Our first record of rabies, the infamous foaming madness disease, dated all the way back to 2000 BC. The foaming at the mouth and excessive aggression are among the most recognizable symptoms of rabies, but the whole list of symptoms is pretty damning:

  • Fever
  • Headache
  • Brain inflammation, resulting in paralysis, insomnia, paranoia, confusion, agitation, abnormal behavior and even hallucinations
  • Fear of water (hence its more popular terminology, "hydrophobia")
  • Death

Like the bubonic plague, you can get rabies if you get bitten by an animal. This illness has been shown numerous times on visual media, being the main conflict of the 1983 horror film Cujo as well as a source of inspiration in the latest episode of Genndy Tartakovsky's Primal titled "Plague of Madness" (though the infected sauropod that was the villain of that episode doesn't display the hydrophobia that rabies is known to be.)

In an alternate history scenario, the "Black Death" that terrorized Europe from 1347 to 1350 didn't come from the bacterium Yersinia pestis, as is the case in our timeline, but the rabies virus. Using as much knowledge as we have of both diseases, would a medieval rabies plague still wipe out half of the European population in three short years, or would it have a different rate and scale of virulence to bubonic plague?

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    $\begingroup$ There are some great documentaries on the subject. Obviously, the Rabies black death would need to be different than actual rabies, or it wouldn't be a global plague. An airborne version would be extremely deadly, especially if it was LESS lethal, and could sometimes go silent so carriers could spread it. If it spread in rats but was non-lethal to rats, that would help a lot. why-sci.com/zombies $\endgroup$
    – DWKraus
    Oct 15, 2020 at 23:20
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    $\begingroup$ The R0 of rabies is barely above 1. The R0 of Bubonic plague is 7. Without altered properties, you aren’t going to see a rabies plague. If, for handwavey reasons, you need it to happen, it’s simple, though. Make it more cold-hardy, and make fleas into carriers. Boom. $\endgroup$
    – Daniel B
    Oct 17, 2020 at 11:09

3 Answers 3


A rabid dog is something that a good wall can deal with. Or a well-thrown rock. Not to mention that the danger was obvious.

Fleas were a lot harder to exterminate, even if you realized that they were the problem. (Note that exterminating rats is also somewhat harder AND leads to fleas leaping to humans as new habitat. People have learned that you deal with the fleas and THEN the rats for safety when coping with the plague.)

So - not unless you posit such changes to rabies as to make it barely recognizable as such.

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    $\begingroup$ I have the impression that the core of this answer is not yet made explicit. Until it stays hidden the answer might not be perceived as such. Can you try reworking it? $\endgroup$
    – L.Dutch
    Oct 16, 2020 at 5:05
  • $\begingroup$ @L.Dutch-ReinstateMonica Looks good to me. $\endgroup$ Oct 16, 2020 at 13:00
  • $\begingroup$ @TheDaleks I mean... This says nothing on the " a different rate and scale of virulence to bubonic plague" It assumes only dogs get rabies and then talks mostly about fleas until it talks about making changes to rabies but not specifically what changes. $\endgroup$
    – IT Alex
    Oct 16, 2020 at 13:11
  • $\begingroup$ The question speaks of the bite of an animal. In one case, it's a dog; in the other, a flea. That is the difference that is crucial. $\endgroup$
    – Mary
    Oct 17, 2020 at 0:07

It would be as virulent as it is today. By that I mean that the spread rate would be proportional to human population. The main issue would be spreading. We could assume that each household had a dog that could catch rabies. The problem is how to spread it.
The dogs were expected to be aggressive and bite everyone. They were released from chain for the night if the house had fence. Or they were forever chained to a doghouse.
Even if the person was bitten it was assumed "some" sickness will show. Just from basic noticeable corelations beetwen broken skin and symptoms of various kind soon showing.
And for some time the dego was considered as "doing it's job" but because of the rabies it would quickly die. Having hard time of spreading the sickness as it previosuly showed they bite.

Also a folk wisdom "any animal that should be afraid or aggresive toward you and is not is carrying disease - run".


Of course your rabies plague wouldn't wipe out half the European population in three short years.

You yourself said rabies has been around "all the way back to 2000 BC".

If rabies could have wiped half of anything in three - or 300 or 3,000 - years, there would never have been an AD… we'd have been exterminated long before BC ran out.

  • $\begingroup$ Bubonic plague and smallpox both have your degree of lethality. $\endgroup$ Oct 17, 2020 at 23:15
  • $\begingroup$ @Loren Pechtel You aren't addressing that to me, are you? $\endgroup$ Oct 17, 2020 at 23:18
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    $\begingroup$ The point is diseases that could wipe out half of the population existed in 2000 BC and didn't take out the human race. $\endgroup$ Oct 17, 2020 at 23:34

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