ZOONOTIC DISEASES

Diseases Acquired from Goats

A zoonotic disease is an illness that animals pass to humans; a disease such as anthrax or ringworm that can be transmitted from vertebrate animals to humans. Many of the following, while they can be spread by goats, are not common in the US. Any treatment should be at the direction of your doctor or vet.

Actinobacillus - small, nonmotile, nonencapsulated, gram-negative coccobacilli spread by direct contact with saliva (also called wooden tongue). It usually occurs in areas with copper deficiency or pasture with abrasive weeds. Infection usually begins as an acute inflammation with sudden onset of: inability to eat or drink for several days, drooling saliva, rapid loss of condition, painful and swollen tongue, and/or nodules and ulcers on the tongue. The tongue is not always affected in goats; multiple purulent granules may occur in the skin on the face, lips, nose, jaw and neck with regional lymph nodes usually being involved. Lesions develop into abscesses that rupture and discharge yellow-green pus containing granules. Affected goats have difficulty in eating and many die of starvation. Actinobacillosis is readily treated. Treatment can involve surgical debridement and flushing with iodine. Antibiotics can be used; streptomycin is considered the treatment of choice, tetracylcines and tilmicosin are also effective.

Anthrax - an infectious bacterial disease of mammals that causes skin ulcers and is transmittable to humans by inhalation and through feces and infected meat. Anthrax infection can occur in three forms: cutaneous (skin), inhalation, and gastrointestinal. B. anthracis spores can live in the soil for many years, and humans can become infected with anthrax by handling products from infected animals or by inhaling anthrax spores from contaminated animal products. Anthrax can also be spread by eating undercooked meat from infected animals. To treat anthrax, doctors can prescribe effective antibiotics. To be effective, treatment should be initiated early. If left untreated, the disease can be fatal.

Brucellosis - a chronic infectious disease of some domestic animals, for example, cattle, dogs, goats, and pigs, caused by bacteria and may lead to spontaneous abortion (also called Bang's disease and undulant fever). Various Brucella species affect sheep, goats, cattle, deer, elk, pigs, dogs, and several other animals. Humans become infected by coming in contact with animals or animal products that are contaminated with these bacteria. In humans brucellosis can cause a range of symptoms that are similar to the flu and may include fever, sweats, headaches, back pains, and physical weakness. Severe infections of the central nervous systems or lining of the heart may occur. Brucellosis can also cause long-lasting or chronic symptoms that include recurrent fevers, joint pain, and fatigue. Humans are generally infected in one of three ways: eating or drinking something that is contaminated with Brucella, breathing in the organism (inhalation), or having the bacteria enter the body through skin wounds. Treatment can be difficult. Doctors can prescribe effective antibiotics. Usually, doxycycline and rifampin are used in combination for 6 weeks to prevent reoccuring infection. Depending on the timing of treatment and severity of illness, recovery may take a few weeks to several months.

Campylobacteriosis - a bacterial infection that affects the intestinal tract and, in rare cases, the bloodstream, spread by eating or drinking contaminated food or water, unpasteurized milk, and by direct or indirect contact with fecal material from an infected person, animal or pet. Virtually all persons infected with Campylobacter will recover without any specific treatment. Patients should drink plenty of fluids as long as the diarrhea lasts. In more severe cases, antibiotics such as erythromycin or a fluoroquinolone can be used, and can shorten the duration of symptoms if they are given early in the illness.

