Your Pets

Avoid topical flea and tick control products to protect your family and San Francisco Bay

Ask your vet if chewable flea and tick medications are an option for your pet


 Fluorescent dye in flea spot treatment to show the transfer of pesticides onto hands.
This research study used fluorescent dye in flea spot treatment to show the transfer of pesticides onto hands. Photographs are reprinted from Bigelow Dyk, M., et al. (2012). Fate and distribution of fipronil on companion animals and in their indoor residences following spot-on flea treatments, Journal of Environmental Science and Health, Part B: Pesticides, Food Contaminants, and Agricultural Wastes, 47(10): 913-924. Reprinted by permission Taylor & Francis LLC.

If you are a pet owner or someone who works with pets, you know how important it is to keep our furry friends free of fleas and ticks. However, you may not know that products used to treat fleas and ticks – such as spot-on treatments, collars, sprays, and foggers – expose your family and home to toxic pesticides.

The California Department of Pesticide Regulation (DPR) reviewed the use of fipronil (a common ingredient in pet/carpet sprays and on-pet topical treatments) and found a potential human health risk to adults and children in households where sprays and topicals are used.[1,2]

In addition, these pesticides are transferred onto hands, clothing, bedding, and other indoor surfaces. Upon washing, these pesticides make their way into the sewer system. Wastewater treatment processes are not designed to remove these pesticides, leading them to be discharged into San Francisco Bay sometimes at concentrations that are toxic to aquatic species.

To avoid exposing pets, their owners, and Bay Area waterways to toxic pesticides from harmful chemicals, use sound flea and tick prevention measures and consider oral medications instead of topical treatments.

Pest management professionals recommend these tips:

  • Ask your vet if chewable flea and tick products are right for your pet. Not only do oral medications reduce exposure to toxic chemicals, they also may be more effective than topical spot treatments. Chewable products also protect pets against other internal parasites.
  • If you use topical flea/tick treatments, avoid products that contain fipronil, bifenthrin, imidacloprid, indoxacarb, deltamethrin, or permethrin.

To Prevent Fleas:

  • Clean your home regularly and thoroughly to prevent flea problems before they start: vacuum carpets, floors, furniture, and inside cracks. Wash pet and human bedding and that pets touch regularly.
  • Avoid indoor flea treatments such as house sprays, foggers, and house “bombs.” These items have limited effectiveness, leave a residue in your home, and expose your family to toxic pesticides.
  • Use flea combs. Dip the comb frequently into soapy water to capture and drown fleas.
  • Use flea traps to determine the size and location of the infestation.
  • Visit for more tips about how to prevent and control fleas around your home.

To Prevent Ticks:

  • If possible, keep your dog’s coat short.
  • Try to keep your dog out of grassy areas. Walk in the center of trails and use shorter leashes when walking in the woods.
  • Thoroughly inspect your pet after walks before ticks have time to attach. Pay particular attention to the nose, mouth, eyes, ears (inside too), around tails, and under the collar. Inspect yourself and your gear as well.
  • Create a tick-free zone in your yard by controlling bushes or tall grass and provide a 3-foot barrier-gap (e.g., wood chips or gravel) between lawns and wooded areas. Keep play and deck equipment away from yard edges. Keep outside areas neat to discourage rodents or other wildlife.


1All DPR fipronil risk assessment documents are available at

2Fipronil Risk Characterization Document, Human Health Assessment Branch, Department of Pesticide Regulation, California Environmental Protection Agency. March 2023.