Rabies

Overview

Rabies is a disease caused by the rabies virus and other related members of the genus Lyssavirus in the family Rhabdoviridae.1 While preventable, once contracted, the virus infects the central nervous system, ultimately causing disease to the brain and resulting in death.2 While rarely reported in humans in the United States, rabies still poses a serious risk, both to humans and domestic animals, and its control in the United States relies largely on the success of vaccination protocols both for humans and domestic animals,3 the latter of which are often required by law.

As a zoonotic disease (that which can infect both animals and humans), however; rabies remains a worldwide concern, with more than 30 to 40 thousand people dying from rabies each year, and 10 to 12 million receiving post-exposure prophylaxis (PEP).4

Vaccination

Per Connecticut state law, any animal vaccinated prior to one (1) year of age, or receiving a primary rabies vaccine at any age, is considered protected for only one (1) year, and must receive a second vaccination one (1) year after the initial vaccination and boosters every three (3) years thereafter.5

An examination is not required for rabies vaccination, providing a pet’s immunization status is confirmed and an appointment is scheduled beforehand. More detailed information is available about our Year-Round Rabies Clinic.

Rabies vaccines are administered according to the following schedules:

Dogs
Cats
Ferrets

Transmission

The rabies virus is found in mammals and can be transmitted by both wild and domestic animals,9 and is nearly always transmitted by the bite of an infected animal carrying the virus in its saliva.1011

Distinct strains of the rabies virus have been identified in the United States in raccoons, skunks, foxes, and coyotes, with several species of insectivorous bats also found to be reservoirs for strains of the rabies virus.11 Yet, since the early 1990’s, raccoons have remained the most common wild reservoir of the rabies virus.12

Symptoms

While symptoms of rabies can vary in their presentation, reliable clinical signs, irrespective of species, include severe behavioral changes and unexplained progressive paralysis.13

Unfortunately, following infection, symptoms can take a period of days, weeks, or even months to manifest;13 however, rabies is always fatal once definitive clinical signs appear.14

Diagnosis

Definitive diagnosis for rabies is made post-mortem using brain tissue,13 as no pre-mortem tests are considered reliable.15 As such, testing requires an animal be euthanized, it is only performed after thoroughly reviewing the circumstances surrounding suspected contraction of the virus, and is not indicated by any suggestive clinical signs, due to possible variations in presentation and time-frame of exhibition.8

Incidence

The rabies virus represents a serious risk to people and their pets, with hundreds of cases in pets each year in the United States.16

Since 1981, more cases of rabies have been reported annually in cats than in dogs.1317 This trend has continued into 2010,18 with incidence in cats up to four (4) times as common as in dogs, or roughly 300 reported cases per year.16

In 1991, a resurgence of rabies in wild animals caused an outbreak in raccoons which spread from the south to the northeast United States.19 The first of such cases of rabies in Connecticut was identified in March of that year.2021 By the end of 1995, all counties in Connecticut had reported cases of rabies, including the first in domestic animals since the 1940’s.21

Rabies has been reported in domestic animals (a cat) within Stratford CT as recently as 2014,22 and locally within Fairfield County (Shelton CT) as early as 2015.23 Additionally, for 2013 through 2015, Fairfield County has had the highest recorded incidence of rabies in wildlife in Connecticut.222425 Nevertheless, rabies incidence in wildlife in Connecticut has greatly decreased since peaking in 1992.26

Current rabies statistics, and those dating back to 2000 are available from the Connecticut Department of Public Health’s (DPH) Rabies Statistics page. This also includes a graph of Domestic Animals Tested Positive for Rabies from 1991 to the current year.

Prevention

While the majority of rabies cases in animals are reported in wildlife,27 most human exposures result from contact with dogs, cats, cattle, or horses; with dogs remaining the primary source of infection in humans.10 To address this fact, and prompted by the reemergence of rabies in wild animals in 1991, in April of that year Connecticut enacted a law making rabies prevention by dog and cat owners compulsory.28

Currently, Connecticut state law requires all owners of dogs or cats over the age of three (3) months to vaccinate their animal(s) against rabies and to keep those vaccinations up-to-date.5

Younger animals are usually more susceptible to the rabies virus than older ones; due to the age at which they should receive the vaccine,29 because of immune response if vaccinated earlier.30 Therefore, it is recommended that puppy owners restrict outdoor activity of their dog(s) until three (3) months of age, when they can receive the vaccine.

