Infectious Disease - Rabies


Infectious Disease - Rabies

Rabies transmission

Question: Been meaning to ask this question: I did read your paper on Rabies & remember the time frame for the bite transference, but is it possible to transfer the virus via salvia without a bite? I.E. two animals hissing at each other? and left behind in salvia on something such as a dish or rug or concrete? If so, how long does the virus live on these items?

I live in a semi-wooded area full of darling, displaced raccoons, possum and fox, and many others. (housing construction.....damn the developer to hell anyway for not giving one single bit of consideration to the animals!).

My boys are strictly house-bound, but I do like to let them out on the porch for air and sun.

When you have time...........thanks so much!

Best Regards, Lyn

Answer: Lyn-

It is possible to transmit rabies through saliva entering a pre-existing wound. There are rare cases in which the virus is aerosolized and enters wounds, as well. I know this has happened at least once in a laboratory. However, the risk of rabies transference in either of these cases is pretty low, since it circumstances have to be just right. Rabies virus does not survive outside the body for more than few seconds, in most cases. If an animal dies of rabies, the rabies virus may survive for up to two days in the body, though. This is a good reason to keep pets away from dead raccoons, opossums, ground hogs, etc.

There has not been a case of rabies, with the currently available vaccines, in a properly vaccinated pet. I am hoping that record is never broken.

I think your guys are safe from rabies. We have seen some nasty bite wounds from raccoons, though. So do continue to be cautious, as you have been.

Mike Richards, DVM 5/8/2000

Rabies vaccination - feline

Question: Hello. I'm a physician (ENT) and a cat lover. Your site is outstanding. Would you kindly clear up a simple pair of questions for me?

1) What is the usual regimen of vaccination to initiate rabies immunity in a kitten? That is, one injection, or a series of 2 or 3?

2) As all rabies sera are killed virus, what significant differences exist between sera marketed as annual versus tri-annual? Thank you very much, Dean MD

Answer: Dean-

Rabies vaccinations are all killed virus products at the present time. The standard protocol is to give one injection of the vaccine at 12 weeks of age or older and to repeat this in one year. Then the vaccine is repeated at one year or three year intervals depending on the state law and choice of vaccine. It has always been my opinion that the one year and three year vaccines were probably the same vaccines marketed differently. I have no proof of this and when I asked one of the vaccine company representatives he told me that there were differences in the adjuvents in some vaccines and rabies strain utilized for the vaccination in others. I have no reason to doubt this but I still can't see where there is probably a lot of difference. There is a significant difference in duration of immunity afforded by the use of differing strains of canine distemper virus, though. So maybe it is important.

It is highly likely that the protection afforded by rabies vaccination lasts much longer than three years but due to the severity of the disease and zoonotic potential most states are very cautious about taking chances and legislate one or three year vaccination intervals.

Mike Richards, DVM

Rabies possible - Human risk - zoonotic

Question: Hi ,I recently lost my 15mo. old Scottish Fold. I rose to find he had been sick all night & vomited repeatedly through out the house. He would try to drink & immediately bring it back up. I rushed him to the vet. The vet could not find anything wrong but gave medication for the vomiting & an antibotic. Vomiting stopped & he seemed okay, eating & playing. Three days later, I rushed him to the vet with a sudden, severe respiratory problem. Given short & long reacting Cortisone shots & antibotics. I was much more worried than the vet seemed to be because it just seemed so severe. He then hid in a corner and wouldn't move for anything, nor would he take food or water. I stayed by him all night trying to keep my eye on him. At 2am he rose to go to the litter box. I followed. It took him forever & he layed down to go, just the tiniest squirts. He was far too weak for just one day without food & water! Leaving the box, he stumbled & fell. Then I bend down to pet him & barely touched his back & his hind legs slipped out from under him! His eyes were too big, dialated & glossy looking. I rushed him immediately to the vet. A steady body tick developed in his hind legs. Broad spectrum antibotics, anti- inflammatories for throat swelling, etc. with no improvement. He quit all food & water intake & was on IVs. Later, on one side of face & tail, twitching & started "foaming at the mouth." Vet & 2 universities consulted with, came up with toxoplasmosis or rabies. (Surprise, the previous vet didn't vaccinate for rabies! I had previously quit that office because too busy, confusion & disorganized! Cat raised indoors strickly! Only allowed out in back yard after 1yr old & for short durations. Not exposed to other animals!) Finally, the toxo.test result came back...negative! We had to put him down. Then rabies, negative. His blood work was clear, no evidence of disease in organs or tissue samples. State Health Dept. destroyed brain tissue, in error, that was to go for further testing. The vet now says he doesn't have a clue. If he had to say something, he would say viral meningitis. He does seems to be quite sure it was a virus of some sort. This cat's litter mate has started showing signs of illness but quite different. This cat is choking & gaging during & after eating. He is eating well though & somewhat active. He was started on the broad spectrum antibiotics immediately.

