K9 Advantix II XL Flea & Tick

Name: K9 Advantix II XL Flea & Tick (1-Mo)
Brand: K9 Advantix
SKU: B07NX2VWYC
Availability: InStock
Rating: 4.5 (48443 reviews)

Words · Craig & Sammy · ASIN B07NX2VWYC · Filed under Flea & Tick Prevention

“Sammy's tiny — this is XL, so not for us — but the data's clear: works on bigger dogs if you don't hit the unlucky 237 who get skin reactions. That's the gamble.”

While this K9 Advantix II formula is designed for extra-large dogs over 55 pounds, it showcases the trusted flea, tick, and mosquito protection technology that has made this brand a veterinarian favorite. For your Yorkie, who typically weighs just 4-7 pounds, you will want to select the appropriately sized small dog formula from the K9 Advantix II line. The importance of proper dosing cannot be overstated for tiny breeds like Yorkshire Terriers. K9 Advantix II works through contact, repelling and killing parasites before they can bite your precious pup.

This means fewer itchy bites and reduced risk of tick-borne illnesses that can be particularly dangerous for small dogs. The waterproof formula maintains effectiveness through baths and rain, while the easy topical application eliminates the stress of giving pills. Always consult your veterinarian about the correct flea and tick prevention size for your Yorkie. Check Amazon for the small dog K9 Advantix II formula that will keep your little companion protected.

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The Notes

Sizing: Sized for Yorkies 4–7 lb · check the printed chest measurement
Source: Amazon · ASIN B07NX2VWYC
Filed: Flea & Tick Prevention
Brand: K9 Advantix
Reviews: 4.5 · 48443 ratings
Verdict: Worth it

What owners loved

+ Mosquito protection rated highly: 319 positive mentions vs. 29 negative — covers fleas, ticks, and mosquitoes in one application
+ Easy to apply topically compared to oral alternatives: 238 positive vs. 14 negative on ease of use
+ Solid value for money for most: 601 positive vs. 265 negative on price — cheaper than vet-only options
+ Fast action reported: multiple reviews cite effectiveness within 24 hours

Watch for

− Skin irritation is a real risk: 237 negative mentions vs. 157 positive on skin reaction theme — reports range from itching to bleeding blisters and oozing pustules
− Inconsistent duration: 94 of 184 duration reviews report it wears off before 30 days, with some reapplying every 3 weeks
− Effectiveness varies significantly: 1,145 negative mentions out of 3,897 total on effectiveness — some batches or individual dogs show poor results or complete failure

What owners say

From the reviews.

K9 Advantix II XL is broadly effective and convenient, with strong ratings (4.5 stars, 48k+ reviews) and solid performance on mosquitoes and ease of application. However, the feedback splits noticeably: roughly 60% of effectiveness reviews are positive, but skin irritation affects a meaningful minority (237 complaints), and duration reliability is questionable — nearly half the duration feedback reports it doesn't last the full month. Value perception depends on whether it works for your dog; those it suits find it a bargain, those it doesn't call it waste.

Source · 48443 verified Amazon reviews · Average 4.5 stars

Customer questions

Things people ask.

Q01. Does K9 Advantix II really last a full 30 days? +

Mixed results. Of 184 reviews mentioning duration, 94 report it wears off before 30 days — some users reapply every 3 weeks. The other half say it lasts the full month. Depends on your dog and environment.

Q02. What are the risks of skin irritation? +

237 negative mentions on skin reaction vs. 157 positive. Reports range from mild itching to severe: burning, bleeding, blisters, and oozing pustules. Some dogs show no reaction; others become worse. Vet consultation recommended if your dog has sensitive skin.

Q03. Is it effective for ticks and fleas? +

Generally yes, but not guaranteed. 2,752 of 3,897 effectiveness reviews are positive — roughly 70%. However, 1,145 report it didn't work, including cases where dogs remained flea-infested even after reapplication. Batch variation or individual dog factors may play a role.

Q04. How easy is it to apply? +

Very easy. 238 of 252 ease-of-use reviews are positive. It's topical — you apply it directly to the dog's skin — which is simpler than pills. Users report doing it successfully in seconds.

Q05. Does it protect against mosquitoes as well as fleas? +

Yes — 319 of 348 mosquito-specific reviews are positive. Users consistently praise it as a three-in-one: fleas, ticks, and mosquitoes in one monthly application.

The verdict