J Wildl Dis. 2023 Oct 1;59(4):734-742. doi: 10.7589/JWD-D-23-00036.
Rabies is an acute progressive encephalitis caused by infection with rabies viruses, with reservoirs among bats and mesocarnivores, but all mammals are susceptible. Despite its distribution and abundance, cases of rabies are much less common in rodents and lagomorphs. Familiarity with current rabies prevalence data is important for informed decisions on human postexposure prophylaxis after rodent and lagomorph bites. This study is an update of rabies cases reported in rodents and lagomorphs in the US from 2011 to 2020. Rabies reports were collected passively from laboratory testing agencies in the US and Puerto Rico from 2011 to 2020. Descriptive analysis was conducted to determine the percent positivity of rabies cases by species. A total of 401 cases of rabies in rodents and lagomorphs were reported from 2011 to 2020. Most reported cases were in groundhogs (Marmota monax), representing >90% of cases, and the trend closely aligned with rabies in raccoons (Procyon lotor). In any given year, the percent positivity of rabies in rodents and lagomorphs was <2.5%, and the trend of percent positivity from 2011 to 2020 was stable. Groundhog and North American beaver (Castor canadensis) percent positivity was significantly higher than the rest of the rodents and lagomorphs. Most rabies cases occurred during the months of May-September. Documented cases of rabies in rodents and lagomorphs are generally rare, but with variation between species. Groundhogs and North American beavers had rabies percent positivity similar to high-risk species, such as bats and raccoons, and constituted 97% of all rodent and lagomorph positive cases. Since 1993, the trend in rabies cases in groundhogs has significantly declined. These results can be used to help inform public health officials on rodent and lagomorph prevention and control efforts, as well as rabies postexposure prophylaxis.
Keywords: Animal bites; lagomorphs; rabies; rodents.
© Wildlife Disease Association 2023.
As part of research and wildlife disease surveillance efforts, we performed necropsy examinations of 125 free-ranging (n = 114) and captive (n = 11) prairie dogs in Colorado from 2009 to 2017. From these cases, we identified three cases of thymic lymphoma in free-ranging Gunnison’s prairie dogs (Cynomys gunnisoni), and we identified a novel retroviral sequence associated with these tumors. The viral sequence is 7700 nucleotides in length and exhibits a genetic organization that is consistent with the characteristics of a type D betaretrovirus. The proposed name of this virus is Gunnison’s prairie dog retrovirus (GPDRV). We screened all 125 prairie dogs for the presence of GPDRV using PCR with envelope-specific primers and DNA extracted from spleen samples. Samples were from Gunnison’s prairie dogs (n = 59), black-tailed prairie dogs (Cynomys ludovicianus) (n = 40), and white-tailed prairie dogs (Cynomys leucurus) (n = 26). We identified GPDRV in a total of 7/125 (5.6%) samples including all three of the prairie dogs with thymic lymphoma, as well as spleen from an additional four Gunnison’s prairie dogs with no tumors recognized at necropsy. None of the GPDRV-negative Gunnison’s prairie dogs had thymic lymphomas. We also identified a related, apparently endogenous retroviral sequence in all prairie dog samples. These results suggest that GPDRV infection may lead to development of thymic lymphoma in Gunnison’s prairie dogs.
- PMID: 32498297
- DOI: 10.3390/v12060606
Rabbit hemorrhagic disease virus 2 (RHDV2), a notifiable foreign animal disease, has been confirmed for
the first time in wild rabbits in the United States.
Read more: Rabbit
If you live in New Mexico….and in the event you find a sick or dead rabbit…
From Wildlife Rescue: “The disease has been found in Southern and Eastern NM and it is only a matter or time when it will be found here in our area. It is highly contagious, but only to other rabbits, domestic rabbits and species within the rabbit family. Baby rabbits don’t seem to be affected at least at this time.”
If we (Wildlife Rescue) receive any phone calls regarding someone reporting dead or sick wild rabbits, we are asking them for info on where these rabbits are located and reporting this to USGS/NMG&F or to our mammal coordinator. We are telling people not to handle or rescue these rabbits themselves or to wear gloves if handling them.
The Black Death was little short of a bacterial apocalypse. The outbreak of bubonic plague, imported along the Silk Road, is thought to have killed between 25m and 50m people as it rampaged through 14th-century Europe. The disease thence resurfaced sporadically: the Great Plague of London, for example, felled a fifth of city dwellers in the 1660s.
While the plague seems to us a medieval affliction, it has never fully disappeared. On average, about 500 cases are documented globally each year, mostly in Africa, South America and India. The infection is treatable with antibiotics if caught early.
Read More: Plague
GUNNISON, Colo. – Work to protect the Gunnison’s prairie dog by Colorado Parks and Wildlife has proven successful during the last four years and biologists are continuing with more research to improve methods to sustain populations.
“In some situations prairie dogs can be seen as pests, but they are critical in the environment and help to promote survival of numerous other species such as burrowing owls, badgers and raptors,” said Dan Tripp, a wildlife disease researcher with Colorado Parks and Wildlife.
