Sniff, Snack, or Roll? From Fox Poo to Healing Herbs: Your Dog’s Secret Code

Dogs eat grass, roll in poo, even vomit - but these odd habits may reveal how they care for themselves and support their own wellbeing.

Sometimes the behaviours that leave us wrinkling our noses or shaking our heads are the very ones that tell us the most about our dogs. Why do they eat grass, roll in something smelly, or bring up mysterious yellow foam on the carpet? We may see mess or mischief, but our dogs may be quietly showing us how they care for themselves.

In this fascinating guest blog, canine practitioner and educator Shelley Mosco takes us behind the scenes of these everyday mysteries. Drawing on applied zoopharmacognosy - the study of how animals self-medicate - Shelley shows us how sniffing, snacking, and rolling can be viewed not as random quirks, but as part of an ancient survival strategy rooted in instinct and biology.

Prepare to look at your dog’s habits in a whole new light in this blog post by Shelley Mosco.

Decoding the Secret Language of Dogs

Every dog guardian knows that moment of bafflement: your dog munching on grass, rolling happily in fox poo, or vomiting something yellow on the carpet. At best, it’s inconvenient. At worst, it feels worrying. But what if these behaviours weren’t random, disgusting quirks, but instead clues to how dogs care for themselves?

In applied zoopharmacognosy, the study of animal self-medication, such habits take on new meaning. Rather than simply eating or rolling at random, dogs may be tapping into deep evolutionary strategies for health.

Purging with Purpose

One of the most misunderstood behaviours is purging. When a dog vomits yellow-green fluid, it is often bile mixed with bacteria, a way of clearing the system. White, foamy vomit suggests irritation or a foreign object. Sometimes undigested food appears, which can indicate an ingredient in the meal was incompatible. Far from being a sign of ‘bad’ behaviour, these distinctions suggest an animal deliberately detoxifying.

The Poo Taxonomy

Not all droppings are equal in canine eyes. Herbivore poo, think cow, horse, sheep or rabbit, is rich in fibre-fermenting microbes, acting a little like live yoghurt or sauerkraut. Carnivore poo, such as cat, is protein-dense and contains taurine breakdown products. Some dogs seek it to top up amino acids or stimulate bile flow. Omnivore droppings (dog or human) offer wide microbial diversity, while bird droppings are high in uric acid and may play a signalling role for liver and kidney function.

It may seem revolting to us, but for dogs these are nuanced, selective choices linked to their gut and skin microbiomes.

Rolling in More than Smells

Rolling in animal remains or droppings may not just be about scent camouflage. Emerging science suggests it could help transfer microbes onto the skin, seeding microbial diversity much like faecal microbiota transplants (FMT) are used in medicine. For dogs, rolling can be a way of sampling the microbial world, boosting both skin and gut health, and even communicating with their social group.

Human Parallels

Humans are not strangers to self-medicating instincts. Pregnant women often experience unusual cravings like ice, chalk, pickles, and aversions to foods or smells. These behaviours are thought to be adaptive, protecting mother and baby or filling nutritional gaps. Just like our dogs, we sometimes seek out exactly what our bodies need, or avoid what could be harmful.

Supporting Dogs Safely

Of course, not everything a dog selects is safe. Sprayed grass, roadside toxins, or certain plants can pose risks. Guardians can support these natural instincts safely by offering alternatives:

Green clay to bind toxins

Chamomile or calendula infusions for gentle digestive and skin support

Taurine-rich foods such as heart meat or sardines when cat litter raiding is an issue

By observing what dogs choose and offering safer options, we can work with their instincts instead of constantly battling them.

A New Perspective

What looks like chaos such as eating, sniffing or rolling, may be an ancient form of self-care. If we take a moment to reframe these behaviours, they become less about disgust and more about wisdom. Dogs are communicating with us in their own secret code; it’s up to us to learn the language.

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About the Author

Shelley Mosco is a UK-based canine practitioner and educator specialising in applied zoopharmacognosy, helping dogs self-select plants and natural compounds to support their wellbeing. Formerly a landscape architect and pioneer of living wall planting design internationally, she has worked as a research fellow and university lecturer. Today, Shelley combines her deep knowledge of plants with her work in Animal Centred Education (ACE), and has also trained in canine trauma and rescue support. Shelley offers online consultations to dog guardians worldwide.

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