1-year-old Toller reactive to skateboards and fast-moving bikes

Hi everyone,

We have a 1-year-old male Nova Scotia Duck Tolling Retriever. He’s generally calm, social, curious, and does well at dog school. On a regular weekday, he gets three walks:

• Short morning sniffy walk
• Long midday walk including dog park
• Medium evening walk (sometimes a fourth short one late at night)

In his puppy phase, we socialized him to skateboards and even went to the skatepark – he was completely at ease back then.

History of problem behaviors we 'solved' in the past:

• Separation anxiety: He would whine, panic, or do naughty things if we went upstairs or left him alone. We worked on this gradually and now we can go upstairs without him doing someting naughty in the living room.
• Destructive behaviours when left alone: We addressed this by making sure nothing was left around that he could chew or destroy, and by providing a puzzle toys whenever we left. This behaviour now also decreased a lot.
• Watchfulness/barking at the window: Now whenever we see someone with a dog, or loud people pass the window, we distract him with a toy or a candy. It’s absolutely not gone yet, but it's a lot better.

It feels like every time we 'solve' one problem, another appears.

The current problem:

Lately, he has developed fear and reactivity to skateboards and fast-moving bikes (but not all bikes, it feels random). When he sees these, he panics, chases, jumps, and barks. For a full minute, he goes in full panic mode and there is nothing we can do with him anymore. This used to be only skateboards, but now seems to be spreading to other fast-moving or unusual vehicles (wheelchairs,…). As far as we know, he never had any bad experiences with skateboards or bikes before.

Walking has become stressful for everyone. We’re constantly on edge, trying to anticipate triggers. It’s exhausting and not fun anymore and it's a safety concern. He even caused a leash burn on a friend’s leg yesterday when he suddenly lunged at someone on a skateboard.

Questions:

1) How can we safely desensitize him to fast-moving objects like skateboards, scooters, and bikes?

2) Are we doing something wrong that could have triggered this?

• We’ve started longer weekend walks (10–15 km with breaks). Could this overstimulate him?
• Since he's 12 months, he now sleeps with the crate door open instead of closed, choosing where he sleeps. He seems sleepier during the day. Could this contribute?

Thanks in advance for any advice or shared experiences!