Rabies is a fatal viral zoonosis and a serious public health problem. All mammals are believed to be susceptible to the disease, and for purposes of this document, use of the term “animal” refers to mammals. The disease is an acute, progressive encephalitis caused by a lyssavirus. Rabies virus is the most important lyssavirus globally.
The virus is usually transmitted from animal to animal through bites. The incubation period is highly variable. In domestic animals it is generally 3-12 weeks, but can range from several days to months, rarely exceeding 6 months. Rabies is communicable during the period of salivary shedding of rabies virus. Experimental and historic evidence document that dogs, cats, and ferrets shed virus a few days prior to clinical onset and during illness. Clinical signs of rabies are variable and include inappetance, dysphagia, cranial nerve deficits, abnormal behavior, ataxia, paralysis, altered vocalization, and seizures. Progression to death is rapid. There are currently no known effective rabies antiviral drugs.
RABIES EXPOSURE: Rabies is transmitted when the virus is introduced into bite wounds, open cuts in skin, or onto mucous membranes from saliva or other potentially infectious material such as neural tissue. Rabies may be transmitted when infected saliva, central nervous system tissue, or cerebral spinal fluid penetrates the skin or mucosa of a susceptible mammal. Rabies is usually transmitted by bite wounds, but may involve saliva contact with mucous membranes or a fresh break in the skin. Rabies is not transmitted by contact with blood, urine, feces, petting or touching fur, or being sprayed by a skunk. Questions regarding possible exposures should be directed promptly to state or local public health authorities.
PUBLIC HEALTH EDUCATION: Essential components of rabies prevention and control include ongoing public education, responsible pet ownership, routine veterinary care and vaccination, and professional continuing education. The majority of animal and human exposures to rabies can be prevented by raising awareness concerning: rabies transmission routes, avoiding contact with wildlife, and following appropriate veterinary care. Prompt recognition and reporting of possible exposures to medical professionals and local public health authorities is critical.
HUMAN RABIES PREVENTION: Rabies in humans can be prevented either by eliminating exposures to rabid animals or by providing exposed persons with prompt local treatment of wounds combined with the appropriate administration of human rabies immune globulin and vaccine. Exposure assessment should occur before postexposure rabies prophylaxis (PEP) is initiated and should include discussion between medical providers and public health officials.
When a domestic animal has direct contact with a rabid or potentially rabid wild animal, it is considered to have had a potential exposure to rabies. It is very important to capture and submit the wild mammal for rabies testing if possible. Wild mammals that are not available for laboratory testing should be presumed rabid. Domestic animals that bite other domestic animals are not usually considered as potentially rabid unless they are exhibiting signs compatible with the disease.
RABIES IN LIVESTOCK
Rabies vaccines are available for cattle, horses, and sheep. There are no rabies vaccines currently licensed for use in swine, goats, camelids (llamas, alpacas), bison, red deer, fallow deer, elk or exotic species of livestock, however rabies vaccines may be used off-label by licensed veterinarians. A veterinarian and livestock owner should decide whether rabies vaccinations are warranted in a herd or in valuable individual animals. In Arizona, livestock maintained in areas with high rabies activity in foxes or skunks should be considered for vaccination. Presently, Santa Cruz county.
Horses: Occasional cases of rabies in horses occur in Arizona. Recent cases include two horses in Santa Cruz County in 2009 (skunk associated) one horse in Maricopa County in 2009 (skunk associated), and one horse in Maricopa County in 2008 (bat associated).
Cattle: One cow in Santa Cruz County developed rabies in 2009 (skunk asociated). Two steers developed rabies in 1999. Both had recently been imported from Mexico, and they were infected with vampire bat rabies virus.
Llamas: Three llamas on one farm in Yavapai County developed rabies in 2002. They were housed in an area with active wildlife corridors and were infected with the Arizona gray fox variant of rabies virus.
Livestock with behavioral/ neurologic abnormalities that are not explained by an identified disease should be considered for rabies testing, especially if human or animal exposure has occurred. Livestock maintained on rural pastures or grazing land may contract rabies from exposure to wild animals.
Livestock that have recently been shipped to Arizona from out of state may be incubating rabies, and should be tested if unexplained neurologic disease develops.
A 14-day quarantine/observation period is required when livestock bite or expose a person.
If clinical signs develop or the animal dies during the 14-day quarantine/observation period, the animal should be euthanized and submitted for rabies testing.
CATS AND BATS
Bats are notorious rabies vectors. In Arizona, an average of 11% of the bats tested at the Arizona State Public Health Laboratory are positive for rabies.
Any contact of an animal with wildlife in areas where rabies is present is considered a possible rabies exposure unless proven otherwise. The only way to do this is to have the bat tested.
If the bat is tested and is negative for rabies at the Arizona State Health Laboratory, then everything’s fine. If the bat is positive or untestable, then the vaccinated cat would need a rabies booster vaccine and would have to be observed at home for 45 days. The unvaccinated cat would need a strict (not at home) six month quarantine or would have to be euthanized. So, it’s clear that the rabies status of the bat and the vaccination status of the cats are crucial.
What about my indoor cat? The answer to that is that there is no way to ensure that any cat is 100% free of risk of potential exposure to rabies. There are stories about rabid raccoons breaking through screens and coming indoors, and it’s quite common for bats, which have a high incidence of rabies, to find their way indoors. Bats can enter homes or apartments through small cracks.
Also, there’s always the chance, however small, that an indoor-only cat might sneak outdoors through an open window or door. Rarely a cat has escaped out of their carrier while traveling, when they become frightened. It has happened.
The consequences as previously described are quite severe. Lengthy quarantines may be required for up to 6 months, sometimes even at veterinary clinics which can get quite expensive. Unfortunately the only way to test an animal for rabies is on their brain tissue, which cannot be done in a live animal. While there is an expensive preventative series of shots that humans can receive to prevent disease after exposure to a rabid animal, no similar preventative protection exists for unvaccinated animals. Vaccinate your cats!
Protect Thy Pocketbook – Human Vaccination – Post Exposure Prophylaxis (PEP)
The cost of a rabies vaccination for humans (PEP) typically includes: a consultation fee, sometimes shot administration fees and/or emergency fees, and the cost of the four required doses of vaccine for a total of $1500 to $5,000. One report indicated emergency room fees and treatment exceeding $20,000. Often health insurance companies do not want to cover rabies treatment because the patient is not currently sick and thus the treatment is deemed elective. Rabies is fatal and treatment must occur prior to the onset of symptoms.
The mean total cost of a suspected human rabies exposure was $3,688, the direct costs per case were $2,564, and the indirect costs were $1,124 of that total. About one third of the total cost for suspected human rabies exposure was attributed to indirect costs (e.g., lost wages, transportation, and day-care fees), most of which were not reimbursable to the patient.
Don’t risk your health or your finances, if you have an animal with unexplained neurologic disease minimize your exposure (e.g. do not put ungloved hands in the mouth), restrict all unnecessary visitors, and report it. If you are a livestock officer or animal control officer and must work with the animal wear latex gloves, glasses, or additional personal protective equipment as needed.
Serving Arizonans…One Animal at a Time