Dog keeps getting out of its harness or collar: how to stop a slip
Check the fit with the two-finger and pull tests, switch to a limited-slip collar, and clip the leash to both collar and harness until your dog stops backing out.
Fix the fit, then add a backup
Many slips come from a dog backing out of something a little too loose. Do three things today. Check the fit with the two tests below. Switch to a limited-slip collar such as a martingale. Then attach the leash to both a collar and a harness, so that if one fails, the other holds. Lucky Dog Animal Rescue says not to rely on a harness alone, because dogs can slip out of harnesses as easily as collars. The Center for Shelter Dogs tells adopters of dogs with a history of escaping to use a limited-slip collar the dog cannot slip out of. If your dog has already got loose twice, do not wait for a new product. Use a backup on the next walk.
The two fit tests
The American Kennel Club gives two checks for a harness. First, the finger test: you should be able to slip two fingers under any strap. Second, the pull test: try to pull the harness over your dog’s head. It should not come off. The goal, the AKC says, is snug but not too tight. Do the checks with your dog standing, not lying down. Do them on every strap, as a harness can be right at the chest and loose at the neck. Then repeat them after a week, because webbing can stretch and straps can creep through their buckles. If your dog fails the pull test even with the straps at their tightest, the harness is the wrong size or the wrong shape for that dog.
Why dogs back out
A slip almost always looks the same. The dog stops, sees or hears something frightening, drops its head and walks backward, and the leash pulls the collar forward over the ears. On many dogs, the head is hardly wider than the neck, so a collar that is comfortable sits very close to coming off. Sighthounds and some slim mixes are the usual examples. Pulling harder on the leash at that moment can make things worse, since it gives the dog something to pull against. If you feel a dog start to reverse, step toward it to take the tension off the leash, and then turn and walk away. That is a handler’s habit, not a study finding, but it is easy to practice at home.
Limited-slip collars
A martingale collar has a second, smaller loop that tightens when the leash is pulled, up to a limit. That is why it is called limited slip. Lucky Dog requires adopters to use one, and describes it as a no-slip collar that keeps a dog from backing out. Follow the maker’s sizing guide, and adjust it while the dog is standing. Many shelters and rescues will show you how it should sit, so ask at the place you got your dog. Since a martingale can tighten, take it off when the dog is unattended or in a crate, unless your vet or trainer says otherwise, as it could catch on something. Keep ID tags on it for walks, or on a flat collar worn at home.
Harness types and how they go on
The way a harness goes on affects how it fits. The AKC describes a standard harness, with one loop around the ribs and one around the neck. A step-in harness forms two triangles, and a dog’s front feet go into them. Some front-clip harnesses have one rib loop and a chest strap with no leg divider. For that style, the AKC says to adjust it until it cannot be pulled over the head. Put the harness on when your dog is calm, and buckle it in the same place each time. If your dog has a narrow chest, or slips one front leg out, try a different shape instead of pulling a strap tighter and tighter. Measure with the maker’s guide before you buy.
Use a double connection
This is the simplest fix of all. Lucky Dog suggests either a double-clip leash attached to both harness and collar, or two leashes, until the dog reliably responds to come. If you use a double clip, keep the collar clip a little slack, so it only takes the load if the harness fails. Do not use a retractable leash on a dog that slips. Lucky Dog discourages them, and a firm grip on a short leash gives you more control at the moment of panic. Check your clips for wear, and replace any that are cracked or bent.
Change the moments when it happens
Think about when your dog gets out. For a lot of dogs, it is at the front door, at a car door, or at a loud noise on the walk. Lucky Dog says to keep a new dog on a leash indoors and in the yard for the first 48 hours, letting it drag so you can grab it. The Center for Shelter Dogs says to teach your dog to sit and stay before you open the door, and to wait until you go out first. Put the leash on before the door opens, and take it off after the door has closed. On walks, keep away from whatever sets your dog off, and cross the street early. If fear is the cause, ask your vet or a qualified trainer for help.
Recheck after any change
Fit is not a one-time job. Puppies grow, older dogs lose muscle, and any dog can gain or lose weight. A heavy winter coat can make a collar seem tight, and then it is loose after a spring shed. Recheck your harness and collar whenever these things change, and every time you buy new gear. Keep your dog’s collar and tag on, because a harness can come off at home. A microchip is not a substitute for a collar with an ID tag, Lucky Dog says, so keep both, and make sure the phone number on the chip record is current. If your dog does slip out, do not chase. Read our post How to catch a scared lost dog without chasing it.
Sources
AKC, how to put on a dog harness: akc.org/expert-advice/training/how-to-put-on-a-dog-harness. Lucky Dog Animal Rescue: luckydoganimalrescue.org/articles/2024-08/ownership-resource/lost-pet-guidance. Center for Shelter Dogs, Animal Rescue League of Boston, Escape Behavior handout: sites.tufts.edu/collaborativeforshelterdogs/files/2016/03/CSD-SA-Handout-ESCAPE-BEHAVIOR.pdf.