Which is more effective, spaying female dogs and cats or neutering the males? (Please see details.)

Well neutering the males is cheaper and far less risky and invasive. On the hand, personally, the racket a female cat in heat makes me want to murder things.

Mathematically it is better to spay the females One rouge male can impregnate an infinite number of females while one female can only impregnate one.

. .

Low-cast spay and neuter clinics are everywhere now, like this one in Maryland. That’s the way to go. As to which you do first, @Darth_Algar is correct both about the cost and the complications, but if one of your females goes into heat, you will attract males from all around.

@LuckyGuy The male has to be wearing rouge? :-)

Why not be responsible with both?

“but if one of your females goes into heat, you will attract males from all around”

Indeed. Personally I’d fix the females first, but if cost is the biggest stumbling block the I guess fix the males and lock the females up while they’re in heat.

It might also be worth noting that unneutered males are often more aggressive and more difficult to control. Dogs, especially, carry a higher risk/potential liability with this.

@filmfann Read details.

Spaying females.

Arrrgh… Too late to change…. Thanks for pointing that it out. Now it will bother me.
Rogue

@LuckyGuy If it makes you feel better, I knew what you meant.

I did too; I just like teasing a friend.

Definitely spaying the females. Unfortunately, that tends to be more expensive, and requires greater care during recovery, but it will dramatically cut down on the number of pregnancies in your friend’s house, which seems to be the point.

You are a good friend, @tedibear.

If you are worried about your niece’s animals getting pregnant, most definitely the females. More expensive, but it eliminates all possibility of a pregnancy. If you do the males she owns and a stray happens by, you could still get a pregnant female. Better yet, though, get rid of some of the animals. I have had a place in the country with a menagerie and I can say it is expensive and intrusive into your life. You have a hard time even taking off for the night or a weekend because you now have to find someone willing to come take care of your group of animals. You cut back on food, vet bills, cat litter (if you have cats), you don’t have as much poop to scoop or step in, and the remaining animals can get more quality time with you.

Well, one Tom can sire 50 million kittens, day in and day out.
A female has several at a time, but she’s out of the birthing business for a few weeks, too.

Both.

I realize that doing both is the best answer, but I’m trying to make sure that I don’t get in over my head.

@Marinelife – I will see if I can find one in her area. She may already have a low-cost clinic that she uses. After all of the animals that have been dumped over her years there, I wouldn’t be surprised if she knew of one.

@seawulf75 – She does try to re-home them, but it’s not always possible. Most of the people that Dawn knows have one of her strays. :)

@canidmajor – Thank you. My niece is a wonderful, kind-hearted person. I like encouraging that behavior even if she is 44 years old.

Spay the females
A.It decreases the chances of mammary cancer and uterine infections, if you do it before the first heat
B.See @LuckyGuy The math speaks for itself.

Also, with dogs at least, normally only the most dominant male and female will breed. Spaying the females will not only prevent pregnancies, it will prevent or reduce conflict among the animals.

https://pethelpful.com/dogs/Dog-behavior-Why-are-My-Intact-Female-Dogs-Fighting

Reproductive rate of a population tends to be based on the fertile females to a much greater extent than the males.

Of course, it all depends on whose POV and whose money is being considered. The dog owner who owns the bitch and doesn’t want the dog to go into heat will prefer spaying the female. Owners of males don’t have to worry about it.