Chlamydia Trachomatis – a sexually transmitted disease/bacterium that causes several eye and urogenital diseases in humans and other animals. Although transmission from buck to doe at breeding is possible, the major sources of infection of clean animals are aborted fetuses, placentas, vaginal discharges, and infected feces. In many areas chlamydial abortion is the second cause of infectious abortions after brucellosis and the main cause in countries where brucellosis is controlled. Chlamydia can be easily treated and cured with antibiotics. A single dose of azithromycin or a week of doxycycline (twice daily) are the most commonly used treatments

Cryptosporidiosis - an infectious condition of humans and domestic animals, characterized by fever, diarrhea, and stomach cramps. It is spread by a protozoan of the genus Cryptosporidium. Cryptosporidium lives in the intestine of infected humans or animals. Consequently, Cryptosporidium is found in soil, food, water, or surfaces that have been contaminated with infected human or animal feces. If a person swallows the parasite they become infected. The most common symptom of cryptosporidiosis is watery diarrhea. Other symptoms include: dehydration, weight loss, stomach cramps or pain, fever, nausea, and/or vomiting. Some people with crypto will have no symptoms at all. While the small intestine is the site most commonly affected , Cryptosporidium infections could possibly affect other areas of the digestive or the respiratory tract . A new drug, nitazoxanide, has been approved for treatment of diarrhea caused by Cryptosporidium in people. Anti-diarrheal medicine may help slow down diarrhea.

Encephalitis (Tick-Borne) - inflammation of the brain, usually caused by a viral infection; this can be passed from goats to humans via ticks. Tick-borne encephalitis (TBE), also known as spring-summer encephalitis, is a flavivirus infection of the central nervous system. The two main serotypes, European and Far Eastern, are transmitted by the hard ticks Ixodes ricinus and I. persulcatus, respectively. Humans acquire disease by the bite of an infected tick or rarely, by ingesting unpasturized dairy products primarily from infected goats, but also sheep or cows. The only treatment currently available is supportive. At this time, tick-borne encephalitis is not currently a problem in the US.

Caprine Arthritis Encephalitis (CAE) - a viral infection of goats which may lead to chronic disease of the joints and on rare occasions encephalitis in goat kids less then six months of age. The CAE virus is intimately associated with white blood cells; therefore, any body secretions which contain white blood cells are potential sources of virus to other goats in the herd. Horizontal transmission also contributes to disease spread within herds and may occur through direct contact, exposure to fomites at feed bunks and waterers, ingestion of contaminated milk in milking parlors, or serial use of needles or equipment contaminated with blood. Unlikely methods of transmission, indicated by experimental studies, include in utero to the fetus, infection of the kid during parturition, breeding, or through embryo transfer. Since CAE is passed to kids from infected does, it stands to reason humans (or other mammals) should not drink raw CAE-infected goat milk although according to Washington University there is NO evidence that the CAE virus is transmissible to humans. Currently, there is no cure for CAE. Treatment for the arthritic form of CAE includes frequent proper foot trimming, providing soft bedding, good pasture management, and administration of nonsteroidal anti-inflammatory drugs. Physical therapy may be of benefit for recumbent kids with the encephalitic form of CAE. Antibiotic therapy may be used if secondary bacterial infection is present in animals with CAE-induced interstitial pneumonia and/or mastitis.

Caseous Lymphadenitis (CL or CLA) - chronic abscesses which occur in the superficial lymph nodes is a worldwide disease of sheep, goats, cattle, horses and more rarely man, caused by Corynebacterium pseudotuberculosis. The infectious bacteria can enter through skin wounds or mucous membranes. The bacteria will generally localize in a subcutaneous lymph node and form an abscess that the animal walls off from the rest of its body. Abscesses may also develop in internal body organs such as the lungs or liver if organisms enter the bloodstream, and external abscesses may not be present. Lymph nodes around the head and neck region are most commonly affected. Treatments include surgical drainage and impaction of lesions with appropriate long-term systemic antibiotic administration. However, complete bacteriological cure cannot be guaranteed and may lead to active infections being overlooked at subsequent clinical examinations. Lancing abscesses may lead to contamination of the environment. CLA can be prevented. Colorado Serum Company manufactures a vaccine for sheep, Case-Bac®, that has proven somewhat effective (though off-label) in the prevention of the disease in goats – assuming the herd is not already infected. An autogenous vaccine can be manufactured (farm specific) by several labs, to include PHL in Davis, CA, which will not cure CL but will stop its spread in previously infected animals and prevent uninfected animals from future contamination.

