We have definitely seen climate changes in Houston! It seems harder and harder to predict what will happen each year. In general, we see a prominent flea surge in spring and fall. But this last year, in spite of the heat and dryness, we had significant flea infestations throughout the summer.   Flea biomass, or the total population of fleas, appears to be increasing because of increased numbers of urban wildlife and perhaps more importantly, feral cats. These animals tend to be nocturnal and will pass through our yards at night merrily dropping eggs and seeding our yards with never-ending flea populations. Therefore even dogs on rigorous flea control will have exposure to fleas on a daily basis if they go outside at all.   Furthermore, fleas will often jump on us and ride into the house to access those indoor cats.   For these reasons, it is highly recommended that all pets, dogs and cats, be treated for fleas every 30 days throughout the year.

So why does it appear that flea control is not working?

1. First and foremost, the product is not being used every 30 days throughout the year. Many people in Houston seem to think that fleas are not present in the winter here. While it is likely true that the numbers of adult fleas may be reduced, there are certainly many cocoons present that contain pre-adult fleas just waiting for optimal conditions.   If owners stop their flea control in the winter, then fleas will be carried into the house and populations established. Then when flea control is reinstituted it can take 8-12 weeks to reduce the indoor population once again. It is important to emphasize every 30 days rather than once monthly. Once monthly to some people means giving it during the first week of January and perhaps the last week of February: technically once a month but not what we really need!
2. Flea control is not being used on all the dogs and cats in the household.   Cats are often ignored, particularly those that are outdoor cats fed as a kindness.
3. Flea control products are not being applied directly to the skin correctly and at the correct dose. It is worth our time and/or our technician's to demonstrate the proper administration of the product you choose to use.
4. One tube of flea control is being split among multiple pets.   This is happening more frequently as people try to save money.
5. Our pets are being exposed to other dogs or cats that they meet at the dog park or day care who are not treated for fleas.
6. Our pets are being exposed to urban wildlife. In particular possums can carry immense numbers of fleas. Dr. Michael Dryden, affectionately known as Dr. Flea, once counted 1000 fleas on one possum!
7. Unreasonable expectations.   No flea control product we use, whether oral or topical, will repel fleas. It can take anywhere from 30 minutes to 24 hrs for a flea to die.   Some products may disable the flea from feeding effectively before they die, which is why flea control can help pets that are allergic to flea saliva.   Because 100% efficacy is hard to achieve for any medication, we recommend using a product that will kill adults and inhibit the development of larvae.

It is important that clients understand the fleas they see on their dogs are only the tip of the iceberg. If they have not used flea control or have restarted flea control after stopping for a few months then they need to understand it will take 8-12 weeks before they stop seeing live fleas. Switching products is often recommended; however, if the switch is made at 4-6 weeks, the second product is going to look more effective because of timing, not true improved function.

For most pets, it is possible to achieve excellent flea control in Houston if flea products are used properly.   I encourage all of us to help people understand the flea life cycle. There is an excellent and entertaining video called "The Dirt on Fleas" made by Dr. Michael Drydren (see http://www.comfortis4dogs.com/about-fleas/ (IF TOO LONG CUT OUT WHAT FOLLOWS THIS) It is also recommended to attend his lectures on the research he has done in Tampa, in which flea control challenged houses participated.   In each of these houses, special situations were found that contributed to flea control failure, and none of these were product-related. Rather there were porches under which dogs and wildlife had access, sheds and other outdoor environments in which fleas were breeding, or access to the substructure of the house by wildlife bearing fleas.

The flea allergic pet presents a different problem. In fact we are less likely to see fleas on these animals due to self grooming. How many fleas an allergic dog can tolerate is likely to be an individual thing. In general though, we find that these animals will need their flea control products applied or given every 2 weeks, especially during the flea surges. This is true for the topicals as well as for spinosad (Comfortis)

The choice of product will be determined by the needs of the individual pet and owner. Some owners will need a product that meets the need to control both fleas and ticks. This may take more than one product. For example, one might wish to combine a product such as imidacloprid + permethrin (Advantix), fipronil (Frontline), or dinotefuran + permethrin + pyriproxyfen (Vectra 3D) with an amitraz collar (Preventic).   Merial's new product, Certifect, which combines fipronil with amitraz is showing good promise and we will have to see how it performs in the field. In general, though, it is a great idea to use products that combine flea adulticide activity with the ability to inhibit the life cycle.  The combination of Sentinel and Comfortis is a great one!   Trifexis offers the combination of using an adulticide oral flea control product with heartworm prevention, which is appealing to many people.