Obesity is recognised as the most common form of malnutrition in
Australian pets, with published national surveys having reported that
41% of dogs and 32% of cats in Australia are either overweight or
Obesity is an important issue in pets as it can lead to a reduced
quality of life for the pet, reduced enjoyment for the owner and it
predisposes the dog or cat to a number of potentially serious
illnesses. The major factor leading to obesity in pets is that the pet
is eating more energy than it needs and in many cases, overweight pets
get little exercise. Energy that is in the food that is excessive to
the pet's underlying metabolic needs is stored as fat.
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This info-bite should be read in conjunction with the PFIAA
info-bite entitled: Weight Management in Pets.
Deciding whether a pet is overweight can be a challenge for some owners
and your veterinarian can assist by weighing your pet and determining
your pet's body condition score. It is widely accepted that "Obesity" is
a condition where the animal is 15% or more over its optimal body weight.
If your pet is overweight, your vet can assist in modifying their diet
and exercise routine to get them back into a healthy body condition and
Incidence of pet obesity in Australian pets
A study to assess the incidence of obesity in dogs was undertaken in
2005. This included responses from 52 Australian Veterinary practices,
providing information about 2661 dogs. Of these,33.5% were identified as
being overweight and 7.6% as obese; with breed, gender and neutering
identified as important factors 1.
In 2008, results of another survey exploring veterinarians' assessment of
obesity in Australian cats was published. This report involved responses
from 428 veterinary practices and the researchers analysed 973 cat
reports from 48 veterinary clinics. This survey found that 33% of cats in
the study were categorised as overweight or obese by veterinarians
What causes pets to be overweight?
By far the most common contributing factors are overfeeding combined with
too little exercise. When (food) energy intake (measured in kilojoules
(kJ) or calories) exceeds the energy expended by the animal the excess
energy eaten is stored as body fat in the dog or cat. This means that
correcting excessive bodyweight and obesity in pets is largely reliant
upon changing the type and / or how much food is provided to the pet and
increasing the amount of energy burned by the animal through increased
Feeding practices and lifestyle factors are common contributing factor in
many obese pets. These includes the frequency of feeding, leaving bowls
of food available (ad-libitum feeding of excess food) when the pet is
left unsupervised, the type and quantity of food offered ( e.g excessive
table scraps). Neutering can also be a factor contributing to weight
gain, because the hormonal changes associated with desexing means animals
may require less energy in their diet. An indoor lifestyle and middle age
are reported to be risk factors for obesity in dogs and cats.
Why pets overeat
Owner feeding behaviour
Many people enjoy seeing their pet eating and they can feel a little
guilty about not being home all day to entertain the pet. As a result,
some owners offer too much and/or inappropriate types of food to their
pets. This can include feeding of high energy table scraps or excessive
amount of "treats" particularly when more than one family member feeds
treats and table scraps to the pet, so no-one takes charge of just how
much (high energy) food the pet consumes each day.
Boredom and emotional stress
A recent study proposes that some pets overeat in response to stresses
such as boredom, anxiety and depression. This might help to explain why
some pets in a household seem to gain an extra kilo or two while others
do not 3.
Competition in multi-pet households
Where there is more than one pet in a home, a dominant pet can
develop, consuming more than their fair share and requirement.
Neutered / desexed pets have a tendency to gain weight as some owners
continue to overfeed without recognising that their pets can have
reduced energy requirements and insufficient exercise. Your vet can
provide advice on the most appropriate amount and type of food for your
Some medications (e.g glucocorticoids) and medical conditions (e.g
hypothyroid disease can contribute to excessive energy consumption
relative to energy expenditure.
Pet health issues associated with being overweight:
Overweight pets may have a shorter lifespan and poorer quality of life as
a wide range of medical conditions may affect obese dogs and cats more
often than animals of normal body weight. It is important to realise that
obesity is a common and preventable condition in the vast majority of
cases and it can increase the risk to the health and quality of life of
pets. Obesity is recognised to be associated with a number of medical
issues including : 4, 5, 6, 7, 8:
Insulin resistance / diabetes
Liver and pancreatic disease
Increased surgical risk
Susceptibility to infection
Increased risk of some types of cancer
If you own an older overweight dog you may notice that he or she has a
declining interest in going for a walk. This might be the first sign that
your overweight dog is developing arthritis (joint inflammation) which
can be exacerbated by the excessive weight which places increased stress
and wear on their joints. We encourage you to seek veterinary advice and
commit to managing their body weight and health.
Over feeding pets - a common issue
(How much food should I feed my pet?)
