Snake venom is only lethal when injected into subcutaneous tissue or a blood vessel. If applied to the skin or external mucous membranes, it causes inflammation but does not result in poisoning or death. Mortality is highest with intravenous injection, lower with intramuscular injection, and lowest with subcutaneous injection. When ingested orally, it is virtually ineffective. The lethal dose of venom varies among different snake species. Some of the most venomous snakes are cobras. One gram of cobra venom can kill 25 dogs, 60 horses, 165 humans, or 300,000 pigeons. Sea snakes are seven to eight times more venomous than these. The vipers and adders native to our region are among the less venomous snakes, although they should not be underestimated.