In Colorado there are three species of prairie dogs. The Gunnison’s prairie dog resides primarily in the southwest portion of the state. The others are the white-tailed prairie dog which lives mainly in northwestern Colorado, and the black-tailed prairie dog which inhabits areas along the Front Range and eastern plains.
Plague, caused by a non-native bacteria carried by fleas, has been identified as a threat to the stability of Gunnison’s prairie dog populations in Colorado. Outbreaks of plague frequently kill every prairie dog in a colony. To treat the sickness, agency scientists are spraying prairie dog burrows with a flea-killing pesticide powder. Researchers are also testing the efficiency of oral vaccination baits for preventing plague in animals. Even though researchers are conducting trials to develop potentially useful vaccinations, such tests and investigations require government funding to be carried out. Several steps in the procedure necessitate the purchase of 25l distilled water in bulk in order to clean the equipment, such as beakers, test tubes, and other lab apparatus. Aside from that, funds are required to purchase chemicals and drugs for testing. That is why it is always said that with government support only, vaccines for different illnesses, including the plague, may be effectively created.
It’s interesting to know that the bacteria that causes plague was transported to North America around 1900 and was subsequently found in Colorado around 1940. Because prairie dogs did not evolve with the bacteria, they carry little immunity to fight off the disease.
“The plague bacteria is a non-native invasive species that devastates prairie dogs and other wildlife species. We’re not attempting to upset nature’s balance with these treatments. We are working to restore balance in the environment and reduce the risk of major plague outbreaks in prairie dog colonies,” Tripp said. “We lose a lot of resilience in the environment when we lose prairie dogs.”
Controlling plague in prairie dogs may also help limit potential exposure to people and their pets.
In 2010, CPW biologists started dusting some burrows in the Gunnison Basin with an insecticide that kills fleas. The experiment has worked. In some cases, nearby colonies that were not dusted were wiped out by plague while colonies that were dusted remain healthy. Biologists also said that they’re seeing many more prairie dogs in more areas in the basin this year compared to five years ago.
Although the insecticide is not harmful to other species, applying it is labor intensive and expensive. For dusting to be effective every burrow in a colony must receive an application annually.
A potentially promising treatment is the oral sylvatic plague vaccine, Tripp said. Developed by the U.S. Geological Survey’s National Wildlife Health Center, the vaccine-still in the experimental stage-works well in the laboratory. It is administered in a cube flavored with peanut butter. The baits also contain a red dye that adheres to animals’ coats which helps researchers track the prairie dogs that eat the bait. This is only the second year that the vaccine has been tested in the field in Colorado. Longer term monitoring will be needed to determine its efficacy.
“So far, we’re encouraged by the results and we are optimistic that the vaccine will be effective in limiting future plague outbreaks,” Tripp said.
In the Gunnison area, four prairie dog colonies are being used for vaccine testing. Two colonies are receiving the vaccine bait, two are receiving no treatment. In Teller County the test is being conducted with two colonies.
The vaccine is also being tested in Arizona, Montana, South Dakota, Texas, Utah, and Wyoming. The experiment will continue for another two years and is a collaborative effort among more than 30 federal, state and tribal agencies and nongovernmental organizations.
In Colorado, the vaccine research in Gunnison’s prairie dogs is occurring on public land-state wildlife areas, BLM and National Park Service property.
Contrary to public perception, prairie dogs don’t reproduce prolifically. Females have only one litter of 3-5 pups each year and the natural mortality rate of the young is about 50 percent. Consequently, the colonies generally do not spread rapidly over wide areas. Tripp explained that few connections between colonies across a landscape exist; so when a colony is wiped out it may have little chance of being re-colonized.
“By preventing plague we can have healthy, stable prairie dog colonies that we can manage on public lands,” Tripp said.
The conservation work is aimed at preserving the ecological niche of prairie dogs and preventing a listing of the Gunnison’s prairie dog under the federal Endangered Species Act. If the animal is listed it could lead to various land-use restrictions.
J Wenum, area wildlife manager in Gunnison, explained that when landscapes are restored to a more natural condition, more uses can be accommodated.
“If you have healthy, functioning landscapes you don’t have to be focused on limiting uses,” Wenum said. “A healthy landscape will accommodate agriculture, recreation and wildlife.”
The testing of the oral vaccine will continue for a few more years, and biologists are cautiously optimistic that the vaccine will prove to be effective at limiting plague.
“We won’t be able to prevent plague in every colony. But this work will help to stabilize the overall population at its current distribution and benefit this important species,” Tripp said.
For more information about prairie dogs and other wildlife species, see cpw.state.co.us.
Description: Yellowish buff mixed with black above, slightly paler below. Short, white-tipped tail. Terminal half of tail grayish white in center. 12-14″ in height, weighing 23-42 ounces. Lives 3-5 years in the wild, longer in captivity.
