When To Start Flea and Tick Prevention for Puppies

Amanda Simonson, DVM
By Amanda Simonson, DVM. Reviewed by Veronica Higgs, DVM on Oct. 18, 2023
puppy sitting and a getting treat

Starting flea and tick prevention in puppies can vary, based on the specific product selected and the needs of the specific puppy. It’s very important to follow the instructions on the specific product—this should be found on the front of the box of label.

Typically, many veterinary products for flea and tick prevention can be started in puppies that are 6–8 weeks old. Some cannot be started until 6 months of age. Working with your vet to find the right flea and tick product for your puppy is an important step in your vet’s preventative care.

Why Flea and Tick Prevention Is Important

Fleas and ticks are external parasites that cause multiple problems and diseases in both pets and people. The U.S. Centers for Disease Control and Prevention (CDC) and many state public health departments maintain detailed tracking information on these pests. All 50 states have reported the presence of fleas and ticks.


Ticks can transmit many diseases, including:

Many of these diseases cause anemia, fevers, head and muscle aches, nausea, vomiting, diarrhea, and loss of appetite. Certain types of ticks are more prevalent in certain areas of the country. Common ticks that carry transmissible diseases in the U.S. include:

  • American dog tick

  • Black-legged tick

  • Brown dog tick

  • Gulf Coast tick

  • Lone Star tick

  • Rocky Mountain wood tick

  • Western black-legged tick


Fleas can spread tapeworms to pets and humans. They also can transmit plague, endemic murine typhus, and cat scratch disease. Signs of infection with these diseases can include:

  • Fever

  • Headache

  • Weakness

  • Swollen painful lymph nodes

  • Nausea

  • Vomiting

  • Stomach pain

  • Diarrhea

If your pet has fleas, you may see flea dirt (flea poop), which looks like dried dark debris, over the tail base of the puppy. Fleas feed on blood, and just one flea on a pet can cause pain and itching, intense hypersensitivity, allergic reactions, and trauma.

Flea and Tick Protection and Prevention

If you are adopting a puppy, flea and tick prevention is important for both you and your pup. There are many safe and effective products that can prevent or treat flea and tick infestations. Understanding some of the science behind flea and tick parasites, and the differences between them, may help as you consider starting a puppy on flea and tick preventives. For example:

  • Fleas and ticks have different life cycles: egg, larval, and adult for fleas; nymph, larval, and adult for ticks.

  • Male and female adult ticks of the same species may look different.

  • Different medications prevent one or multiple stages of the parasite or have been proven effective in treating the parasite.

  • Because tick species vary by region of the country, location may be a factor in your choice of medication.

Since these pests live in the environment all around us and can be continuously carried by wildlife, it is important to treat all pets in your household (both dogs and cats) and the environment at the same time. Treatment of the environment includes:

  • Using products made to kill/control pests

  • Trimming bushes and shrubs

  • Cleaning up leaves and excess debris

  • Limiting standing/stagnant water

  • Minimizing wildlife exposure

  • Removing wood piles near your home

Does My Puppy Need to Be on a Flea and Tick Preventive?

Even if puppies are primarily indoor pets, most go outside for potty breaks. A small number of pups are trained indoors with potty pads, but human family members and fellow pets can still bring fleas and ticks into the house. This means all puppies can be exposed to parasites.

Some internal parasites (such as roundworms) can be passed to puppies both in the mother’s placenta and in the milk when nursing—all before a pup is adopted and enters a new home.

A number of these internal parasites are zoonotic, meaning they are transmissible to humans. Many flea and tick preventives contain internal parasite preventives, so this is an added benefit for new puppies and their human companions.

If your new pup comes home to you already infested with fleas and/or ticks, a treatment medication may be prescribed to eliminate the pests before maintenance with a preventive is introduced.

Considerations to discuss with your vet when choosing flea and tick prevention include:

  • Most convenient dosing method (oral tablets or chews, topical products, collars)

  • Number and type of other pets in the home

  • Young children or immunocompromised family members living in the home

  • Outdoor environment of the home

  • What your puppy’s lifestyle will ultimately include (dog shows, agility competitions, hunting, water sports)

  • Age and weight of your puppy at adoption

  • Overall health status of your puppy

First-time puppy parents should keep in mind that even though there is an expense with prevention, this is the best strategy to lower the risk of disease, which would be much more costly to treat. Lapses in prevention can lead to drug-resistant fleas and ticks on your pet.

