What Every Veterinarian Needs to Know about Rabies Jamie Snow DVM,MPH Wyoming Department of Health

Rabies Background Rabies is a fatal viral zoonosis and a serious public health problem Virus enters central nervous system causing an encephalomyelitis that is almost always fatal Virus is inactivated by desiccation and ultraviolet irradiation –If material containing virus is dry, the virus can be considered noninfectious All mammals can be infected by rabies

Rabies Background The NASPHV has created a Compendium on Animal Rabies Prevention on Control It can be accessed at ml/rr5403a1.htm ml/rr5403a1.htm

Transmission Various routes of transmission have been documented –Contamination of mucous membranes (i.e., eyes, nose, mouth) –Aerosol transmission (laboratory workers, with a very high concentration of bats in cave) –Corneal transplantation –The most common mode of rabies virus transmission is through the bite and virus- containing saliva of an infected host

Terrestrial Rabies There are 8 antigenic variants of the rabies virus in the U.S. Each variant occurs in a distinct geographic region In each region there is a single reservoir species

Distribution of Major Terrestrial Reservoirs of Rabies in the United States

Bat Rabies There are also multiple independent reservoirs of the rabies virus in insectivorous bats Each species of bat has its own variant More difficult to localize to a specific geographic region

Source of Rabies in Wyoming Primary Source –Skunks and Bats Secondary Source –Cats, dogs and cattle (all other mammals)

Rabies in Wyoming Wyoming has had 14 animals test positive for rabies in 2005 (as of August 2005) Numerous people receive rabies PEP each year in Wyoming due to possible exposures –The cost is anywhere from $1,000 - $2,000 per person

Rabies in Wyoming skunks 70 bats 11 cats 9 horses 8 cows 4 dogs 1 raccoons 1 squirrel 1 fox 410 animals diagnosed with rabies

Rabies Activity in Animals in Wyoming Numbers of animals tested and numbers testing positive (as of August 17 th, 2005) –2003 5/638 –2004 8/745 – /220

Animals testing positive for rabies in 2005 (as of August 17 th, 2005) Skunks (12 total) –2 Campbell county –8 Johnson county –1 Albany county –1 Crook county 2 Bats (2 total) –Hot Springs –Big Horn

Rabies Vaccination All dogs, cats and ferrets should be vaccinated by a licensed veterinarian Boosters should be given in compliance with manufacturers recommendations (i.e. if it is a one year vaccine booster annual if it is a 3 year booster every 3 years)

Livestock Consideration should be given to vaccinating livestock that are valuable or that have frequent contact with humans –(e.g., in petting zoos, fairs, and other public exhibitions), Horses traveling interstate should be currently vaccinated against rabies

Post exposure Management Any animal potentially exposed to rabies virus by a wild, carnivorous mammal or a bat that is not available for testing should be regarded as having been exposed to rabies

You are the Rabies Expert You are the rabies experts in your community Your actions may save an animal or person from becoming infected with rabies Your actions may prevent a person from requiring rabies Post Exposure Prophylaxis (PEP) –PEP is expensive and can cost from $1,000- $2,000

BE an Educator Encourage owners to vaccinate their pets against rabies Tell owners if an animal is exposed to wildlife and it is not vaccinated –It may be euthanized

Scenario One An owner reports their unvaccinated dog came into contact with a skunk that was seen during daylight hours the skunk wandered off. They did not see the specific interaction between the dog and skunk. What do you recommend?

Unvaccinated Pets Unvaccinated dogs, cats, and ferrets exposed to a rabid animal should be euthanized immediately If the owner is unwilling to have this done –animal should be placed in strict isolation for 6 months Rabies vaccine should be administered upon isolation or 1 month prior to release Animals with expired vaccinations evaluated on a case-by-case basis Call the Wyoming Department of Health for consultation

Scenario Two An owner of a cat that is current on vaccine calls your clinic and says that her cat came inside carrying a bat. She startled the cat and the bat flew off. What do you recommend?