Similar Species: White-tailed and Utah prairie dogs have white in center of tail rather than grayish. Black-tailed Prairie Dog’s tail has black tip.
Breeding: 1 litter per year of 1–8 young, born in early May; gestation 27–33 days, pups emerge mid June.
Habitat: Short grass prairies in high mountain valleys and plateaus of southern Rocky Mountains at elevations of 6,000–12,000’ (1,800–3,600 m). Habitat is much more variable topographically and vegetationally than that of the Black-tailed Prairie Dog, which occurs at lower elevations.
Range: Southeastern Utah, south and central Colorado, northeast and central Arizona, and northwest New Mexico.
Discussion: The Gunnison’s Prairie Dog, like the rest of its kin, is active only when the sun is up, and is most energetic near dawn and dusk. It is constantly vigilant while aboveground, often sitting upright on its hind feet while it pursues its main activities: mainly feeding, but also grooming and playing. This animal generally is seen from April to October. It hibernates (torpor) in winter, living on stored body fat. It usually emerges in April, though they will emerge earlier if the winter is mild. Gunnison’s Prairie Dog feeds on green vegetation, particularly grasses, but also forbs, sedges, and shrubs, as well as a few insects. Its colonies are generally smaller and less closely knit than those of other prairie dogs, resembling ground squirrel aggregations, with fewer than 50 to 100 individuals. The animals in the colony cannot always see one another because their habitat is in such varied and patchy terrain, which is caused in part by human activities. On flat ground and where this prairie dog is protected colonies are much larger and more extensive. This species’ burrow systems can be up to 80 feet long and 16 feet deep in well-established colonies. Burrows can have food storage, flood, nesting, communal and excrement chambers. Territoriality is not well developed in Gunnison’s Prairie Dog, although old males may defend small areas outside their burrows. Mother-young relationships form the basic social unit. Newborns remain in the burrow about three weeks before emerging and are weaned about three weeks later. The female sits almost straight up on her haunches to nurse her young, who suckle either pectoral or inguinal (hind leg) nipples. Gunnison’s alarm call, distinctive among prairie dogs, is important to the survival and structure of the community. It is a series of high-pitched barks of one or two distinct syllables, with the second syllable lower and more guttural. The call may be repeated frequently and may continue for as long as half an hour. It increases in intensity as danger escalates, and ends in chatter as the animal enters its burrow. Predators include American Badgers, Coyotes, weasels, and raptors. Plague (Yersina pestis), carried by fleas, can decimate populations of this species. However, humans, through their extermination programs, are the chief enemy of Gunnison’s Prairie Dog.
My goal in writing this article is to help educate people about prairie dogs, and to provide people with objective information backed by valid scientific research. As many of us in New Mexico live among prairie dogs, I feel it is especially critical that people are well educated about these native animals.
What are prairie dogs?
Prairie dogs are large, colonial, ground-nesting squirrels. They live in large communities (colonies) in grassland habitats. They are highly social animals, and have evolved a complex language system. Prairie dogs eat grasses and weeds, and they will clip grasses to enable them to detect predators. They live in family units called coteries that consist of usually one male and several females. Females often remain in the same burrow system during their lifetime and juvenile males leave the burrow during their first year. Prairie dogs usually live for about 5 years in the wild.
What species do we have in New Mexico?
Both black-tailed prairie dogs and Gunnison’s prairie dogs occur within New Mexico.
Black-tailed prairie dogs are the most social of all the prairie dog species, and occur in the Great Plains region. They used to be common in the eastern and southwestern part of New Mexico, but have been eliminated from most of their native habitat within the state.
Gunnison’s prairie dogs occur throughout the four corners region and are found in Santa Fe, Albuquerque, Socorro, Gallup, and Grants. Gunnison’s prairie dogs also have declined significantly, and have been petitioned to be listed under the endangered species list.
Prairie dog reproduction
Prairie dogs are not prolific breeders. They only have one litter per year, consisting of about four young, of which only two usually survive.
The ecological role of prairie dogs
Prairie dogs were once among the most numerous and widespread herbivores in North American grasslands. Human activities such as habitat destruction and poisoning efforts have significantly reduced prairie dog populations. Three of the five species are federally listed as threatened or endangered. The most widespread species, the black-tailed prairie dog, now occupies less than 2% of its historical range. Scientists studying prairie dogs have estimated that at least 163 animal species are associated with prairie dog colonies, indicating that the prairie dog is a “keystone” (i.e., critically important) species in these ecosystems. Prairie dogs create ecological disturbances resulting in a diverse landscape that provides a variety of habitats for many plant and animal species, including black-footed ferrets, rabbits, squirrels, lizards, snakes, burrowing owls, and invertebrates. Prairie dogs also affect grassland plant species composition and vegetation structure and enhance soil and plant nutritional quality, which benefits antelope, bison, and cattle.
