Airsacculitis | |
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Other names | Air sacculitis, aerosacculitis, air sac disease, air sac infection, air sac syndrome, sac disease |
Airsacs as shown in common kestrel (Falco tinnunculus): 1. cervical air sac, 2. clavicular air sac, 3. cranial thoracal air sac, 4. caudal thoracal air sac, 5. abdominal air sac (5' diverticels into pelvic girdle), 6. lung, 7. trachea | |
Specialty | Veterinary medicine |
Symptoms | Swelling of the neck, difficult breathing, coughing, loss of appetite, loss of weight, watery eyes, nasal discharge, lethargy, ruffled feathers, clogged nares, stunted growth in juveniles, fewer eggs in hens |
Usual onset | Between 6 and 12 weeks of age |
Causes | Bacterial, fungal or viral inflammatory disease |
Differential diagnosis | Rhinitis, avian infectious bronchitis, gapeworm infection, chronic respiratory disease |
Treatment | Pharmacotherapy, symptomatic treatment |
Medication | Antibiotics |
Frequency | Common |
Airsacculitis, [1] [2] also known as air sacculitis, [3] aerosacculitis, [4] air sac disease, [5] air sac infection, air sac syndrome and simply sac disease, [6] is a common inflammatory condition of air sacs that occurs in birds [5] [7] and is caused by various microbial (mostly bacterial) taxa. [7] Having multiple different causative agents, the condition is widely distributed around the world. [6]
Since the disease is highly infectious it is especially dangerous for domesticated birds (poultry) bred on big farms. [5] [6] Occurrence of airsacculitis in big flocks can mean high economic loss, as infected poultry needs to be carefully observed, with all of the infected tissue disposed of and not used for human food. In severe cases of the disease whole infected bird carcasses need to be disposed. [8]
Usually the disease affects younger birds, aged between 6 and 12 weeks. [6] The most characteristic sign of airsacculitis is an inflamed mucous membrane of bird air sacs, [9] which swells and becomes red, [8] with infected birds exhibiting different symptoms, such as coughing, lethargy, swelling of the neck, difficult breathing, appetite and weight loss etc. [6] [9]
The same term is used for bacterial infection and subsequent inflammation of laryngeal air sacs in non-human primates. [3]
The respiratory system of birds differs significantly from that found in mammals. Birds have relatively small lungs that are rigid and not contractile like those of mammals, in which lungs expand and contract during the breathing cycle. Another critical difference is the absence of so-called air sacs in mammals. Such structures help birds to regulate air flow through their respiratory system. [10] Birds also lack the diaphragm. [6]
Airsacculitis is an inflammatory condition, [5] that appears as a consequence of infection with various species of microbes, mostly bacteria. [7] The condition itself resembles mammal bronchitis and pneumonia, even though different body parts are infected and inflamed. [6]
In a few cases the condition is asymptomatic. [11] Infected birds usually appear sick; lower part of their neck can swell and animals experience difficulties breathing. [9] They may cough, lose their appetite and subsequently their weight, often exhibit nasal discharge, apparent clogged nares, ruffled feathers, have watery eyes and appear lethargic. [6] [12] Affected adult females (hens) lay fewer eggs, while juveniles exhibit stunted growth. [6]
When doing an autopsy congestion of air sacs, throat and nares is evident. [6] Air sacs are red, swollen and produce a lot of liquid. [8]
The cause of airsacculitis is a bacterial infection of air sacs. [6] The common disease causative agents are species, such as pathogenic Escherichia coli, Mycoplasma gallisepticum (MG), Mycoplasma synoviae (MS), Mycoplasma meleagridis (MM), [9] Ornithobacterium rhinotracheale (ORT) and Bordetella avium . [13] [14] Airsacculitis can also be caused by other microbes, such as fungi and in rare cases even viruses. [7] Only rarely airsacculitis is a consequence of improper vaccine or its administration. [6] [15]
This disease is highly infectious in birds, but the infectivity is dependent on the causative agent itself. Specific bacteria species (particularly E. coli), causing the airsacculitis in birds, can be transmitted to people. In some cases this disease can be latent, meaning bacteria remain dormant in survivors and potentially attack non-infected birds after a while. [6]
Typical symptoms should be observed. [6] The disease can be diagnosed with a help of radiography [16] and endoscopy. [11] After a close inspection (e.g. an air sac biopsy) veterinarians usually prescribe antibiotics for the exact infectious agent. It is also important to diagnose any additional (comorbid) diseases. [6] Abscess and granuloma can be removed surgically. [11]
To prevent the disease poultry should be kept in dry and warm (not chilled or over-heated) conditions, with appropriate sanitation, source of clean water and an access to enough fresh air (ventilation). [6] [9]
Prognosis is usually favorable, with poultry experiencing moderate pain for some time. [17] [18] It has been reported that commonly about 2/3 of infected birds recover after exhibiting symptoms for some time. Prompt care increases the likelihood of survival. [6] In specific birds unwanted feather-plucking can occur as a consequence of infection and inflammation. [17] [18]
Some other diseases that affect bird's respiratory system and have similar signs are rhinitis (coryza), avian infectious bronchitis (IB), infection of trachea with a gapeworm and chronic respiratory disease (CRD). [6] Among other diseases associated with the onset of airsacculitis are also avian chlamydiosis (AC), newcastle disease (ND), aspergillosis and ornithobacteriosis. [7]
