Can cats and dogs digest all forms of raw vegetables?

When wild dogs, foxes and dingos capture their wild prey for food, the first thing they eat is the stomach and intestines along with the crushed, partly digested plant matter (Billinghurst 1993).  This information alone should allow most conscientious pet owners to realise that the method in which dogs and cats absorb vegetable matter best is when it is in its crushed and partly digested form.  However, as most cat and dog owners, including myself are not prepared to bring home a live kill from the bush which includes such beautifully prepared vegetable matter, we are left to improvise.

Before we can decide how to prepare the form in which our pets eat their vegetables we need to have an appreciation of what fresh vegetables bring to our pets health, their longevity and vital energy.

In general terms vegetables give our pets fibre, to prevent and treat diseases of the digestive tract, an abundance of vitamins and minerals, antioxidants and digestive enzymes.  They can also provide some essential fatty acids and protein.  As vegetables contain significant omega 3 fatty acids, wild dogs generally have healthy skin, are less likely to develop growth problems, reproductive problems and degenerative diseases. (Billinghurst 1993)

Raw leafy greens have an array of nutrients including vitamins A, C, E and K.  They contain most of the B vitamins with the exception of B12, thiamine and choline. (Billinghurst 1993)  The best liked green vegetables for cats and dogs are parsley, alfalfa, zucchini, broccoli, and peas.  As cats are fussier when it comes to vegetables, cucumber appears to be well liked, as does roast or pureed pumpkin.  Other vegetables that are popular are carrots, green peas, winter squash, capsicum peppers, spinach, corn, beetroot and green beans.  Some vegetables, which should be cooked before serving, are corn, peas, green beans, broccoli, cauliflower and winter squash. (Pitcairn 2005) 

According to author of, ‘The Longevity Program, Natural Care for Cats and Dogs,’ the best vegetables are watercress, parsley, dandelion, beet greens, broccoli and zucchini.  He suggests the vegetables for optimum health are carrot, spinach, celery, asparagus and string beans.  It is interesting to note that although this author makes no recommendation of quantity, he does however state that the vegetables should be organic to avoid pesticides and herbicides (Goldstein et al 2005).

In addition to vegetables in the diet, a selection of grasses (known to have anti cancerous properties) can be freshly grown and added; such as wheat grass, barley grass, oat and rye.  Cats enjoy eating them straight from the growing pot. (Arora 2006)

There is however a discrepancy into which vegetables should be given regularly and which should be limited to occasional.  The general consensus amongst authors of natural diets appears to be that the following vegetables should be given only occasionally: asparagus, spinach, broccoli, brussel sprouts, cabbage, cauliflower and rhubarb.  Vegetables such as rhubarb and spinach are high in oxalic acid, which can prevent the absorption of calcium (Pitcairn 2005).  The others may cause digestive upsets or in the case of cabbage, cauliflower, broccoli and brussel sprouts, they can depress the thyroid gland function. (Billinghurst 1993)

The most highly regarded vegetables or plant matter appear to be kelp and alfalfa.  Kelp boasts a host of nutrients, which includes vitamins A, B’s, C, E, biotin, bromine, zinc, calcium, choline, copper, inositol, iodine, potassium, sodium, sulphur and selenium.  Whilst alfalfa contains vitamins B, C, D, E, K, beta-carotene, biotin, folic acid, calcium, phosphorus, potassium, magnesium, iron, zinc, copper and protein.  Alfalfa has the ability to fight negative gram bacteria, is good for inflammation and can be used with diabetes and ulcers. (Schultze 1998) 

Vegetables, which can also be used, in very small quantities are garlic and ginger.  Ginger includes enzymes to assist digestion and is known for its anti-inflammatory effects. (Schultze 1998)  Garlic is known for its anti-parasitic effects in the digestive tract.

The form in which all of the vegetables should be given to our pets is in the most crushed state as possible.  Unless the vegetables are somehow broken down, cats and dogs do not digest them.  This is also the case with herbivore animals.  Cell walls of plant material must be broken down to release the nutrients from within the plant cells themselves otherwise they are lost through the digestive tract without being absorbed into the blood.