OR completion disappointment

I learned recently about completion compulsion, where some humans feel a psychological need to clean the plate, regardless of whether they are full or satisfied. As I watched the ritual that my dogs perform at the end of every meal, a concentrated sweep of the floor in an (invariably vain) search for microscopic crumbs that might just have jettisoned unnoticed from their bowls whilst they were eating, my brain somehow coined a new phrase for this diametrically opposite behaviour: completion disappointment. Double- and triple-checking until they finally give up, sloping slowly away, in grudging acceptance that this particular meal is at an end.

It’s a disappointment I celebrate. I imagine this concentrated hunt for lost molecules as an indicator of success: their version of a chef’s kiss.

That is where nutrition aligns with enjoyment. A real win-win scenario. And for me, the pleasure of seeing their unswerving concentration and even (especially?) hearing those slurping noises, for which any human would be subjected to a very Paddington Bear stare.

*****

We know the nutrition works – this seems to be proof positive on palatability. Was it wishful thinking that dogs enjoy “my cooking” – or is there science to support the idea?

Aroma drives engagement: the appetitive phase

Palatability has been defined as the momentary and subjective orosensory pleasantness associated with food consumption[1]. Sensory evaluation is predominantly guided by olfaction, followed by taste and texture.

The nose is the gateway to the bowl. The first anticipatory sniff, activated by specific biological cues, is essential for the initial attraction and selection that determines whether a dog will even taste the food. Research has shown that dogs prioritise scent over almost every other factor, showing a clear preference for meat-scented diets[2]. An initial umami “handshake” is what makes a dog so eager to reach the bowl.

Temperature affects palatability

Increasing the temperature of a moist meal by 10°C can increase vapour release two- to three-fold, “broadcasting” more aromatics to the dog’s 300 million olfactory receptors[3]. From real life experience, eating lukewarm food also seems to induce a state of happy relaxation in my dogs – not quite a food coma, but not far off!  I discovered this phenomenon – wonderfully defined as postprandial somnolence – when I fed slow-cooked chicken that hadn’t quite cooled to room temperature. I haven’t researched it, but claims that warm(ish) food mimics natural prey temperatures, satisfying a primal urge that can promote a sense of security and contentment after eating, seem logical. It certainly does something!

Moisture supports continuous eating

Research shows that dogs eat fresh diets (averaging 70% water) more continuously than dry formats. Cohesive, hydrated meals are typically eaten with fewer pauses than dry or separated components. Moist food facilitates a continuous motor pattern without the interruptions caused by oral dehydration, providing a unified food matrix[4]. Beyond the rhythm of the meal, this high moisture level is clinically proven to exceed daily water requirements and improve renal markers[5].

Fat distribution matters

Fat is a major driver of long-term palatability and sustained interest. Lipids carry flavour and aroma; integrating fats into a moisture-rich environment creates an emulsified mouthfeel that coats the oral cavity, providing continuous tactile feedback to the brain’s reward centre (with a neurochemical pay-off). And while moisture provides the initial sensory draw and eases prehension, fat sustains the eating rhythm after the initial sniff and reinforces the desire to finish the meal.

Umami and Chemical Signalling

A dog’s taste receptors are essentially biological sensors for high-quality protein, specifically tuned to the free glutamate and nucleotides found in meats and organ blends. These compounds trigger their umami receptors, making food that contains them highly palatable. This isn’t just a flavour preference; it’s a physiological confirmation of value. A meal rich in these amino acids hits a biological “reward” that affirms the food is high value, sustaining interest after the meal is finished[6][7].

Texture and cohesion

For dogs, texture is a functional concern. A cohesive structure, with ingredients like moisture and protein thoroughly integrated, allows the dog to engage in a natural lap and swallow rhythm without the food fragmenting. The goal is a seamless transition from the appetitive phase to the consummatory phase, where oral handling triggers the release of digestive enzymes as the food begins its journey to the stomach[8]. The holy grail in the context of canine palatability research is a texture that facilitates an uninterrupted consumption rhythm.

The canine hedonist

In canine nutrition research, variety is studied through neophilia: an innate attraction to novel sensory cues. Recent trials show many dogs initially choose a new diet over the one they have eaten for several days and that this preference diminishes as the new diet becomes familiar[9]. Rotating ingredients in a home-cooked regime taps into this neophilic response.

Then there’s hedonic value. In animal science, hedonic value refers to the immediate pleasure or reward derived from a stimulus. Whereas the appetitive phase is immediate sensory pleasure, the hedonic feedback is the sustained sense of pleasure, the reward signals from the brain, that keeps them in focus. When this consummatory reward is high, the dog continues to engage with the sensory cues long after the physical food is gone: the hedonic reward is still resonating.