Sometimes, the term airsacculitis is used for bacterial infection of the laryngeal air sacs in mammals, the most commonly primates. [3] [19] Such airsacculitis in non-human primates often leads to various chronic respiratory diseases. [3] The infected air sacs thicken. Under the microscope one can detect hyperplasia or hypertrophy of epithelium, cell necrosis, fibrosis, cellular infiltrates, as well as an occurrence of bacterial colonies. Among typical symptoms of the disease are halitosis (bad breath), coughing, rhinorrhea (nasal discharge), depression, anorexia and weight loss. [19]
It is critically important to note, that laryngeal air sac is not a synonym of pulmonary alveolus (sometimes also called an air sac), [20] which represents the end of the bronchiole and serves as an exchanging agent of gases between lungs and blood. [21] Infected lungs and inflamed lung tissue (with alveoli) is a sign of pneumonia and not airsacculitis. [22]
In primates laryngeal air sacs occur in apes and gibbons, while such structures are absent in people and some smaller gibbon species. These air sacs are useful when producing fast and extended call sequences. Such behaviour often leads to the risk of hyperventilation if there are no air sacs to allow re-breathing of an exhaled air. [20]
Researchers proposed the absence of laryngeal air sacs in humans is a result of people's ability to adjust their speech breathing patterns and consequently lower probability of hyperventilation. It is thought that the lack of laryngeal air sacs in humans represents a derived feature. [20]
Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severity of the condition is variable.
Psittacosis—also known as parrot fever, and ornithosis—is a zoonotic infectious disease in humans caused by a bacterium called Chlamydia psittaci and contracted from infected parrots, such as macaws, cockatiels, and budgerigars, and from pigeons, sparrows, ducks, hens, gulls and many other species of birds. The incidence of infection in canaries and finches is believed to be lower than in psittacine birds.
Mycoplasma pneumoniae is a very small bacterium in the class Mollicutes. It is a human pathogen that causes the disease mycoplasma pneumonia, a form of atypical bacterial pneumonia related to cold agglutinin disease. M. pneumoniae is characterized by the absence of a peptidoglycan cell wall and resulting resistance to many antibacterial agents. The persistence of M. pneumoniae infections even after treatment is associated with its ability to mimic host cell surface composition.
Lower respiratory tract infection (LRTI) is a term often used as a synonym for pneumonia but can also be applied to other types of infection including lung abscess and acute bronchitis. Symptoms include shortness of breath, weakness, fever, coughing and fatigue. A routine chest X-ray is not always necessary for people who have symptoms of a lower respiratory tract infection.
Influenza A virus subtype H5N1 (A/H5N1) is a subtype of the influenza A virus which can cause illness in humans and many other species. A bird-adapted strain of H5N1, called HPAI A(H5N1) for highly pathogenic avian influenza virus of type A of subtype H5N1, is the highly pathogenic causative agent of H5N1 flu, commonly known as avian influenza. It is enzootic in many bird populations, especially in Southeast Asia. One strain of HPAI A(H5N1) is spreading globally after first appearing in Asia. It is epizootic and panzootic, killing tens of millions of birds and spurring the culling of hundreds of millions of others to stem its spread. Many references to "bird flu" and H5N1 in the popular media refer to this strain.
Avian infectious bronchitis (IB) is an acute and highly contagious respiratory disease of chickens. The disease is caused by avian infectious bronchitis virus (IBV), a coronavirus, and characterized by respiratory signs including gasping, coughing, sneezing, tracheal rales, and nasal discharge. In young chickens, severe respiratory distress may occur. In layers, respiratory distress, nephritis, decrease in egg production, and loss of internal and external egg quality are reported.
Avian coronavirus is a species of virus from the genus Gammacoronavirus that infects birds; since 2018, all gammacoronaviruses which infect birds have been classified as this single species. The strain of avian coronavirus previously known as infectious bronchitis virus (IBV) is the only coronavirus that infects chickens. It causes avian infectious bronchitis, a highly infectious disease that affects the respiratory tract, gut, kidney and reproductive system. IBV affects the performance of both meat-producing and egg-producing chickens and is responsible for substantial economic loss within the poultry industry. The strain of avian coronavirus previously classified as Turkey coronavirus causes gastrointestinal disease in turkeys.
Chlamydia psittaci is a lethal intracellular bacterial species that may cause endemic avian chlamydiosis, epizootic outbreaks in mammals, and respiratory psittacosis in humans. Potential hosts include feral birds and domesticated poultry, as well as cattle, pigs, sheep, and horses. C. psittaci is transmitted by inhalation, contact, or ingestion among birds and to mammals. Psittacosis in birds and in humans often starts with flu-like symptoms and becomes a life-threatening pneumonia. Many strains remain quiescent in birds until activated by stress. Birds are excellent, highly mobile vectors for the distribution of chlamydia infection, because they feed on, and have access to, the detritus of infected animals of all sorts.
