Why Pets Get Overweight and How Smart Nutrition Can Make a Difference

Pet obesity is one of the most common health issues today. Studies show that 30–40% of cats and dogs are overweight or obese, putting them at risk of arthritis, diabetes, urinary problems, and shorter lifespan (Linder & Parker, 2016; German, 2006).

 

This guide explains why it happens and how you can help your pet safely lose weight using evidence-based nutrition, hydration, activity and supportive supplements.

 

1. Why Pets Gain Weight: The Underlying Causes

 

1.1 Energy Imbalance & Metabolic Shifts

 

Weight gain occurs when calorie intake exceeds energy expenditure. Excess fat becomes metabolically active and produces inflammatory mediators that impair long-term health (Hoenig, 2006).

 

Neutered and aging pets have reduced basal metabolic rate, making them more prone to weight gain even without obvious overfeeding (Wei et al., 2014).

 

1.2 Diet That Doesn’t Match Biological Needs

 

Cats, as obligate carnivores are adapted to high-protein, high-moisture, low-carbohydrate diets.

However, many dry kibbles contain high carbohydrates and low water content, promoting both fat accumulation and urinary concentration (Zoran, 2002; Backus et al., 2007).

 

Dogs, while more omnivorous, are often overfed due to:

• energy-dense kibble
• free-feeding practices
• excessive treats

 

Dietary management remains essential for weight control.

 

1.3 Hydration & Urinary Health (Especially in Cats)

 

Cats naturally drink less water. Low-moisture diets lead to concentrated urine, increasing the risk of urinary crystals and stones (Markwell et al., 1999; Buffington, 2011).

Obesity worsens this by reducing activity and altering metabolism.

 

1.4 Behavioural & Environmental Factors

 

Common contributors include:

• overfeeding treats
• emotional feeding
• limited exercise (especially for indoor pets)
• genetic predispositions

(Robertson, 2003)

 

2. How to Help Overweight Pets: A Science-Based Plan

 

2.1 Step 1: Assess Body Condition

 

Veterinarians use Body Condition Score (BCS) and Muscle Condition Score (MCS) to measure fat coverage and muscle mass (Larsen & Farcas, 2014).

 

2.2 Step 2: Create a Tailored Dietary Plan

 

A successful weight-loss diet should include:

• High protein → preserves lean mass (Backus et al., 2007)
• Moderate fibre → increases fullness
• Lower fat → reduces caloric density
• High moisture → improves hydration and reduces calorie density (Markwell et al., 1999)

 

For cats, high-protein diets are especially effective in maintaining metabolic rate (Zoran, 2002).

 

2.3 Step 3: Increase Daily Activity

 

Dogs:

Daily walks, play sessions, food puzzles, agility activities.

 

Cats:

Vertical shelves, chase toys, slow feeders, environmental enrichment.

 

Owner participation significantly improves outcomes (German et al., 2010).

 

2.4 Step 4: Monitor Every 2–4 Weeks

 

Evidence shows that many weight-loss programs fail because of insufficient monitoring or inconsistent feeding practices (German et al., 2010).

 

Regular weigh-ins and adjusting feeding amounts are essential.

 

3. How Supplements Can Support the Process

 

Supplements are not weight-loss medications, but they can support metabolic health, joints and immunity during the weight-loss process.

 

3.1 CoQ10 + Krill Oil (CANDYPETI)

 

Supports mitochondrial energy production and cardiovascular resilience (McCarty, 2010; Kwak et al., 2017).

Useful for pets with reduced calories or increasing activity.

 

3.2 Glucosamine Plus

 

Supports joint cartilage and mobility, especially important for overweight pets becoming more active (Comblain et al., 2016).

 

3.3 Lactoferrin

 

Enhances immunity, gut health and helps manage low-grade inflammation (Legrand, 2016).

 

4. Frequently Searched Questions

 

“Why is my cat overweight?”

Dry food, low moisture intake, lack of activity and free-feeding.

 

“Why is my dog gaining weight even though I feed correctly?”

