What it is
Anaesthesia sends the brain into a deep, controlled sleep, and afterwards the body has to clear away the substances that caused it. Some dogs break down certain drugs more slowly, or have less body fat for those substances to spread into, so the same amount acts more strongly on the brain and lingers longer.
It comes down to how a dog is built and how its body handles these substances. Lean, deep-chested dogs with very little body fat are the clearest example, and the tendency can run in families.
It makes no difference to everyday life: the dog plays, eats and sleeps like any other. It only matters on the day of a procedure. Tell the vet beforehand that your dog may be sensitive, and once home, give them a warm, quiet, safe spot to sleep it off, with no stairs to tackle while they are still wobbly.
Signs you may notice
- Slow to wake after anaesthesia
- Drowsy for longer afterwards
- Feels cold or shivers
- Wobbly on the legs afterwards
In everyday life this sensitivity causes no signs at all. It may only show after anaesthesia or sedation, when the dog is slow to wake, stays drowsy for longer or struggles to warm up.
When to see a vet
Before any procedure that needs anaesthesia or sedation, make sure the vet knows your dog may be sensitive. Call the vet if, after a procedure, your dog is very hard to wake, stays cold or seems to be getting worse rather than better.
This is general information, not veterinary advice. For your own dog's health, tests and treatment, see a vet.