nose Axis

A broader literature review[3] also affirms how overall physical condition and nutritional intake are fundamentally tied to the ability to smell. In particular, it uses existing research to put the spotlight on the microbiota-gut-brain axis, and how it may extend to influence olfactory function.

The trillions of microbes living in a dog’s gut produce an array of compounds that can influence digestion, systemic inflammation and even neurological function. When the community is disturbed – by diet, stress, antibiotics or disease – it can lead to a cascade of systemic effects, including inflammation that can alter nasal blood flow and hydration.

From Science to Strategy

For the dedicated working or hunting dog owner, this research provides more than just academic curiosity; it offers actionable insights that can be integrated into the daily care of their dog. The scientific literature supports several simple but effective methods to optimise a dog’s scenting performance.

1. Evaluate Fat Sources: The most direct takeaway from the scientific literature is to scrutinise the fat sources in your dog’s diet. While a diet that incorporates healthy polyunsaturated fats (PUFAs) may offer a subtle but meaningful advantage, it’s essential to maintain a balanced fat profile by including sources like fish oil (rich in omega-3 and omega-6 fatty acids) or algae oil. It is equally important to avoid diets with an over-reliance on a single fat source, especially if they are lower in PUFAs, as this could have a negative effect on long-term olfactory acuity. Low-PUFA fats like beef tallow can still provide a dense, stable energy source that supports endurance and stamina in active dogs. But for optimal olfactory performance and cellular health, they should be balanced with PUFA-rich ingredients such as fish oil, which supplies readily usable omega-3s like EPA and DHA.
2. Optimise the Microbiome: The link between diet and the gut microbiome is well-established, and the connection between the microbiome and olfaction is gaining traction. Providing a diet rich in prebiotic fibres and feeding probiotics can help maintain a diverse and balanced gut ecosystem.
3. Prioritise Hydration and Strategic Feeding: The review also supports the importance of proper hydration and feeding patterns. A dog’s ability to smell relies on a moist nasal environment. Ensuring your dog has constant access to fresh water is not a general wellness tip, but a fundamental lever for olfactory performance. Similarly, the size and timing of meals can influence a dog’s physiological state before and during a work session, making it a key factor in performance.
4. Beyond nutrition, physical conditioning matters: The fact that unconditioned dogs were shown to exhibit a clear decline in scenting ability after strenuous exercise, in contrast to conditioned dogs, underlines the importance of a consistent training regimen.

The nose of a working dog is not an isolated instrument but an integrated component and reflection of its overall health and, by extension, the care and nutrition we provide.

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References

[1] Baker, Janice & Davis, Michael. (2018). Effect of conditioning on exercise-induced hyperthermia and post-exercise cooling in dogs. Comparative Exercise Physiology. 14. 91-97. 10.3920/CEP170039.

[2] Altom EK, Davenport GM, Myers LJ, Cummins KA. Effect of dietary fat source and exercise on odorant-detecting ability of canine athletes. Res Vet Sci. 2003 Oct;75(2):149-55. doi: 10.1016/s0034-5288(03)00071-7. PMID: 12893164.

[3] Jenkins EK, DeChant MT, Perry EB. When the Nose Doesn’t Know: Canine Olfactory Function Associated with Health, Management, and Potential Links to Microbiota. Front Vet Sci. 2018 Mar 29;5:56. doi: 10.3389/fvets.2018.00056. PMID: 29651421; PMCID: PMC5884888.

 

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Important Considerations:

• Always consult your veterinarian before making any significant dietary changes, particularly where there are pre-existing health conditions or dietary restrictions.
• If you are feeding commercial food, check the label for ingredients before giving more. Excessive intake of any foods can have adverse effects.
• Ensure (where possible) that you use high-quality, organic products specifically formulated for pets (or better still, human grade ingredients) to avoid any potential adverse effects.
• Introduce new foods gradually to avoid adverse effects such as gastrointestinal upset or diarrhoea.
• I provide nutritional information purely as a helpful guide. Nutritional information on ingredients is obtained from the US Department of Agriculture’s FoodData Central site (https://fdc.nal.usda.gov/index.html) and any nutritional information provided in recipes is based on an online calculator: calories and other information will vary based on brands, ingredients and other factors.
• Check nutrient levels and recommendations for your dog’s weight, age and activity. For example this nutritional guideline produced by FEDIAF.
• I am not a professional canine nutritionist but supporting research is cited.
• The recipes shared were created by me and tested in my kitchen – and tasted and approved by our doggy friends!