Prairie dog eradication has caused significant biological degradation and decline in biological diversity on grasslands in North America. Research has found that prairie dogs inhibit woody plants from invading grasslands, and has indicated that the elimination of these rodents has played a significant role in desertification of grasslands. In addition, removal of prairie dogs causes secondary extinctions of other species, altering the entire food web associated with prairie dogs. For example, the black-footed ferret, burrowing owl, mountain plover, and ferruginous hawk are among the most endangered prairie dog-dependent species. Despite their importance, people often want to exterminate prairie dogs because of misconceptions about proliferation, children being bitten, destruction of landscaped areas, plague, competition for forage with livestock, and animals breaking their legs in the burrows.
Are they dangerous to humans?
Prairie dogs are not a threat to children. They are timid animals, and when approached by humans, prairie dogs quickly scurry into the safety of their burrows. People should never hand feed prairie dogs or try to grab them. Hand feeding may cause the animals to be accustomed to humans, and result in bites when humans get too close.
Prairie dogs and hantavirus
Prairie dogs are not known to contract or transmit hantaviruses. Worldwide, hantaviruses are associated with deer mice and other rodents in the family Muridae, which are distant relatives of prairie dogs (Squirrels, in the family Sciuridae).
Prairie dogs and plague
Prairie dogs do not carry plague. Plague is a non-native disease, introduced to North America from Europe by humans. Prairie dogs have not evolved immunity to plague, and therefore, it kills 99% of the individuals in an infected colony. Plague has been a major contributor to causing the decline in prairie dog populations.
Fleas carry the plague. These fleas can be found on many wild animals, and are not limited to prairie dogs. Killing prairie dogs just causes fleas to search for another host, and is not recommended by the Center for Disease Control (CDC) as an effective method of plague control. The key to preventing plague is to control fleas, not prairie dogs. Avoiding contact with dead wild animals and dusting pets and rodent burrows with flea powder can successfully prevent plague. Plague is also easily overcome with antibiotics when detected early, so people should educate themselves about the symptoms of plague. A colony of active prairie dogs is indicative of healthy, plague-free prairie dogs, and should not cause concern.
What if they are damaging the landscape in your yard?
If prairie dogs are causing damage to landscaped areas, you can use visual barriers such as vegetation or low walls and additional below ground barriers to contain the animals. Prairie dogs are highly discouraged by tall vegetation, so plant native shrubs and do not mow native grasses. Xeriscaping the area will also help discourage prairie dogs, and conserve water.
How to get rid of prairie dogs
Rat poison should not be used to kill prairie dogs because it causes secondary poisoning of dogs, cats, and other animals, and is dangerous to children. The only legal method for killing prairie dogs involves the use of poisonous gas by licensed professionals (in most states), which is costly. The poisonous gases used are inhumane, causing slow and painful deaths, and can take up to 72 hours to induce death in an animal. During which time the animals suffer from burning of the mucus membranes to paralysis.
The best recommendation is to learn to live with these native animals, and, if for some reason, prairie dogs must be removed, you can contact professional relocators in the state that can be referred by People for Native Ecosystems (PNE) (505) 982-0496 or the City of Santa Fe Permit Development and Review (505) 955-6480. Prairie Dog Pals of Albuquerque also conducts some relocations, though mostly on public lands.
Shooting prairie dogs
Shooting is often used as a means of reducing the size of a prairie dog colony. Varmint hunters gather together in many states where prairie dogs occur to shoot them. They do not eat the prairie dogs; rather, they shoot them with rifles for target practice fun. In our national grasslands, bullet shells and literally exploded prairie dogs can be found littering the colonies. It is important to keep in mind that that these are highly social animals that are greatly affected by the shooting of their family members. Prairie dogs have become threatened species and are not prolific breeders, so sport shooting should be banned.
Do prairie dogs compete with cattle for forage?
Recent research has found that prairie dogs compete little for forage with cattle (~5%). In fact, by clipping grasses, prairie dogs eliminate old plant tissue and stimulate new plant growth. New plant growth contains more protein, so the nutritional quality of the vegetation on prairie dog colonies is greater than off colonies, despite the lower quantity of vegetation. Cattle have been found to gain similar to more weight when foraging on prairie dog colonies than off. Keep in mind that prairie dogs and bison have coexisted for millions of years, and bison and other ungulates consistently prefer to graze on prairie dog colonies.
What about falling into prairie dog holes?
The myth that cattle fall into prairie dog holes apparently began in the late 1800’s. During this time, cattle were over-stocked on rangeland here in the Southwest. Cattle were overgrazing the lands, and combined with a 25 year drought period at the end of the century, many of the grasslands became desertified. There was little forage for cattle to eat and many became sick and lethargic, causing some of the cattle to apparently fall into the burrows. A healthy cow slowly grazes with its head down and does not fall into burrows. Remember, bison evolved along with prairie dogs.
Some people like to ride their horses in the mountains but feel they can’t because prairie dog burrows are present. My advice is not to run your horse on a prairie dog colony, and find an alternative place to ride. These animals no longer occur in large colonies due to their population declines, and therefore, it should not be difficult to find an alternative place to ride. If we live in the mountains or are recreationally enjoying them it is important to remember that wildlife are present in these areas and we need to learn how to live with them, not eliminate them because they are in our way.
