Pet Weight & Obesity: How to Tell If Your Dog or Cat Is Overweight

Maintaining a healthy bodyweight is one of the most important aspects of long-term pet health. Excessive bodyweight in dogs and cats is now one of the leading causes of reduced quality of life and shorter lifespan.

Why Excess Weight Is a Problem

Being overweight affects far more than your pet’s appearance. It can lead to:

• Increased strain on the heart, liver, and pancreas

• Higher risk of diabetes and metabolic disorders

• Reduced mobility and joint discomfort

• Lower energy levels and reduced overall wellbeing

Managing your pet’s weight is essential for preventing chronic health problems later in life.

Is My Pet Overweight?

Use Body Condition Scoring (BCS)

The most reliable way to determine whether your dog or cat is at a healthy weight is by using a Body Condition Score (BCS). This method involves gently feeling your pet’s ribs and backbone and assessing how much fat is covering them.

Body condition scores typically range from:

• 1 – Very thin: Ribs and bones are clearly visible with no fat cover
• 3 – Ideal weight: Ribs can be felt easily but are not visible
• 5 – Very overweight: Ribs cannot be felt even with gentle pressure

Body condition scoring is far more accurate than relying on weight alone, as there can be significant variation in size and shape even within the same breed.

Should I Still Weigh My Pet?

Yes. Once you have identified whether your pet is over- or underweight:

• Record their current weight
• Use it as a baseline to monitor progress
• Track whether dietary changes are effective over time

My Pet Is Overweight – What Should I Do?

1. Review Their Diet

Start by assessing how much and what your pet is eating:

• Is the food high quality and age-appropriate?
• Are you feeding the correct portion size?
• Are you accounting for all calories, including treats and snacks, table scraps, natural or fresh food and training rewards.

Even small extras can significantly increase daily calorie intake.

2. Focus on Calories

From a veterinary perspective, most weight issues come down to:

• Eating too many calories
• Burning too few calories

For many pets—especially cats—increasing exercise can be difficult, so dietary control is often the most effective solution.

3. Consider Weight-Management Diets

There are no quick fixes, but calorie-controlled diets can help.

4. Veterinary Check-Up Is Important

Before starting major diet or exercise changes, a vet check is strongly recommended. Certain medical conditions can cause weight gain, including:

• Thyroid disorders
• Cushing’s disease (especially in dogs)

The Importance of Exercise

Exercise plays an essential role in weight management, particularly for dogs.

How to Increase Activity Safely

• Start slowly and build up gradually
• Increase exercise by around 10% per week
• Focus on low-impact activities for overweight pets

Good exercise options include walking, swimming, playing fetch and interactive play sessions.

What If My Pet Is Underweight?

While less common than obesity, being underweight can also be a concern.

• Check that your pet is eating enough
• Ensure the diet is appropriate for their life stage and health needs

Possible Medical Causes

Being underweight is more likely linked to underlying health issues, such as:

• Intestinal parasites (worms)
• Kidney disease
• Hyperthyroidism

If you believe your pet is underweight, a veterinary examination is strongly recommended to identify and treat the cause.