Ear Infections
Flea & Tick
Heart Problems
Hot Spots
Shedding Control
Skin Irritation
Tear Stains
Urinary Infections
Weight Management
See All A-Z
Ear Infections
Flea & Tick
Heart Problems
Hot Spots
Shedding Control
Skin Irritation
Tear Stains
Urinary Infections
Weight Management
See All A-Z
Breath Fresheners
Chews & Treats
Rinses & Water Additives
Toothpaste & Toothbrushes
Ear Cleansers
Ear Infection Remedies
Ear Mite Treatments
Antibiotic Anti-Infective
Artificial Tears & Lubricants
Eye Inflammation
Tear Stain Removers
Flea & Tick Prevention
Heartworm & Flea Control
Home & Yard Treatments
Immediate Relief
Oral Flea Treatments
Tick & Flea Collars
Canned Pet Food
Dry Pet Food
Raw Pet Food
Adult Pet Food
Glucose Balance
Digestive Health & Support
Grain Free
Joint Support
Kitten Food
Puppy Food
Senior Pet Food
Skin Support
Small Breed Dog Food
Weight Loss & Management
Pet Food Storage
Joint Pain
Joint Supplements
Lifting Harness
Orthopedic Beds
Steps & Ramps for Mobility
Allergy Relief
Compound Medications
Cough Relief
Digestive Health & Enzymes
High Blood Pressure
Hormonal Endocrine
Insulin & Glucose Balance
Motion Sickness & Nausea
Seizure Disorder
Urinary Tract & Kidneys
Bowls & Elevated Feeders
Car Seats & Pet Carriers
Cat Litter
Cesar Millan Training Aids
Crates & Kennels
Drinking Fountains
First Aid
Furniture Protectors
Grooming Tools
Leashes & Harnesses
Outdoor Cat Pens
Pet Cams & Monitoring Systems
Pet Food Storage
Stain Removers
Steps & Ramps
Training Aids
Wireless Dog Fences
Fish Oils & Omega 3
Fly Control
Grooming Tools
Hairball Remedies
Itch Relief
Ringworm Treatments
Shedding Control
Skin Care Supplements
Skin Medications
Digestive Enzymes
Fish Oils & Omega 3
Liver Support
Senior Support
Whole Food Supplements
Pet Health Topics
Share on Facebook Share on Twitter

Rapid Weight Loss in Dogs and Cats


Unhealthy Weight Loss in Dogs and Cats

A significant and sudden decrease in weight accompanied by weakness is considered an unhealthy weight loss in your pet. Being slightly thin is actually a benefit for your pet, as thin pets tend to live longer than overweight pets, but unhealthy weight loss that happens quickly is a sign that your pet could be sick.

Because 2/3 of your pet's body is water, sudden weight loss may be caused by dehydration rather than by loss of fat. Under some circumstances, your pet becomes dehydrated and loses weight too. It's important to understand which is happening because dehydration quickly leads to death. Unhealthy weight loss slowly leads to death.

Sudden or rapid weight loss in dogs and cats is not normal and could be a sign of illness.
Key Facts of Weight Loss in Dogs and Cats
  • Rapid weight loss is often a sign of illness.
  • Symptoms include low energy levels, low resistance to infection, lethargy, and dull coats that grow in splotches.

Find Panacur C at 1-800-PetMeds
Panacur C
(for Dogs)
Find Drontal at 1-800-PetMeds
(for Cats)


Pets Most at Risk for Sudden or Unexplained Weight Loss

Pets with Dental Disease

Pets with dental disease often lose weight because eating is painful. In addition, bacteria in their mouths spread over the body and cause disease in the kidneys, liver, and heart. Disease of major organs often leads to weight loss.

Pets with Intestinal Worms or Heartworms

Pets with worms lose weight, but for different reasons. Pets with intestinal worms have the nutrients sucked out of them. Pets with heartworms waste energy as their hearts no longer contract efficiently. Their lungs, where worms also reside, no longer have normal blood flow. In pets with heartworm infections, the kidneys and liver work harder than normal to help the body respond to constant parasite abuse.

Pets with Organ Disease

Pets with a disease in vital organs, including in the heart, lungs, kidneys, liver and spleen, often lose weight. Functioning of these organs is essential to sustain life. When these organs are compromised, the rest of your pet's body doesn't function well either. A poorly functioning metabolism creates a large energy drain, and your pet often metabolizes fat and eventually muscles to sustain life.

Pets with Cancer

Cancerous pets lose weight for several reasons. Many cancers demand nutrients and rob the body of nutrition so that fat and muscle tissue disappears. In addition, cancer often stimulates the liver to make tumor necrosis factor (TNF). TNF resets the body's thermostat so that all cells consume more energy than normal. TNF also affects the body so the pet feels sick and doesn't want to eat. This anorexia is characteristic of most cancers.

Pets with Infectious Diseases

These pets lose weight for the same reasons that pets with cancer lose weight: TNF is stimulated. The body's thermostat is set higher, which is why pets with infections have fevers, and most are anorexic. In addition, pets with infectious diseases are often given medications that cause nausea and loss of appetite.

Pets with Burns

A burned pet loses weight due to several factors: pain, stress-induced ulcers, medication affecting the stomach and intestines, and depression. Pets with burns have lost the skin's barrier to infectious bacteria and are often overwhelmed with infections. The immune system revs as if it is launching a Saturn missile, using an incredible amount of energy, but is not always able to save your pet's life.

Senior Pets

Aging pets lose weight because they often have nagging pain from arthritic joints and dental infections. They also experience weakening of vital organs. In addition, senior pets do not smell or taste their food as they had. They may suffer from confusion and depression.

Depressed Pets

If your pet is depressed, he or she does not have the spirit to eat. Pets can become depressed and lose weight when a family member dies, when they can't engage in the sports they loved, or climb on the bed.


Max's Tip: Don't fail to give your pet monthly heartworm prevention and to use dewormers, because worms are a common cause of weight loss in pets.  

Medical Terms for Weight Loss in Dogs and Cats Medical Terms for Sudden or Unexplained Weight Loss in Dogs and Cats: Dentition, dysgeusia, diarrhea, disease, depression, dementia, dysfunction

More Information on Weight Loss in Dogs and Cats

Help / Customer Service
My Account
PetMeds® Sites
PetMeds® Programs
Our 100% Guarantee
About Us
Contact Us
PetMeds® Help
Privacy Policy
Printable Order Form
Site Map
Vet Directory
Request a Catalog

Email Preferences
Easy refill
Track my order
My Account Page
My pet has passed away
PetMeds® Blog
PetHealth 101®
PetMeds® Charitable Causes
1-800-PetMeds® Careers
PetMeds® Investor Relations
pet meds
Pet Meds Photos
Pet Meds News
Pet Health Articles
Affiliate Program
Shelter & Rescue Program
Join our Social Network
    PetMeds® on Facebook
    PetMeds® on Twitter
    PetMeds® on YouTube
    PetMeds® Google+
    PetMeds® LinkedIn
    PetMeds® on Instagram
Copyright © 2014 PetMed Express, Inc. All Rights Reserved.
Vet-VIPPSVETERINARY-VERIFIED INTERNET PHARMACY PRACTICE SITES(CM) Online Veterinary Pharmacy Services has earned Veterinary-Verified Internet Pharmacy Practice Sites(CM) (Vet-VIPPS(CM)) accreditation through the National Association of Boards of Pharmacy® (NABP®).
Verisign Secured Click for the BBB Business Review of this Pharmacies in Pompano Beach FL
Share Website Feedback