Prairie dogs as pets
Prairie dogs express social behavior that humans can relate to, but they do not make good pets. Because they are highly social animals, they should never be kept in isolation. Prairie dogs require considerable attention, and also are highly active with lots of energy and desire to chew and dig. They often will chew furniture when let out of their cage and will dig at rugs, tearing them up. In addition, prairie dogs have a breeding season each year, during which their hormones change and they can become aggressive. During this time even friendly prairie dogs can bite. Moreover, most prairie dogs sold as pets are taken directly from the wild. They have not been bred in captivity for generations, unlike most animals that we have for pets. Keep in mind that dogs have been domesticated for 10,000 years. Because prairie dogs have not been domesticated, they exhibit wild tendencies and may not always be friendly to the people they live with.
Wild prairie dogs sold for pets are often collected from areas where landowners want to reduce or eliminate the prairie dog population on their land. These prairie dogs have been acquired through unregulated harvest to provide profit for the pet trade. Some of the methods used to obtain prairie dogs for pets, such as removing prairie dogs with a “sucker truck,” a truck with a vacuum hose, are inhumane. The pet trade contributes to the decline of the species. If prairie dogs must be removed or controlled in an area, the animals should be humanely relocated to appropriate areas where their populations are desired.
Current efforts to protect prairie dogs within the state
Currently there are no efforts established to protect the Gunnison’s prairie dogs. However, both the city of Albuquerque and of Santa Fe do not allow the poisoning of this species within the city limits. The US Fish and Wildlife Service (USFWS) has determined that black-tailed prairie dogs have declined significantly throughout their range and that their status as a threatened species is “warranted but precluded.” Meaning that there are significant threats affecting the long-term viability of the black-tailed prairie dog, but there are insufficient resources to protect this species. The limited funds available to the USFWS for threatened and endangered species is currently being used for species that are of greater concern.
Game and fish departments from most states in which prairie dogs occur have established black-tailed prairie dog working groups. These working groups are designed to develop a management plan to reduce the decline of prairie dogs so that listing will not be necessary.
Why are they endangered? I see so many of them!
Often people think that because they see “lots” of prairie dogs that they couldn’t be declining. Keep in mind that they once occurred in huge numbers (~5 billion) throughout most of the grasslands in the central United States. They have declined greatly relative to their former abundance. There are many large threats affecting their populations: continued poisoning and shooting, habitat loss through development and desertification, and plague. In addition, many animal species that are dependent on the prairie dog require large colonies in order to support them. Most of the prairie dog colonies have become fragmented and isolated from one another, which lowers the long-term viability of maintaining the population and the other species dependent on them. The plight of the prairie dog is analogous to the passenger pigeon, once one of the most abundant and common species that has now become extinct due to human persecution.
How you can help
People are greatly needed to help in education, legislation, and relocation efforts. Contact a local wildlife organization such as Prairie Dog Pals or People for Native Ecosystems (contact info above) if you have an interest in helping the prairie dogs. You can also find more information about prairie dogs on the web at http://www.prairiedogs.org and http://www.gprc.org .
Ana D. Davidson, Ph.D.
Department of Biology
The University of New Mexico
- Prairie dogs are a keystone species with up to 205 associated vertebrates (9 considered dependent) living with them, using their burrows, or predating upon them
- There are 5 species of prairie dogs. The ones in Albuquerque are Gunnison’s, the others include Mexican, Utah, white and black tailed.
- Gunnison’s prairie dogs hibernate during the winter months.
- Over the last 100 years prairie dogs have been reduced to 1% of their former range and 2% of their population.
- Some of the species are listed under the Endangered Species Act. Others are being considered for listing.
- New Mexico has the smallest remaining acreage of prairie dogs.
- Prairie dogs are territorial and will remain in or near their ancestral habitat if at all possible. The prairie dogs you see here in Albuquerque are the remnants of vast prairie dog towns that existed for hundreds of years.
- Prairie dogs live an average of 3-5 years in the wild.
- Prairie dogs are annual breeders. 50% of females over 2 years of age will breed and produce an average of 4 pups.
- Pups are usually born in early May and will emerge from their burrows after about thirty days.
- Prairie dogs have the most complex language of any animal ever studied.
- They have over 200 words and can form sentences identifying intruders by color, size and type of risk.
- Burrows are complex with a different area for each function of life. There are living chambers, sleeping and nesting rooms, a food storage area,
- toilet rooms, and flood chambers. The burrows themselves generally include a second entrance or escape way, air chambers, and listening posts in addition to the main entrance.
- As with humans, prairie dogs are the victims of plague. Virus carrying fleas are brought into the colony by wild animals or off leash cats or dogs.
- As they have no immunity to the plague they will die within days.
- Poisoning prairie dogs in both cruel and ineffective. The poison causes a slow agonizing death that may take up to three days.
