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Thursday, March 31, 2011

Bacterial Diseases RIEMERELLA ANATIPESTIFER INFECTIONS

Bacterial Diseases

RIEMERELLA ANATIPESTIFER INFECTIONS

Riemerella anatipestifer (RA) infection is a contagious disease in domestic ducks, turkeys and other fowl. It is encountered as acute or chronic septicaemia and is characterized with serous fibrinous polyserosites. The respiratory tract could be also affected. The ducklings at the age of 18 weeks are especially susceptible. Clinically, sneezing, cough, trembling of the head and neck, ataxia and greenish diarrhoea could be present. 82.Riemerella anatipestifer (RA) infection is a contagious disease in domestic ducks, turkeys and other fowl. It is encountered as acute or chronic septicaemia and is characterized with serous fibrinous polyserosites. The respiratory tract could be also affected. The ducklings at the age of 18 weeks are especially susceptible. Clinically, sneezing, cough, trembling of the head and neck, ataxia and greenish diarrhoea could be present.
 
The most characteristic gross lesion is the deposit of fibrinous exudate on the pericardium, the liver capsule or air sacs. The chronic lesions affect the skin and the joints. Although a tentative diagnosis could be made on the basis of observed clinical symptoms and lesions, it is confirmed upon the isolation and identification of RA. The RA infection should be distinguished from septicaemiae due to P. multocida, E. coli, Salmonella etc. The treatment with antibiotics (Flumequine) and sulfonamides IJrimetoprim, Sulfadiazine) has a varying success. 83. The most characteristic gross lesion is the deposit of fibrinous exudate on the pericardium, the liver capsule or air sacs. The chronic lesions affect the skin and the joints. Although a tentative diagnosis could be made on the basis of observed clinical symptoms and lesions, it is confirmed upon the isolation and identification of RA. The RA infection should be distinguished from septicaemiae due to P. multocida, E. coli, Salmonella etc. The treatment with antibiotics (Flumequine) and sulfonamides IJrimetoprim, Sulfadiazine) has a varying success.
 
Fig. 1. Fig. 1. 84. 85. Staphylococcus aureus infections are commonly seen in poultry. Usually, bones, tendon sheaths and joints, particularly coxofemoral and tibiotarsal joints are affected. The clinical signs include unilateral or bilateral lameness, reluctance to move and lying down. When the tibiotarsal joints are affected, swellings, fever and sometimes necroses of overlying tissues and purulent exudation are observed.
 
As a sequel to septicaemia, osteomyelitis could occur. The lesions are usually detected in the region of the proximal femur, where inflammatory necrotic foci in the bone marrow and partial or complete fracture of the femoral head are observed. As a sequel to septicaemia, osteomyelitis could occur. The lesions are usually detected in the region of the proximal femur, where inflammatory necrotic foci in the bone marrow and partial or complete fracture of the femoral head are observed. 86. 87.As a sequel to septicaemia, osteomyelitis could occur. The lesions are usually detected in the region of the proximal femur, where inflammatory necrotic foci in the bone marrow and partial or complete fracture of the femoral head are observed.
 
The outcomes of skin injuries are the appearance of cellulites, characterized by extensive purulent inflammation of the subcutaneous tissue. Most staphylococcal isolates are identified as Staphylococcus aureus, Gram-positive cocci, arranged in clusters. 88. The outcomes of skin injuries are the appearance of cellulites, characterized by extensive purulent inflammation of the subcutaneous tissue. Most staphylococcal isolates are identified as Staphylococcus aureus, Gram-positive cocci, arranged in clusters.
 
Plantar abscesses are a kind of local purulent inflammation. They are located on the plantar surface or adjacently to it and appear following puncture wounds. Staphylococci are moderately resistant to common disinfectants. Chlorine-containing disinfectants are efficient in the absence of organic matter. Plantar abscesses are a kind of local purulent inflammation. They are located on the plantar surface or adjacently to it and appear following puncture wounds. Staphylococci are moderately resistant to common disinfectants. Chlorine-containing disinfectants are efficient in the absence of organic matter. 89. 90. Plantar abscesses are a kind of local purulent inflammation. They are located on the plantar surface or adjacently to it and appear following puncture wounds. Staphylococci are moderately resistant to common disinfectants. Chlorine-containing disinfectants are efficient in the absence of organic matter.
 
. Other local forms of staphylococcosis are sternal bursites. The sternal bursa is enlarged at a various extent because of gathering of purulent substance. Sometimes, the covering skin is necrotized. The microorganism is widely distributed in the environment and mainly on the skin. Most of Staphylococcus oureus-induced lesions are associated with skin injuries, debeaking, finger cuts. All categories of birds are affected. Toxicogenic strains are able to induce food intoxications. . Other local forms of staphylococcosis are sternal bursites. The sternal bursa is enlarged at a various extent because of gathering of purulent substance. Sometimes, the covering skin is necrotized. The microorganism is widely distributed in the environment and mainly on the skin. Most of Staphylococcus oureus-induced lesions are associated with skin injuries, debeaking, finger cuts. All categories of birds are affected. Toxicogenic strains are able to induce food intoxications. 91. 92.. Other local forms of staphylococcosis are sternal bursites. The sternal bursa is enlarged at a various extent because of gathering of purulent substance. Sometimes, the covering skin is necrotized. The microorganism is widely distributed in the environment and mainly on the skin. Most of Staphylococcus oureus-induced lesions are associated with skin injuries, debeaking, finger cuts. All categories of birds are affected. Toxicogenic strains are able to induce food intoxications.
 