Due to the success of both wild- and domestically-targeted vaccination programs, cats have recently replaced dogs as the most commonly rabid domestic animal in the United States,29 indicating the importance of vaccination. We do not recommend cats be let outdoors due to their potential to disrupt local wildlife, but vaccination protects against possible exposure should an indoor cat get outdoors, and is required by law.5 Cats can be vaccinated after eight (8) weeks,31 and must be by at least three (3) months, of age.5

Prevention Tips

Rabies Certificate

A Rabies Certificate is a generic, informal certificate issued by a veterinary hospital, but which includes detailed information about the vaccine administered, and which, in Connecticut, must be presented at the time of Dog Licensing.33

Two copies of a pet’s Rabies Certificate are provided following vaccination. If you require an additional copy or copies of your pet(s)’s Rabies Certificate(s) please return to our hospital. Be mindful there is a small fee for this service, and there may be a significant wait to obtain a veterinarian’s signature (many towns, including Stratford CT, require a hand-written signature).

Additional Resources

Simple Steps Save Lives

An informational video about rabies provided by the American Veterinary Medical Association (AVMA).

Local, State, & National Resources

Additional information regarding prevention of rabies locally is available from Stratford Animal Control, statewide from the Connecticut Department of Public Health, and nationwide from the Centers for Disease Control and Prevention (CDC).

International Resources

To learn more about international rabies prevention, visit the Global Alliance for Rabies Control (GARC). World Rabies Day, an initiative of the GARC to raise awareness about the impact of rabies worldwide, takes place annually on September 28th.

