Harness for Havanese with long coat — no bald patches

Bald patches from harness straps are a real problem with long-coated breeds — the strap edges press and twist through the coat with every step, and over time the friction damages the hair follicles right where the chest and shoulder straps sit. Before I suggest anything, can you tell me roughly how much your Havanese weighs, what you're mainly using the harness for — daily walks, travel, something else — and where exactly the bald patches tend to appear? Chest, behind the front legs, or both?

That's the classic axilla rub — the girth strap loops right through that soft skin and coat behind the legs, and on a Havanese with fine, dense fur it can wear a patch bare surprisingly fast. A few things make it worse: straps that are too narrow concentrate pressure into a thin line, any strap that isn't padded moves against the coat rather than with it, and most step-in or H-harness designs are the worst offenders because the girth strap has nowhere to go except straight through that fold. Have any of the harnesses you've tried had padding or fleece lining on that back strap, or have they all been plain webbing?

That's really useful — stiff padding is almost as bad as webbing because it doesn't flex with her movement, so it still rubs. What you need is a harness where the girth strap is wide, soft, and designed to spread load rather than concentrate it, and ideally one with a back-clip only so there's no front chest loop adding a second pressure point. For a 5.5kg Havanese with this exact problem, I'd go with the Ruffwear Flagline harness in size XX-Small. It has a single low-profile foam-padded hipbelt-style girth strap that's quite wide and wraps around rather than digging in, the chest piece is a broad floating panel rather than a strap, and the whole thing is very lightweight and flexible — nothing like the stiff padded harnesses you've tried. It was originally designed for small active dogs on trails, which means it's engineered not to restrict movement or create friction points. A lot of long-coated small breed owners specifically use it for this reason.

Yes — the Flagline has independent adjustment on the chest panel and the girth strap, so you can fit the chest snugly without the girth strap being pulled too tight, which matters a lot for a deep-chested, short-legged build like a Havanese. The XX-Small fits a girth of roughly 33–43cm, so measure around her ribcage just behind her front legs and check that first. One practical tip: when you first put it on, run your fingers under the girth strap through her coat to make sure no fur is folded under the edge — it takes ten seconds and prevents a lot of the problem before it starts.

Good — measure twice before you order, and if she's right on the edge of the size range, go up rather than down because a slightly looser girth strap is far kinder to the coat than one pulled snug. With any luck her coat behind those legs should start recovering within a few weeks once the pressure's gone. Hope it works out for her.