Inbreeding cats

[CreativeChicken08]

Sup yall, I have two unneutered/unspayed cats. Wesley and Maisy. We want to let them mate to have kittens next year, but we were wondering if it’s safe because they are related. They have the same dad, but different moms. Is it as risky as purely inbreeding true siblings cats? I heard that inbreeding can cause mutations and defects. Please leave as much info as you can. Thanks!

 

[Stravager]

Are they a rare breed? Why do you want to mate them? Inbreeding of any sort does inherently carry risk, especially if you do not know the pedigree's genetic issues that you're breeding from. Even most typical breeders will only mate sibling to sibling (even half siblings) to find the genetic faults and then cull the resulting litter.
If all you want is to have cute kittens to look at, I strongly advise against. There are so many kittens already out there leading to feral cat populations or overcrowded shelters.

 

[Nym]

I wonder if they would mate together if they were in the wild, left to their own devices. If not, then perhaps they shouldn't mate in captivity.

 

[1cock2hens]

I'm not sure why people just aren't answering your question and are instead telling you there opinions.

One close mating won't be an issue

 

[nuthatched]

You don't have ancestry information farther back, I'd have them fixed, you don't want kittens to happen.

 

[Stravager]

One close mating won't be an issue

It might not be an issue, but without knowing the potential issues from the parents, then the risks become higher. Unless you are specifically breeding for a desired trait, inbreeding shouldn't be deliberately done.
Female cats also are viable at first heat, which is typically 6 months old, but that doesn't make it safe for them either, and having intact males and females together from a young age will increase the risks of having early pregnancy. It might not be an "issue", but it does have risks for both the mom and the litter. What those risks are depends on the cat. I've lost many, many, many kittens in my lifetime to some issue or another just from non-inbred parents.
Are the chances of genetic defect less because the inbreeding is a little bit less, yes. Does that make it a wise choice? Most cats will not show signs of genetic issues until late in life - you can't tell just by looking at a "healthy" litter.
But as you say, this is just my opinion... CreativeChicken08 has to make her own choice for her cats at the end of the day.

 

[1cock2hens]

It might not be an issue, but without knowing the potential issues from the parents, then the risks become higher. Unless you are specifically breeding for a desired trait, inbreeding shouldn't be deliberately done.
Female cats also are viable at first heat, which is typically 6 months old, but that doesn't make it safe for them either, and having intact males and females together from a young age will increase the risks of having early pregnancy. It might not be an "issue", but it does have risks for both the mom and the litter. What those risks are depends on the cat. I've lost many, many, many kittens in my lifetime to some issue or another just from non-inbred parents.
Are the chances of genetic defect less because the inbreeding is a little bit less, yes. Does that make it a wise choice? Most cats will not show signs of genetic issues until late in life - you can't tell just by looking at a "healthy" litter.
But as you say, this is just my opinion... CreativeChicken08 has to make her own choice for her cats at the end of the day.

Mhmm.. I understand that you believe your anecdotel evidence is valid. like I said, one close breeding of healthy animals generally isn't an issue.

 

[ShrekDawg]

Are they a rare breed? Why do you want to mate them? Inbreeding of any sort does inherently carry risk, especially if you do not know the pedigree's genetic issues that you're breeding from. Even most typical breeders will only mate sibling to sibling (even half siblings) to find the genetic faults and then cull the resulting litter.
If all you want is to have cute kittens to look at, I strongly advise against. There are so many kittens already out there leading to feral cat populations or overcrowded shelters.

Agreed. There’s already soooo many kittens in the world. It’s unwise and unethical to bring more into the world without good reason especially inbred ones.

 

[Stravager]

Mhmm.. I understand that you believe your anecdotel evidence is valid. like I said, one close breeding of healthy animals generally isn't an issue.

Anecdotal on my part or not, the Coefficient of Inbreeding is something pretty well researched, and something I learned about in basic high school. One breeding may not generally be an issue, but it usually doesn't end with one instance, so why perpetuate a problem that doesn't even need to be started?
For pure funsies I'll quote the Institute of Canine Biology understanding that this is speaking in broad terms of general populations:

"The deleterious effects of inbreeding begin to become evident at a COI of about 5%. At a COI of 10%, there is significant loss of vitality in the offspring as well as an increase in the expression of deleterious recessive mutations. The combined effects of these make 10% the threshold of the "extinction vortex" - the level of inbreeding at which smaller litters, higher mortality, and expression of genetic defects have a negative effect on the size of the population, and as the population gets smaller the rate of inbreeding goes up, resulting in a negative feedback loop that eventually drives a population to extinction.

So, in terms of health, a COI less than 5% is definitely best. Above that, there are detrimental effects and risks, and the breeder needs to weigh these against whatever benefit is expected to gained. Inbreeding levels of 5-10% will have modest detrimental effects on the offspring. Inbreeding levels above 10% will have significant effects not just on the quality of the offspring, but there will also be detrimental effects on the breed.

For comparison, mating of first cousins produces a COI of 6.25%; in many societies this is considered incest and is forbidden by law). Mating of half-siblings produces a COI of 12.5%; mating of full siblings produces a COI of 25%"

 

[ShrekDawg]

So they’re just generic barn cats. All the more reason to not let them breed. There’s a million of those around. The world doesn’t need more. Especially inbred ones. But since you insist…