All Pets Veterinary Clinic
Anorexia or lack of appetite is a common complaint among pet owners. It is one of the
first signs that owners notice when their pet is becoming ill and is a common reason
for presentation of animals to the veterinary clinic. Unfortunately, lack of appetite
is not a sign that is specific for any one disease or illness-there are multiple causes.
The remainder of this article will discuss some of the reasons animals stop eating, some
of the methods of determining an underlying cause, and some of the things that can be
done if your pet decides to stop eating.
CAUSES OF ANOREXIA
Anorexia can have a multitude of causes ranging from behavioral and environmental causes
to illness. While this list is not all-inclusive, some of the most common causes of
anorexia in pets are listed below.
Environmental/weather changes. Hot, humid weather conditions can cause animals
to have a decreased appetite. It is not uncommon for pets to be less active and eat
less during hot summer weather. Typically, with cooler temperatures, appetite will
improve if this is the sole cause of anorexia.
Stress and depression. Things that cause a change in the animal's normal routine
can cause some animals to stop eating. For example, the loss of a companion pet or loss
of a human can cause animals to be depressed/stressed and result in lack of appetite.
Other stressors such as moving, adding a new pet, the presence of a new baby, or visiting
guests, can also result in anorexia.
Food change. A sudden change in diet can cause animals to refuse food, especially
if food is changed to something that is less palatable than the original diet. Slow,
gradual change between diets can help eliminate lack of appetite due to a change in diet.
Food intolerance and food allergy. Like people, certain types of foods can cause
GI irritation in pets. For example, fatty or greasy foods may cause a pet to experience
gas and cramping and result in a lack of appetite. Some animals can be allergic to
certain proteins contained in pet foods such as chicken, beef, wheat, corn, or soy.
Animals with food allergy can have signs ranging from lack of appetite to vomiting and
Side effects of medications. Some long-term medications, such as medications for
heart failure (not heartworm medications) and arthritis medications, can cause GI
irritation and lack of appetite. Some short-term medications, such as antibiotics,
can cause similar problems.
Picky eater/spoiled appetite. Some pets become very picky eaters and are tempted
with human foods. This can often compound a pet's refusal to eat pet foods. Some pets
become spoiled with pet treats and human foods and will become too full to eat their
Fractured/damaged teeth. Excessively worn or fractured teeth can be painful and
can cause a pet to refuse to eat.
Illness. Illnesses such as gastrointestinal disease, kidney disease, heart
disease, liver disease, dental disease, cancer, etc. can cause an animal to stop or
decrease eating. Some of these diseases can cause nausea, which will impair the desire
of a pet to eat. Some of these diseases can cause painful lesions or ulcers with in
the mouth that can hinder a pet's ability to eat. Some of these diseases cause
weakness, which can result in a decreased appetite.
Looking for the cause of appetite loss is the most important consideration of caring
for pets with anorexia. Healthy animals typically have good appetites. A thorough
physical examination of the pet, paying special attention to the oral cavity, lymph
nodes, and GI tract may provide important clues as to the cause. Diagnostic testing
such as bloodwork, x-rays, and GI endoscopy may be warranted. Specific testing based
on the history and physical examination should be recommended by the veterinarian.
Obtaining a proper diagnosis is the first and most important step to treating anorexia.
Treating the cause of the appetite loss is critical for success. For example,
changing foods or adding moisture to the diet will have little or no long-term results
if the pet is suffering from undiagnosed cancer. Without determining the underlying
cause, many treatment options will be successful for short periods of time or completely
While you are waiting for laboratory testing results or early on in mild cases of
anorexia some general tips that can be tried to improve appetite include: 1) Moistening
the food. Adding a little bit of warm water to dry food can stimulate appetite.
2) Heating food. Some animals will eat food better if it is warmed slightly. 3) Canned
food. For animals that are accustomed to dry food, canned food may perk up the
appetite. Mix small amounts of canned food with the dry food first as large quantities
of canned food can cause diarrhea in pets that normally get dry food. 4) Changing brands
or flavors of food. Moving to a higher quality and/or more palatable food may stimulate
a pet's appetite. Again, mix small amounts of the new food with the regular food to
avoid diarrhea. 5) Appetite stimulants. Some prescription medications are available
that can help to stimulate the appetite in some cases. 6) Change bowl shape/size.
While this is often not successful, in some cases changing from a bowl to a plate or
moving to a larger bowl can make a difference for a picky eater. 7) Top dress food
with boiled chicken and rice. While feeding human foods is not generally recommended,
adding small amounts of boiled chicken and rice to the regular food may encourage a
picky eater to finish his/her bowl. However, extreme caution should be used as some
animals will not return to their normal diet once they have been tempted with human
foods. 8)Try a nutritional supplement. Several are available at our online store.
(See link below.)
The information provided is for educational purposes only and is not
intended to take the place of your regular veterinarian. Please do not hesitate
to contact your regular veterinarian if you have questions regarding your pet.
Karen Blakeley, DVM, MPH
27 September 2009