Cryptosporidiosis - an infectious condition of humans and domestic animals, characterized by fever, diarrhea, and stomach cramps. It is spread by a protozoan of the genus Cryptosporidium (coccidian protozoan parasites), and the infection is principally on the intestinal epithelium (a thin protective layer of tissue). The thick-walled oocysts are disinfectant resistant and survive for long period of time in cool, moist environments. If dehydration occurs, treat with electrolytes. Treatment with halfuginone may reduce severity and prevent spread of the disease; but this drug can cause other problems if not used correctly.

Dermatophytosis - caused by an obligate parasite localized from lesions of infected hosts; a fungal infection. It is a natural disease of sheep, goats, rabbits, lizards and humans. Humans may become infected following contact with infected animals. Arthropod vectors may transmit the disease between animals, although objects that have had contact with lesions may also transmit the pathogen to a new host.

Francisella Tularensis – a small gram-negative aerobic bacillus. The disease is usually contracted by handling infected animal carcasses, consuming contaminated food or water, or by inhaling the bacteria (also called rabbit fever). Human tularemia presents as an indolent ulcer at site of infection, accompanied by swelling of the regional lymph nodes (ulceroglandular); sudden on set of pain and fever, fever generally lasts 3 - 6 weeks without treatment. Transmitted through inoculation of skin, conjunctival sac or oropharyngeal mucosa with blood or tissue while handling infected animals, or by fluids from infected flies, ticks or other animals; bite of arthropods (deerfly, mosquito) and ticks; ingestion of contaminated food and drinking water; inhalation of contaminated dust; able to pass through unbroken skin; rarely through bites of animals. Treat with streptomycin for severe disease and tetracycline for less severe cases.

Giardiasis –infection of the gut by a water-borne microscopic protozoan. It is usually caused by drinking contaminated water and results in severe diarrhea and vomiting (also called giardia). Giardia infection can cause a variety of intestinal symptoms, which include: diarrhea, gas or flatulence, greasy stools that tend to float, stomach cramps, or upset stomach or nausea. These symptoms may lead to weight loss and dehydration. Some people with giardiasis have no symptoms at all. The recommended treatment for giardiasis is to ingest an abundance of liquids.

Johne's Disease (Mycobacterium paratuberculosis or M. paratuberculosis) – a bacterium that infects the last part of the small intestine and causes an inflammation called granulomatous inflammation. While Johne's disease is found in sheep, goats, elk, deer, bison, llamas and wild ruminants, there is debate whether this can be passed to humans (called in humans Crohn's Disease). Johne's disease usually enters a herd when an infected, but healthy-looking, animal is purchased. Since symptoms take years to manifest, the owners are normally unaware of the problem. Johne's disease causes diarrhea and rapid weight loss (although not all goats have signs of diarrhea). Young animals are most susceptible to infection, catching the disease by nursing teats that have been in contact with contaminated manure/soil. A doe with later stages of the disease may pass it through her milk. Tests for this disease are unreliable; a positive animal may test negative simply because it is not "shedding" the bacterium at the time of the test. According to the University of Wisconsin School of Veterinary Medicine, "It has not been considered economically prudent to treat animals with Johne's disease. The chances of curing the animal are low, the cost of the drugs is high and the meat and milk derived from animals treated with the kind of potent drugs required are not suitable for human consumption." While it is not proven than humans can become infected, there is enough of a zoonotic potential that Johne's disease is included here.

Leptospirosis - a disease affecting human beings and domestic animals caused by spiral-shaped bacteria (spirochetes) of the genus Leptospira, sometimes with fever, jaundice, and kidney failure. Outbreaks of leptospirosis are usually caused by exposure to water contaminated with the urine of infected animals. Many different kinds of animals carry the bacterium; they may become sick but sometimes have no symptoms. Leptospira organisms have been found in cattle, pigs, horses, dogs, rodents, and wild animals. Humans become infected through contact with water, food, or soil containing urine from these infected animals. This may happen by swallowing contaminated food or water or through skin contact, especially with mucosal surfaces, such as the eyes or nose, or with broken skin. Leptospirosis is treated with antibiotics, such as doxycycline or penicillin, which should be given early in the course of the disease. Intravenous antibiotics may be required for more severe symptoms.