Hidden calories, reduced metabolism after neutering, treats, low activity.

 

“Is wet food better for weight loss?”

Yes, wet food has lower calorie density and improves hydration.

 

“Do supplements help overweight pets?”

They support metabolism, joints, and immunity—but cannot replace diet and exercise.

 

5. Key Takeaways

• Pet obesity is common and serious but highly treatable.
• Best approach = high protein + adequate fibre + high moisture + controlled portions.
• Activity and environmental enrichment are crucial.
• Supplements are helpful adjuncts, not replacements, for proper nutrition and exercise.
• Early intervention produces better long-term outcomes.

 

6. Reference

Linder, D. E., & Parker, V. J. (2016). Nutritional management of obesity in veterinary patients. Veterinary Clinics of North America: Small Animal Practice, 46(5), 761–772. https://doi.org/10.1016/j.cvsm.2016.04.002

 

German, A. J. (2006). The growing problem of obesity in dogs and cats. Journal of Nutrition, 136(7 Suppl), 1940S–1946S. https://doi.org/10.1093/jn/136.7.1940S

 

Hoenig, M. (2006). Obesity in the dog and cat. Veterinary Clinics of North America: Small Animal Practice, 36(6), 1283–1296. https://doi.org/10.1016/j.cvsm.2006.08.005

 

Wei, A., Fascetti, A. J., & Kim, K. (2014). Effects of neutering on energy expenditure in cats. Journal of Animal Physiology and Animal Nutrition, 98(6), 1145–1150.

 

Zoran, D. L. (2002). The carnivore connection to nutrition in cats. Journal of the American Veterinary Medical Association, 221(11), 1559–1567. https://doi.org/10.2460/javma.2002.221.1559

 

Backus, R. C., et al. (2007). Cats and dietary protein: Metabolic and body composition outcomes. American Journal of Veterinary Research, 68(11), 1095–1105.

 

Markwell, P. J., Buffington, C. A. T., Smith, B. H. E., & Others. (1999). The effect of dietary moisture on feline urinary tract health. Journal of Small Animal Practice, 40(6), 227–231. https://doi.org/10.1111/j.1748-5827.1999.tb03063.x

 

Buffington, C. A. T. (2011). Idiopathic cystitis and environmental stress in cats. Journal of Veterinary Internal Medicine, 25(3), 539–548. https://doi.org/10.1111/j.1939-1676.2011.0725.x

 

Robertson, I. D. (2003). The association of exercise, diet, and obesity in dogs. Veterinary Record, 153(18), 531–534. https://doi.org/10.1136/vr.153.18.531

 

German, A. J., Holden, S. L., Morris, P. J., & Biourge, V. (2010). Long-term follow-up after weight management in obese dogs: The role of regular monitoring. Journal of Veterinary Internal Medicine, 24(5), 1330–1336. https://doi.org/10.1111/j.1939-1676.2010.0590.x

 

Larsen, J. A., & Farcas, A. (2014). Nutrition of aging dogs and cats. Veterinary Clinics of North America: Small Animal Practice, 44(4), 741–759. https://doi.org/10.1016/j.cvsm.2014.03.004

 

McCarty, M. F. (2010). Supplementation strategies for optimizing mitochondrial function. Medical Hypotheses, 75(1), 58–63. https://doi.org/10.1016/j.mehy.2010.02.023

 

Comblain, F., Serisier, S., Barthelemy, N., Balligand, M., & Henrotin, Y. (2016). Review of dietary supplements for the management of osteoarthritis in dogs. Veterinary Journal, 212, 9–16. https://doi.org/10.1016/j.tvjl.2015.10.009

 

Kwak, J. H., et al. (2017). Bioavailability of omega-3 fatty acids from krill oil. Nutrition Reviews, 75(7), 551–562. https://doi.org/10.1093/nutrit/nux024

 

Legrand, D. (2016). Overview of lactoferrin as an immune-modulating protein. Biochemistry and Cell Biology, 94(1), 1–6. https://doi.org/10.1139/bcb-2015-0153