Introduction: Cat-and-kitten-tolerated Harness (pullover, No-sew Version)

About: Licensed quantum mechanic. Experienced cat-herder (literal and figurative). Aspiring open-sourceress. Linguam (note the "u") legalicum loquor.
***Tested on Animals - and they liked it!***

Why harness a cat? Don't they hate it?

Depends on the cat! Some actually enjoy being accessories (before or after the fact), going places with you and being admired by passersby. The rest might still have to be prevented from fleeing if startled while already stressed - such as when they're handled by strangers at vets' offices or adoption events. I once saw airport security make a passenger remove a VERY nervous cat from its already-X-rayed crate while they disassembled and carefully examined every piece - and then somebody in the nearby arrival aisle tripped the "wrong-way" alarm, strobes and sirens and all. . .

Depends on the harness too! When I realized I had a foster-cat amenable to leashed walks, I tried several different harness types to see which she liked best. That would be the type I'd try out on new candidates. I discovered:
  1. Like me with scuba gear, they prefer minimal weight, bulk, stiffness, and hard lumps.
  2. They don't like having their heads pushed through a tight-fitting loop that bends back their ears, eyebrows, and whiskers on its way on or off. However, they don't seem to mind putting their heads into a bigger loop that clears all their various protuberances.
  3. They have no patience for prolonged fiddling to get the harness on and adjusted properly.
    • It shouldn't be easy to put the harness on inside-out or backwards, or get the straps twisted.
    • If there is a "wrong way" to put it on, the goof should be detectable well before the very last step.
    • Goofs should be fixable without taking the whole thing off and starting over.
    • Size adjustments should be quick, smooth, and not require much iteration.
Most commercial cat harnesses are just smaller dog harnesses. These produce mixed results, both in security and in wearer acceptance. I've observed
  • Most dogs usually take a Terminator-1 approach to escape, leveraging their musculo-skeletal strength, momentum and, well, doggedness. Therefore, they need every bit of that Mil-Spec material and hardware you find on dog harnesses.
  • By contrast, most cats (also ferrets, rabbits, rodents, otters and others) escape more like Terminator 2 They change shape, shift their centers all over the place, even seem to temporarily liquefy, vaporize, or fold through some eldritch parallel dimension. They don't need as much ruggedness, but they need a shape that will adhere to their contortions like white (or brown, red, black, or purple) on rice without blocking their breath or circulation.

Escape shouldn't be absolutely impossible, because "what if" they get the harness caught on something and can't summon human help? But it should either require emergency adrenaline or prolonged work on the cat's part; it should stay on unless it really needs to come off.

Harnessing a non-consenting cat can be very difficult. Kittens, on average, tend to be most open to new adventures. I've also had good luck with young "re-entry moms" who get fidgety and bored once they're spayed and the kids are growing up and moving out. Unfortunately, the "backpack-type" buckles and clasps on commercial harnesses can be too small for grownup helper-monkey fingers to operate easily and yet still too big and bumpy for kittens to wear. The parts for this harness are soft, flexible, and lightweight without being too fiddly.

Commercial cat harnesses retail for $10-30. Kittens outgrow them quickly, Some cats shred the outer surfaces. Adopters often ask if their new cat can keep the harness. I don't have the heart to say no or charge them extra (I do draw the line at letting them keep my iPad with the hiccup.com games for cats though). These harnesses can cost less than $2 each to make, and can be a kids' class project. The second one you make will probably take you less time than reading this page. And if a piece gets messed up, it's easy to replace it or re-use other pieces.

Props to (non-marshmallow) peeps:

  • Thanks very much to DoggieStylish, whose "Small Dog Harness out of Grosgrain Ribbon" Instructable pointed me in the direction I'd been looking for.
  • Models courtesy of Captivating Cats Rescue in San Jose, CA. LOLworthy Norah just got adopted - Yayyy! Unsettlingly clever MaReine (who TOOK OUR SIDE DOOR APART!!) and her intrepid sons Giacomo and AnDe have their "spades & newts," shots, chips and are ready to take over your world. . .

