has your pet gained weight after being spayed or neutered?

has your pet gained weight after being spayed or neutered?

At Freely, we want to help you keep your pet as healthy as possible by giving you honest advice based on relevant science. So, why do we ask if your pet has been spayed or neutered? Isn’t that a little TMI?

The decision about when, or if, you should have your pet spayed or neutered is deeply personal and should be made after speaking with a veterinarian who you know and trust. Shelter pets or those adopted later in life frequently have had this procedure prior to arriving in your home. This article is not intended to discuss the benefits or challenges of these surgeries but rather to address how the procedures affect your pet’s nutritional needs.

Many pets experience weight gain after they are spayed or neutered. This is true for both cats and dogs, girls and boys1. There are many causes of this, but some are related to hunger levels increasing in the absence of reproductive hormones1. This change in hormones may cause pets to eat more per pound of their bodyweight than they would without the surgery. As a result, many veterinarians recommend decreasing the amount of food per pound of bodyweight for pets who have recently been spayed or neutered. This decrease helps your pet maintain a healthy body condition going forward. Additionally, many pet parents elect to have these surgeries when the pet reaches adulthood  and naturally become less active. With less activity, your pet is burning fewer calories so keeping them at a lean, but mid-range, body condition is best for their lifelong health. This has been associated with many benefits, such as better joint health and a reduced risk of many chronic conditions2.

When creating our How Much to Feed calculator, we factored in a decrease in the caloric needs of spayed or neutered pets. If your pet has had one of these procedures recently, you may want to revisit the calculator to ensure you are still feeding the right amount of your favorite Freely foods. Ultimately, you know your pet best and will want to watch their weight more closely in the weeks and months following their procedure. We are confident that our recommendations will suit your pet’s needs; however, you and your vet may want to make some minor adjustments as you get to know your pet’s unique situation.

Still have questions?

Our pet nutrition team is here for you. Send us an email, give us a call, or connect with us through LiveChat. We’d love to talk through your pet’s unique nutritional needs!



1. Scott KC, Levy JK, Gorman SP, et al. Body condition of feral cats and the effect of neutering. J Appl Anim Welf Sci. 2002;5(3):203-213.
2. Fettman MJ, Stanton CA, Banks LL, et al. Effects of neutering on bodyweight, metabolic rate, and glucose tolerance of domestic cats. Res Vet Sci 1997;62(2):131-136. doi: 10.1016/s0034-5288(97)90134-x.