Caseous lymphadenitis | |
---|---|
Other names | Thin ewe syndrome |
Specialty | Veterinary medicine |
Symptoms | Pus-filled abscesses in lymph nodes and internal organs, weight loss |
Causes | Corynebacterium pseudotuberculosis |
Treatment | Drainage of abscesses, chemical cauterization, removal of external lymph nodes, antibiotics |
Caseous lymphadenitis (CLA) is an infectious disease caused by the bacterium Corynebacterium pseudotuberculosis , that affects the lymphatic system, resulting in abscesses in the lymph nodes and internal organs. It is found mostly in goats and sheep and at the moment it has no cure. [1]
This disease is widely distributed throughout the world. It is found in North and South America, Australia, New Zealand, Europe, Asia and Africa.[ citation needed ] Caseous lymphadenitis causes considerable economic harm, because skins and carcasses have to be condemned. It seriously affects reproduction efficiency, wool, meat and milk production. Particularly in Australia, one of the largest producers of meat and wool. Studies have found CL incidence in commercial goat herds as high as 30%. [2]
The causative organism of caseous lymphadenitis is Corynebacterium pseudotuberculosis. Once successfully established within the host, this pathogen will circumvent the immune system with ease. As a result, it causes chronic infection that may last for most or all of an animal’s life, although it is seldom lethal. [3]
It manifests itself predominantly in the form of large, pus-filled cysts on the neck, sides and udders of goats and sheep. Abscesses can also develop on internal organs. [1] An abscess can develop either at the location where the bacteria enters the body or at a nearby lymph node. The infection can spread through the blood or lymphatic system, causing abscesses to form in other lymph nodes or internal organs throughout the body. Most commonly affected organs are the liver, lungs, kidneys and lymph nodes associated these organs. Abscesses grow gradually over time, and if they are located close to the skin, rupture is common. The abscesses are reported not to be painful. [1] [4]
The disease is highly contagious. [5] When abscess rupture, releases it huge numbers of bacteria onto the skin and wool and it results to the consequent contamination of the surrounding environment. Neighboring animals may then be infected by the bacteria through immediate physical contact with the affected individual or indirectly via already contaminated fomites. [3] Infected animals can contaminate the feed, water, soil, pasture and facilities. Even away from its mammalian host, the organism is well equipped for long-term survival in the environment. The disease is also easily spread through the materials that are used during the operation of the animals such as castration, identification with ear tags or by tattooing, and dehydration of abscesses. It is thought to also be spread by coughing or even by flies. [6]
Culture remains the gold standard for diagnosis in small ruminants. Synergistic hemolysis inhibition testing, as done for equine species has the ability to generate false positive results when applied to small ruminants. [7]
Corynebacterium pseudotuberculosis has also been isolated from occurring in other species such as such as deer, cattle, pigs, hedgehogs, laboratory mice, camels, horses, and humans. In only three species; sheep, goats and horses, it is recognized as a specific disease syndrome. The biotype of Corynebacterium pseudotuberculosis affecting horses and cattle is distinguishable from the biotype that infects small ruminants based on its ability to reduce nitrate in vitro. The equine and bovine strains can reduce nitrate, whereas the small ruminant strains typically do not. [6]
Treatment of affected animals consists of the drainage of abscesses, followed by cleansing and chemical cauterization, usually with 10% iodine, or even removal of the affected superficial lymph nodes. Also there is antibiotic therapy, which can be used as a treatment. Despite the fact that C. pseudotuberculosis is sensitive in vitro to almost all antibiotics that have been tested, antibiotic therapy is not very efficient.[ citation needed ]
The most effective way of controlling caseous lymphadenitis is still a topic of discussion. Vaccination is the primary remedy for the control of the disease in several countries, whereby immunisation reduces the spread of infection, leading to a gradual decline in incidence of the disease. However, proprietary caseous lymphadenitis vaccine is still not available, which would be a complete protection against the disease. [5] [8]
Plague is an infectious disease caused by the bacterium Yersinia pestis. Symptoms include fever, weakness and headache. Usually this begins one to seven days after exposure. There are three forms of plague, each affecting a different part of the body and causing associated symptoms. Pneumonic plague infects the lungs, causing shortness of breath, coughing and chest pain; bubonic plague affects the lymph nodes, making them swell; and septicemic plague infects the blood and can cause tissues to turn black and die.
Pharyngitis is inflammation of the back of the throat, known as the pharynx. It typically results in a sore throat and fever. Other symptoms may include a runny nose, cough, headache, difficulty swallowing, swollen lymph nodes, and a hoarse voice. Symptoms usually last 3–5 days. Complications can include sinusitis and acute otitis media. Pharyngitis is a type of upper respiratory tract infection.
Lymphogranuloma venereum is a sexually transmitted disease caused by the invasive serovars L1, L2, L2a, L2b, or L3 of Chlamydia trachomatis.
The disease mycobacterial cervical lymphadenitis, also known as scrofula and historically as king's evil, involves a lymphadenitis of the cervical lymph nodes associated with tuberculosis as well as nontuberculous (atypical) mycobacteria.
Septicemic plague is one of the three forms of plague, and is caused by Yersinia pestis, a gram-negative species of bacterium. Septicemic plague is a systemic disease involving infection of the blood, and is most commonly spread by bites from infected fleas. Septicemic plague can cause disseminated intravascular coagulation, and is almost always fatal when untreated. The other varieties of the plague are bubonic plague and pneumonic plague.
Cellulitis is a bacterial infection involving the inner layers of the skin. It specifically affects the dermis and subcutaneous fat. Signs and symptoms include an area of redness which increases in size over a few days. The borders of the area of redness are generally not sharp and the skin may be swollen. While the redness often turns white when pressure is applied, this is not always the case. The area of infection is usually painful. Lymphatic vessels may occasionally be involved, and the person may have a fever and feel tired.
