Can the 20-day-old saliva of a dog cause rabies?

Viruses won't survive for very long time in external environment. In your case, I don't think you'll be at risk of getting rabies for two reasons. First thing is, we don't know whether the dog is infected with rabies or not. Only if the dog is rabid, it's saliva will contain viruses. read more

Also clothes do not get rabies. If the saliva is on the cloth you can always wash it (i am surprised you haven’t washed a cloth with dog saliva on it for 20 days) or better yet, discard that piece of clothing to have peace of mind. read more

Not all dog bites leads to rabies, bites from rabid dog only causes rabies. Hence after the bite clean the area with copious amounts of soap and water because most of the virus gets eliminated in the process. Secondly observe the dog carefully for rabies symptoms. A rabid dog cannot survive more than 10 days. read more

It can be transmitted by bites and scratches from an infected animal, often a dog. Rabies is caused by a virus that affects the central nervous system. It can be transmitted by bites and scratches from an infected animal, often a dog. read more