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A presumptive diagnosis can be made based on the history and clinical signs. Definitive diagnosis is achieved by direct or indirect fluorescent antibody testing (FAT), PCR, post mortem (signs include petechia and pulmonary congestion), histopathology or electron microscopy.
François Madec, a French author, has written many recommendations on how reduce PMWS symptoms. They are mostly measures for disinfection, management, and hygiene, referred to as the "20 Madec Points" [Madec & Waddilove, 2002].
These measures have recently been expanded upon by Dr. David Barcellos, a professor at the Veterinary College in the Universidade Federal do Rio Grande do Sul, Rio Grande do Sul, Brazil. He presented these points at "1st Universidade Federal do Rio Grande do Sul Symposium about swine management, reproduction, and hygiene".
He divided his points by pig growth stage, and they can be loosely summarized as:
- keep the gutters clean
- increase feeder space
- use pens or small cages with solid dividers
- avoid mixing pigs from different origins
- improve the quality of air
- decrease maximum capacity, giving each pig more room
- separate sick animals as soon as possible, and treat them in a hospital pen. If they do not respond to antibiotics in three days, they should be culled
- control access of people and other animals
- reduce invironmental stress factors such as gases and air currents
- use immunizations and preventive medications for secondary agents commonly associated with PMWS
There is currently no specific treatment for the virus. A vaccine is available, but only experimentally. It has not been released to the public due to the risk it poses to already exposed birds.
Therapeutic intervention is limited to treating secondary infections. The individual bird can sometimes recover, but this is rare. If only the feathers are affected and the bird suffers no other symptoms, it can usually experience an acceptable quality of life. But if the bird's beak or nails are affected, veterinarians will recommend euthanasia.
The management of the disease lies thus mostly in prevention. Every new bird that enters a pen with other birds should be quarantined first and be tested for BFDV. Birds which are known carriers should not be introduced into new pens, especially not if those contain young birds.
A vaccine is available in the UK and Europe, however in laboratory tests it is not possible to distinguish between antibodies produced as a result of vaccination and those produced in response to infection with the virus. Management also plays an important part in the prevention of EVA.
Tiamulin, chlortetracycline or tilmicosin may be used to treat and prevent the spread of the disease.
Vaccination is a very effective method of control, and also has an effect on pig productivity.
Eradication of the disease is possible but the organism commonly reinfects herds.
Often no treatment is required. However, as porcine cytomegalovirus is a herpes virus it remains latent and sheds at times of stress. Therefore husbandry measures to minimise stress levels should be in place.
Porcine circoviral disease (PCVD) and Porcine circovirus associated disease (PCVAD), is a disease seen in domestic pigs. This disease causes illness in piglets, with clinical signs including progressive loss of body condition, visibly enlarged lymph nodes, difficulty in breathing, and sometimes diarrhea, pale skin, and jaundice. PCVD is very damaging to the pig-producing industry and has been reported worldwide. PCVD is caused by porcine circovirus type 2 (PCV-2).
The North American industry endorses "PCVAD" and European use "PCVD" to describe this disease.
Antigen detection, polymerase chain reaction assay, virus isolation, and serology can be used to identify adenovirus infections. Adenovirus typing is usually accomplished by hemagglutination-inhibition and/or neutralization with type-specific antisera. Since adenovirus can be excreted for prolonged periods, the presence of virus does not necessarily mean it is associated with disease.
Because of the variability of symptoms, diagnosis is by laboratory testing. Blood samples, nasal swabs and semen can be used for isolation of the virus, detection of the viral RNA by polymerase chain reaction (PCR), and detection of antibodies by ELISA and virus neutralisation tests.
Pigs usually cough and may show more severe respiratory signs if secondary bacteria have invaded. This may lead to signs of pneumonia and systemic involvement.
Diagnosis relies on culture and isolation of the bacteria but this can be challenging.
PCR, ELISA, fluorescent antibody testing and post-mortem findings all help in making the diagnosis.
Definite diagnosis of brucellosis requires the isolation of the organism from the blood, body fluids, or tissues, but serological methods may be the only tests available in many settings. Positive blood culture yield ranges between 40% and 70% and is less commonly positive for "B. abortus" than "B. melitensis" or "B. suis". Identification of specific antibodies against bacterial lipopolysaccharide and other antigens can be detected by the standard agglutination test (SAT), rose Bengal, 2-mercaptoethanol (2-ME), antihuman globulin (Coombs’) and indirect enzymelinked immunosorbent assay (ELISA). SAT is the most commonly used serology in endemic areas. An agglutination titre greater than 1:160 is considered significant in nonendemic areas and greater than 1:320 in endemic areas. Due to the similarity of the O polysaccharide of "Brucella" to that of various other Gram-negative bacteria (e.g. "Francisella tularensis", "Escherichia coli", "Salmonella urbana", "Yersinia enterocolitica", "Vibrio cholerae", and "Stenotrophomonas maltophilia") the appearance of cross-reactions of class M immunoglobulins may occur. The inability to diagnose "B. canis" by SAT due to lack of cross-reaction is another drawback. False-negative SAT may be caused by the presence of blocking antibodies (the prozone phenomenon) in the α2-globulin (IgA) and in the α-globulin (IgG) fractions. Dipstick assays are new and promising, based on the binding of "Brucella" IgM antibodies, and found to be simple, accurate, and rapid. ELISA typically uses cytoplasmic proteins as antigens. It measures IgM, IgG, and IgA with better sensitivity and specificity than the SAT in most recent comparative studies. The commercial Brucellacapt test, a single-step immunocapture assay for the detection of total anti-"Brucella" antibodies, is an increasingly used adjunctive test when resources permit. PCR is fast and should be specific. Many varieties of PCR have been developed (e.g. nested PCR, realtime PCR and PCR-ELISA) and found to have superior specificity and sensitivity in detecting both primary infection and relapse after treatment. Unfortunately, these have yet to be standardized for routine use, and some centres have reported persistent PCR positivity after clinically successful treatment, fuelling the controversy about the existence of prolonged chronic brucellosis. Other laboratory findings include normal peripheral white cell count, and occasional leucopenia with relative lymphocytosis. The serum biochemical profiles are commonly normal.
