Mountainsmith K9 Adjustable Dog Backpack with Zip Pockets – Small


✅ Editor’s Pick


✈️ Airline & Flight Travel


🧳 Under-Seat Carry-On


🌬️ Cabin Ventilation

📸 Product Images

Mountainsmith K9 Adjustable Dog Backpack with Zip Pockets – Small

Current Amazon Price
EUR18.62
(as of Jan 19, 2026 13:58:26 UTC)
Prices and availability can change. Amazon’s price at checkout applies.

🧭 How This Flight Carrier Was Evaluated

  • 📏 Under-seat fit (dimensions, flexibility, structure)
  • 🧾 Airline-policy alignment (size limits vary by airline/aircraft)
  • 🌬️ Ventilation and airflow (mesh coverage)
  • 🔒 Security (zippers, clip points, closure reliability)
  • 🧳 Airport handling (carry comfort, stability while walking)
  • 🧼 Cleaning (removable pad, wipeable materials)

📏 Flight Fit Check (Under-Seat Compatibility)

  • 🧾 Compare the carrier’s listed dimensions with your airline’s under-seat requirements
  • 🐕 Confirm your dog can turn and lie down comfortably inside the interior space
  • 🧳 Soft-sided carriers typically compress better under the seat during flight
📝 Airlines and aircraft layouts differ; approval depends on measurements and under-seat clearance.

🛫 Boarding & Layovers (What Matters in Airports)

  • 🧳 Carry comfort: strap/handles for longer terminal walks
  • 🔒 Secure closures: reduces risk during security checks and crowded gates
  • 🌬️ Ventilation: useful during boarding lines and delays
  • 🧼 Easy cleanup: helpful for long travel days


⚙️ Airline & Flight Travel Overview

✈️ Best Use In-cabin flights, under-seat carry-on pet travel
📏 Under-Seat Fit Flexible structure to adapt to under-seat space (model dependent)
🌬️ Ventilation Mesh panels designed to maintain airflow
🔒 Security Closures aimed at reliable travel use (zippers/clips vary by model)
🧼 Cleaning Removable pad or wipe-clean materials (model dependent)

See reviews + more photos on Amazon


👉 View on Amazon (Reviews + Photos)

🌟 Pros & Cons

✅ Pros

  • ✈️ Built around in-cabin flight needs
  • 🌬️ Breathable mesh for airflow
  • 🧳 Comfortable to carry through airports
  • 🔒 Secure closures for travel environments (model dependent)
⚠️ Cons

  • 📏 Under-seat clearance varies by airline and aircraft
  • 🐕 Fit depends on dog measurements and carrier interior space