Community-acquired pneumonia (CAP) refers to pneumonia contracted by a person outside of the healthcare system. In contrast, hospital-acquired pneumonia (HAP) is seen in patients who have recently visited a hospital or who live in long-term care facilities. CAP is common, affecting people of all ages, and its symptoms occur as a result of oxygen-absorbing areas of the lung (alveoli) filling with fluid. This inhibits lung function, causing dyspnea, fever, chest pains and cough.
Parasitic bronchitis, also known as hoose, husk, or verminous bronchitis, is a disease of sheep, cattle, goats, and swine caused by the presence of various species of parasite, commonly known as lungworms, in the bronchial tubes or in the lungs. It is marked by cough, dyspnea, anorexia and constipation. Lungworms which cause parasitic bronchitis include nematodes of the genera Dictyocaulus, Metastrongylus, and Protostrongylus. Hoose is essentially an infantile disease, almost always afflicting animals under one year of age.
Respiratory diseases, or lung diseases, are pathological conditions affecting the organs and tissues that make gas exchange difficult in air-breathing animals. They include conditions of the respiratory tract including the trachea, bronchi, bronchioles, alveoli, pleurae, pleural cavity, the nerves and muscles of respiration. Respiratory diseases range from mild and self-limiting, such as the common cold, influenza, and pharyngitis to life-threatening diseases such as bacterial pneumonia, pulmonary embolism, tuberculosis, acute asthma, lung cancer, and severe acute respiratory syndromes, such as COVID-19. Respiratory diseases can be classified in many different ways, including by the organ or tissue involved, by the type and pattern of associated signs and symptoms, or by the cause of the disease.
Transmission and infection of H5N1 from infected avian sources to humans has been a concern since the first documented case of human infection in 1997, due to the global spread of H5N1 that constitutes a pandemic threat.
Specific-pathogen-free (SPF) is a term used for laboratory animals that are guaranteed free of particular pathogens. Use of SPF animals ensures that specified diseases do not interfere with an experiment. For example, absence of respiratory pathogens such as influenza is desirable when investigating a drug's effect on lung function.
Pasteurella multocida is a Gram-negative, nonmotile, penicillin-sensitive coccobacillus of the family Pasteurellaceae. Strains of the species are currently classified into five serogroups based on capsular composition and 16 somatic serovars (1–16). P. multocida is the cause of a range of diseases in mammals and birds, including fowl cholera in poultry, atrophic rhinitis in pigs, and bovine hemorrhagic septicemia in cattle and buffalo. It can also cause a zoonotic infection in humans, which typically is a result of bites or scratches from domestic pets. Many mammals and birds harbor it as part of their normal respiratory microbiota.
Avipoxvirus is a genus of viruses within the family Poxviridae. Poxviridae is the family of viruses which cause the afflicted organism to have poxes as a symptom. Poxviruses have generally large genomes, and other such examples include smallpox and monkeypox. Members of the genus Avipoxvirus infect specifically birds. Avipoxviruses are unable to complete their replication cycle in non-avian species. Although it is comparably slow-spreading, Avipoxvirus is known to cause symptoms like pustules full of pus lining the skin and diphtheria-like symptoms. These diphtheria-like symptoms might include diphtheric necrotic membranes lining the mouth and the upper respiratory tract. Like other avian viruses, it can be transmitted through vectors mechanically such as through mosquitoes. There is no evidence that this virus can infect humans.
Mycoplasma gallisepticum (MG) is a bacterium belonging to the class Mollicutes and the family Mycoplasmataceae. It is the causative agent of chronic respiratory disease (CRD) in chickens and infectious sinusitis in turkeys, chickens, game birds, pigeons, and passerine birds of all ages.
Influenza, commonly known as "the flu", is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptoms begin from one to four days after exposure to the virus and last for about 2–8 days. Diarrhea and vomiting can occur, particularly in children. Influenza may progress to pneumonia, which can be caused by the virus or by a subsequent bacterial infection. Other complications of infection include acute respiratory distress syndrome, meningitis, encephalitis, and worsening of pre-existing health problems such as asthma and cardiovascular disease.
Avian orthoreovirus, also known as avian reovirus, is an orthoreovirus from the Reoviridae family. Infection causes arthritis and tenosynovitis in poultry. It can also cause respiratory disease.
Mycoplasma synoviae is a species of bacterium in the genus Mycoplasma. It causes disease in the joints, bones and respiratory system of birds. It is found throughout the world and infection may be referred to as infectious synovitis, avian mycoplasmosis, infectious sinusitis, or mycoplasma arthritis. It is of economic importance because infection can cause a drop in egg production. The disease is most commonly seen in chickens, and transmission occurs both vertically and horizontally.