Do you think viral meningitis? Zoonotic? Are most viruses zoonotic? The health dept. said to me, "We keep a small frozen tissue sample, for a year, incase someone dies, we can retest." Ahhh! How accurate is this test?! As soon as the toxo. came back negative, I contacted the state health dept., the rabies anti-serum is only available though them. They denied saying it couldn't be rabies, besides if it was I would have months, no rush. How wrong! They wouldn't even listen to how I was exposed! However, to the vet they had a different story & told him he had to put down this animal. Wouldn't it be against state & federal laws to deny the anti-serum under these circumstances? I would be a class III exposure according to the CDC. Who would you contact regarding this?

FYI, Two days after the negative diagnoses, the newspaper headlines were: "Rabid Cat Infects Family" According to the article this area has been under an rabies alert since april. I find myself worriyng about my daily headaches that have started at this time. They could be tension or stress, I don't know, I don't normally get them but this has been stressful. Karen

Answer: Karen- I wish that I could help supply some insight as far as a diagnosis goes but in reading your note I was thinking in such a totally different direction that I think I must have misunderstood part of it. My thoughts were of urinary blockage and pleuritis or other respiratory illness. These almost certainly would have shown up on an autopsy, though. Farther into the letter it did seem more like rabies or toxoplasmosis would be good diagnostic rule-outs. Rabies would be the major zoonotic concern. I can't think of another cat virus that has the potential to infect humans.

There are several tests for rabies but the most commonly used one is the fluorescent antibody test. I could not find specific data on the accuracy of this test but I remember seeing something on this and there was a small margin of error (I think it was about 2%). I can't say this is true everywhere but our health department is pretty careful about any possible case of rabies in which saliva could have contacted an open wound. If you think this is possible I'd call your physician. Again, I can't say this is true everywhere but I don't recall a case in which the health department was not cooperative when a local physician felt that rabies exposure was possible even when testing was negative. I do not recall the health department using rabies serum, though. I only remember a couple of clients being vaccinated with the three or five dose regimens.

The state lab and the local health departments often have differing views on how to handle these cases so if you have only spoken with the state level health department you might want to try your local one.

In Virginia our best reference for rabies information is Dr. Suzanne Jenkins of the state health department. She is considered an expert on rabies and may be a good source of information for your physician or veterinarian. Dr. Deborah Briggs at Kansas State is also supposed to be a leading expert on this disease if you live nearer to Kansas than Virginia.

It may be reassuring to know that of the rabies cases in humans in the United States in the last few years 15 out of 17 cases involved exposure from bats -- only two exposures resulting in rabies occurred from other animal bites. The testing must be pretty accurate if all possible exposures resulted in only two cases of rabies.

I have sweated out this situation personally. I know the anxiety it can cause to be bitten by a potentially rabid animal. Keep working with your vet and your physician to understand the situation fully and to develop an appropriate plan of action.

Mike Richards, DVM

Last edited 04/20/04


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...