Cat Bites and Lymphangitis

Our dear little kitty is almost 19 years old. She has become friendlier in her old age than she ever was as a young cat. This seems odd to us because she will now come and climb in a lap to take a long nap. Suddenly being treated as a friend instead of with complete aloofness is hard to resist. However, she has some other consequences of aging as well. One of these is that there is some sort of tender spot on one of her sides. When touched there, or sometimes for no reason at all, she goes completely berserk, biting herself on the side and ripping out wads of fur. This only lasts a few seconds.

Well, about two weeks ago, late one night, she was in my lap and I happened to touch her side when I was trying to change positions. My hand happened to be in the wrong place and she bit me. This was not a simple puncture wound; she ripped the middle finger on my left hand open, across the inside of the middle joint. Needless to say, I was not too happy.

I am not prone to infections at all. Although I knew it would take a while to heal, I washed the wound well, got the bleeding stopped, treated it with betadine and neosporin, and bandaged it up. The next morning the entire finger was red, swollen and hot. I was surprised, but continued to treat the finger with fresh betadine and neosporin.

About 36 hours after the bite, I was in the grocery store and looked at the back of my hand. There was a wide red river headed from my finger to the arm. I pulled up my sleeve, and the redness continued about halfway to my elbow. I knew it wasn't blood poisoning because that travels in a vein, not as a wide band. Nevertheless, as soon as I got the groceries home, I headed for the local walk-in clinic.

It seems that the bite had caused an infection of my lymph system called lymphangitis. This is completely different from a localized infection of the tissue at the wound site. The wound itself actually looked clean and as good as could be expected.

I quickly learned that it was a good thing I went in when I did. If the infection had traveled any farther, or if any of my lymph nodes had been tender, they would have sent me to the hospital with a need for intravenous antibiotics. It seems that this kind of infection is nothing to be trifled with.

As it was, I was given a shot of Rocephin, a tetanus shot, and 10 days of 500 mg Augmentin. Augmentin is a heavy-duty penicillin relative, one of a handful that works for animal bites. In another 12 hours the redness was gone from my arm, and in 12 more, also from the hand. Only the finger remained swollen for a couple more days. The wound site never did get infected.

So it ended up that everything was fine. However the complications could have been serious if the infection had spread throughout my lymph system. The joint itself could have become infected and damaged if the bacteria had entered the synovial space. I could have lost my finger.

This type of infection is often caused by a bacteria of the genus Pasteurella. It is a gram-negative, rod-sharped bacteria. Our cat was up to date on her shots, and is no longer an outside cat. Other than the fact that she is old, there was no particular reason that a bite from her should be more than usually dangerous. That said, the Pasteurella bacteria is found in 60-75% of all cat saliva (1).

The lesson here is that a cat bite, no matter how insignificant it may seem, can cause serious problems. If serious swelling occurs, and especially if a red band moves from the injury site toward the body, get immediate medical attention.

1. http://www.cocoaspride.com/catbite.html
2. http://www.vetmed.lsu.edu/animal_bites.htm