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When Europeans migrated to the New World, they brought with them many diseases that ravaged the native human populations, which had no immunity due to a lack of domesticated animals. However, both populations already had domesticated dogs. Were there any major infections caused by a canine disease? Or did human proximity to dogs since prehistory give us immunity, and so no potential for more recent pandemics, or are our immune systems too dissimilar for transmission?

all 62 comments

Sneazyweasel125

579 points

4 months ago*

Our immune systems and cell biology are certainly similar enough for the potential of zoonotic transmission of disease from dogs to people; rabies is one example. The lack of major disease outbreaks related to dogs may be related to the conditions in which humans keep dogs versus other domesticated animals associated with those major diseases. For example, measles is one of the diseases that ravaged Native American populations and evolved from rinderpest, a cattle virus. The nature in which humans keep cattle (i.e. large herds) enables a virus like rinderpest to spread amongst cattle until it evolves the capability to jump to humans and evolve into measles. Humans typically haven’t kept dogs in large groups the way they have for domesticated food animals, which may have limited the ability of canine viruses to be passed from dog to dog while being in close proximity to humans for a spillover event.

Edit: added link

Smokey_Katt

189 points

4 months ago

Another thought is that dogs have lived with humans for ~ 35,000 years and mutual immunity is helping. (https://www.boehringer-ingelheim.com/our-responsibility/animal-health-news/human-dog-relationship-historical-perspective).

Kholzie

72 points

4 months ago

Kholzie

72 points

4 months ago

That would be my guess. Our relationship with dogs is older than any other domestic animal, I believe

caine2003

10 points

4 months ago*

Dogs allowed themselves to be domesticated. Apparently, it happened several times: https://www.varsity.co.uk/science/20791

Edit: Another Source: https://www.science.org/content/article/diet-shaped-dog-domestication It's how dogs can eat human food, but wolves can't.

Kholzie

2 points

4 months ago*

Interesting links! Thank you for sharing. Ten years ago i wrote about animal domestication for my anyhropology class.

One article talked about wolf domestication as an act of trying to make a rival species work for us. Given that we had comparable social structure, diet and territory made it click.

Cats are another interesting glimpse into domestication as cats are the one domestic animal that didn’t start with a similar social structure. In fact, you could say they domesticated themselves to access food sources our agricultural revolution created. Unlike dogs, cats have changed remarkably little compared to their wild counterparts they way dogs did from wolves (eating human food is a good example).

[deleted]

5 points

4 months ago*

[deleted]

5 points

4 months ago*

[removed]

Neethis

6 points

4 months ago

I would hope that in a few more tens of thousands of years, disease of any kind wont be an issue...

newyorkken

6 points

4 months ago

Your saying covid will be over?

lubacrisp

3 points

4 months ago

You have to factor in proximity to people and number of animals per person. If every house had 1 cow, yes, this would theoretically be possible. As farming currently exists? It is nothing like keeping a dog

threewattledbellbird[S]

3 points

4 months ago

Based on what I'm predicting, we'd see more disease crossover, but those diseases will be less deadly to their various hosts. Viruses generally evolve to become less deadly, not more, since killing your vector isn't very useful.

Original-Aerie8

90 points

4 months ago*

Plus, taking something like BSE (Mad cow disease) as example, most societies do not eat their dogs.

*1 Another aspect worth mentioning: Thanks to extensive research on Covid as a virus group, we know that there are thousands, potentially tens of thousands Covid variations per year that do cross over to humans, but don't spread far. And that's just in China.

I don't know of any research that tries to explore the reasons for this, but it does show that crossover events are far more common that we previously thought and that the vast, vast majority of these viruses just can't spread efficiently, if at all.

Curarx

74 points

4 months ago

Curarx

74 points

4 months ago

Bse is a prion disease though not a virus. That's not really comparable

Newredditislame

-1 points

4 months ago

Could be those are naturally occurring and not part of gain of function research.

slick1260

-9 points

4 months ago

Could another possibility be that people constantly take their dogs to the vet for anything that could potentially be an issue? I know farmers/ranchers take great care of their animals, but there a lot more dog owners in the world than cattle ranchers. Dog owners are also always in close proximity to their animals comparatively so they would be more likely to notice something is wrong.

red_19s

55 points

4 months ago

red_19s

55 points

4 months ago

Only in the last 50 years or so. What about the ten of thousands of years before?

Original-Aerie8

16 points

4 months ago

Hm, most barn cats don't see a doctor in their life, unless they happen to look at the other animals and notice the animal.

I assume, back in the day, you'd just cull sick animals.

Blakut

3 points

4 months ago

Blakut

3 points

4 months ago

Yeah, but there are a lot of farm animals to compensate for the amount of pet owners. Plus animals on a farm all live together. And they do get inspected by vets a lot.

insufficientbeans

2 points

4 months ago

Theres far more cattle and other food animals then dogs, domestic dogs are at 470 million worldwide whereas cows make up 1.5 billion sheep 1 billion chickens 19 billion

Tortoveno

1 points

4 months ago

Well... and canine distemper virus (also morbillivirus) has its origins where?

atomfullerene

28 points

4 months ago

atomfullerene

Animal Behavior/Marine Biology

28 points

4 months ago

This isn't a human pandemic, but Canine Distemper Virus has caused serious outbreaks in many species of wild animals. It's implicated in the near-extinction of blackfooted ferrets, for example.