First-time puppy parents should keep in mind that even though there is an expense with prevention, this is the best strategy to lower the risk of disease, which would be much more costly to treat.

Types of Flea and Tick Prevention for Puppies

Many products contain combinations of drugs and chemicals to protect against multiple parasites. As you discuss your needs and individual situation with your veterinarian, keep in mind that certain dog breeds can have drug sensitivities. A common example is a genetic mutation called MDR1 in some collies, sheepdogs, and collie or sheepdog crossbreeds that makes them sensitive to the drug ivermectin.

Safe Flea and Tick Products for Puppies

Do not use cat flea and tick products on dogs. Dogs and cats have different metabolisms and process medication differently. Also, weight range and dosing vary depending on the medication strength required between species. Always use a medication that is specifically labeled for dogs and that is the correct weight range for your puppy to avoid toxicity.

Examples of common types of prescription prevention for puppies include:

  • Revolution®
    • Type: Topical product, monthly
    • For puppies at least 6 weeks old
    • Labeled for:
      • Heartworms (adults)
      • Fleas (adults and eggs)
      • Ticks (American dog)
      • Ear mites
      • Sarcoptic mange
  • Credelio®
    • Type: Oral product, monthly
    • For puppies at least 8 weeks old
    • Labeled for:
      • Fleas (adults)
      • Ticks (Lone Star, American dog, black-legged, brown dog)
  • Simparica Trio™
    • Type: Oral product, monthly
    • For puppies at least 8 weeks old
    • Labeled for:
      • Heartworms (adults)
      • Intestinal parasites (Roundworms and hookworms)
      • Fleas (adults)
      • Ticks (Lone Star, Gulf Coast, American dog, black-legged, brown dog)
  • Advantage Multi™
    • Type: Topical product, monthly
    • For puppies at least 7 weeks old
    • Labeled for:
      • Heartworms (adults and microfilaria)
      • Fleas (adults)
      • Intestinal parasites (roundworms, hookworms, whipworms)
      • Sarcoptic mange
  • Sentinel Spectrum®
    • Type: Oral product, monthly
    • For puppies at least 6 weeks old
    • Labeled for:
      • Heartworms (adults) 
      • Fleas (eggs)
      • Intestinal parasites (roundworms, hookworms, whipworms, tapeworms)

Maintain a Schedule for Your Puppy’s Flea and Tick Prevention

Many flea and tick treatments are given monthly. It is important to give each dose around the same time each month, so pick a day that you can remember or set a reminder on your phone.

Always check the specific label instructions for dosing. There are some products that can last up to 12 weeks before needing to re-dose. Some products are best given with food; others can be given on an empty stomach. Some products are topically applied; with those, the pup should not be bathed or go swimming for 48 hours after application.

Puppy Flea and Tick Prevention FAQs

At what age can you start flea treatment on a puppy?

If your puppy is less than 4 weeks old, do not use any products. Simple bathing and regular combing will remove adult fleas. Isolate your pup from other pets. Only apply products that are specifically labeled for your pet’s age and size. Capstar® is a product that is labeled for puppies and kittens at least 4 weeks old and weighing at least 2 pounds.

At what age can you start flea preventives on a puppy?

Revolution® is a product that has dosing available for puppies at least 6 weeks of age and weighing less than 5 pounds. Other products may vary.  Again, only apply products that are specifically labeled for your pet’s age and size.

Featured Image: iStock.com/fotografixx


Fleas | NIOSH| CDC. Centers for Disease Control and Prevention. 2020, www.cdc.gov/fleas.

Mealey K, et al. Ivermectin Sensitivity in Collies Is Associated with a Deletion Mutation of the Mdr1 Gene. Pharmacogenetics. 2001;11(8):727–733. 10.1097/00008571-200111000-00012.


Amanda Simonson, DVM


Amanda Simonson, DVM


I am a veterinarian passionate about helping animals. I practiced for 15 years in the hospital setting doing medicine, surgery, preventive...

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