Fennel

Known for its delicate, anise-like flavour, fennel (Foeniculum vulgare) has a long history as a culinary and medicinal herb. Belonging to the Apiaceae family, also known as the carrot or parsley family, fennel shares its lineage with nutrient-rich plants such as carrots, celery, and parsley.

Functional properties

Thought to be amongst the world’s oldest medicinal herbs, and with its wealth of nutrients and bioactive compounds, fennel is used after meals for its digestive aid – and even breath-freshening – qualities, and in some countries to treat IBD[1]. This vegetable has also been studied for its effect as an anti-stress agent[2] and its memory-enhancing properties[3]. Data from various pharmacological studies have suggested the efficacy of the fennel plant in antibacterial, antifungal, antioxidant, anti-inflammatory, antiviral, bronchodilatory and memory enhancing activities[4].

In moderation, fennel can be used in the canine diet: either in vegetable form (florence or bulb fennel), or fennel seeds and fennel seed powder.

Note:

Fennel should NOT be given to pregnant and/or lactating dogs.

Main Nutrients and Phytochemicals

Fibre
Fennel is a good source of dietary fibre, which is essential for maintaining digestive health in dogs. Fibre promotes regular bowel movements, prevents constipation, and supports the growth of beneficial gut bacteria. Fennel also contains soluble fibres like inulin, which act as prebiotics, further enhancing gut health.
Antioxidants (Including beta-carotene)
Fennel is rich in antioxidants, such as flavonoids, quercetin, and anethole, which help neutralise free radicals and reduce oxidative stress. Additionally, fennel contains beta-carotene, a precursor to vitamin A, which supports vision, immune function, and skin health. These antioxidants play a critical role in protecting dogs from cellular damage and supporting longevity.
Antimicrobial Effects
Fennel contains essential oils, such as anethole, fenchone, and estragole, which have natural antimicrobial properties. These compounds help inhibit the growth of harmful bacteria and fungi, making fennel a valuable addition to the diet for promoting a healthy microbiome and overall wellness. That said, dogs fed commercial foodstuffs containing estragole should monitor levels (recommended at 2.3 mg/kg for dogs[5].
Essential Oils
The unique essential oils in fennel contribute to its digestive-supporting, anti-inflammatory, and antimicrobial properties. These oils help soothe the digestive system, making fennel particularly beneficial for dogs with occasional bloating or gas.

Main Vitamins

Vitamin C
Although dogs do not have a dietary requirement for vitamin C (they can synthesise it on their own), it this still beneficial. Vitamin C is a powerful antioxidant which may[6] support immune health, neutralises free radicals, and promotes collagen production for healthy skin and connective tissues.
Vitamin A (Beta-Carotene)
Fennel provides beta-carotene, a precursor to vitamin A, which is vital for vision, immune function, and maintaining healthy skin and mucous membranes.
B Vitamins
Fennel contains several B vitamins, including folate (B9) and pyridoxine (B6), which support energy metabolism, red blood cell production, and nerve function.

Minerals

Potassium
Potassium in fennel helps regulate muscle contractions, nerve signalling, and fluid balance. It is also essential for maintaining healthy heart function and supporting active dogs.
Calcium
An important mineral for bone health, calcium in fennel supports the skeletal structure and dental health of dogs.
Manganese
Manganese supports the formation of bone and cartilage, particularly important for growing puppies and senior dogs prone to joint issues. Manganese is also used to produce energy and to synthesise connective tissue and collagen.
Magnesium
Magnesium contributes to muscle and nerve function, energy metabolism, and the absorption of other essential nutrients.
Iron
Iron in fennel is essential for red blood cell production, oxygen transport, and overall energy levels.

Benefits – Key Takeaways
 
Immune Support

The array of antioxidants and vitamin C in fennel significantly boosts immune function in dogs. These compounds enhance the body’s ability to fight off infections and diseases while reducing inflammation and oxidative stress.

Gut Health

The fibre, prebiotic content, and antimicrobial properties of fennel promote a healthy gut microbiome, aiding digestion and nutrient absorption. Its essential oils help soothe thdigestive system, reducing bloating and gas.

Liver Function Support

Emerging evidence suggests fennel may support liver health due to its high levels of antioxidants and bioactive compounds, including flavonoids and essential oils. These compounds help reduce oxidative stress in the liver and may assist in detoxification processes. Its antimicrobial and anti-inflammatory properties make fennel a useful ingredient for promoting overall hepatic health in dogs.

Anti-Inflammatory Properties

Fennel’s essential oils, particularly anethole, have anti-inflammatory effects that benefit dogs with chronic inflammatory conditions.