In a septicaemic staphylococcal infection, hyperaemia, enlargement and various-degree coagulation necroses in the liver or the spleen are observed. As staphylococci are ubiquitous, their presence could not be prevented. The measures should be directed toward minimizing the possibilities for traumas of skin, respiratory and intestinal mucosa. 93. In a septicaemic staphylococcal infection, hyperaemia, enlargement and various-degree coagulation necroses in the liver or the spleen are observed. As staphylococci are ubiquitous, their presence could not be prevented. The measures should be directed toward minimizing the possibilities for traumas of skin, respiratory and intestinal mucosa.
 
A typical secondary infection is staphylococcal gangrenous dermatitis that is usually resulting from immunosuppressive infections (IBD, CIA). Affected skin areas are dark red to blue-greenish, moist and sharply defined from the adjacent healthy skin. 94. A typical secondary infection is staphylococcal gangrenous dermatitis that is usually resulting from immunosuppressive infections (IBD, CIA). Affected skin areas are dark red to blue-greenish, moist and sharply defined from the adjacent healthy skin.
 
Histologically, staphylococcal lesions consist of necroses, bacterial colonization and heterophilic infiltration. The isolation and identification of Staphylococcus spp. confirms the diagnosis. From a differential diagnostical point of view, infections with E. coli, S. gallinarum, P. multocida, M. synoviae and reoviruses should be considered. 95. Histologically, staphylococcal lesions consist of necroses, bacterial colonization and heterophilic infiltration. The isolation and identification of Staphylococcus spp. confirms the diagnosis. From a differential diagnostical point of view, infections with E. coli, S. gallinarum, P. multocida, M. synoviae and reoviruses should be considered.
 
. Streptococcosis in poultry is encountered as acute septicaemia or chronic infections with a death rate between 0.5 and 50%. The agent that is most commonly associated with several pathological conditions in poultry is 5. zooepidemicus. The lesions in chronic streptococcal infections include arthrites, tenosynovites, myocardites and valve endocardites. Endocardites affect predominantly mitral valves and less frequently, aortal and tricuspid valves. 96. . Streptococcosis in poultry is encountered as acute septicaemia or chronic infections with a death rate between 0.5 and 50%. The agent that is most commonly associated with several pathological conditions in poultry is 5. zooepidemicus. The lesions in chronic streptococcal infections include arthrites, tenosynovites, myocardites and valve endocardites. Endocardites affect predominantly mitral valves and less frequently, aortal and tricuspid valves.
 
Other lesions related to endocardites, are heart, liver and spleen infarctions. Liver infarctions are usually peripherally located on margins, have a pale creamy colour and are sharply demarcated. The penetration of the infection occurs mainly via the oral or aerogenic route, but could also enter through the injured skin, especially in battery cage layer hens. The differential diagnosis includes other bacterial septicaemias as staphylococcosis, fowl cholera, E. coli infections etc.. Other lesions related to endocardites, are heart, liver and spleen infarctions. Liver infarctions are usually peripherally located on margins, have a pale creamy colour and are sharply demarcated. The penetration of the infection occurs mainly via the oral or aerogenic route, but could also enter through the injured skin, especially in battery cage layer hens. The differential diagnosis includes other bacterial septicaemias as staphylococcosis, fowl cholera, E. coli infections etc.. 97. 98. Other lesions related to endocardites, are heart, liver and spleen infarctions. Liver infarctions are usually peripherally located on margins, have a pale creamy colour and are sharply demarcated. The penetration of the infection occurs mainly via the oral or aerogenic route, but could also enter through the injured skin, especially in battery cage layer hens. The differential diagnosis includes other bacterial septicaemias as staphylococcosis, fowl cholera, E. coli infections etc.

Bacterial Diseases FOWL CHOLERA

Bacterial Diseases

FOWL CHOLERA

. Fowl cholera is an infectious disease in domestic fowl, waterfowl and other avian species. It is manifested either in acute septicaemic form with a high morbidity and death rates or as chronic local forms (independently or secondary to acute ones). Acute fowl cholera. The sudden and unexpected death could be the first sign of the disease. In this form, the lesions are predominantly related to vascular injuries. . Fowl cholera is an infectious disease in domestic fowl, waterfowl and other avian species. It is manifested either in acute septicaemic form with a high morbidity and death rates or as chronic local forms (independently or secondary to acute ones). Acute fowl cholera. The sudden and unexpected death could be the first sign of the disease. In this form, the lesions are predominantly related to vascular injuries. 68. 69.. Fowl cholera is an infectious disease in domestic fowl, waterfowl and other avian species. It is manifested either in acute septicaemic form with a high morbidity and death rates or as chronic local forms (independently or secondary to acute ones). Acute fowl cholera. The sudden and unexpected death could be the first sign of the disease. In this form, the lesions are predominantly related to vascular injuries.
 