References

  1. ^ Demattos CA, Demattos CC, Rupprecht CE. Rhabdoviruses. In: Knipe DM, Howley PM, eds. Fields Virology 5th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2006: 1245-1277.
  2. ^ CDC – Rabies. Centers for Disease Control and Prevention. http://www.cdc.gov/rabies. Updated September 24, 2013.
  3. ^ CDC – Rabies in the U.S. – Rabies. Centers for Disease Control and Prevention. http://www.cdc.gov/rabies/location/usa. Updated April 22, 2011.
  4. ^ Dressen DW. A global review of rabies vaccines for human use. Vaccine. 1997; 15: 801-809.
  5. ^ a b c d State of Connecticut: General Assembly. Conn Gen Stat Ch 435 § 22-339(b). https://cga.ct.gov/current/pub/chap_435.htm#sec_22-339b. 2009.
  6. ^ a b CDC – Prevention in Animals – Rabies. Centers for Disease Control and Prevention. http://www.cdc.gov/rabies/prevention/animals.html. Updated April 22, 2011.
  7. ^ Eckart TL. Rabies and the Domestic Ferret. Ferret Family Services. http://www-personal.ksu.edu/~sprite/RABIES.HTML.
  8. ^ a b DOAG: Rabies Manual. State of Connecticut: Department of Agriculture. http://ct.gov/doag/cwp/view.asp?a=1367&q=456520&doagPNavCtr=|44678|#44683. Published 2010.
  9. ^ Childs JE, Rehl LA. Epidemiology. In: Jackson AC, Wunver WH, eds. Rabies 2nd ed. New York, NY: Elsevier; 2007: 127.
  10. ^ a b Greene CE, ed. Infectious Diseases of the Dog and Cat 4th ed. St. Louis, MO: Elsevier; 2012: 181.
  11. ^ a b CDC – Transmission – Rabies. Centers for Disease Control and Prevention. http://www.cdc.gov/rabies/transmission. Updated April 22, 2011.
  12. ^ CDC – 2010 Surveillance: Rabies in Wild Animals 1960-2010. Centers for Disease Control and Prevention. http://www.cdc.gov/rabies/resources/publications/2010-surveillance/rabid-wild-animals.html. Updated November 10, 2011.
  13. ^ a b c d Bingham J, van der Merwe M. Distribution of rabies antigen in infected brain material: determining the reliability of different regions of the brain for the rabies fluorescent antibody test. J Virol Methods. 2002; 101: 85-94.
  14. ^ Rupprecht CE. Rabies. In: Kahn DM, ed. Merck Veterinary Manual 10th ed. Whitehouse Station, NJ: Merck & Co; 2007: 1067-1071.
  15. ^ Greene CE, ed. Infectious Diseases of the Dog and Cat 4th ed. St. Louis, MO: Elsevier; 2012: 188-189.
  16. ^ a b Blanton JD, Hanlon CA, Rupprecht CE. Rabies surveillance in the United States during 2006. JAVMA-J Am Vet Med Assoc. 2007; 231(4): 540-556. doi:10.2460/javma.231.4.540.
  17. ^ Greene CE, ed. Infectious Diseases of the Dog and Cat 4th ed. St. Louis, MO: Elsevier; 2012: 183.
  18. ^ CDC – 2010 Surveillance: Rabid Cats and Dogs Reported in the United States […]. Centers for Disease Control and Prevention. http://www.cdc.gov/rabies/resources/publications/2010-surveillance/cats-and-dogs.html. Updated November 10, 2011.
  19. ^ DPH: Rabies. State of Connecticut: Department of Public Health. http://ct.gov/dph/cwp/view.asp?a=3136&q=396178. Updated October 22, 2010.
  20. ^ Wilson ML, Bretsky PM, Cooper GH Jr., Egbertson SH, Van Kruiningen HJ, Cartter ML. Emergence of raccoon rabies in Connecticut, 1991-1994: spatial and temporal characteristics of animal infection and human contact. Am J Trop Med Hyg. October 1997; 57(4): 457-63.
  21. ^ a b DPH: Rabies Statistics. State of Connecticut Department of Public Health. http://ct.gov/dph/cwp/view.asp?a=3136&q=396744. Updated April 14, 2014.
  22. ^ a b Animals Tested for Rabies by Town Found and Species Report Period: 01/01/2014-12/31/2014. Hartford, CT: Department of Public Health; April 21, 2015. http://www.ct.gov/dph/lib/dph/infectious_diseases/rabies/rabiestowncounty2014.pdf.
  23. ^ Animals Tested for Rabies by City, County, and Species. Hartford, CT: Department of Public Health; December 11, 2015. Retrieved from Internet Archive: https://web.archive.org/web/20170304013758/http://www.ct.gov/dph/lib/dph/infectious_diseases/rabies/2015_current_rabies_stats.pdf.
  24. ^ Animals Tested for Rabies by Town Found and Species Report Period: 01/01/2013-12/31/2013. Hartford, CT: Department of Public Health; April 9, 2014. http://www.ct.gov/dph/lib/dph/infectious_diseases/rabies/2013_annual_stats.pdf.
  25. ^ Animals Tested for Rabies by Town Found and Species Report Period: 01/01/2016-12/31/2016. Hartford, CT: Department of Public Health; March 23, 2017. http://www.ct.gov/dph/lib/dph/infectious_diseases/rabies/rabiestowncounty2016.pdf.
  26. ^ Terrestrial Animals Tested Positive for Rabies, Connecticut, 1991-2014. Hartford, CT: Department of Public Health; April 21, 2015. http://www.ct.gov/dph/lib/dph/infectious_diseases/rabies/terrestrial_animals_1991_2016.pdf.
  27. ^ CDC – Rabies Surveillance Data in the United States – Rabies. Centers for Disease Control and Prevention. http://www.cdc.gov/rabies/location/usa/surveillance. Updated November 15, 2011.
  28. ^ State of Connecticut: General Assembly. Conn Pub Act No 91-46. https://cga.ct.gov/ps91/Act/pa/1991PA-00046-R00SB-00717-PA.htm. Published April 12, 1991.
  29. ^ a b Greene CE, ed. Infectious Diseases of the Dog and Cat 4th ed. St. Louis, MO: Elsevier; 2012: 195.
  30. ^ Greene CE, ed. Infectious Diseases of the Dog and Cat 4th ed. St. Louis, MO: Elsevier; 2012: 192.
  31. ^ Merial Ltd. PUREVAX Feline Rabies; 2001.
  32. ^ World Survey of Rabies for the year 1999. World Health Organization. http://who.int/rabies/resources/wsr1999/en. Published 1999.
  33. ^ State of Connecticut: General Assembly. Conn Gen Stat Ch. 435 § 22-338. https://cga.ct.gov/current/pub/chap_435.htm#sec_22-338. Published January, 2011.