VetHelpDirect blog: “Was I wrong to castrate my dog?” “Could it be a mistake to spay a female dog?” Update on the pros and cons of neutering and spaying | Vet Help Direct
Article Paws for thought: an average vet carries out euthanasia a hundred times a year | The Telegraph
Please note that I am unable to answer veterinary questions in comments. If you have questions or concerns about your pet's health it is always better to contact your vet.