It is important to understand how much food should be offered to your pet
to provide for their energy needs. Foods vary dramatically in regards to
how much energy (kJ) are provided per 100 g of food. For instance, dry
food provides a lot more energy per 100g than the same weight of canned
food, so much less weight of dry food is required to provide the
equivalent amount of energy compared with canned foods. Feeding guides
included on pet food packaging should be used as a guide only
and owners are the best placed to assess their own pet's food needs and
adjust the amount and type of food provided to suit the pet's breed/size,
age, lifestyle, environmental conditions, body condition and level of
exercise. If the dog or cat is getting a bit "tubby", it means they
are getting more kilojoules (calories) than they need, so less food can
be offered, or perhaps offer the food only in set portion meals, rather
than providing access to food all day.
How to assess dogs and cats for obesity
Pet owners can learn to assess the body condition of their dog or cat by
feeling along the ribs, back and waist and to assess the pet's condition
against a recognised body condition / weight guide chart. When viewed
from above, dogs and cats should have a noticeable waist, between the end
of the rib cage and the start of the hind quarters 9. When you run a hand over the pet's back and
sides with light pressure, you should be able to feel both the spine and
individual ribs. Your veterinarian can assist in helping you to assess
your pet's body condition.
Your pet's ideal body condition
You can assess your pet's body condition by its appearance and by
referring to weight charts for its breed and sex. The following examples
of a body condition guides will help you to estimate your pet's body
If your pet has a body condition score of 7-9 (overweight - obesity) you
can and should do something about it.
If your pet is overweight (body condition score 7) or obese (body
condition score 8/9), you should have it assessed by your vet. Prior to
any weight loss program a thorough vet examination is recommended to
check your pet's general health. Occasionally pathology tests such as a
routine blood screen may be necessary to rule out underlying disease.
Your vet can give you an estimate of your pet's ideal body weight, and
then calculate the amount of energy your pet needs to be fed each day
until it reaches its target weight. Your vet may advise changes to your
pet's diet or even prescribe a special veterinary diet if your pet is
obese, and needs to achieve a significant weight loss (usually a target
greater than 15% of its current bodyweight).
Achieving success is up to you and other members of your family. Only you
can ensure that your pet really does lose weight. It will need effort and
commitment, but is well worth it in terms of the extra quality of life,
health and companionship your pet and you will enjoy. Feeding your pet a
food that is "lighter" in energy content (kJ / calories) is a convenient
and often effective way of keeping their calorie intake under control
than simply giving less of their normal diet.
Achieving and maintaining a healthy body weight is not all about diet.
Regular exercise is good for slimming animals as it increases the energy
they burn. When used in conjunction with an energy- controlled diet,
exercise helps the animal to shed those excess kilos faster. Getting your
dog out for walks and runs are of obvious benefit for both you and your
pet. Getting cats to exercise is generally tougher, but using your
creativity to engage your cats in "object play", that mimics the cat's
natural hunting instincts: chasing toys and playing with materials that
encourage the cat to jump or follow vigorously will help entertain and
exercise your cat. Cat scratch poles and dedicated "cat gyms" can all
assist in increasing your cat's energy expenditure 10.
PFIAA resources for weight loss programs
A number of PFIAA member companies provide a variety of information and
resources to assist veterinarians and owners to manage controlled weight
loss in their pets. The PFIAA supports these initiatives and encourages
all pet owners who are concerned about their pets' condition to visit
these PFIAA members' websites and to seek veterinary advice to manage
their pet's body condition and health.
1. The Veterinary Record, May 2005. P.D McGreevy, P.C Thomson,
C.Pride, A. Fawcett, T.Grassi, B. Jones. "Prevalence of obesity in dogs
examined by Australian veterinary practices and the risk factors
2. McGreevy et al. "Overweight or obese cats presented to Aust.
Veterinary practices: Risk factors and prevalence. Aust. Veterinary
Practitioner 38 93):98-107.
3. Stress-induced and emotional eating in animals A review of the
experimental evidence and implications for companion animals. Franklin D.
McMillan, Journal of Veterinary Behaviour Vol 8, Issue 5, Sept 2013
http://www.adelaidevet.com.au/weighty-problems-weight-loss-for-your-pet5. Joshua, J.O. (1970). The obese dog and some clinical
repercussions, J Sm Anim Pract, 11, 601- 606.
6. Williams, G.D. and Newberne, P.M.(1971). Decreased
resistance to salmonella infection in obese dogs, Fed Proc, 30,
7. Center, S.A.(1986). Feline liver disorders and their management, Comp
Cont Ed, 8, 889-903.
8. Thornburg, L. P., Simpson, S. and Diglio, K. (1982). Fatty
liver syndrome in cats. J Amer Hosp Assoc, 18, 397.The Veterinary Record,
This article is for general information only This information is provided
by the PFIAA as general information only. For advice and information
concerning treatment and feeding your individual pet, we recommend that
you seek the advice of your veterinarian.
This article is for general information only:
This information is provided by the PFIAA as general information only.
For advice and information concerning feeding your individual pet, we
recommend that you seek the advice of your veterinarian.