Listeriosis – a disease of the nervous system of mammals, birds, and occasionally humans that can cause fever, meningitis, miscarriage, or premature birth and is spread by eating food (i.e., milk) contaminated with listeria. It is a sporadic bacterial infection. The bacteria appear to be soil and mammalian GI tracts. Grazing animals ingest the organism and further contaminate vegetation and soil. Animal-to-animal transmission occurs via the fecal-oral route. Clinical signs in goats, sheep, cattle, and pigs include facial paralysis and circling. Listeria monocytogenes is susceptible to high doses of penicillin, the treatment of choice.

Louping Ill - a serious viral disease spread by ticks that damages the central nervous system, causing tremors and difficulty in mobility. It affects many animals, including sheep, cattle, goats, and hogs. The disease is caused by a member of the Flaviviridae family. It is antigenically closely related to other members of this family, which are transmitted by Ioxodid ticks. The tick-borne encephalitides caused by these viruses are primarily a problem of infections in man and it is only louping-ill virus that produces disease in domestic animals. At this time, looping ill is found in England, Scotland, and Russia and is not currently a problem in the US.

Orf (soremouth) - a pox caused by a virus, affecting sheep and goats, and also transmittable to humans, in which pus-filled blisters form on the animals’ lips (also called sore mouth). This virus can survive for very long periods in scabs of infected goats. This may serve as a source of infection many years. About two to three days after exposure to the virus, vesicles, pustules, and finally scabs appear on the lips, nostrils, and other affected areas. The scabs last from one to two weeks. Resulting pain causes reduced feed consumption and subsequent economic loss. The disease can resemble ulcerative dermatosis and Staphylococcus dermatitis. Treatment with a broadspectrum antibiotic ointment to affected areas is commonly used, but has little effect on the course of the disease.

Q-Fever - an infectious disease caused by Coxiella burnetii (or rickettsial bacteria) and characterized by fever, chills, and muscle pain. Cattle, sheep, and goats are the primary reservoirs of C. burnetii. Infection has been noted in a wide variety of other animals, including other species of livestock and in domesticated pets. Coxiella burnetii does not usually cause clinical disease in these animals, although abortion in goats and sheep has been linked to C. burnetii infection. Organisms are excreted in milk, urine, and feces of infected animals. Most importantly, during birthing the organisms are shed in high numbers within the amniotic fluids and the placenta. Infection of humans usually occurs by inhalation of these organisms from air that contains airborne barnyard dust contaminated by dried placental material, birth fluids, and excreta of infected herd animals. Humans are often very susceptible to the disease, and very few organisms may be required to cause infection. Doxycycline is the treatment of choice for acute Q fever.

Rabies - an often fatal viral disease that affects the central nervous systems of most warm-blooded animals and is transmitted in the saliva of an infected animal. According to Dr. Pamela Parnell, Clemson Veterinary Diagnostic Center, "Goat rabies is very rarely diagnosed, but goats are about as susceptible as dogs and cattle." Currently there is no known vaccine approved for goats. There is no treatment and no cure, and the infection is uniformly fatal. According to Dr. Parnell, "Any animal showing signs of neurological disease should be euthanized and submitted for examination. Other conditions/diseases that can look like rabies include listeriosis, lead poisoning, brackenfern toxicity, polioencephalomalacia, scrapie, and "pseudorabies," another viral disease that rarely affects goats who are in pastures with or near pigs."

