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Defend (Canada)

This page contains information on Defend for veterinary use.
The information provided typically includes the following:
  • Defend Indications
  • Warnings and cautions for Defend
  • Direction and dosage information for Defend


This treatment applies to the following species:
Manufacturer: Merck Animal Health

Topical Insecticide for Dogs

Controls fleas and ticks for up to four weeks. Reduces mosquito bites for up to four weeks. Controls lice.

For use on dogs



For Veterinary Use Only

GUARANTEE: permethrin 65% w/w



Defend Caution

Eye Irritant



Directions For Use

Remove one tube from the package by tearing along the serrations. Leaving the plastic tube attached to the cardboard backing, hold the tube upright and cut along dotted line. Invert the card over the dog and use the point of the card to part the hair of the dog at the application site. Squeeze the tube firmly to apply the required dosage of the solution. To be effective, the product must be applied directly on the skin, not on the hair. Correctly dispose of the tube. (See DISPOSAL).

For mosquitoes: Apply only when mosquitoes become a nuisance for the pet. The product should reduce mosquito bites for up to a month, but some factors such as bathing or swimming may reduce the duration of effectiveness. Do not apply at intervals of less than 7 days.

For lice: If the product is used specifically for lice, apply only when the pest problem occurs on the pet. Treatment should only be repeated if the pest problem persists or reoccurs but do not apply at intervals of less than 7 days.

Dosage for dogs weighing 15 kg (33 pounds) or less: Apply 1 mL to the dog’s back between the shoulder blades.

Dosage for dogs weighing 15-30 kg (33-66 pounds): Apply 1 mL to the dog’s back between the shoulder blades and apply 1 mL to the dog’s back to the area at the base of the tail.

Dosage for dogs weighing more than 30 kg (66 pounds): Apply 2 mL to the dog’s back between the shoulder blades and apply 2 mL to the dog’s back to the area at the base of the tail.

GENERAL: Defend® is an effective and easy to use product. Defend® demonstrates greater than 95% control of fleas and ticks within 3 days of application. One application controls fleas and ticks for up to one month. It may be desirable to use knockdown agents or remove attached ticks at time of treatment. Defend® is not an organophosphate. Defend® has been shown to have a wide margin of safety in dogs and may be used on any breed of dog. As with all flea and tick control products, Defend® should be used as part of a control program aimed at reducing flea populations in the dog’s environment (bedding, carpets, kennel, yard). Consult your veterinarian or entomologist for program recommendations. Defend® reduces mosquito bites within one day of application. Defend® has shown control of lice infestations within 7 days of application.


KEEP OUT OF REACH OF CHILDREN. PETS: Consult a veterinarian before using this product on sick, debilitated, aged, medicated, pregnant, nursing dogs or on puppies under 8 weeks of age. Avoid application of the product onto an open wound. Sensitivities may occur after using any pesticide product for pets. Adverse Reactions: Some animals may be sensitive to ingredients in this product. Reported reactions in dogs have included, skin sensitivity, increased itchiness, redness or rash. Observe the dog following treatment. If sensitivity to Defend® treatment occurs, discontinue use and bathe the dog with mild soap and rinse with large amounts of water. Seek veterinary advice.

Do not apply at intervals of less than 7 days.

Toxic to cats: DO NOT USE ON CATS. DO NOT ALLOW CATS CLOSE PHYSICAL CONTACT WITH RECENTLY TREATED DOGS. Cats which actively groom or engage in close physical contact with recently treated dogs may be at risk of toxic exposure.

HUMANS: KEEP OUT OF REACH OF CHILDREN. Harmful if swallowed or absorbed through the skin. If swallowed: call a physician or a poison control centre IMMEDIATELY. Do not get in eyes. Avoid contact with skin or clothing. Wear chemical resistant gloves when treating dog and avoid contact with treated area until application is dry. Wash thoroughly after handling.

FIRST AID: HUMANS: If in eyes: Hold eye open and rinse slowly and gently with water for 15-20 minutes. Remove contact lenses, if present, after the first 5 minutes, then continue rinsing eye. Call a poison control centre or doctor for treatment advice. If on skin or clothing: Take off contaminated clothing. Rinse skin immediately with plenty of water for 15-20 minutes. Call a poison control centre or doctor for treatment advice. If swallowed: Call a poison control centre or doctor immediately for treatment advice. Have person sip a glass of water if able to swallow. Do not induce vomiting unless told to do so by a poison control centre or doctor. Do not give anything by mouth to an unconscious person. PETS: Sensitivities may occur after using ANY pesticide for pets. If signs of sensitivity occur bathe your pet with mild soap and rinse with large amounts of water. If signs continue, consult a veterinarian immediately.

Take container, label, or product name and P.C.P. Registration Number with you when seeking medical or veterinary attention.

TOXICOLOGICAL INFORMATION: There is no specific antidote for this product. Treatment is symptomatic and supportive.


Store in a cool, dry place. Protect from freezing.


Securely wrap original container in several layers of newspaper and discard in garbage.

ENVIRONMENTAL HAZARDS: This product is very toxic to fish. Do not add directly to water or contaminate water by cleaning of equipment or disposal of wastes.

NOTICE TO USER: This pest control product is to be used only in accordance with the directions on the label. It is an offense under the Pest Control Products Act to use this product in a way that is inconsistent with the directions on the label. The user assumes the risk to persons or property that arises from any such use of this product.

® Registered trademark of Schering-Plough Animal Health Corporation, used under license by Intervet Canada Corp.

Intervet Canada Corp., 16750, route Transcanadienne, Kirkland QC, H9H 4M7

For product information please call 1 800 605-2584.

For technical service please call 1 888 306-0069.

NET CONTENTS: 12 Packets of 6 x 1 mL Tubes - Product Code: 0504420

NAC No.: 12080205

Intervet Canada Corp.

Order Desk:   514-428-7013
Toll-Free:   866-683-7838
Fax:   Toll-free 888-498-4444; local 514-428-7014
Every effort has been made to ensure the accuracy of the Defend information published above. However, it remains the responsibility of the readers to familiarize themselves with the product information contained on the Canadian product label or package insert.

Copyright © 2018 North American Compendiums. Updated: 2018-01-04