Bought this as my ECS had to go in for a spay, lumpectomy and mastectomy. I bought a large for a medium sized spaniel, so measure carefully before you buy. It can be adjusted to three levels of tightness, so it worked fine size-wise. This can also be used as a ThunderShirt, as a matter of fact, it's advertised for this purpose. She'll have to go in for a second operation, so I'm happy that I bought this.
While I wouldn't recommend it specifically for post-surgery use, I found that the suit provided great anxiety relief for my Nala. I bought an XL per measurements, but it didn't fit right. Although the suit seemed like a good option for after surgery, I noticed that it made Nala uncomfortable and trapped moisture, which caused some irritation. Seems like a good option for Anxiety relief but we haven't been able to get that far yet.
This is a great vest and it fits my dog perfectly and seems comfortable. Here is the complaint. I have a long haired dog and it rips his hair out when I am taking the vest off. I have tried moving, adjusting, being very careful to get no hair in the Velcro, with placement and it still happens. Maybe while he is moving around.
Ordered a few different suits to try. The size medium for my 60 pound mix, was too small/snug.