Next Generation Flea & Tick Protection

Sponsored by Merial.

Fleas are one of the most important ectoparasites of dogs in the United States. When assessing flea control products, several criteria are often used to determine the convenience and practical application for a pet owner. These factors include speed of action, duration and spectrum of activity, route of administration, and systemic versus topical action of the product.¹ Other important factors include owner compliance with administration and dosing recommendations as well as excessive bathing or swimming.² All of these are important characteristics for veterinarians to consider when recommending a flea and tick control product for a patient. 

Animal health companies must also address these issues when developing flea and tick control products for pets. In January 2014, Merial launched NexGard® (afoxolaner), the first oral flea and tick control product for dogs. The development of NexGard has provided a convenient, easy-to-use monthly flea and tick control product for dogs in a chewable form that is highly palatable.³

Flea Tenacity

The most commonly encountered flea in North America is the “cat flea,” or Ctenocephalides felis felis.² Although the name can be misleading, C felis is the most important flea species of dogs.¹ The tenacity of C felis in the environment of the host presents challenges for a control program. The life cycle depends on the temperature and humidity of the microenvironment and can be as short as 12-14 days or as long as 174 days.² The pre-emergent adult can subsist as a pupa for weeks to months waiting for a suitable host to arrive.² 

Flea infestations are common in the United States. A well-developed flea control program often includes host-targeted and environmental insecticides or mechanical means of eliminating various flea stages, such as vacuuming carpets and other infested fabrics and washing pet bedding and bed sheets.²  

Afoxolaner kills fleas before they can lay eggs.

Speed of Kill & Residual Activity

Afoxolaner has rapid, month-long residual effectiveness in the dog. Client-owned dogs with flea infestations in Tampa, Florida, were included in a recent study to evaluate flea control within their private residences. The dogs were treated with 2 monthly doses of afoxolaner. On-animal flea counts 7 days after the first administration were reduced by 99.3% and were reduced by 99.9% when evaluated 28-30 days after administration. Additionally, 97.3% (or 36 out of 37) of participating dogs were found to be flea free after one month.⁴ After the second administration of afoxolaner, given between days 28-30 of the study, the on-dog flea burden was reduced by 100% on study days 40-45 and 54-60.⁴  

It has been previously demonstrated that if flea reproduction is inhibited, a gender shift will occur from a female-dominated, or at least gender-neutral population, to a male-dominated population. If the product fails to stop reproduction, there will be no gender shift.⁵ In this study, a dramatic shift from a female-dominated population to a male-dominated population suggested that afoxolaner not only acted as an excellent form of flea control, but also that its residual speed of kill was so rapid that it likely killed female fleas before they could produce viable eggs.

Client Appeal & Suitability

Oral flea control appeals to the consumer who prefers a safe and effective product that is easy to administer and does not involve physical contact with liquids, sprays, or collars. It also benefits the dog with dermal sensitivity to such products. Afoxolaner is an excellent addition to the existing market of topicals, sprays, and spot-on insecticides, and is a safe and effective way to treat and prevent flea infestations.