📝 Product Details

In the 1980s, Mountainsmith built one of the industry’s earliest dog packs. Today, after 35+ years of continued dog pack innovation, we introduce our most advanced pack to date. The K9 Pack presents the same, trusted fit-designed with and approved by a local, Golden, Colorado veterinarian. The 4-point adjustable chest harness, independently adjustable back harness, non-slip buckle system, mesh panels, and perforated EVA foam offer a custom, comfortable fit and added breathability. Now with added water resistance, your dog’s gear is protected from unpredictable weather, shallow river crossings, and inevitable mud puddles. The increased space of the pannier compartments and the added zipper accessory pockets also mean more room for the K9 essentials. This hiking season, let your dog explore the wild (while carrying his own sh*t… sometimes literally). Review the Mountainsmith K9 Pack Guide and sizing below for best fit: Large: best for dogs over 80 pounds with large girth chests. Medium: best for dogs 40-90 pounds with medium girth chests. Small: best for dogs 20-50 pounds with small girth chests. All Mountainsmith products come with the Forged for Life Guarantee, the official Mountainsmith lifetime warranty.
Is Discontinued By Manufacturer ‏ : ‎ No
Product Dimensions ‏ : ‎ 2.25 x 9.5 x 8.25 inches; 5 ounces
Item model number ‏ : ‎ 19-80035-50
Department ‏ : ‎ unisex-adult
Date First Available ‏ : ‎ January 7, 2019
Manufacturer ‏ : ‎ Mountainsmith
ASIN ‏ : ‎ B07MFN39GF
Best Sellers Rank: #184,714 in Pet Supplies (See Top 100 in Pet Supplies) #60 in Dog Backpacks
Customer Reviews: 4.4 4.4 out of 5 stars (57) var dpAcrHasRegisteredArcLinkClickAction; P.when(‘A’, ‘ready’).execute(function(A) { if (dpAcrHasRegisteredArcLinkClickAction !== true) { dpAcrHasRegisteredArcLinkClickAction = true; A.declarative( ‘acrLink-click-metrics’, ‘click’, { “allowLinkDefault”: true }, function (event) { if (window.ue) { ue.count(“acrLinkClickCount”, (ue.count(“acrLinkClickCount”) || 0) + 1); } } ); } }); P.when(‘A’, ‘cf’).execute(function(A) { A.declarative(‘acrStarsLink-click-metrics’, ‘click’, { “allowLinkDefault” : true }, function(event){ if(window.ue) { ue.count(“acrStarsLinkWithPopoverClickCount”, (ue.count(“acrStarsLinkWithPopoverClickCount”) || 0) + 1); } }); });
MOUNTAINSMITH’S K9 DOG PACK: A saddle bag style backpack carrier for your pet so they can carry their own accessories during outdoor activities, camping, hiking, walking and travel.
BUILT WITH DOG IN MIND: Metal D-ring attachment point for leash. Ergonomically tapered torso shape (Vet approved). Reflective trim on front, rear, and side panels. Weather and water-resistant interior coating.
COMFORT AND STORAGE: 4-point adjustable chest harness with padded sternum pad. Independently adjustable back harness for custom fit. Two pannier compartments with zippered accessory pockets. Single adjustable belly strap. Padded tubular grab handle. Mesh panels and perforated EVA foam against canine body for increased ventilation.
MULTIPLE SIZES: LARGE: best for dogs over 80 pounds with large girth chests. Each pannier holds 9L and measures 13.5” x 9.5” x 3.25” and weighs 1lb 7oz total. MEDIUM: best for dogs 40-90 pounds with medium girth chests. Each pannier holds 5L and measures 12.25” x 8.25” x 3” and weighs 1lb 3oz total. SMALL: best for dogs 20-50 pounds with small girth chests. Each pannier holds 3L and measures 9.5” x 8.25” x 2.25” and weighs 16oz total.
FORGED FOR LIFE: All Mountainsmith packs and gear are known for their quality and are built to last. One of the industry’s earliest Dog Pack, the K9 Pack is known to be a favorite amongst pet owners that take their four-legged friends on every adventure.

🏁 Final Assessment

As an airline-approved dog carrier for airline & flight travel, this option is most appropriate for
owners seeking an under-seat, in-cabin carrier with ventilation and travel handling suited to airports, boarding lines, and flights.
Performance depends on matching the carrier’s dimensions to airline requirements and choosing the correct size for the dog.

  • ✅ Best match: in-cabin pet travelers with small dogs
  • ✅ Best use: flights, airports, and layovers
  • ✅ Priority features: under-seat fit, airflow, secure closures

If the size and materials match what you need, check today’s price and the latest reviews before you decide.


🛒 Get It on Amazon (Check Availability)


❓ FAQ: Airline & Flight Travel

Does “airline-approved” mean it fits every airline?

No. Under-seat dimensions and pet policies vary by airline and aircraft. Compatibility depends on carrier measurements and airline limits.

What matters most for in-cabin flights?

Under-seat fit, ventilation, secure closures, and carry comfort for airports and boarding lines.

How do I choose the right size for my dog?

Compare your dog’s length/height to the carrier’s interior dimensions listed on the retailer page.



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Prices and availability are subject to change.

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