Pets Current on Vaccine Dogs, cats, and ferrets should be revaccinated immediately Kept under the owner's control Observed for 45 days Any illness in an isolated or confined animal should be reported immediately to Health Department and State Vet. Office *if the bat is available for testing and tests negative for rabies the cat may be released from quarantine

Scenario Three An owner of a valuable Charlais Bull calls you and reports a skunk wandering around their herd. What do you recommend?

Livestock Livestock should be evaluated on a case by case basis Contact your State veterinary office and the Wyoming Department of Health

Recommendations for owners of livestock exposed to rabid animals If animal is slaughtered within 7 days of being bitten, its tissues may be eaten, if liberal portions of exposed area are discarded Federal guidelines for meat inspectors require any animal known to have been exposed to rabies within 8 months be rejected for slaughter after the first 7 days of exposure Neither tissues nor milk from a rabid animal should be used for human or animal consumption –Pasteurization temperatures will inactivate rabies virus; therefore, drinking pasteurized milk or eating cooked meat does not constitute a rabies exposure

Recommendations for owners of livestock exposed to rabid animals Neither tissues nor milk from a rabid animal should be used for human or animal consumption –Pasteurization temperatures will inactivate rabies virus; therefore, drinking pasteurized milk or eating cooked meat does not constitute a rabies exposure

BATS

Scenario 4 A client calls to tell you she found a bat that appears injured. She took it in and is feeding it with her 5 and 7 year old daughters. The client asks you what bats like to eat? What do you recommend?

Rabies and Bats Rabid bats have been documented in Wyoming –Over 50 Recent data suggests human transmission of rabies virus from bats can occur from –Minor bites –Unrecognized bites –Seemingly unimportant contact

Human Rabies from Bats 27 human cases of rabies from bat strain since 1990’s in the U.S. –In just a few cases a bite was documented –In many cases contact only was documented or no contact was reported In Texas in the 1990’s a man reported a bat crawling on his chest. His wife inspected the area very well looking for bite marks. She did not notice any. They killed the bat and disposed of it. The man died a few months later from bat strain of rabies.

PEP and Bat Exposure If a person cannot rule out contact with a bat they should receive PEP This includes –If someone woke up and found a bat in their bedroom –A bat was around a small unattended child or a pet –If a bat has contact with someone even if bite marks are not detected

Management of Animals That Bite Humans Healthy Dogs, Cats, and Ferrets –If they bite a person, they should be confined and observed for 10 days –Don’t vaccinate during the observation period! –Evaluate animal at first sign of illness –Any illness should be reported immediately to state health department –If signs suggestive of rabies develop, euthanize and send for testing –strays can be euthanized immediately and sent in for testing

Report to the WDH Animal bites and rabies post exposure treatment are reportable to WDH If either of these events are reported to your office please report them to WDH Call or

Human Rabies Pre-exposure Prophylaxis Veterinarians and staff should receive rabies pre-exposure vaccination Does Pre-exposure vaccination ELIMINATE the need for additional therapy after a rabies exposure? NO It simplifies therapy –eliminating need for RIG and decreases the doses of vaccine from 5 to 2 doses It might provide protection for inapparent exposures to rabies

Rabies Pre-exp Veterinarians and staff should have a serum sample tested for rabies antibody EVERY 2 YEARS If titer is less than complete neutralization at a 1:5 serum dilution receive a booster vaccination

Cost of Rabies Pre Exposure Many veterinary clinics pay for their staff to receive rabies pre-exposure treatment. Cost vs. benefit –Rabies pre exposure cost – $ /person –Rabies post exposure cost – $1,000-2,000 –Or DEATH of an employee You decide!

Conclusion Every veterinarian should be familiar with the NASPHV Compendium on Animal Rabies Control Call the Wyoming Department of Health ( or ) and/or the State Veterinary Office ( ) with any questions regarding possible human or animal rabies exposures