Heart Health

Rich in potassium, fennel supports healthy blood pressure and cardiovascular function. Its antioxidants also protect the heart from oxidative damage and high dietary fibre helps to manage blood sugar, reducing the risk of cardiovascular disease.

Energy and Vitality

The combination of B vitamins, iron, and magnesium in fennel supports energy production and vitality, ensuring dogs remain active and healthy.

And don’t forget the fresh breath!

Tip:
Use fennel bulb and fennel seeds in toppings, fennel seeds and fennel powder in baked products. Fennel seeds can also be used to make a light tea – for you and (once it’s cooled down) your dog.

 

References:

[1] Das B, Rabalais J, Kozan P, Lu T, Durali N, Okamoto K, McGeough MD, Lee BJ, Barrett KE, Marchelletta R, Sivagnanam M. The effect of a fennel seed extract on the STAT signaling and intestinal barrier function. PLoS One. 2022 Jul 8;17(7):e0271045. doi: 10.1371/journal.pone.0271045. PMID: 35802574; PMCID: PMC9269469.

[2] Naga Kishore R, Anjaneyulu N, Naga  Ganesh  M,  Sravya  N  (2012),  “Evaluation  of  anxiolytic  activity  of ethanolic  extract  of Foeniculum  vulgare in  mice model”, International  Journal  of  Pharmacy  and  Pharmaceutical  Sciences,  Volume  4,  Issue 3, pp. 584–586.

[3] Koppula  S,  Kumar  H  (2013),  “Foeniculum  vulgare Mill  (Umbelliferae)  attenuates  stress  and  improves  memory  in  wister  rats”,  Tropical  Journal  of  Pharmaceutical  Research, Volume  12,  Issue  4,  pp. 553–558.

[4] Rafieian, F., Amani, R., Rezaei, A., Karaça, A. C., & Jafari, S. M. (2023). Exploring fennel (Foeniculum vulgare): Composition, functional properties, potential health benefits, and safety. Critical Reviews in Food Science and Nutrition, 64(20), 6924–6941. https://doi.org/10.1080/10408398.2023.2176817

[5] EFSA FEEDAP Panel (EFSA Panel on Additives and Products or Substances used in Animal Feed),  Bampidis, V.,  Azimonti, G.,  Bastos, M. L.,  Christensen, H.,  Durjava, M.,  Kouba, M.,  López-Alonso, M.,  López Puente, S.,  Marcon, F.,  Mayo, B.,  Pechová, A.,  Petkova, M.,  Ramos, F.,  Villa, R. E., Woutersen, R.,  Brantom, P.,  Chesson, A., …  Dusemund, B. (2023).  Safety and efficacy of feed additives consisting of essential oils from the fruit and stems of Foeniculum vulgare Mill. ssp. vulgare: Bitter fennel oil for use in all animal species and sweet fennel oil for use in dogs and cats (FEFANA asbl). EFSA Journal, 21(10), 1–36. https://doi.org/10.2903/j.efsa.2023.8348

[6] Hesta, M., Ottermans, C., Krammer-Lukas, S., Zentek, J., Hellweg, P., Buyse, J., & Janssens, G. (2009). The effect of vitamin C supplementation in healthy dogs on antioxidative capacity and immune parameters. JOURNAL OF ANIMAL PHYSIOLOGY AND ANIMAL NUTRITION, 93(1), 26–34.

*****

Want to know more? These studies may be useful:

  • Noreen, S., Tufail, T., Badar Ul Ain, H., & Awuchi, C. G. (2023). Pharmacological, nutraceutical, functional and therapeutic properties of fennel (foeniculum vulgare). International Journal of Food Properties, 26(1), 915–927. https://doi.org/10.1080/10942912.2023.2192436
  • Zameer, S., Najmi, A. K., Vohora, D., & Akhtar, M. (2017). A review on therapeutic potentials of Trigonella foenum graecum(fenugreek) and its chemical constituents in neurological disorders: Complementary roles to its hypolipidemic, hypoglycemic, and antioxidant potential. Nutritional Neuroscience, 21(8), 539–545. https://doi.org/10.1080/1028415X.2017.1327200
  • Rafieian, F., Amani, R., Rezaei, A., Karaça, A. C., & Jafari, S. M. (2023). Exploring fennel (Foeniculum vulgare): Composition, functional properties, potential health benefits, and safety. Critical Reviews in Food Science and Nutrition, 64(20), 6924–6941. https://doi.org/10.1080/10408398.2023.2176817

*****

Nutritional information:

Fennel, bulb, raw:

For full nutrient content see Food Data Central

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!