- A mature colony tends to expand at approximately 2% annually. A poisoned colony can expand at an annual rate of 70%. Additionally the poison can pose a danger to humans, cats, dogs, and other animals in the area.
Prairie dogs are not known to contract or transmit Hantavirus. It is only associated with deer mice (Peromyscus spp.), and some closely related species of rodents in the family Muridae. Prairie dogs are in an entirely different family of rodents, Sciuridae, and there are no known associations of hantavirus with prairie dogs and that association is not considered likely given that these species are not closely related.
Hantavirus is in our environment all the time, and we are probably exposed to minute amounts on a regular basis. It takes high concentrations of the virus in the air for someone to catch it. The primary time you should be concerned about Hantavirus is when you are cleaning (stirring up dust) in a closed-confined space where there is minimal air space, where small mouse droppings are present. The classic situation is when someone is cleaning an old closet or garage with a broom and the place has lots of droppings from deer mice. The best thing to do in that case is open the doors, wet the surface, and wear a mask. A full respiratory mask is required for protection from Hantavirus. Most mammalogists are not very concerned about contracting Hantavirus when trapping rodents because they are outdoors, exposed to the open air.
What is Tularemia?
Tularemia (also known as rabbit fever or deerfly fever) is an infectious disease in ticks and rabbits that is caused by a bacterium (Francisella tularensis). The disease was first described in Japan in 1837. Its name relates to the description in 1911 of a plague-like in ground squirrels in Tulare county, California (hence the name tularemia) and the subsequent work done by Dr. Edward Francis.
Tularemia occurs throughout North America and in many parts of Europe and Asia. Francisella tularensis is found worldwide in over a hundred species of wild animals, birds and insects. Some examples of animals, other than rabbits, that carry tularemia are meadow mice, ground hogs (woodchucks), ground squirrels, tree squirrels, beavers, coyotes, muskrats, opossums, sheep, and various game birds.
There are two common ways that humans can contract tularemia:
- From the bite of an infected tick, deerfly (Chrysops discalis), or mosquito. When transmitted to humans by insects, exposed body surfaces are bitten, and the on set of pain and fever is sudden.
- When broken skin (cuts, abrasions) comes into direct contact with an infected rabbit carcass (namely rabbit species of the genus Sylvilagus which are the cottontails).
Less common means of spreading the disease are drinking contaminated water, inhaling dust from contaminated soil, or handling contaminated pelts or paws of animals. Human-to-human transmission of tularemia is uncommon.
What are the clinical features or symptoms of tularemia?
In humans, tularemia may appear in two forms depending on how a patient contracted the disease. The most common form is usually acquired through the bite of an infected tick (especially wood ticks and deer ticks) or from contact with infected rabbits. Patients will develop an ulcer at the site of infection and lymph glands become inflamed and swollen. Severe fever and flu-like symptoms may accompany the ulcer or lesion. Symptoms start to show within 1-14 days after contracting the disease, with 3-5 days being most common. The fever generally lasts for 3 to 6 weeks if no type of antibiotic therapy is used to combat the bacteria. Patients with the less common form of tularemia, which occurs mainly after inhalation of bacteria, typically experience sudden chills, fever, weight loss, abdominal pains, tiredness, and headaches. Patients with this form of tularemia may develop an unusual pneumonia that can be fatal.
Symptoms of the disease in a rabbit are a white spotted liver, swollen spleen, and an ulcerated or raw area about 1⁄4 inch in diameter which is where the animal was bitten by a tick or deer fly and thus infected.
How is tularemia transmitted to humans through wild game?
Reports of tularemia outbreaks indicate two primary modes of disease transmission. An increase in the number of reported cases in the eastern and midwestern United States during fall and winter coincides with hunting season when hunters are skinning rabbits. In the southwestern and western United States, the incidence of tularemia is highest during summer months due to tick bites.
The risk of contracting tularemia from rabbits is greatest when handling rabbits after the hunt during the cleaning process. Hunters skinning rabbits are advised to wear protective rubber gloves to reduce the risk of contracting the bacteria that cause tularemia when broken skin (cuts, scratches, openwounds, abrasions) comes into contact with an infected carcass or alive, infected rabbit.
Other than hunters, who else may be at risk for illness from tularemia?
Approximately 150-300 tularemia cases are reported in the United States annually, with a majority of those from Alaska, Arkansas, Illinois, Oklahoma, Missouri, Tennessee, Texas, Utah, and Virginia. The frequency of tularemia has dropped markedly over the last 50 years and there has been a shift from winter disease (usually from rabbits) to summer disease (more likely from ticks). The bacteria F. tularensis is a hazard to laboratory staff that work closely with rabbits. Matter of fact, nearly all cases reported each year are by people that receive the bacterial disease from a tick bite rather than from cleaning rabbits. Note: as few as 5-10 bacteria can result in disease. Others at risk may include timber industry personnel, outdoor enthusiasts, as well as those who work, play, or live in tick-infested regions during summer months.
