How to buy sentinel for dogs online

Updated November 21, 2016

Online pet pharmacies have become a convenient way to keep man's best friend healthy without breaking the bank. Sentinel is a monthly oral medication prescribed by veterinarians to prevent heartworms, adult roundworms, adult hookworms and whipworms in dogs. Sentinel also prevents the development of flea eggs. The product is available from numerous virtual pharmacies on the Internet, many of which claim to offer the product at reduced or discount prices.

Check that your vet will accommodate your request to use an online pharmacy. Any reputable online pet pharmacy will require your vet to phone or fax them a prescription for Sentinel. Some vets are not in favour of online pharmacies because they fear the pharmacy may not be legitimate and will refuse to send the prescription.

Check that your dog has had a heartworm test within the previous 12 months. If your dog starts a preventive heartworm treatment (like Sentinel) and has already contracted heartworm, there can be serious consequences to your dog's health. You will assume that your dog is safe from heartworm, while the disease is actually progressing. In some rare cases, heartworm prevention medication can cause severe reactions in dogs with an active case of heartworm.

Choose a reputable online pet pharmacy. A reputable pharmacy should meet the following criteria: require a veterinarian's prescription before shipping medication; have a licensed pharmacist available to answer your questions; have a physical address and phone number located in the U.S. or Canada; and offer prices that are not dramatically lower than your vet's prices.

Complete the online purchase of Sentinel. Some online pharmacies will contact your vet to get the prescription while others require the vet send the info to them. Check with your vet after 24 hours to make sure that the prescription information was sent. This will avoid delays in shipping the product to you. Online purchases will require a credit card or PayPal account.


Visit your vet before investigating any online prescription options for your dog. Your vet will prescribe medications that are specifically suited to your dog's needs. Get this information--and the "okay" from your vet--before you go shopping online.

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About the Author

Jennifer Dawson is a Canadian researcher and writer who started freelancing in 2007. Specializing in environment and health topics, her work has appeared in “The Health Journal,” "Nutrition and Your Health," "Alternatives" and “Together Family.” Dawson has a Bachelor of Arts in English and a Master of Arts in anthropology from McMaster University.