Why Has My Dog Gained Weight After Being Spayed or Neutered?
Weight gain in dogs after a neutering is really common. Why does it happen and what can you do as a dog owner to prevent it?
Spaying and neutering are common procedures that offer many health and behavioral benefits for dogs. However, one common concern among pet owners is unexpected weight gain after the surgery. If your dog has put on extra pounds following their spay or neuter procedure, you’re not alone. This is a widespread issue that can be managed with the right approach.
In this article, we’ll explore why dogs gain weight after being spayed or neutered, the role of metabolism and hormones, and how to keep your pet at a healthy weight.
Why Do Dogs Gain Weight After Being Spayed or Neutered?
There are several reasons why a dog may gain weight after being desexed. The primary factors include hormonal changes, a slower metabolism, and changes in appetite.
1. Hormonal Changes Affect Metabolism
Spaying (for females) and neutering (for males) involve removing the reproductive organs, which play a role in regulating hormones. Estrogen and testosterone influence energy expenditure, and once these hormones are reduced, a dog’s metabolism can slow down by up to 20–30%.
With a lower metabolic rate, your dog may burn fewer calories while maintaining the same eating habits, leading to gradual weight gain.
For example a 25kg intact male dog would need 1,476Kcals per day. If they are neutered their calories requirements reduce to 1,230. If this dog was to carry on eating their original calorie intake they would be consuming an excess of 1,722 kcals per week. So whilst weight gain doesn’t happen over night you may notice it within the first 2-3 months.
2. Increased Appetite
Many pet owners notice that their dog becomes hungrier after being spayed or neutered. Research suggests that hormone changes can affect hunger signals, making dogs feel hungrier than before. If food intake is not adjusted accordingly, weight gain becomes inevitable.
3. Reduced Activity Levels
Some dogs naturally become less active after desexing, leading to fewer calories burned. This can be due to a slight decrease in testosterone-driven behaviors like roaming and high-energy play in males, while females may experience similar shifts in energy levels.
How to Prevent Weight Gain After Spaying or Neutering
If your dog has gained weight after their surgery or you want to prevent excessive weight gain, there are several steps you can take to maintain their health and fitness.
1. Adjust Caloric Intake
Since metabolism slows down after desexing, your dog may need up to 30% fewer calories. Adjust their food portions accordingly by following these tips:
Check food labels and reduce portion sizes if necessary.
Know your dogs daily calorie requirements when spayed or neutered 30 x (weight in KG) + 70 x 1.5
Switch to a lower-calorie diet if weight gain becomes an issue don’t just reduce food by a percentage without knowing how much your dog needs.
Use a body condition score (BCS) to assess if your dog is at a healthy weight.
2. Choose High-Quality, Nutrient-Dense Food
Opt for high-protein, fiber-rich diets that keep your dog full while avoiding unnecessary weight gain. Consider foods with:
Lean protein sources (chicken, turkey, fish, or single-protein diets if your dog has sensitivities).
Healthy fiber (pumpkin, sweet potatoes, green beans) to promote satiety.
3. Monitor Treat Intake
Many pet owners unknowingly overfeed treats, which can contribute to weight gain. Try these strategies:
Limit treats to 10% of daily caloric intake (this includes toppers)
Use low-calorie training treats like small pieces of lean meat or vegetables.
Do calculate the calories in your dogs treats using a calorie calculator
Incorporate healthy rewards such as playtime, affection, or interactive toys instead of food.
4. Encourage Regular Exercise
Physical activity is key to maintaining a healthy weight. Ensure your dog stays active with:
Daily walks and playtime tailored to their energy levels.
Interactive toys and puzzles to encourage movement.
Hydrotherapy or swimming (great for dogs prone to joint issues or weight gain).
5. Weigh Your Dog Regularly
Monitor your dog’s weight and adjust their diet and exercise accordingly. Regular weigh-ins at home or at the vet can help catch early signs of weight gain before it becomes a problem.
When to Be Concerned About Your Dog’s Weight
If your dog is gaining weight despite reduced food intake and increased exercise, consult your vet. Weight gain can sometimes be a sign of underlying health issues such as:
Hypothyroidism – A common condition where the thyroid gland doesn’t produce enough hormones, leading to weight gain and lethargy.
Cushing’s Disease – A disorder caused by excessive cortisol production, often resulting in increased appetite and obesity.
Insulin Resistance – Some spayed and neutered dogs develop insulin resistance, affecting how their body processes food.
Final Thoughts
Weight gain after spaying or neutering is a common issue, but it can be managed with the right diet and exercise routine. Understanding the hormonal and metabolic changes in your dog’s body allows you to make informed adjustments to their lifestyle.
By monitoring food intake, keeping up with exercise, and maintaining regular vet check-ups, you can help your dog stay healthy and happy post-surgery. If you’re ever in doubt about your dog’s weight, seek advice from a veterinarian or canine nutritionist for personalized guidance.
Does your dog struggle with weight after spaying or neutering? GET A FREE DIET ASSESSMENT today to get started.
If you have more questions, don’t hesitate to reach out! With our expert guidance, you can tailor a diet that supports your dog’s unique needs—helping them thrive from the inside out