As recently as 1984, 20 people from the Crow Creek and Lower Brule Indian reservations in west-central South Dakota were diagnosed with tularemia. Tularemia was spread through these two reservations by dog ticks (Dermacentor variabilis) that carried the bacteria.
PRAIRIE DOGS DO NOT TRANSMIT DISEASE TO HUMANS!
In the wild, prairie dogs are the victims of only one disease, plague. Plague was introduced to the west by settlers near the turn of the century and, “…we gave it to the prairie dogs”(1). It was first discovered in New Mexico in 1938(2). This non-native disease is spread by fleas and is carried into prairie dog towns by other animals such as mice, coyotes, and domestic dogs and cats. All mammals are capable of contracting plague. Once the fleas are present in a prairie dog colony, the entire town will perish within days, and individuals live for only a few hours.
Thus, if the plague is present, there are no active prairie dogs within about one week’s time. Such cases suggest that dogs infected with these diseases should be checked and admitted to a veterinary clinic as soon as possible. To prevent the spread of the plague, infected dogs can be euthanized humanely and compassionately if treatment is not possible. For more info on euthanization, visit this article.
Proven cases of human plague contracted from prairie dogs are virtually non-existent. The Centers for Disease Control and the department of health continually reinforce this fact. The CDC’s official position on destroying Prairie Dogs to control plague is, ” We do not recommend routine destruction of prairie dog colonies”(3). One CDC report specifically on plague says, “Plague in Cynomys Gunnisoni (Gunnison’s Prairie Dog) is devastating. Mortality during a plague epizootic typically exceeds 99%. Although mortality is great and flea infection rates may reach tremendous levels, human cases resulting from prairie dog plague are relatively few….and result from direct contact with an infected animal…Opisocrostis spp, (the fleas), maybe reluctant to bite humans”(4).
Cases of people contracting plague from live prairie dogs are non-existent. People who have been known to contract plague from prairie dogs can be traced to handling the corpse of an infected animal (5).
Some states have no record of anyone ever contracting disease from prairie dogs. The chances of contracting plague from a live prairie dog are so infinitesimally slim, it is simply a non-issue. Fleas will only seek a new host if the original host is deceased. For this reason, The Colorado Department of Health states, ...poisoning of burrowing rodents should not be routinely employed because this could release fleas into the environment and cause an increased risk to humans and pets” (6). Poisoning causes fleas to leave prairie dogs and other rodents in their burrows. This is the only time when a human health risk becomes a factor. Common sense points to the fact that having dozens of corpses present in an area is not a healthy environment for human activity. In contrast, everyone who regularly works with prairie dogs is vitally healthy. The writers of this plan have handled thousands of prairie dogs and they are all alive and well today. Nobody who regularly works with prairie dogs has ever suffered health complications of any kind. Though nearly impossible, if plague did strike in our times, plague is not synonymous with death. The disease can be treated with modern antibiotics and recovery rate is high, recovery time fairly brief.
Existing prairie dog colonies in Albuquerque neither have plague or would infect humans. One value of ‘city dogs’ is that if there is a large plague outbreak in an ecologically significant colony, these healthy animals can be reintroduced to prevent the collapse of the ecosystem. Plague can be controlled or prevented by using proper flea powder in prairie dog burrows once or twice per year (7). This practice is common in New Mexico and is generally conducted by the Department of Health or Environmental Divisions.
May we take this opportunity to reinforce the fact that prairie dogs are not able to become infected by or transmit any other disease including rabies or hanta virus. Plague is just another, tremendous threat against the survival of prairie dogs and their ecosystem. Gunnison’s prairie dogs, the variety in Albuquerque, are down to about 2% of their historical range (8) and are under consideration for listing under the Endangered Species Act (9).
Find out more about the dynamics of a plague outbreak here.
1. Coniff, Richard 1998. Citing Pape, John. Epidiologist for Co Dept. of Health. Quoted on Wildlife Adventures, “Underdogs, Prairie Dogs Under Attack” Turner Productions, TBS
2. Cully, Jack. 1986 Metapopulation Characteristics of Sylvatic Plague Among Gunnison’s Prairie Dogs In the Moreno Valley, NM.(Citing Webber, 1978) Museum for Southwestern Biology, Department of Biology, University of New Mexico, Albuquerque, NM.
Cully, Jack F., Williams, Elizabeth S. 2001.Interspecific Comparisons of Sylvatic Plague in Prairie Dogs. Journal of Mammalogy. 82: 894-905
3. Reply letter to Prairie Ecosystems regarding official position of the CDC on prairie dogs and plague. Kathleen Orloski, DVM, MS, Epidemic Intelligence Service Officer. April 26, 1995.
4.. Centers for Disease Control Morbidity and Mortality Weekly Report. “Human Plague”, April 8, 2004, Vol. 43, No 13.
5.. Rocky Mountain News Spotlight article, “Dogs of War” quoting John Pape, Infectious Disease Specialist for The Colorado Dept. of Health. May 4, 1998.