Behavioural markers of success

Behavioural markers of meal success include speed of approach, uninterrupted eating and the voluntary return to the feeding spot.

First, the drooling that Pavlov referred to as psychic secretions. This drooling as the meal is built isn’t just anticipatory excitement. It’s the start of a systemic chain reaction, as the brain initiates the chemical breakdown process before the first bite is even taken. These anticipatory digestive and metabolic responses to signs that feeding is imminent allow organisms to get “ahead of the curve”[10].

The speed of the approach and the latency to the first bite are standard measures used to determine the perceived value of a food source. Logically, a faster approach is associated with higher palatability. So, approaching the bowl rapidly and eating without a significant nose-pause indicates immediate acceptance, a sensory confirmation of the meal’s promise.

Lastly, ingestion rhythm. Research into the preference patterns of domestic dogs shows that the fluidity of eating is a reliable indicator of meal acceptance. Frequent interruptions or selective behaviour are recognised signs that the physical or chemical properties of the diet are not aligned with the dog’s preferences.

Completion disappointment?

So now we come full circle, back to my sense of completion disappointment.

A dog’s behaviour in the moments after finishing the bowl reflects its hedonic value. The sweep of the surrounding floor is a sign of sustained focus. Not a search for more, as we might assume, but continued engagement with residual sensory cues. Academic ethograms score this behaviour (interest post-consumption) in palatability trials for up to one minute; persistence is used to distinguish a high-value, preferred diet.

Little did I know, when I started looking into this, how to interpret these signs. That focussed slurping is the best uninterrupted form of eating. And the evidence in the kitchen, from the first sniff to that final search, is a dog’s way of confirming success. Surely, a “Chef’s Kiss” in a nutshell.

*****

 

References:

[1] Hall, J. A., J. C. Vondran, M. A. Vanchina, and D. E. Jewell. 2018. “When Fed Foods with Similar Palatability, Healthy Adult Dogs and Cats Choose Different Macronutrient Compositions.” Journal of Experimental Biology221, no. 14: jeb173450.
[2] Houpt, Katherine & Hintz, Harold & Shepherd, Paul. (1978). The role of olfaction in canine food preferences. Chemical Senses. 3. 10.1093/chemse/3.3.281.
[3] Alegría-Morán RA, Guzmán-Pino SA, Egaña JI, Muñoz C, Figueroa J. Food Preferences in Dogs: Effect of Dietary Composition and Intrinsic Variables on Diet Selection. Animals (Basel). 2019 May 6;9(5):219. doi: 10.3390/ani9050219. PMID: 31064159; PMCID: PMC6562821.
[4] Le Guillas, G., Vanacker, P., Salles, C., & Labouré, H. (2024). Insights to study, understand and manage extruded dry pet food palatability. Animals, 14(7), 1095. https://doi.org/10.3390/ani14071095
[5] Sires R, Yamka R and Wakshlag J (2025) Feeding fresh food and providing water ad libitum is clinically proven to exceed calculated daily water requirements and impact urine relative supersaturation in dogs. Front. Vet. Sci. 12:1675990. doi: 10.3389/fvets.2025.1675990
[6] The Molecular Signature of Umami Palatability in Dogs Based on Amino Acid Interactions with Canine Taste Receptors Margaux Brewer, Arun HS Kumar bioRxiv 2025.10.13.681969; doi: https://doi.org/10.1101/2025.10.13.681969
[7] Calderón N, White BL, Seo HS. Measuring palatability of pet food products: Sensory components, evaluations, challenges, and opportunities. J Food Sci. 2024 Dec;89(12):8175-8196. doi: 10.1111/1750-3841.17511. Epub 2024 Oct 29. PMID: 39468886; PMCID: PMC11673441.
[8] Bradshaw, J. W. (2006). The evolutionary basis for the feeding behavior of domestic dogs. The Journal of Nutrition, 136(7).
[9] Crepalde, L. T., M. S. da Silva, G. C.Rocha, M. C. T. R.Vidigal, and V. P. R.Minim. 2026. New Perspective in Consumer Sensory Science: Acceptance and Preference Testing of Dry Dog Food. Journal of Sensory Studies 41, no. 2: e70124. https://doi.org/10.1111/joss.70124.
[10] Power ML, Schulkin J. Anticipatory physiological regulation in feeding biology: cephalic phase responses. Appetite. 2008 Mar-May;50(2-3):194-206. doi: 10.1016/j.appet.2007.10.006. Epub 2007 Oct 24. PMID: 18045735; PMCID: PMC2297467.

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!