When choosing food for a Jack Russell Terrier, there are many factors to consider: their age, lifestyle, activity level, physiological condition and health, including potential sickness or sensitivities. Food provides energy to cover a dog’s vital functions and a complete nutritional formula should contain an adjusted balance of nutrients to avoid any deficiency or excess in their diet, both of which could have adverse effects on the dog. Clean and fresh water should be available at all times to support good urinary regularity. In hot weather and especially when out exercising, bring water along for your dog’s frequent water breaks. The following recommendations are for healthy animals. If your dog has health problems,
please consult your veterinarian who will prescribe an exclusively veterinary diet.

A Jack Russell Terrier puppy’s requirements, in terms of energy, protein, minerals and vitamins, are much greater than those of an adult dog. They need energy and nutrients to maintain their body, as well as to grow and build new cells. Until they are 10 months old, a Jack Russell Terrier puppy’s immune system develops gradually. A complex of antioxidants, including vitamin E, can help to support their natural defences during this time of big changes, discoveries and new encounters. Their digestive functions are different from an adult Jack Russell Terrier, too: their digestive system is not mature yet so it’s important to provide highly digestible proteins that will be effectively used. Prebiotics, such as fructo-oligosaccharides, support digestive health by helping balance the intestinal flora, resulting in good stool.

Similarly, a puppy’s teeth – starting with the milk teeth, or first teeth, then the permanent teeth – are an important factor that needs to be taken into account when choosing the
size, shape, and hardness of kibble. This intense growth phase also means high energy needs, so the food must have a high energy content (expressed in Kcal/100g of food), while concentrations of all other nutrients will also be higher than normal in a specially formulated growth food. It is recommended to split the daily allowance into three meals until they are six months old, then to switch to two meals per day.

Throughout their life, it is important to avoid feeding them human foods or fatty snacks. Instead, reward your dog with kibble taken from their daily meal allowance, and strictly follow the feeding guidelines written on the package in order to prevent excessive weight gain.

The main nutritional goals for adult Jack Russell Terriers are:

Maintaining an ideal body weight by using highly digestible ingredients and keeping the fat content at a sensible level.

Preserving the health and beauty of the skin and coat with the enriched addition of essential fatty acids (especially EPA-DHA), essential amino acids, and B vitamins.

In adulthood, small breed dogs are more prone to oral and dental issues, more precisely, accumulation of dental plaque and tartar. The Jack Russell Terrier’s teeth and jaws need a lot of support. A formula containing calcium chelators will help reduce tartar formation, hence helping to support daily oral hygiene. Small breed dogs are well known for being fussy eaters. Exclusive formula and flavourings, as well as a kibble size with a special texture, will stimulate their appetite.

Small breed dogs are prone to urinary stones; a diet that supports a healthy urinary system is recommended.

For Jack Russell Terriers living mainly indoors, highly digestible proteins, an appropriate fibre content, and very high quality carbohydrate sources will help reduce faecal smell and volume. Because an indoor lifestyle often means less exercise, an adapted calorie content, which meets the reduced energy needs, and a diet that contains L-carnitine, which promotes fat metabolism, can help maintain an ideal weight. Apart from an indoor lifestyle, neutering is also a factor in overweight dogs.

After 8 years old, Jack Russell Terriers start facing the first signs of ageing. A formula enriched with antioxidants will help support their vitality and an adapted phosphorus content will support their renal system. Ageing is also accompanied by the modification of digestive capacities and particular nutritional requirements, so food for older Jack Russell Terriers should have the following characteristics:

Higher vitamin C and E content. These nutrients have antioxidant properties, helping to support the body’s cells against the harmful effects of the oxidative stress linked to ageing.

High-quality protein. Contrary to a widely held misconception, lowering the protein content in food brings little benefit in limiting kidney failure. In addition, older dogs are less efficient at using dietary protein than younger dogs. Reducing the phosphorous content is a good way of helping to slow down the gradual deterioration of kidney function.

A higher proportion of the trace elements iron, zinc, and manganese to help maintain the good condition of the skin and coat.

A higher quantity of polyunsaturated fatty acids to help maintain the quality of the coat. Dogs can normally produce these fatty acids, but ageing can affect this physiological process.

As they age, dogs increasingly suffer from teeth problems. To ensure they continue to eat in sufficient quantities, the shape, size, and hardness of their kibble needs to be tailored to their jaw.