Paratuberculosis is a contagious, chronic and sometimes fatal infection that primarily affects the small intestine of ruminants. It is caused by the bacterium Mycobacterium avium subspecies paratuberculosis. Infections normally affect ruminants, but have also been seen in a variety of nonruminant species, including rabbits, foxes, and birds. Horses, dogs, and nonhuman primates have been infected experimentally. Paratuberculosis is found worldwide, with some states in Australia being the only areas proven to be free of the disease. At least in Canada, the signs of BJD usually start when cattle are four to seven years of age, and then usually only are diagnosed in one animal at a time. Cattle "with signs of Johne’s disease shed billions of bacteria through their manure and serve as a major source of infection for future calves."
Haemonchus contortus, also known as the barber's pole worm, is a very common parasite and one of the most pathogenic nematodes of ruminants. Adult worms attach to abomasal mucosa and feed on the blood. This parasite is responsible for anemia, oedema, and death of infected sheep and goats, mainly during summer in warm, humid climates.
Tuberculous lymphadenitis is the most common form of tuberculosis infections that appears outside the lungs. Tuberculous lymphadenitis is a chronic, specific granulomatous inflammation of the lymph node with caseation necrosis, caused by infection with Mycobacterium tuberculosis or related bacteria.
Lymphangitis is an inflammation or an infection of the lymphatic channels that occurs as a result of infection at a site distal to the channel. The most common cause of lymphangitis in humans is Streptococcus pyogenes, hemolythic streptococci, and in some cases, mononucleosis, cytomegalovirus, tuberculosis, syphilis, and the fungus Sporothrix schenckii. Lymphangitis is sometimes mistakenly called "blood poisoning". In reality, "blood poisoning" is synonymous with sepsis.
Strangles is a contagious upper respiratory tract infection of horses and other equines caused by a Gram-positive bacterium, Streptococcus equi. As a result, the lymph nodes swell, compressing the pharynx, larynx, and trachea, and can cause airway obstruction leading to death, hence the name strangles. Strangles is enzootic in domesticated horses worldwide. The contagious nature of the infection has at times led to limitations on sporting events.
Anaplasmosis is a tick-borne disease affecting ruminants, dogs, and horses, and is caused by Anaplasma bacteria. Anaplasmosis is an infectious but not contagious disease. Anaplasmosis can be transmitted through mechanical and biological vector processes. Anaplasmosis can also be referred to as "yellow bag" or "yellow fever" because the infected animal can develop a jaundiced look. Other signs of infection include weight loss, diarrhea, paleness of the skin, aggressive behavior, and high fever.
Equine lymphangitis is an inflammation or swelling associated with impairment of the lymphatic system, particularly in a limb, in horses. It is most commonly a bacterial infection, although bacterial culture may be negative.
Actinobacillosis is a zoonotic disease caused by Actinobacillus.
Juvenile cellulitis, also known as puppy strangles or juvenile pyoderma, is an uncommon disease of dogs. Symptoms include dermatitis, lethargy, depression and lameness. When puppies are first presented with what appears to be staphylococcal pyoderma, juvenile cellulitis, a relatively rare condition, may not be considered.
Anaplasma bovis is gram negative, obligate intracellular organism, which can be found in wild and domestic ruminants, and potentially a wide variety of other species. It is one of the last species of the Family Anaplasmaceae to be formally described. It preferentially infects host monocytes, and is often diagnosed via blood smears, PCR, and ELISA. A. bovis is not currently considered zoonotic, and does not frequently cause serious clinical disease in its host. This organism is transmitted by tick vectors, so tick bite prevention is the mainstay of A. bovis control, although clinical infections can be treated with tetracyclines. This organism has a global distribution, with infections noted in many areas, including Korea, Japan, Europe, Brazil, Africa, and North America.
Pigeon fever is a disease of horses, also known as dryland distemper or equine distemper, caused by the Gram-positive bacteria Corynebacterium pseudotuberculosis biovar equi. Infected horses commonly have swelling in the chest area, making it look similar to a "pigeon chest". This disease is common in dry areas. Pigeon fever is sometimes confused with strangles, another infection that causes abscesses.
Corynebacterium pseudotuberculosis is a Gram-positive bacterium known globally to infect ruminants, horses, and rarely people. This bacterium is a facultative anaerobic organism that is catalase positive and capable of beta-hemolysis. In small ruminants, C. pseudotuberculosis causes a disease called caseous lymphadenitis characterized by pyogranulomatous abscess formation. In general, this bacterium causes lesions of the skin, lymph nodes, and internal organs. A disease known as ulcerative lymphagenitis can also result from infection with C. pseudotuberculosis in the distal limbs of horses. This bacterium uses the virulence factors phospholipase D and mycolic acid to damage eukaryotic cell walls and resist phagocytic lysosomal degradation, respectively. Infection with this bacterium is often confirmed by bacterial culture of the purulent exudate. Once the diagnosis has been made, treatment of the infection can begin, but this is difficult due to the nature of the organism and the lesions it forms. Specifically, C. pseudotuberculosis is intrinsically resistant to streptomycin, with varying resistance to penicillin and neomycin depending on the strain. It has been shown to be susceptible to ampicillin, gentamicin, tetracycline, lincomycin, and chloramphenicol. Vaccines have also been produced to develop acquired immunity to this infection.
Abdominal tuberculosis is a type of extrapulmonary tuberculosis which involves the abdominal organs such as intestines, peritoneum and abdominal lymph nodes. It can either occur in isolation or along with a primary focus in patients with disseminated tuberculosis.