B. Factors that Influence Obesity

 Beechwood Animal Hospital

Goal:  To achieve 1.3 – 2.6% weight loss per week until ideal body weight is reached. To establish a new, healthy, active lifestyle, while modifying behaviors and attitudes to achieve long term weight control and vitality.

Developed / modified from lecture notes of Dr Alexander German BVSc, Phd, CertSAM, DipECVIM-CA MRCVS.  University of Liverpool, England. The Royal Canin Weight Management Clinic.

And Tara Estra’s Senior Seminar Paper, Cornell University April 2003, among other searches and personal thoughts and experience (exercise/psychology/enrichment etc).

Part 1 of notes:


“Overweight” (OW) =  > 15% above ideal body weight  (excess WAT)

“Obesity” (O) =  > 30% above ideal body weight (excess WAT)

W.A.T (WAT) = White Adipose Tissue or Fat (in these papers)

Estimate of Prevalence: 

                   Overweight and obese pets: 22-40%  (1 in 3 dogs)

 Causes of Obesity

1. Diseases:e.g.. Hypothyroidism, Hyperadrenocorticism

2. Drugs: e.g. Corticosteroids (Prednisone, other), Anti-seizure medications (Phenobarbital), Antianxiety medications (Amitriptyline-cats)

3. Genetic defects    eg. Breed disposition

4. Imbalance of the ‘energy balance equation’

                   When “energy in” is greater than “energy out”.

                     **The main reason is 4


Factors that Influence the rate of weight gain

1. Genetics:

e.g.  Breed predispositions  – Labrador Retrievers, Cairn Terrier, West Highland Terrier, Scottish Terrier, Cocker Spaniel, Cavalier King Charles Spaniel and Golden Retrievers among others.

Domestic Short Haired Cats (DSH)

2. Neutering: 

(important factor) Energy requirements are 20% lower after ovarioectomy. Neutering results in the net loss of circulating hormones, slowing an animal’s metabolism and predisposing the neutered animal to becoming OW or O. Changes in sex hormones after neutering directly affect the satiety center in the brain through changes in leptin and ghrelin concentrations.

Gonadectomy in dogs also results in modified feeding patterns – Energy intake should be reduced by 30% after ovariectomy to maintain  optimal body weight for a period of 6 months.

3. Gender:             

Female dogs are over represented in obesity cases.

4. Indoor lifestyle

 5. Inactivity:  

(NB: orthopedic problems lead to more inactivity and are commonly caused or exacerbated by being overweight)

 6. Middle age:

The total daily energy needs of an averaged-sized 7 yr old dog may decrease by as much as 20% when compared with its needs as a young adult.

 7. Dietary Factors

- number of meals
- amount and frequency of snacks/treats
- table scraps
- animals present where owners prepare meals  or  dine.
- free choice feeding   *NB-Cats

7. Behavioral Factors

Cats   - anxiety, depression (importance of lifestyle enrichment)

- failure to establish normal feeding behavior or    satiety control

- human-animal relationship (has been found to be more intense with owners of obese cats) Humans may misread the signals the pet gives when they initiate contact and often interpret them as asking for food or treats. This becomes a learned behavior in pets as they get food rewards.

Dogs   - likely anxiety, depression and boredom as for cats

- owner’s  observation of their dog(s) eating (increased with fat dogs)

- owner’s  interest in pet nutrition (lower with fat dogs)

- health consciousness of the owner (for themselves and the pet is lower with fat dogs)

     Why is being overweight or obese (OW+O) a problem for my pet?

  1. The effects on pets being overweight and obese (OW+O) are very similar to those seen in human studies. The news is not good.
  2. There is an increased risk for a variety of diseases
  3. OW+O is associated with an increased incidence of sickness and poor vitality  (morbidity)
  4. OW+O in pets leads to increased mortality.  Life is shortened on average by 1.8 years. (Based on a study of 48 Lab. Retrievers. The comparison was between a control group with free choice feeding the first 3 years followed by controlled feeding versus a restricted fed group given 25% less food. BCS 2+-3 (4-5) restricted fed vs. BCS 3+-4+ (6-7) for the control group).
  5. Pets in good body condition have more energy, strength and have more desire to be active. (Dogs want to walk more and longer and cats jump and play more)
  6. Inability to properly groom (hygiene)…Among others.  (Thermoregulation – over heat, etc.)