Hartz UltraGuard Flea & Tick Collar for Dogs, up to 26" Neck, 1 Collar (7-mos. supply)

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About This Item

Details

  • Can combat both fleas and ticks for up to 7 months, giving your pal the long-lasting protection she needs.
  • Water-resistant collar continues to fight fleas when wet.
  • Kills through contact—eliminates fleas and ticks.
  • This collar is designed for large dogs.
  • Proudly made in the USA.

Ingredients

Instructions

Size

FAQ

Important Information

Fleas rise to the top of your pet's coat as they die, so consider it a triumph if you start seeing more fleas at first, after treating your pet. If you’re still seeing fleas after application, it may be because your pet has picked up new fleas from the environment, which may include other pets, surfaces and outdoor areas. It may take up to 30 days to break the entire flea life cycle. Additionally, you should also treat sources of new fleas (i.e., carpet, yard, etc.) to ensure complete flea control.

About Hartz Ultraguard Dog Collars

Why Choose a Hartz Flea & Tick Collar?

Hartz Flea & Tick Collars provide convenient, mess-free flea and tick protection. Easy to put on and adjust for comfort, they can be worn alongside your dog’s regular collar.

How Hartz Flea & Tick Collars Work

Hartz Flea & Tick Dog Collars contain active ingredients that are slowly released and distributed over your dog’s body. These active ingredients kill and repel fleas and ticks to keep your pup pest-free and happy.

Long-Lasting Flea & Tick Protection

Pest Protection

Hartz UltraGuard dog collars kill and repel fleas and ticks and can be worn with your dog’s regular collar.

Full Body Protection

The active ingredients spread across your dog’s skin, providing continuous, full-body coverage for up to 6 months.

Water Resistant

UltraGuard collars are water-resistant, so they won’t lose their effectiveness if your pup takes a stroll in the rain.

Don’t Settle for Stiff

Hartz UltraGuard collars are soft and flexible to provide comfortable flea and tick protection.

About Hartz

For more than 95 years, Hartz has been dedicated to creating products that show pets the same unconditional love they give us. Hartz is a leader in quality, innovative products for dogs and cats, including Oinkies, Delectables, UltraGuard, Nature’s Shield, Home Protection, Comfitables, and Groomer's Best brands. Through the Hartz Loving Paws shelter outreach program, Hartz is committed to helping animal welfare organizations that protect and care for pets until they find their forever homes.

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Questions & Answers

1 Customer Questions

Is this safe to be used on dogs that are around cats?

Answer by Chewy • Oct 13, 2025
A flea and tick collar specifically formulated for dogs is potentially unsafe to be used on a dog that is around cats. Many dog-specific flea and tick products contain active ingredients that are safe for dogs but can be highly toxic, and even fatal, to cats if they are exposed (such as by grooming the dog or licking the area). It is strongly recommended to consult with your veterinarian for advice on the safest and most effective flea and tick prevention products for all your pets, especially when cats and dogs share the same living space. Veterinarians can recommend products that are proven safe for use in multi-pet households.
Reviews
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4.2
Rated 4.2 out of 5 stars
307 Ratings
Terms & Conditions

Customers Mention

Chewy identifies key considerations with the help of artificial intelligence and our veterinarians.

Active Ingredients

82% Positive

Comfort and Fit

77% Positive

Duration of Protection

74% Positive

Effectiveness

80% Positive

71 Customer Reviews

Always consult a veterinarian about your pet’s health needs. Customer reviews should not be used as medical advice.

