Rainfall and High Humidity Help Ticks and Fleas Flourish

Warm temperatures, frequent rains, and high humidity are factors that help survival and reproduction of ticks and fleas. This summer has provided ideal conditions for both to flourish.

EntFacts 602 (Flea Control and Protection) and EntFacts 628 (Smarter Flea Control) provide information on flea control. However, there are many new options for pet owners. The table below provides some examples for dogs. No disrespect is intended for cats or their proud owners; the limitation is to keep the list somewhat manageable.

Owners of both species should note that the insecticide permethrin can be fatal to cats and keep this in mind. Read the active ingredients and precautions before buying products. Check carefully for use limitations- species, age, weight, etc.

Figure 1. The cat flea (Photo by L. Townsend)

With the exception of Capgard and Capstar, tablet or chewable formulations of flea and tick control products are preventive, so they must be used throughout the season and may require a prescription.

All products contain a contact insecticide that is active against both fleas and ticks. The active ingredient(s) move from collars or spot-on applications to cover much of the animal’s skin or hair coat. Some combination products, often designated by “Plus” in the brand name, contain the insect growth regulators (IGRs) methoprene or pyriproxyfen, These active ingredients control immature (egg, larva, or pupa) of fleas.

Examples of Flea and Tick Control Products for Dogs

 Table 1.  Collars — Active ingredients in insecticidal collars spread over the coat in skin oils. It may take several days for the product to move enough to provide complete body coverage.

Product Active ingredients Target pests
Adams Flea and Tick Collar 14.55% tetrachlorvinfos fleas (+ eggs & larvae), ticks, & lice
Hartz Ultraguard Plus 1.2% methoprene
Seresto Flea  & Tick Collar 4.5% flumethrin fleas, ticks, & lice
10% imidacloprid
Scalibor Protector Band; Proact Flea and Tick Collar 4% deltamethrin fleas & ticks


Table 2. Shampoos provide quick knockdown of fleas. Attached ticks may need to be removed physically.

Product Active ingredients Target pests
Adams Flea & Tick Shampoo 0.075% pyrethrins fleas, ticks, & lice
0.75% synergist
0.086% pyriproxyfen
Sentry Flea & Tick Shampoo permethrin + synergist fleas, ticks, & lice


Table 3. Tablets – Except for Capgard and Capstar, these products are given through the tick/flea season or year and provide systemic control of the pests. Capgard and Capstar are given when infestations are detected.

Product Active ingredients Target pests
Bravecto Chews (prescription only) fluralaner fleas and ticks
Capguard and Capstar nitenpyram fleas – when present
Credelio  (prescription only) lotilaner fleas & ticks
Simparica (prescription only) sarolaner fleas & ticks
Trifexis (prescription only) spinosad + fleas & ticks
milbemycin oxime fleas, heartworm, and certain intestinal worms


Table 4. Topical (Spot-on) The active ingredients in “spot on” applications usually are applied between the shoulders and spread over the coat in skin oils. It may take several days for the product to move enough to provide complete body coverage.

Product Active ingredients Target pests
Adams Flea & Tick Spot on 50% etofenprox + synergist + fleas (+ eggs & larvae), ticks
Bio Spot Active Care 0.23% methoprene
K9 Advantix II 8.8% imidacloprid + fleas (+ eggs & larvae), ticks,
44% permethrin* mosquitoes, biting flies, lice
0.44% pyriproxyfen
Advantage II 9.1% imidacloprid + fleas (+ eggs & larvae)
0.46% pyriproxyfen
Frontline Plus and 9.8% fipronil + fleas (+ eggs & larvae), ticks, chewing
PetArmour Plus 8.8% methoprene lice


Premise Treatments

Only about 10% of the fleas in a typical infestation are on the animal. The other 90% are in the environment in the form of eggs, larvae and pupae in pet bedding, and other places where the pet spends time. If the pet spends time indoors, the interior of the home should also be treated. Before treatment, the pet owner should:

  1. Remove all toys, clothing, and stored items from floors, under beds, and in closets. This step is essential so that all areas will be accessible for treatment.
  2. Remove pet food and water dishes, cover fish tanks and disconnect their aerators.
  3. Wash, dry-clean, or destroy all pet bedding.
  4. Vacuum!— vacuuming removes many of the eggs, larvae, and pupae developing within the home. Vacuuming also stimulates pre-adult fleas to emerge sooner from their insecticide-resistant cocoons, thus, hastening their contact with insecticide residues in the carpet. By raising the nap of the carpet, vacuuming improves the insecticide’s penetration down to the base of the carpet fibers where the developing fleas live. Vacuum thoroughly, especially in areas where pets rest or sleep. Don’t forget to vacuum along edges of rooms and beneath furniture, cushions, beds, and throw rugs. After vacuuming, seal the vacuum bag in a garbage bag and discard it in an outdoor trash container.


By Lee Townsend and Mike Potter, Extension Entomologists



Posted in Pet Pests
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