Step 1: Get Your Stuff Together

Clockwise spiraling in from top:
  1. Ribbon or braid, 0.5-1.5m long, 6-25mm wide, depending on size of cat -- should have some texture and body but not be too scratchy or stiff. Grosgrain or velvet ribbon, bias tape, hem tape and lightweight cotton twill braid seem to work pretty well. I avoid florist's ribbon with wire inside, in case kitties chew it. Satin ribbon is kind of slippery and flaccid for this design; if you've got some that's otherwise sublime, sew or fuse it to a grosgrain or velvet backing. This will be the strapping.
  2. Scissors to cut the strapping; Good Sewing Scissors (GSS) OK.
  3. Side Cutters (or Small Craft Knife e.g. X-Acto(TM)) to cut vinyl tubing. The GSS is the wrong tool for that part of the job and not worth risking the Stitcher's Holy Wrath.
  4. Bent Wire, 18-24ga., 3-4"/75-100mm long before bending, A bobby pin works in a pinch but is a bit harder to use. This will be the bodkin - a tool, not a permanent part of the harness, so you can use it over and over
  5. Hair Elastics (2) -- the continuous-ring knit-covered kind with no pokey metal or plastic clasp. Little-kid ones (~1"/25mm dia.) are best for cats under 5lb but a regular one (about 2x as big, as shown here) will also work. These come in all kinds of colors, patterns and textures to match or contrast with the strapping. These will be the sliders.
  6. Split Rings (2), 12-19mm, strong metal e.g. nickel or steel. AKA "keyrings for pixies." Both jewelry and fishing ones work. These will be the leash links (also handy for a tag, reflector, or jinglebell), so jump-rings are NOT a good substitute; they'd pull apart easily and expose sharp ends.
  7. Vinyl Tubing, 0.25"/6.4mm OD (or thereabouts) 1-2" long depending on size of cat. This will be the cord-stop. Readymade cord-stops for duffels and jackets will work, but these are more comfortable for the cat (as well as cheaper).

Step 2: Take the Cat's Measure

(First picture)

If possible, wait until the cat is relaxed or even asleep. They sleep, like, 14-17 hours a day so you won't have to wait too long.

Wrap the end of the strapping all the way around the cat's ribs right behind the forelegs. Tight enough to disturb the fur but not squeeze the body; extreme precision not required. Pinch or mark where the unwinding ribbon meets the free end.

Think, breathe, and move like this is no big deal and you know exactly what you're doing; don't even look the cat straight in the eye, Giacomo, our model here, is a very active 5-month-old, yet he's being a good sport about this.

(Second picture)

With the scissors, Cut a section of strapping2.5x as long as the girth you just measured. Here Giacomo's mom, MaReine (who does have another eye, really) helicopters nearby to supervise her son's wardrobe progress.

Step 3: String the Rings

Thread the strapping through both the leash links.
Cats love to help with this part.

Step 4: The Cord-stop's Here

(First picture)
Use the very tips of the end-cutters to make 2 little slits in the side wall of the tube.
Don't let the cat do this part.

(Second picture)

This is about what you want: 2 crosswise slits letting into the same side of the interior of the tube, 1/8 to 1/4" (3-6mm) on either side of the middle. Positioning accuracy is not crucial, but it IS important not to make the cuts too LONG. 1/4 to 1/3 of the tube perimeter is a good size.
If you cut halfway through or further, the cord-stop won't be strong enough; the tube will bend too easily, letting the slits gap open so the strapping slides through. This can be hard to control with scissors; much easier with end-cutters or a small craft knife.

Step 5: Use the Odd Bodkin: Knot Now

(First picture)
Use the bent-wire bodkin to pull an end of the strapping into one end of the vinyl-tubing cord-stop and out one of the slits you just cut. Usually the easiest way is:
  1. Bend the tube away from the slit side so the slit opens up.
  2. Poke the folded end of the bodkin into the slit and out the nearest tube end.
  3. Thread the strapping through the folded end of the bodkin.
(Second picture)
Pull the bodkin back the way it came to pull the strapping end into the end of the tube and out through the slit. Note: This should be pretty hard to do. That friction you're fighting now is what will keep the harness from coming loose unnecessarily.
  • If it's too easy (little or no resistance), get another piece of tubing, slightly longer. Cut shorter slits in it and try that one.
  • If it seems impossible, try these solutions before lengthening the slit:
    • Bend the tube back further away from the slit so the slit opens up.
    • Grab the loose ends of the bodkin with a pliers or vise-grip and use the tool to pull.
    • Back the bodkin out the open end of the tube and use one of the wire ends to pierce through the strapping 1/4" / 6mm or so from the end, stringing the strapping onto the bodkin instead of through it.
      • Poke the bodkin's two free ends into the tube end and out the slit. You may need to bend the tube further and wiggle the bodkin to get both ends out together.
      • Pull the strapping after it. This time the strapping isn't doubled over like last time; you're only pulling one thickness through the slit. It should be easier.
Once the end of the strapping is through the cord-stop, tie an overhand knot in the end of the strapping to keep it from accidentally pulling out. (In an emergency, the cat will be able to get out of the harness without having to pull the strapping all the way out). Besides or instead of a knot, a soft embellishment like a tassel or pompom can be securely sewn to the end for the same purpose (securely!!! because the cat - and any other cats passing by - will probably want to play with the "dangley" and shouldn't be able to swallow all or part of it).

