Text Box: Pre-op Instructions Animals must be crated or on a leash when you drop them off at the clinic. If the weather permits, please leave your animal in your vehicle during the check in process. It is best but not required to have your pet fully vaccinated prior to surgery. We HIGHLY recommend your dog’s heartworm status be known prior to surgery. Heartworms can cause problems with clotting and other blood issues. We do not require it, but we recommend that your dog have had a heartworm test within the last 12 months and be current on heartworm prevention. If you would like to have us test your dog, please come in and see us on a Saturday from 10am to 1pm. We can operate on heartworm positive dogs, but it is very important that pet owners understand the additional risks involved. Animals over 4 pounds Withhold food after midnight. Keep the pet indoors the night before surgery so that you are sure he/she did not eat. Animals 4 pounds and smaller DO NOT withhold food. If your pet is current on his/her rabies vaccine, please bring the rabies CERTIFICATE. That is the only legal proof of rabies in the State of Texas. The tag will not work. You must have it with you. We do not take faxed copies. If your pet has not had the rabies shot, we can give it to him/her the day of surgery. Spay/Houston does not perform high risk surgeries on owned pets. High risk surgeries include but are not limited to: Term Pregnant Pets Heartworm Disease or High Positive for Heartworms Pets with Severe Mange or Skin Infections Pets Extremely Under Weight Pets Extremely Over Weight Pets with Heart Problems Pets with an Upper Respiratory Illness Pets Over the Age of 7 Years Age and Weight Requirements: Kittens must weigh 3lbs and be at least 12 weeks of age. Puppies must weigh 6lbs and must be at least 12 weeks of age. Some smaller breeds may be done under 6lbs. Please call or email. Rescue groups and those trapping feral cats, please contact us directly for policies specific to you. We have different policies concerning weight requirements and high risk conditions for rescue groups and feral cats.