Practice Scenario

Meet Dewey, a senior cat that has lost weight.

Get to know DEWEY

A 13-year-old, neutered male cat

  • Dewey is an indoor cat presented for gradual weight loss.
  • Owner has not noticed a change in Dewey’s appetite. However, she has 3 cats and group feeds them an adult dry cat food ad libitum plus a “small amount” of canned food occasionally as a treat. She is not sure if Dewey is drinking or urinating more.
  • Dewey has a body condition score of 3/9, weighs 4.3 kg (9.5 pounds), and has moderate muscle loss. Dewey has not been examined in over 2 years. His last recorded body condition score was 5/9 when he weighed 5.4 kg (almost 12 pounds).
  • On exam, Dewey is quiet, but responsive. Mucous membranes are somewhat dry with a normal capillary refill time. Although he is purring, heart and lung sounds appear normal. He exhibits no pain on abdominal palpation. His kidneys feel slightly small.

Abnormal Body Condition

Unexplained Weight Loss

Weight loss occurs when caloric intake does not meet energy needs. Weight loss can be seen secondary to many diseases, e.g., chronic heart failure or kidney disease, endocrine disease, gastrointestinal conditions, liver disease, or neoplasia. However, if the history, exam, and diagnostics all exclude a medical cause, weight loss could be driven by increased metabolic energy needs or decreased consumption. Recognizing the underlying issue and instituting targeted nutrition can help the pet regain a healthy weight and body condition, which promotes optimal health and longevity.

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Key Messages

  • Routine nutritional assessments that include body weight, body condition scoring, and muscle condition scoring aid in early identification of unintended weight loss.
  • If the cause of weight loss remains unexplained after exam and diagnostics:
    • Revisit the pet’s diet history – has the owner switched the pet to a lower calorie (“light”) diet (thus, feeding the same amount would provide fewer calories) or to a diet that is nutritionally inadequate for the pet’s life stage?
    • Is the pet being fed enough of the current diet to meet current caloric needs?
      • Senior cats may lose weight once they enter their geriatric years around age 12. Weight loss may be caused by a reduced ability to digest fat and protein and other metabolic changes.
      • A change in activity, lifestyle, or environment can affect calorie requirements. Also consider that energy needs may not be consistent year-round, e.g., some dogs may be more active during the summer months.
    • Has the pet’s appetite decreased?
      • Senior pets may have a decreased appetite due to an age-related reduction in the sense of smell and taste.
      • Consider behavioral causes, e.g., stress or, in a multi-pet household, competition for food (e.g., one pet is blocking a housemate’s access to the food bowl).
      • Has the pet become a picky eater?
  • Diet and feeding management strategies can help the pet regain a healthy weight and body condition:
    • Estimate the pet’s daily calorie needs. Ensure that the owner measures food using a gram scale or measuring cup.
    • Add calories to the diet by recommending an energy-dense, nutrient-dense, highly palatable food (e.g., growth or performance diet, therapeutic critical care diet, or, for dogs, cat food). This helps a pet gain weight while maintaining or rebuilding lean body mass.
    • More frequent feeding provides more opportunities for the pet to eat and helps ensure the food is always fresh.
    • For pets with a decreased appetite:
      • ​​​​​​​Warming of the food to body temperature can help enhance aroma and taste to encourage appetite.
      • If the pet usually eats dry food, moistening the kibble or adding/switching to wet food may encourage eating. Flavor enhancers may also help.
      • To eliminate competition in multi-pet households, pets should be fed separately.
      • Pets should be fed in a noise-free, stress-free environment.
      • Provided that it doesn’t cause stress, the owner can try calmly encouraging the pet to eat.
      • For cats in particular, food should be offered in different types of bowls to determine if the cat has developed a preference. Some cats prefer wide and shallow bowls so that their whiskers do not touch the sides of the bowl.
    • Monitor to ensure the pet reaches ideal body condition and weight. Once the pet reaches this milestone, calculate energy requirements for maintenance.
    • Encourage activity to maintain lean body mass.
Conversation starter

“Our goal is to help your pet reach ideal body condition because this can help your pet live a longer, healthier life. We’ll use a tasty, energy-dense diet to add calories. To ensure your pet is gaining weight, we will monitor your pet’s body condition at every visit, and you can regularly monitor your pet at home as well. It is easy – simply check their waist, their tummy tuck and feel their ribs.”

Related Tools and Content:

Components of Nutritional Assessment

Nutritional assessment uses an iterative process to make specific diet recommendations tailored to individual dogs and cats.

View Brief 1 min to 5 min

Taking a Good Diet History

The only way to know what each patient really eats is to ask ꟷ and document the information in the medical record.

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The Purina Body Condition System

The Purina Body Condition System is an easy and practical tool for assessing a pet's body composition.​

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How to Perform a Body Condition Assessment - Cat

Assess a cat's Body Condition Score in just 3 simple steps.​

View Video 1 min to 5 min

How to Perform a Body Condition Assessment - Dog

Assess a dog's Body Condition Score in just 3 simple steps.​

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Use Muscle Condition Scoring to Detect Muscle Loss in Patients

Muscle condition scoring is a hands-on method for evaluating lean body mass that can be used as part of nutritional assessments.

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Feeding Senior Cats

Nutrition tailored to the unique needs of senior cats can help them live longer, healthier lives.

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To Share With Pet Owner:

Evaluating Your Cat’s Body Condition

Assess your cat's Body Condition in just 3 simple steps.​

View Video 1 min to 5 min

Evaluating Your Dog’s Body Condition

Assess your dog's Body Condition in just 3 simple steps.​

View Video 1 min to 5 min

Feline Body Condition System Sheet

A visual aid to the Purina Body Condition Score System for cats.​

View Tool 1 min to 5 min

Canine Body Condition System Sheet

A visual aid to the Purina Body Condition Score System for dogs.​

View Tool 1 min to 5 min

Body Condition System Progress Chart Cat

The Progress Chart should be used with the Feline Body Condition System Sheet to help track a pet’s weight loss or gain.

View Tool 1 min to 5 min

Body Condition System Progress Chart Dog

The Progress Chart should be used with the Canine Body Condition System Sheet to help track a pet’s weight loss or gain.

View Tool 1 min to 5 min

Switching Pet Foods - Cats

Gradually transitioning onto a new diet minimizes the risk of stomach upset.

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Switching Pet Foods - Dogs

Gradually transitioning onto a new diet minimizes the risk of stomach upset.​

View Brief 1 min to 5 min