6. Colorado Department of Health brochure, “Facts About Plague”, 1993.
7. Department of Health regular practice for controlling fleas. Rocky Mountain Arsenal National Wildlife Refuge and Plains Conservation Center have had tremendous success in controlling the spread of plague to reintroduced prairie dogs through this technique.
8. Knowles, C. 2001. Status of the Gunnison’s prairie dog. FWS & NWF.
9. Forest Guardians. 2004. Petition to List the Gunnison’s Prairie Dog as Threatened or Endangered Throughout its Range. Feb 23, 2004. www.fguardians.org
Prepared by: Prairie Ecosystems
Sadly, some misguided, misinformed, and malignant individual has been posting signs trying to connect prairie dogs and monkey pox. Monkey pox, as it is aptly named, comes from African monkeys. As prairie dogs and monkeys do not inhabit the same habitat, it is unlikely that a wild prairie dog could ever contract the disease under normal circumstances.
Monkey pox reached the United States in 2003, from infected Gambian rats being imported by a less than diligent exotic pet sales house. The rats infected adjacent, captive prairie dogs, and the disease was transmitted to humans. The USDA stepped in and stopped the pet trade in prairie dogs, a blessing for the prairie dogs, as no longer could unscrupulous people take young from their families for sale.
In 2008, Prairie Dog Pals submitted a proposal to the city for the rescue and relocation of prairie dogs. The RFP (Request for Proposals) contained some interesting language that gave us cause to review and update some of our procedures. The RFP required that we determine the necessary vaccinations for handling prairie dogs. While we were not aware of any requirements we researched CDC files and talked with our local health officials.
There are no vaccination requirements (please refer to the letter from the city regarding this.)
Based on the letter and our review of CDC recommendations for handling animals during rescue operations, we’ve developed our own protocol to protect our volunteers.
Personal Protection for Caretakers
• Wash hands with soap and water:
Before and after handling each animal
After coming into contact with animal urine, feces, or blood
After cleaning cages
Before eating meals, taking breaks, smoking, or leaving the shelter
Before and after using the restroom
• Use anti-bacterial cleanser after washing.
• Wear heavy protective gloves when handling prairie dogs.
• Wear surgical gloves when handling sick or wounded animals.
• Wear surgical and protective gloves when cleaning cages.
• Consider use of goggles or face protection if splashes from contaminated surfaces may occur.
• Do not allow rescued animals to bite or scratch you.
• Do not eat in animal care areas.
• Pregnant women and immuno-compromised persons should not volunteer for positions involving direct animal contact.
• Bring a change of clothes to wear home at the end of the day.
• Bag and thoroughly clean clothes worn at the shelter.
• Whenever possible, caretakers should have completed a 3-dose prophylactic vaccination series for rabies.
• Whenever possible, caretakers should have a tetanus shot to protect against infections from accidental scratches or bites.
• In the event that a person is bitten by a prairie dog that appears to be ill or acting strangely, the animal will be surrendered for rabies testing and the person be given prophylactic vaccination as a precaution. In addition, the testing should include plague/tularemia screening in case the sick animal represents the first stage of a plague epizootic.
The Food and Drug Administration (FDA) is removing its regulation that established restrictions on the capture, transport, sale, barter, exchange, distribution, and release of African rodents, prairie dogs, and certain other animals. Read more about it on the FDA’s Federal Register here.
My name is Myra and I am a prairie dog. I live in one of the isolated prairie dog villages in Albuquerque. For some reason, many members of your species seem to hate mine. I think it is probably because they don’t understand us.
We are not dangerous and we do not carry diseases. We simply live in little villages and mind our own business. Some people think we kill trees but that is not true. We do not feed on tree roots unless there is absolutely nothing else to eat. We find most of our food above ground.
Other little animals such as gophers will feed on the roots of trees and bushes. Other people think we carry the plague and can spread it to your species. This is also not true. When the fleas that carry the plague invade our villages, we die just as humans do. If our village is full of healthy, fun loving prairie dogs, then I can assure you that the fleas that carry the plague aren’t in our village.
Unlike some other small animals, we are not a prolific species. I may have four pups a year but generally only two will survive. We are lucky to be able to maintain a population if we are left alone.
For whatever reasons; fear, misunderstanding or just plain meanness, your species likes to persecute us. Recently some friends of mine who lived in a prairie dog village close to a church in northeast Albuquerque had their village covered by the church because the church officials were expanding their parking lot. One church official, when questioned, said he doesn’t give a “rat’s ass” about prairie dogs.
Doesn’t he understand that the same Being that created your species created us? Doesn’t he understand that all species can live in peace? Why does your species with your superior intelligence find it necessary to destroy other species?
Over at Kirtland Air Force Base, the military is gassing more of my friends. The gas that they use is very painful and very slow working. My friends will suffer in great pain for as long as 72 hours after being gassed, before they finally, mercifully, die. Other people like to shoot us with high-powered rifles so they can see us “explode” when the bullet rips us apart.