Rift Valley Fever - acute, fever-causing viral disease that affects domestic animals (such as cattle, buffalo, sheep, goats, and camels) and humans. RVF is most commonly associated with mosquito-borne epidemics during years of unusually heavy rainfall. RVF is generally found in regions of eastern and southern Africa. Humans can get RVF as a result of bites from mosquitoes and possibly other bloodsucking insects that serve as vectors. Humans can also get the disease if they are exposed to either the blood or other body fluids of infected animals. The most severe impact is observed in pregnant livestock infected with RVF, which results in abortion of virtually 100% of fetuses. There is no established course of treatment for patients infected with RVF virus but ribavirin, an antiviral drug, or interferon, immune modulators, may prove effective for use in humans.

Ringworm – a fungal disease of the skin or scalp in which intensely itchy ring-shaped patches develop. The fungi that cause ringworm thrive in warm, moist areas. Ringworm is transmitted from direct contact with an infected animal's skin or hair. Dogs and cats, especially kittens or puppies, cows, goats, pigs, and horses can pass ringworm to people. People can also get ringworm from other people and their personal items. Treat by keeping skin clean and dry. Apply over-the-counter antifungal or drying powders, lotions, or creams. Those that contain miconazole, clotrimazole, or similar ingredients are often effective.

Salmonellosis - food poisoning caused by infection with salmonella organisms, usually characterized by gastrointestinal upset, diarrhea, fever, and occasionally death (also called salmonella). The Salmonella germ is a group of bacteria that can cause diarrheal illness in humans and other animals. They are microscopic living creatures that pass from the feces of people or animals, to other people or other animals. Antibiotics are not usually necessary to treat salmonellosis unless the infection spreads from the intestines, then it can be treated with ampicillin, gentamicin, trimethoprim/sulfamethoxazole, or ciprofloxacin. Unfortunately, some Salmonella bacteria have become resistant to antibiotics because of the use of antibiotics to promote the growth of feed animals.

Tetanus (Clostridium tetani) - an acute infectious disease, usually contracted through a penetrating wound; it causes severe muscular spasms and contractions, especially around the neck and jaw (also called lockjaw). The spores that cause tetanus are found in soil contaminated by horse feces. These spores can live in soil for several years. Infection with tetanus is of concern with bites from any animal, or from injuries that may result from working around animals. Mortality from tetanus is 70 percent (untreated). Tetanus can be treated with Tetanus: immune globulin (tetanus anti-toxoid), penicillin, valium, and barbituates (to minimize damage). Vaccination (tetanus toxoid) is effective in preventing the disease; booster shots should be given every ten years, or if there is an acute injury.

Toxoplasmosis – a disease of mammals caused by protozoon toxoplasma gondii via undercooked meat or through contact with infectious animals, especially cats. The ingestion of raw goat milk can also transmit the disease to humans. Toxoplasmosis is contagious disease of swine, sheep, goats, and other species characterized with encephalitis, pneumonia, and neonatal mortality. The illness may vary from flu-like symptoms to more severe symptoms such as enlarged, painful lymph nodes, fever or eye infection. Any organ may be involved and the condition may spread throughout the body. There is no known treatment.

Wesselsbron Disease - an acute, arthropod-borne flavivirus infection of sheep, cattle, and goats. This viral disease primarily affects goats, sheep, and cattle in southern Africa. It resembles Rift Valley fever. The virus can be distinguished from that of Rift Valley fever by intraperitoneally injecting weaned mice. It does not kill weaned mice injected by this route, whereas Rift Valley fever virus does. Wesselsbron disease causes death in newborn kids and lambs and abortion in cows and ewes; human infection results in mild febrile illness; it causes a nonfatal influenza-like disease. No treatment identified.

Yersinia Enterocolitica - any of several gram-negative bacteria, many of which cause disease in humans and animals. The major animal reservoir for Y. enterocolitica strains that cause human illness is pigs, but other strains are also found in many other animals including rodents, rabbits, sheep, cattle, horses, dogs, and cats. Uncomplicated cases of diarrhea due to Y. enterocolitica usually resolve on their own without antibiotic treatment. However, in more severe or complicated infections, antibiotics such as aminoglycosides, doxycycline, trimethoprim-sulfamethoxazole, or fluoroquinolones may be useful.