Belgian Tervuren vs Great Pyrenees

This breed has an "arrested" predatory sequence that stops just short of the kill bite, but heavily features the "chase" and "nip" behaviors. They will instinctively nip the heels of running children, cyclists, and joggers. This is often misidentified as aggression, but it is a hardwired working trait that is extremely difficult to train out completely.

Unlike the "loves everyone" temperament of many sporting breeds, the Tervuren is naturally aloof and suspicious. Without extensive early socialization, this caution can escalate into fear-based reactivity or "sharpness" (biting out of defensive fear).

If under-exercised, Tervurens do not just lay around; they deconstruct their environment. They are prone to obsessive-compulsive behaviors like tail chasing, shadow staring, and flank sucking if their mental needs are not met.

The #1 complaint from suburban owners. Pyrs are genetically hardwired to patrol and bark at night - they were bred to ward off wolves and bears. This instinct cannot be trained out, only managed. Expect deep, booming barks at 2 AM when a leaf blows across the driveway.

Great Pyrenees do not believe in property lines. Without a secure 5-6 foot physical fence, they will expand their territory to include the entire neighborhood. They are notorious escape artists and will take the shock from invisible fences to pursue threats.

Adult Pyrs often exhibit severe aggression toward dogs of the same sex, particularly females. This usually manifests around social maturity (18-24 months). Opposite-sex pairs are generally recommended.

Pyrs are not dumb - they are independent. When called, they evaluate whether coming is more important than what they are currently doing (usually guarding). If they decide it isn't, they will ignore you completely.