Rated 5 out of 5 stars
By Christina on Jan 16, 2026

Unexpected Chewy Compassion

This order had other items included. When ordered, I could not have known it would be the last order for our dog who died on January 8th. This last order was in

This order had other items included. When ordered, I could not have known it would be the last order for our dog who died on January 8th. This last order was in transit. Because it would not be needed by our dog, Chewy was called and asked if the carrier could return the delivery. The representative said to locate a rescue facility and donate the Chewy delivery. Additionally, the Chewy representative said that a full refund would be made. ... And then ... four days ago ... a beautiful yellow-rose flower arrangement with baby's breath, complementary bouquet flowers, and greenery, arrived from the local florist. I had no idea who this lovely flower arrangement was from until the enveloped-card was open. It read: "All of us at Chewy are so sorry to hear about your loss. We hope these flowers bring you a smile and remind you of the love Nellie left on your heart. Love, Your Chewy Family." This flower arrangement's arrival was delivered in quintessential, even divine, timing. Our dog's death was preceded by two close family member's recent deaths during 2025. God, through the agency of Chewy associates, brought to my heart and home compassion so very much needed and so very much appreciated.

Rated 1 out of 5 stars
By Maria on Jan 11, 2026

You get what you pay for

Unfortunately, we were trying to save some money since the cost of the collars we usually get are so expensive. We have picked off ticks from all three of our dogs

Unfortunately, we were trying to save some money since the cost of the collars we usually get are so expensive. We have picked off ticks from all three of our dogs. We will be bringing them in for testing since we did find engorged ticks on them. Unfortunately this particular product didn’t work well and will be purchasing the collars we usually buy for our dogs.

Rated 5 out of 5 stars
By Shay on Nov 16, 2025

Chewy Is The Best then the rest

I have been a customer of chewy for many years now with a few pets..they have never disappointed me always go way out to make sure my orders are just right..What

I have been a customer of chewy for many years now with a few pets..they have never disappointed me always go way out to make sure my orders are just right..What I like mostly about Chewy is how personal they are tuned for nto your fur baby's the keep in n from le their names.. even the meaning of the pets names I.. not only feel I actually know for a fact that chewy is the best

Rated 5 out of 5 stars
By A on Dec 11, 2025

Great product

Been using this product for years. Always reliable. Safer than using by mouth pesticides.

Been using this product for years. Always reliable. Safer than using by mouth pesticides.

Rated 1 out of 5 stars
By Ismael on Aug 22, 2025

Horrible allergic reaction

We tried it for the first time on our medium sized doodle and it gave her a horrible red blistering rash on her neck. We took it off immediately and took her to

We tried it for the first time on our medium sized doodle and it gave her a horrible red blistering rash on her neck. We took it off immediately and took her to the vet and they agreed it was a reaction to this collar. Never again!

Rated 1 out of 5 stars
By Jessica on Aug 15, 2025

Do not buy. My dog passed away at age 4.5 from lymphoma 3 months after using these collars. Coincidence? Possibly. But after he passed I thoroughly researched these

Do not buy. My dog passed away at age 4.5 from lymphoma 3 months after using these collars. Coincidence? Possibly. But after he passed I thoroughly researched these collars, and he is not the only one.

Rated 5 out of 5 stars
By alejandra on Nov 21, 2025

It work very good!

I buy it for my bunny and I can said it work very good .

I buy it for my bunny and I can said it work very good .

Rated 1 out of 5 stars
By Erin on Jul 28, 2025

No help!

This is the first time trying a flea and tick collar and never again. She has so many fleas even located right under the collar at her neck. Very disappointed

This is the first time trying a flea and tick collar and never again. She has so many fleas even located right under the collar at her neck. Very disappointed

Rated 5 out of 5 stars
By Lilli on Apr 26, 2025

Efficacy and affordability

We live in Maine in the woods with lots of ticks. Our dogs get an oral tick/flea medicine that prevents them from biting but they are still crawling on the dogs

We live in Maine in the woods with lots of ticks. Our dogs get an oral tick/flea medicine that prevents them from biting but they are still crawling on the dogs and transfer to us. One weekend I found 30 ticks on my dog. When talking to a friend in the area they said they used these and had no ticks on their dogs. We tried these cheap collars and they actually work so well, only a few days later on the same trail I only found 1 tick on my dog. Definitely worth it!!

Rated 5 out of 5 stars
By Tom on Aug 13, 2025

Good brand

I actually was impressed this time, well vented box, 90 percent live rate , will buy top hat brand again

I actually was impressed this time, well vented box, 90 percent live rate , will buy top hat brand again