Why Keep Pets Lean

Weight is linked to many diseases with our pets, much the same as it is in humans. Fat is a metabolically active tissue in the body. It impacts on hormones, inflammation and regulation of energy. In a study of 31 dogs that were identified as obese only 6 of these did not have significant changes to chemical levels within their body. Free thyroxine, cortisol, thyroid-stimulating hormone, prolacin and furosamide were tested and showed varying changes. These are regulated within the body to maintain the dogs health and function, so changes indicate a problem, even though these dogs were considered otherwise healthy.

Excess body fat has been associated with


Joint disorders


Endocrine disorders (Diabetes miletus, Hypothyroidism, hyperadrenocorticism, insulin resistance)

Tracheal Collapse

Brachycephalic airway syndrome


Heat intolerance

Increased Anaesthetic risk

Reduced life span

Lower Urinary Tract disease

Cardiovascular changes

Increased inflammatory Mediators


Some Cancers (Transitional Cell Carcinoma)

Oral Cavity Disease

In times past dogs and cats were able to regulate their calorie consumption themselves because they were not eating calorie dense foods. By the time they had managed to eat a days worth of calories they were full and couldn't fit more in. Dogs had an average life span of 5-7 years and were left entire. What we feed them today is much higher in calories for the same amount of bulk being taken in by our companions with significantly less energy expenditure required to get it.

While some dogs and cats still manage to regulate their calorie intake themselves, that is certainly not the case in my household! My dogs will quickly scoff down anything they can get their mouths on. So often it is up to us, the owner, to identify the correct type and amount of food for out pet.

Restricted calorie diets have been proven to decrease the risk of developing Hip Dysplasia in Labradors. It also lowers your feed bill and decreases the number of poops you have to pick up in the back yard. It's a win win.

Results of a 14 year life span study that evaluated the effect of calorie restriction on development and progression of hip osteoarthritis was performed in dogs predisposed to developing hip dysplasia. 

Control fed dogs

Restricted-fed dogs

Dogs with Radiographic evidence of hip dysplasiaat 5yrs of age



Dogs with greater than 2 joints affected at 8 years of age



Age at which 50% of dogs required treatment of osteoarthritis



Median life span



Similar studies have shown that arthritis progresses much slower in the shoulder joint in dogs that are kept lean on a restricted calorie diet.

Some dogs may be genetically pre-disposed to weight gain. This does not mean that they are automatically going to be overweight, it just means that you need to be proactive with their nutrition and exercise management. My own dog Demi falls into this category, she looks at the Kelpies eating their dinner and puts on weight. And it is not helped by all her adoring fans at the nursing home she visits. Regular free running, smaller meals before and after nursing home visits and selecting lower calorie food are all methods that I employ to keep her at a body condition score of 5. Demi is much more active and happier when she is at her correct weight.


Demi- at a body condition score of 5. Proving that with effort you can beat genetics.

Demi- at a body condition score of 5. Proving that with effort you can beat genetics.



I don't believe that there is 'one' correct diet out there. However, our companions all have different requirements and do better on different foods. Luckily there is a way to know if your pet is at the correct weight, known as body condition scoring. You can find more details of what a lean and healthy dog or cat should look like in our body condition article. If you are worried about your pets weight (over or under) then please email or call me so you can start a food diary today.

Dr Jaime Jackson