LAMORINDA WEEKLY | Pet Projects


Dr. Mona Miller lives in Lafayette with her son, two cats and yellow Labrador. She attended UC Berkeley as an undergraduate, and received her DVM from UC Davis. She has been happy to call Lafayette home since 2001. She can be reached via email at MonaSDVM@aol.com. She welcomes questions from readers that may get incorporated into a column.

I am often asked, "What's the best flea and tick product?" and I wish I had a short simple answer. There are now so many options, due in part from differences in formulations and from pharmaceutical company competition for the market. There are pros and cons to each type. Additionally, most of these flea control products also help protect against ticks.

The factors that a pet owner might consider when choosing a product include safety, effectiveness, potential toxicity reactions or side effects, cost, availability (through their veterinary hospital directly, mail order pharmacy or warehouse or pet store) and effects on the environment.

There are basically two types of formulations: oral chewable monthly tablets and topical spot-on liquid applications. The oral tablets get absorbed into the pet's system and kill adult fleas and ticks when they contact or bite into the pet's skin. Usually the kill is within a couple hours, and the tab is effective for a month (about 28-31 days). This formulation is comparable to the old-fashioned "flea bath" in that there's no repellent activity - it doesn't keep fleas off the pet. For the most part, these tabs are fairly safe, especially when given with food. Some pets, however, experience nausea, loss of appetite or diarrhea. Very rarely, seizures have been reported with some of these tabs.

The spot-on topicals are applied on the back of the pet's neck (if a cat) or between the shoulder blades (if a dog). It takes about 48 hours for the liquid to absorb into the skin and translocate through the skin layers all over the body. Most of these products do not get absorbed into the pet's body system other than skin. This formulation is comparable to the old-fashioned "flea dip" in that there's repellent activity and most life stages (juveniles, adults and in some cases eggs) are killed. These topicals are labeled for "once a month" but effectiveness seems to decrease by the third week or so. Side effects to the pet are rare - occasionally, I've seen lethargy or loss of appetite, or a mild skin rash at the site of application.

These two types of formulation can be used together for maximum flea control, and I often recommend this when faced with either a severe flea problem or a flea-allergic pet who is having high levels of itchiness. Otherwise, I generally recommend the oral product to clients who desire low to moderate protection; and the topical products for flea allergic pets, high-load flea issues and for clients who want high-level protection.

There may be a concern with the topical products on environmental impact. An article published in the Central Contra Costa Sanitary District "Pipeline" last year asked as its title "Is your Pet's Flea Treatment Sending Toxic Pollutants to the Bay?" There has been documentation that fipronil has been detected in Bay Area water systems, and has been placed on a list of pollutants of "moderate level concern." Fipronil is an active ingredient in one of the most popular topical spot-on flea products that has been in use for 20 years or more. It is also used as ant and termite control in industrial and construction sites.

I'd like to make a specific note that cat owners should use only cat products, since cats are more sensitive to toxicities than dogs (as a general rule). A wonderful resource to compare the many products available can be found at www.veterinarypartner.com by searching "flea and tick control products."