Humans as Animal Blood Donors, Women's Birth Control Pill, More on Rats Eating Car Wiring

Hey Matt: Do different mammals have the same or different blood types as humans? I’m thinking dogs, cats, whales, deer, bears, etc. Could I give a blood transfusion to Fido if he needed it? — Just wondering, via email

Gee, sorry, Just. Fido’s confined to transfusions of doggie blood. All animals have their own species-specific blood types, so human-dog tradeoffs would be disastrous. Blood groups are determined by antigens (proteins) that cling to particular red cells, and if the antigens don’t match, blood cells can clump together and form deadly blobs that block blood flow. The structure of human and animal antigens is different. Dogs actually have about a dozen blood groups; we have four. Cats? Three. Horses 34, pigs 16, chickens and cattle 11.

Maybe not so surprisingly, humans, chimps, and gorillas share some of the same antigens in the human A-B-AB-O blood-typing system. Not that a transfusion from human to chimp is going to work, but it does demonstrate the genetic link of blood types. You’ll also find a predominance of particular human blood groups in particular geographical areas. There is some thought being given to xenotransplantation — tissue, organ, or cell transplantation between species — to help fill the gaps in the organ-donation system. You’d have to trick a human’s immune system into not reading the pig or baboon kidney as a foreign item and reject it. So, where does doggie get a good transfusion these days? Vets have access to animal blood banks, which contain donations from generous pet owners. Check with your vet and see if Fido would make a good donor to help out your fellow dog owners. (Same with cats, rabbits, whatever ya got.)

Dear Matthew: Why is it only women who have a birth control pill? Is it because the doctor who invented it was a man? Not fair. — Alice C., San Diego

Well, you see, a woman, reproduction-wise, has a handy, built-in “off” switch, a natural state in which no eggs are presented for fertilization. That off switch is called pregnancy. Mother Nature was kind enough to make it so that once pregnant, you can’t be impregnated again a month or two later. Simple enough for the pharmaceutical industry to develop a hormone-tweaking system that would trick a woman’s body into thinking it is pregnant, thus flipping the egg off switch. Guys have no such handy toggle.

Hi Matt: Just read LG’s letter to you [about keeping rats from chewing car electrical wires] and I agree the rodents are a real costly pain. I finally got them out of my car after trying everything that was mentioned and didn’t work. Auto shops and mechanics are of no help except for the repairs, which can be very costly. Being a 90% retired contractor, I had come to the conclusion that it may require encasing in concrete to starve them out. I’ll spare you all the “Wack-a-Mouse” methods I tried and get to the solution. Go to Dixieline and get a 50ft by 8 inch wide roll of aluminum flashing ($25) and a box of 3/4 inch drywall screws. Find a flat concrete or asphalt area and build a mouse fence. They won’t jump over the 8 inch high flashing. Lay 2 x 4s down flat around the vehicle and attach the flashing. The 2 x 4’s can be random scraps. Just enough to make the flashing stand up with minimum gaps under. Have the overlap at the back where you drive in and out. Use small clips to close the overlap every evening. Get your car in there every night before dark. Leave a brick or blocks inside the corral and no food or water and they will exit [by climbing up the brick] and can’t get back in. Hope this isn’t too confusing. — Captain Jack, via email

After exchanging emails and photos, I think I have an idea of Jack’s finished project. It looks like a tiny eight-inch-high wood-and-flashing border around the car’s parking spot. Of course, you have to close off the back once you’re parked. At one corner, a cinderblock or brick is leaned against the fence, giving the mice a route out of the little arena (when they cooperatively decide to leave on their own?). Of course, I have to admit all Alice eyebrows went up when we saw the finished product. Rats and even mice can easily scale an eight-inch fence. It’s laughably simple for them. If I believe Capt. Jack’s declarations of success, I guess I have to believe he is surrounded by unfortunately disabled rodents. One afterthought Jack added, and one that seemed quite satisfactory, was that he keeps the parking area brightly lighted. No rodent is going to expose itself under a spotlight in the dark and become the perfect target for an owl. So, maybe neighbor-annoying, screamingly bright floodlights on your car will keep a rat from gnawing on your Prius. Though, stay tuned. We’re off on another wild rat chase, PhD division, so we might have more hints next week.