Get the Offline ArchiveFree lifetime updates

Dogs

5 min read

Parent
🐕
Animal Sentinels
Current
🐕‍🦺
Dogs

A dog is the best all-round sentinel because it moves, smells and hears at distances you cannot, and the parent article gives an alert range of 200-400 m in calm conditions, which means each dog watches roughly 12.6-50.3 ha. The range depends on the wind, and the dog is also a bite risk to children, visitors and neighbours, so place it for the wind and plan for the bite before the first night.

Part of Early Warning Systems

A sentinel dog is a household dog whose sleeping place, handling and training are arranged so that it announces unfamiliar people or animals approaching a dwelling.

What The Dog Detects Depends On The Wind

The parent article lists the dog’s strengths: scent detection from hundreds of metres, hearing beyond human range, autonomous patrol and a bond that makes it reliable. It gives a typical alert range of 200-400 m in calm conditions, further downwind. “Downwind” here means the wind blows from the approach toward the dog, carrying the scent to it. In the other direction, with the wind blowing from the dog toward the approach, the dog hears but cannot smell, and the range falls back toward hearing alone.

Training, breeds and feeding are covered in Guard Dog Training, which aims at an alert dog and not an attack dog. This page deals with using the dog as part of a warning system.

What You Need

  • A dog that is confident, bonded to the household and alert, as the guard-dog article describes.
  • A sleeping place near the most vulnerable route, as that article recommends, sheltered from weather.
  • A way to restrain the dog when visitors come: a fenced run or a stout lead and post.
  • Water and food every day and a vaccination and parasite plan.
  • A written bite plan known to every adult.

Method: Place, Calibrate, Restrain

Step 1: Place the dog by the wind. Find the direction your prevailing wind blows from. The dog’s detection of an approach from that side is best when the wind carries the scent to it. Put it near the downwind end of the likeliest approach.

Step 2: Calibrate its range. Have a known person approach unseen from different directions and note at what distance the dog alerts. Do this in different wind and weather and record the results.

Step 3: Do not assume it is on duty. Dogs sleep, are ill and get excited by squirrels. Add other layers.

Step 4: Rehearse visitors. Restrain the dog before the gate opens; introduce the household’s neighbours to the dog under control.

Step 5: Plan for leaving. A dog is part of the evacuation plan: who takes it, on what lead, and what to do if it will not come.

Worked Example: What 200-400 m Covers

If a dog alerts reliably to a person approaching from any direction at a distance r, the ground it watches is a circle of area π × r².

  • r = 200 m: π × (200 m)² = 3.14 × 40,000 = 125,664 m², about 12.6 ha.
  • r = 400 m: π × (400 m)² = 3.14 × 160,000 = 502,655 m², about 50.3 ha.

Wind and sound shadows change the circle into a lopsided shape, long downwind and short upwind. If the upwind range is only half the downwind range, the dog watches a narrower sector on that side. The circle is an upper bound, and what the dog actually covers should be measured by the calibration walks in Step 2. A chained dog covers only a small circle of its own chain length.

Common Mistakes

  • Chaining the dog. A chained dog covers little and often becomes more aggressive, as animal behaviourists commonly report.
  • Leaving it to guard the gate unrestrained. Visitors, trade partners and neighbours are bitten.
  • Trusting the bark alone. A dog cannot tell a deer from a person at 300 m, as the guard-dog article says, so read the alert (see Interpreting Animal Alerts).
  • Neglecting its health. A hungry or sick dog is an unreliable alarm.

Safety

The household's own dog is the likeliest source of a dog bite

Bites to children come most often from a dog the child knows, in the family or neighbourhood; I am recalling this from injury studies and do not have a figure. Never leave a young child alone with a guard dog, teach children not to approach a dog that is eating, sleeping or guarding, and restrain the dog whenever visitors, neighbours’ children or strangers come. If someone is bitten: irrigate at once for at least 5 minutes with running water or pressurised flushing and leave the wound open, as in Wound Management. A bite from an animal of unknown vaccination status carries a rabies risk with no field treatment once symptoms show; see Zoonotic Diseases.

What’s Next