A. Veterinarians have been aware of this purported connection since the late 1990s, when several studies were published claiming to demonstrate a correlation between microchips and tumors in mice. While the studies got lots of attention in the veterinary field, the connection was not proven and veterinarians moved on, confident in the thousands of microchips we have implanted. Now these studies are being dredged up again because of the recent decision by the FDA to approve microchips for use in humans. Once again, the connection will be shown to be unfounded. In a nutshell, the mice used in these studies were mice specifically bred to study cancer, and there were no control mice - mice that did not receive microchips - to see whether or not they developed tumors without a microchip. Microchip manufacturers have conducted numerous studies in dogs and cats and have not duplicated any microchip/cancer connection.
There have also been anecdotal reports of individual animals developing tumors after having a microchip. Hmmm, do animals develop tumors if they're not microchipped? Yes, they do. The bottom line is that millions of dogs, cats, horses and other animals have been microchipped - some for over a decade - with few if any problems. The news media are just looking for an interesting story.
Q. Our cat had kittens about six weeks ago and all of a sudden her behavior has really changed. She is being very aggressive and swatting and hissing at the four kittens and us, too. We tried separating them and the mom doesn't seem to be eating. She has very smelly, loose stools. We're not sure what to do for her at this point.
A. It sounds as if your cat is exhibiting normal weaning behavior. The hormonal drive to get away from her kittens is a strong one, and is designed so she can stop lactating, come into heat, and, yes, get pregnant again. Often aggression toward the kittens turns into aggression toward other cats and other people in the household. As long as the kittens are eating well on their own, there is no need for them to continue nursing. You can separate the mom and definitely have her spayed after a couple weeks. The loose stools may be caused by the stress of weaning. Also, if you are feeding the kittens something new, the mom may be affected by the diet change. If the loose stools persist after separating the mom, you should have her examined by your veterinarian.
--Dr. Heidi Strand is a veterinarian for the East Bay SPCA in Dublin. She has lived in the Tri-Valley for 10 years with her family and an assortment of four-legged friends. Questions can be mailed to 315 Diablo Road, Suite 100, Danville 94526; or e-mailed to firstname.lastname@example.org. Her column runs every other week.