Weighing In On Your Pet

Just like humans, healthy weight control for our pets can mean a longer healthier life. Especially as our pets age, it’s better for them to carry a little less weight. However, we do not want to keep them so thin that they don’t have some muscle and fat reserves should they become ill. Make certain you discuss your pet’s body condition when you’re in for an annual examination. Your veterinarian can help set a weight goal and caloric intake that’s best for your pet. If there is a concern about your pet’s weight (too high or low) your veterinarian may want you to come in for a weekly or monthly weight check. The first step is measuring and identifying the right amount of calories for a pet and their metabolic rate and exercise habits. This varies from pet to pet so a discussion with your veterinarian  to determine their ideal ‘body condition score’ may be indicated.

Weight loss that is not intentional may be the result of a medical condition. Early intervention and screening increases the chance that a medical condition can be indentified and treated successfully. When pets are losing weight without explanation a physical examination and blood test can help explain the cause. When those tests do not identify the reason and a review of calorie intake indicates that pets are consuming adequate calories, then further investigation is indicated.  Tests such as chest films and abdominal ultrasound can be used to find reasons for weight loss. Your veterinarian will want to consider primary intestinal disease as reason for weight loss in pets whose other tests do not identify a cause.

Most common in older pets are metabolic diseases such as thyroid dysfunction. In dogs, low thyroid—hypothyroid—is more common and causes weight gain. In cats thyroid dysfunction is usually overactive—hyperthyroid—and causes weight loss.  Liver and kidney disease can also cause changes in weight. If an animal has disease that causes fluid retention then weight gain can be seen. Heart and lung disease may influence weight loss because these pets are not feeling well or working hard to breathe and aren’t as interested in their food.  A thorough physical examination of your pet can help identify heart murmurs or lung changes as well as abnormalities that might be palpated in the abdomen. A metabolic screen with a blood test looking at kidney, liver and thyroid function is important when looking for a reason that a pet’s weight may be fluctuating.

When a pet has a normal physical examination and blood tests and the veterinarian and owner have determined that the calorie intake is adequate to maintain weight, then other forces are at work. Those pets might have primary intestinal disease including inflammation, bacterial imbalance in their intestines or poor absorption of nutrition from pancreatic or intestinal disease. Imaging of the intestines using radiographs (xrays) and ultrasound might be indicated in these pets. When there is evidence of intestinal disease such as vomiting, diarrhea, or loss of appetite, then some pets can undergo an endoscopy using digital camera imaging to visualize the inside of the intestines and obtain biopsies. Sometimes additional blood tests evaluating pancreatic enzyme function and B vitamin levels can identify treatable intestinal diseases such as bacterial imbalance in the intestines or inadequate digestive enzymes.

Cancer can be another reason for unexplained weight loss in pets. If you have an older pet that is losing weight without other obvious signs of disease, then xrays of the chest and an ultrasound of the abdomen is the next step in screening.  Ideally this evaluation should be done by a boarded radiologist who is skilled at identifying subtle abnormalities in the intestines and internal organs. The goal of early identification of a cancer process is that treatments including surgical removal, chemotherapy or radiation might be life sparing and in some cases might put that cancer into remission for a long period of time if not cure it. Cancer is no longer always a death sentence in pets and many can live a good quality of life after diagnosis. If your pet is diagnosed with cancer consulting with a board certified oncologist gives you the best opportunity to find out options and success rate of different treatments. The choice to treat cancer is individual and some owners might not chose to treat cancer in their pets. However, being able to make aninformed choice about options lies in knowing the options available and making the best choice for you and your pet.

Any pet over 10 years of age should have a blood test annually and a thorough physical examination with a veterinarian. Educating yourself with the reasons for any changes in your pet’s weight can help give BOTH of you more time together.

Blog Post Author: 

Merrianne Burtch, DVM, DACVIM