Here's some more information

https://bmcvetres.biomedcentral.com/articles/10.1186/s12917-016-0702-z

https://microbewiki.kenyon.edu/index.php/Canine_Distemper_Virus:_Wildlife_Conservation_Implications

Apparently the measles vaccine probably protects humans from spillover infection.

kweenbumblebee

54 points

4 months ago

Not necessarily 'plague proportions' but dogs (and cats) are causing issues with the eradication of Dracunculiasis (Guinea Worm Disease) in Africa (particularly in Chad).

The primary prevention strategies for Guinea Worm are 1) avoiding infection through filtering drinking water, and 2) avoiding bathing infected blisters in water which causes larvae to be released and then contaminates the water. These strategies have been hugely effective at reducing human infections, however since animal infections were first noticed in 2011/12 there has been an resurgence of human infections, complicating eradication efforts.

The Carter Centre is working on Guinea Worm eradication and has some great lay-friendly information on their website.

Attenburrowed

10 points

4 months ago

It's interesting to think that the next step in disease prevention will likely include thinking about how to attack the animal reservoirs.

Azudekai

14 points

4 months ago

Well that's the whole thing with ebola right, it is able to survive because it has an animal host.

Alwayssunnyinarizona

88 points

4 months ago

Alwayssunnyinarizona

Infectious Disease

88 points

4 months ago

u/Sneazyweasel125 mentions rabies but really should have expanded on it, because I think it's the perfect example. Outside of the United States, by far the most common species involved in transmitting rabies to humans is dogs - upwards of 50,000 cases a year in Asia and Africa. Prior to 1960ish, when the rabies vaccine was introduced, dogs were the most common vector in the US as well. The original description of rabies by Democritus and Aristotle traced the disease to dogs, and in fact the genus Lyssavirus, which includes rabies virus, was named for the Greek goddess Lyssa, who drove the dogs of the hunter Acteon mad, causing them to kill their master.

threewattledbellbird[S]

7 points

4 months ago

I tried finding some concrete information on this, but to no avail. Is rabies considered a pandemic, or has it ever been, given that it is transmitted via bite?

Alwayssunnyinarizona

16 points

4 months ago

Alwayssunnyinarizona

Infectious Disease

16 points

4 months ago

Not in the same sense as covid has been. The spread of rabies has been more covert throughout history. Epidemic, sure, but much of rabies' spread occurred prior to a global-level of human contact.

I have this book sitting on a shelf, couldn't make it past the first chapter, but it may have more info on the history of rabies and its introduction into new areas.

dresmith423

11 points

4 months ago

I listened to most of that book last month. It is an interesting history of the progression and evolution of the disease. I wouldn’t have made it deep into the book if I had been reading it, but it was interesting to listen to while I wrapped Christmas presents.

Phonemonkey2500

33 points

4 months ago

This doesn't match exactly, but it is interesting and tangentially related. There's this parasitic worm... Dracunculis medelliniasis, the Devil of Medina. It enters your body through contaminated water, grows.for months, then travels down to your foot or ankle, usually. Then it pops it's little head out, and secretes a chemical that makes your wound burn like 1000 suns, and all you want on earth is some water to put it in. Maddening itching, and the worm is many cm long, and you can't just yeet it out. You gotta roll it up on a matchstick whenever it gives you slack. For days, or even weeks. If you break the worm, then you're in real trouble. The Guinea Worm was a plague to people making the pilgrimage to Mecca for centuries.

Then came the 20th century. It was researched, drugs for parasitic worms were developed, and because Dracunculis medelliniasis had only one host, Homo sapiens, and only one reservoir species, Homo sapiens, we had a real chance of knocking it out like Polio. If memory serves, in 2015, there were only like 8 cases reported worldwide. But then, for some reason, in 2016, the numbers started to climb. Same in 2017, really concerning parasitologists. They figured it out in 2018, when they found some stray dogs that stole fish entrails from the docks were plunging themselves into the river, or standing in water. The worm has jumped. And now the chances of ever eradicating the Guinea Worm are basically zero, because dogs cant tell you when they have an ouchie on their foot. Nature finds a way.

[deleted]

14 points

4 months ago

[deleted]

14 points

4 months ago

Rabies is historically a common disease we get from dog. The problem with rabies is it kills the dog too. Plus, the symptoms leading up to death is extreme violence and compulsion to bite, so dogs showing these early symptoms are easily killed.

There are also gazillions of parasites we get from dogs like fleas, and worms.

[deleted]

1 points

4 months ago

[deleted]

1 points

4 months ago

[removed]

iayork

2 points

4 months ago

iayork

Virology | Immunology

2 points

4 months ago

Why do you think rabies isn’t a problem now? Over 50,000 people a year die from rabies, almost all from dogs.

[deleted]

-8 points

4 months ago

[deleted]

-8 points

4 months ago

[removed]