Advantage (original formula by Bayer)

(OTC, spot-on medication for lice and flea control)

Active single ingredient: imidacloprid


  • Advantage (orange label-4 pack for cats/kittens). Tubes/pipettes are available in sizes of 0.4 ml (for cats and kittens under 9 pounds).
  • *Warning notice for pet rat owners! K9 Advantix for Dogs (containing pymethrin), Advantage ll (containing pyriproxyfen) should not be used with rats due to increased toxicity. Check to ensure that the product you are purchasing is Advantage (orange label), containing only the ingredient imidacloprid, for cats/kittens 9 pounds and under.


Advantage is a topical/”spot-on” insecticide medication for the control of lice and fleas. Its active ingredient is the parasiticide imidacloprid. Its mode of action interferes with the transmission of impulses in the nerve system of insects.

Imidacloprid will kill both the adult and the larval stage of flea. Upon application imidacloprid spreads over the body with the body oils collecting in hair follicles where it is released over time (up to 1 month) onto the skin. It will remain on even if the rat is bathed, although it will diminish with each subsequent bath.

Imidacloprid is not appreciably absorbed into the body, and although it is reported to have a wide margin of safety some animals may develop hypersensitivity.

Studies indicate that imidacloprid is not teratogenic. However, it is reportedly not recommended for use in pregnant animals, nor should it be used on rats younger than 5 weeks old.


Used to treat lice (on rats) and flea infestation.

Drug Interactions or Contraindications

  • Do not allow to be taken internally or apply to eyes.
  • Do not use in combination with other insecticides.

*Note: supported recommendation of Vanessa Pisano DVM. 21:

Do not use Advantage on sick or malnutritioned rats, or on rats that are under 5 weeks old. For smaller sized rats greater than 5 weeks and under 4 months reduce dosage by half.”*

Adverse Reactions

CNS: twitching or muscle weakness

GI: Taste is bitter in the event the animal licks or ingests it may cause drooling

Other: hypersensitivity allergic reactions

Dosage Recommendations

Advantage Topical Application:
Apply 1 drop for rat weighing less than 1 pound. For a larger rat greater than 1 pound, apply 2 drops. 21
Apply once per month or based on veterinary assessment.


0.05 mL/lb, topical application once per month or based on veterinary assessment. 33

To Administer Advantage:

Hold applicator tube in an upright position. Pull the cap from off the tube. Turn the cap around and place other end of the cap back on the tube. Twist the cap to break the seal and then remove the cap from the tube.

Squeeze tube till a tiny bead is on the tip of tube. Part the rat’s fur at the base of the neck behind the head (an area difficult for the rat to clean off) and touch the tube with the tiny bead of liquid to the skin.

Do not massage liquid into skin. Allow the area to dry before returning the rat to his cage.

If too much liquid is accidentally applied, wash the rat immediately and wait 1 week before reapplying.  21

When application is completed, discard empty tube by securely wrapping in several layers of newspaper and discarding in trash.


  • *Note for humans: can cause eye irritation. Do not get in eyes and avoid direct contact with skin. Wash hands with soap and water immediately after skin contact with product. In the event of eye contact flush eyes copiously with water. Keep out of reach of children and do not contaminate feed or food.
  • Store in a dry cool area.


Links to


The Rat Guide and its affiliates accept no responsibility for misuse or misunderstanding of its information. This guide in whole or part, exists solely for the purpose of recognizing and understanding the care and illnesses in the pet rat. Please seek advice and treatment from a qualified Veterinarian if your rat is ill.

2000 - 2024 by Karen Grant RN. All rights reserved.
All other written and visual materials used by permission of specific authors for the sole use of the Rat Guide. Please visit our Privacy Policy for details.
Brought to you by KuddlyKorner4u
See Logos page for linking to the Rat Guide.
Contact us here: Rat Guide Team
Please note: Rat Guide email is not checked daily. Send e-mail to if you have an urgent medical problem with your pet rat. When possible, it is always best to take your rat to a qualified rat veterinarian.