moll i,ll have 2 disagree in my case,my bitch got neutered a year ago after having a bad time with a litter,you said that is an excuse for lazy pet owners,well not in my case ,i,ve allways bring my dogs on ,on my bike that how i get them matchfit ,since the operation ovisily a rest after the pup ,i noticed the weight graduly ,anyway i do alot of road walking asweel 2 aviel ,when i do take take them out the bike she laggs behind my other dogs,once i took her on a big 1 say 10 /15 mile ,we must have 5 mile into the ride and turn around a just ran home ,i,ve done every from changeing food ,less a