How to Deal with Your Pet’s Obesity

People usually land on a page like this after a quiet realisation: the dog’s harness is getting tight, the cat no longer has a waist, and everyday movement looks a little heavier than it used to. It’s easy to miss because weight creeps on slowly, then suddenly it’s affecting breathing, joints, and the risk of long-term disease.

Pet obesity isn’t a moral failing or a “lazy pet” problem. It’s a practical one: too many calories, not enough movement, and sometimes a medical or life-stage change tipping the balance. The aim here is simple—help you spot the signs early, understand what’s driving the weight gain, and take steady, safe steps back towards a healthier body condition.

Understanding pet obesity

Pet obesity describes an unhealthy excess of body fat that can harm health and shorten life. In Australian veterinary practice data, around 41% of dogs were classified as overweight or obese (combined).¹ Similar patterns are reported widely in companion animals: once weight is gained, it tends to stay unless feeding and activity change.

Why it matters (beyond appearance)

Extra body fat behaves like an active tissue, contributing to chronic inflammation and placing ongoing strain on the heart, lungs, and joints. Obesity is associated with problems such as osteoarthritis and endocrine disease (including diabetes mellitus), and it’s linked with shortened lifespan in dogs when compared with dogs kept in a normal body condition.^{4, 5, 6}

How to tell if your pet is overweight

Scales are helpful, but they don’t tell the whole story. Body shape, fat cover, and muscle all matter—especially in pets that are small, fluffy, or naturally stocky.

Quick visual and hands-on checks

• Ribs: You should be able to feel the ribs with light pressure, without digging your fingers in.
• Waist: Viewed from above, there should be a visible waist behind the ribs (in most dogs, and many cats).
• Tuck: From the side, the abdomen should tuck up behind the ribcage.
• Movement: Reluctance to jump, slower walks, or getting puffed early can be clues, though pain or heart/lung disease can look similar.

Body Condition Score (BCS): the tool vets use

BCS is a standardised scoring system that estimates body fat stores using touch and observation. The World Small Animal Veterinary Association (WSAVA) provides BCS tools for dogs and cats that veterinary teams use at visits and that owners can learn to apply at home.²

Why regular vet check-ups help

Weight gain is easiest to address when it’s small. Routine check-ups give you an accurate weight trend, a BCS assessment, and a chance to catch medical contributors (like endocrine disease) before you’re fighting an uphill battle.³

What causes pet obesity (most of the time)

Weight gain happens when calories in exceed calories out for long enough. In real homes, that imbalance usually comes from a few familiar pressures.

• Portion creep: Meals slowly get larger, “just this once” becomes daily, and measuring turns into guessing.
• Treats and extras: Treats, table scraps, dental chews, and food used to hide tablets all add up. Guidelines commonly recommend keeping treats to no more than 10% of daily calories.³
• Low activity: Indoor lifestyles, short walks, and limited play reduce daily energy use—especially in cats.
• Life stage and desexing: Energy requirements often drop after desexing, so the same amount of food can begin to overshoot needs unless portions change.³
• Medical factors: Conditions such as hypothyroidism (dogs) or hyperadrenocorticism (Cushing’s disease) can contribute to weight gain and should be assessed by a veterinarian, particularly if weight changes are sudden or paired with other symptoms.³

Start with a safe plan (and go gently)

Healthy weight loss is slow, steady, and deliberate. Fast restriction can be risky—especially for cats, where prolonged poor intake can lead to serious illness. If your pet is clearly overweight, start with a vet visit before making big changes, particularly if they’re older, arthritic, or have known health conditions.³

What to bring to the appointment

• Everything your pet eats in a typical day (food type, brand, amount).
• Treats, chews, scraps, and “extras” (including what other family members give).
• Current activity level (walks, play, indoor/outdoor routine).
• Any changes in thirst, appetite, coat, toileting, or energy.

Diet: the quiet work that makes the difference

Exercise is important, but most weight loss is won in the food bowl. A measured, nutritionally complete diet—matched to your pet’s ideal body weight—creates the calorie deficit without starving them of protein, vitamins, and minerals.

Portion control that actually holds up

• Measure meals: Use kitchen scales or a proper measuring cup; “by eye” drifts over time.
• Feed to an ideal weight target: Your vet can help set this using BCS and frame size.³
• Make treats count: Keep treats within 10% of daily calories, or use a portion of the day’s kibble as training rewards.³

Reading pet food labels (without getting lost)

Labels vary by brand, and the feeding guide is only a starting point. What matters is your pet’s body condition trend. If weight is rising, the current amount is too much—regardless of what the packet suggests. Your veterinarian can help you choose an appropriate diet and calculate a realistic daily energy intake for weight control.³

Human foods and “little extras”

Some human foods are unsafe for pets, and many are simply too energy-dense. Even when the food itself is not toxic, using it often (cheese, fatty meat, peanut butter) can quietly undo weeks of careful feeding. When in doubt, ask your vet for a short list of low-calorie options that fit your pet’s plan.

Exercise: build capacity, protect joints

Movement helps preserve muscle, improves mobility, and supports long-term maintenance once weight begins to drop. For overweight pets, the goal is consistency, not intensity.

Dogs: steady, repeatable movement

• Start with short, comfortable walks and increase duration gradually.
• Avoid hard stops and sharp turns if your dog is sore or stiff—gentler routes help.
• In hot weather, exercise early or late; overweight dogs can overheat more easily.⁷

Cats: small bursts, woven into the day

Cats tend to exercise in short sprints. Interactive play (wand toys, tossing small toys, food puzzles) is often more realistic than expecting long “workouts”.

Older pets or pets with arthritis

Choose low-impact activity and let comfort set the pace. Swimming can suit some dogs, but it’s not appropriate for every animal—especially those anxious in water or with certain medical conditions. If your pet is sore, your vet can help manage pain so movement becomes possible again.

Behaviour changes that help (without turning meals into a battle)

Most pets aren’t “asking for food”; they’re repeating a pattern that works. Change the pattern, and the pressure often fades.

Practical techniques

• Slow the meal: Use puzzle feeders or slow-feeder bowls to extend eating time and add enrichment.³
• Keep routines predictable: Scheduled meals reduce constant grazing and make intake easier to track.
• Swap food rewards: Use play, pats, grooming, or a short training session as reinforcement.

Maintaining a healthy weight long-term

Weight loss is only the first phase. The real work is keeping it off once the obvious momentum is gone.

• Track trends: Weigh your pet regularly and re-check BCS; small gains are easier to reverse than big ones.^{2, 3}
• Adjust as life changes: Desexing, ageing, injury, and seasonal routines can shift calorie needs.³
• Use your veterinary team: Follow-up visits help fine-tune feeding amounts and keep weight loss safe and steady.³

References

1. McGreevy PD, Thomson PC, Pride C, et al. Prevalence of obesity in dogs examined by Australian veterinary practices and the risk factors involved (Veterinary Record, 2005) – PubMed abstract
2. World Small Animal Veterinary Association (WSAVA). Global Nutrition Guidelines and body condition score tools
3. American Animal Hospital Association (AAHA). 2021 Nutrition and Weight Management Guidelines for Dogs and Cats
4. AAHA. Prevention of Obesity (comorbidities and prevention guidance)
5. Banfield Pet Hospital data: Association between life span and body condition in neutered client-owned dogs (PubMed abstract)
6. American Veterinary Medical Association (AVMA). Press release on obesity and potential impact on pets’ life expectancy (2024)
7. RSPCA Australia. 4 ways to avoid obesity in your dog
8. MSD Veterinary Manual. Overview of Nutrition: Small Animals (notes on obesity as a common nutritional disorder)