A list of the more common and well-known diseases associated with infectious pathogens is provided and is not intended to be a complete listing.
Infectious pathogen-associated diseases include many of the most common and costly chronic illnesses. The treatment of chronic diseases accounts for 75% of all US healthcare costs (amounting to $1.7 trillion in 2009).
According to a study published in 2002, an estimated 10–13% of farm animals are infected with "Brucella" species. Annual losses from the disease were calculated to be around 60 million dollars. Since 1932, government agencies have undertaken efforts to contain the disease. Currently, all cattle of ages 3–8 months is required to be given the "Brucella abortus" strain 19 vaccine.
PBFD is usually acquired by nestlings from their parents (vertical transmission) or from other members of the flock (horizontal transmission). The immature immune system of young birds makes them susceptible to the PBFDV. The virus may be transferred in crop secretions, in fresh or dried feces, and in feather and skin particles.
Adult birds coming into contact with the virus usually (but not always) develop resistance to it, but the virus is retained in their body and, in most cases, is excreted in feces and feather debris for the rest of their lives.
Infections are treated with antibiotics, particularly doxycycline, and the acute symptoms appear to respond to these drugs.
Safe and effective adenovirus vaccines were developed for adenovirus serotypes 4 and 7, but were available only for preventing ARD among US military recruits, and production stopped in 1996. Strict attention to good infection-control practices is effective for stopping transmission in hospitals of adenovirus-associated disease, such as epidemic keratoconjunctivitis. Maintaining adequate levels of chlorination is necessary for preventing swimming pool-associated outbreaks of adenovirus conjunctivitis.
Treatment is symptomatic and aims to prevent dehydration in young pigs, using products such as electrolyte and energy supplements. Good biosecurity protocols such as adequate quarantine, isolation of cases, and disinfection help prevent entry or spread of the disease in the herd. In Canada, the Canadian Swine Health Board developed detailed protocols on how to adequately disinfect transportation vehicles for live hogs and ensure the quality of the disinfecttion protocol.
No serious long-term effects are known for this disease, but preliminary evidence suggests, if such symptoms do occur, they are less severe than those associated with Lyme disease.
In adult swine, the disease is very mild and mortalities are rare. The primary signs are a watery diarrhoea and mild systemic signs such as pyrexia, anorexia and lethargy.
Diagnosis is via immunofluorescence or immunohistochemistry, and ELISA can detect antigen or antibodies.
Truckloads or railcar loads of PSS-susceptible pigs may be found with a higher-than-average percentage dead on arrival after stressful events such as transport.
Initial signs of the onset of PSS are pyrexia, panting, sweating, tachycardia and arrhythmias. Chronic cases may show muscle atrophy.
Under halothane anaesthesia, pigs will suddenly become rigid and pyrexic.
The halothane challenge was the historical method of diagnosis.
Genetic testing via a PCR enables affected and carrier animals to be found.
Psychologist Melanie Joy has likened PSS to post-traumatic stress disorder in humans.
Removing the pig from the stressful situation can prevent the episode.
Sedation and glucocorticoids may be beneficial.
Under anaesthesia, dantrolene sodium is a very effective treatment.
Genetic testing enables animals to be removed from the herd if they are positive for the gene. This means that the disorder is rare in the developed world these days.
Stress at slaughter should be minimised in all cases.
Unlike most food allergies, it may be possible for the alpha-gal allergy to recede with time, as long as the person is not bitten by another tick. The recovery period can take anywhere from eight months to five years. This recovery potential is not confirmed. More research needs to be conducted to determine why some patients seem to recover and some do not.
This depends on the age of the animal affected and the efficiency of its immune system.
Colostral protection lasts up to 5 months of age, after which it decreases to an all-time low to increase yet again at about 12 months of age.
- Prenatal infection: virus travels from infected mother to fetus via the placenta. In this case, the time of gestation determines the result of the infection.
- If the fetus is infected in the first 30 days of fetal life, death and absorption of all, or some of the fetuses may occur. In this case, some immunotolerant healthy piglets may be born.
- If the infection happens at 40 days, death and mummification may occur. Also in this case, some or all the fetuses are involved, i.e. some of the fetuses can be born healthy and immunotolerant, or else carriers of the disease.
- If the viruses crosses the placenta in the last trimester, neonatal death may occur, or the birth of healthy piglets with a protective pre-colostral immunity.
- Postnatal infection (pigs up to 1 year of age): Infection occurs oro-nasally, followed by a viremic period associated with transitory leucopenia.
- Infection in adults (over 1 year of age): These subject would have an active, protective immune system which protects them from future exposures (e.g. mating with an infected male).
Therefore, it is important to note that the virus is particularly dangerous for the sow in her first gestation, which would be at 7–8 months of age, as she would have a particularly low antibody count at this age and could easily contract the virus via copulation.
A traditional skin prick allergy test for allergy to meat may give a false negative answer. Blood tests for IgE response indicating alpha-gal allergy have not been approved by the U.S. Food and Drug Administration (FDA), and must usually be purchased by private individuals, but are available and are in use. Determination of specific IgE to alpha-gal testing is commercially available. The highest sensitivity is observed with skin and basophil activation tests with cetuximab which is, however, limited by its high costs.