(Third picture)
Fish the other end of the strapping through the other side of the cord-stop and make a knot or attach something to the end to keep it from pulling out. You now have a big loop with two leash-links strung on it and the ends joined by a cord-stop. Submit for customer approval.

(Fourth picture)
OPTIONAL: Dab some clear nail polish on the ends of the strapping to prevent unraveling. Let it dry before harnessing the cat.

(Fifth picture)
OPTIONAL: You can use an indelible marker to write your contact, the cat's name, or a vet contact on the strapping near the ends.

Step 6: The Itsy-bitsy Sliders

(First picture)

Thread one of the hair elastics onto the partially assembled harness between the cord-stop and the leash links.

(Second picture)

Twist and double the hair elastic multiple times, just as when securing a ponytail. It's tight enough when the ribbon moderately resists being slid through it. Kind of like the zippers on boots that are just a little tight. Less resistance than the cord-stop, but it shouldn't slide around easily by itself or if the cat rubs it against something.

You can see here that it ends up wrapped around a very small radius. If it had a hard clasp, the ends of it would be sticking out. It would feel like having a barbecue skewer stuck crosswise in the knot of a necktie.

(Third picture)

Do the same with the second hair elastic, so that the leash links are trapped between the two hair-elastic-based sliders.

Step 7: The Fun Part: Insert Cat a Into Harness B. . .

I've had professors who probably would have "left this as an exercise for the student." I'm not quite that sadistic.

The first time you do this, choose a time that you're not under pressure. Think of it as a game so you won't smell nervous. If at first you don't succeed, laugh it off and try again when the cat is less skittery (or even napping).

(First picture)
  • Make the harness as big as possible. Bend the cord-stop so the strapping will slide, and pull the loose ends in down to the knots.
  • Form two loops that are as big as possible. Put the sliders close together and fiddle the strapping through so both loops are the same size - keeping the cord-stop centered opposite the sliders.
(Second picture)

Open up those two big loops and slide them over the cat's head. Since it's not a tight fit most of them won't mind, as long as they're OK with being handled in general. Using your free fingers to scritch the sides of their necks will make them want to stay put.

(Third picture)

"Straighten the necktie": Find the slider FARTHEST from the cord-stop and slide it to the top of the cat's breastbone.
  • If the cat has long hair, it might tend to get caught in the sliders. Try to avoid that, and pull the hair back out if it does start to get in.
  • From this point on, if the cat gets away, the harness will probably stay on until the cat calms down and you can finish.

(Third picture)

The slider you just adjusted made the "no-cord-stop" loop smaller.
  • Make the cord-stop loop bigger by sliding the second slider up close to the first one.
  • Gently guide the cat's forelegs through the cord-stop loop on either side of the sliders,
Now you have one loop around the cat's neck, and one around the ribcage.

(Fourth picture)

Bend the cord-stop to open up the slits and pull the knots to tighten the loop until the strapping slightly compresses the cat's fur, but doesn't squeeze the ribcage hard.

(Fifth picture)
  • If the cat will hold still, you can move the second slider down near the bottom of the cat's breastbone so the strapping doesn't chafe under the armpits.
  • You should be able to slip a finger under either loop of the harness, but not much more.
  • Thank the cat for cooperating with happy words, petting, or even a treat!
As with any harness, remove it at least one night our of every 3 to avoid dents in the fur. Check for any balding or sore spots that might indicate a refitting or change of materials.