Commonly observed signs are anorexia, ruffled feathers, oral and nasal mucus discharge, cyanosis and white or greenish watery mucoid diarrhoea. Frequently, subserous petechial or ecchymosed haemorrhages in the anterior part of the small intestine, the gizzard or the abdominal fat are discovered. 70. Commonly observed signs are anorexia, ruffled feathers, oral and nasal mucus discharge, cyanosis and white or greenish watery mucoid diarrhoea. Frequently, subserous petechial or ecchymosed haemorrhages in the anterior part of the small intestine, the gizzard or the abdominal fat are discovered.
 
. In the liver, multiple milliary or submilliary necroses are present. Fowl cholera is encountered sporadically or enzootically, sometimes with a high mortality, sometimes yet the losses are insignificant. The disease prevails during the late summer, the autumn and the winter. The affected birds are in the period of sexual maturation or older. The aetiological agent is Pasteurella multocida, a Gram-negative micro¬organism with bipolar staining, growing easily on blood agar, but not on McConkey's agar. The virulence of isolates varies considerably. P. multocida is easily killed by routine disinfectants. . In the liver, multiple milliary or submilliary necroses are present. Fowl cholera is encountered sporadically or enzootically, sometimes with a high mortality, sometimes yet the losses are insignificant. The disease prevails during the late summer, the autumn and the winter. The affected birds are in the period of sexual maturation or older. The aetiological agent is Pasteurella multocida, a Gram-negative micro¬organism with bipolar staining, growing easily on blood agar, but not on McConkey's agar. The virulence of isolates varies considerably. P. multocida is easily killed by routine disinfectants. 71. 72. Congestion (overfilling of blood vessels with red blood cells) of the liver as an initial manifestation of E. coli septicaemia in a broiler chicken. H/E, Bar = 40 µm.
 
In layers (commercial or breeders), acute oophorites with regressing follicles and consequently, diffuse peritonites are commonly observed. 73.In layers (commercial or breeders), acute oophorites with regressing follicles and consequently, diffuse peritonites are commonly observed.
 
Chronic fowl cholera.  It is characterized by local inflammations. The periorbital sinuses are frequently affected by a serofibrinous inflammation. 74. Chronic fowl cholera. It is characterized by local inflammations. The periorbital sinuses are frequently affected by a serofibrinous inflammation.
 
Another local form is the injury of wattles that are strongly distended because of their filling with fibrinous caseous content. The flocks that recuperated from fowl cholera continue to carry and shed Pasteurella multocida. The carriers store the organism in nasal choanas and contaminate the forage, water and the environment with oral discharges. Wild birds and some mammals (swine) could also carry the agent and introduce it into poultry flocks. Cannibalism is an essential route of spreading the infection. Another local form is the injury of wattles that are strongly distended because of their filling with fibrinous caseous content. The flocks that recuperated from fowl cholera continue to carry and shed Pasteurella multocida. The carriers store the organism in nasal choanas and contaminate the forage, water and the environment with oral discharges. Wild birds and some mammals (swine) could also carry the agent and introduce it into poultry flocks. Cannibalism is an essential route of spreading the infection. FAnother local form is the injury of wattles that are strongly distended because of their filling with fibrinous caseous content. The flocks that recuperated from fowl cholera continue to carry and shed Pasteurella multocida. The carriers store the organism in nasal choanas and contaminate the forage, water and the environment with oral discharges. Wild birds and some mammals (swine) could also carry the agent and introduce it into poultry flocks. Cannibalism is an essential route of spreading the infection. 75. 76. 77. Another local form is the injury of wattles that are strongly distended because of their filling with fibrinous caseous content. The flocks that recuperated from fowl cholera continue to carry and shed Pasteurella multocida. The carriers store the organism in nasal choanas and contaminate the forage, water and the environment with oral discharges. Wild birds and some mammals (swine) could also carry the agent and introduce it into poultry flocks. Cannibalism is an essential route of spreading the infection.
 
In turkeys a common finding is the unilateral or bilateral croupous pleuropneumonia 78. In turkeys a common finding is the unilateral or bilateral croupous pleuropneumonia
 
the fibrinous caseous exuate accumilated in wattles sometimes leads to gangrene of the covering skin. 79. the fibrinous caseous exuate accumilated in wattles sometimes leads to gangrene of the covering skin.
 
possibly be spread from sinuses to adjacent air-filled skull bones with subsequent necrosis and onset of neurological signs (opisthotonus and torticolis). The diagnosis is made on the basis of disease history, clinical signs, the lesions and the results of bacteriological studies. Fowl cholera should be differentiated from acute E. coli septicaemia, erysipeloid, fowl typhoid etc. The immunization of birds at the age of 8 -12 weeks gives very promising results. Many antibiotics and sulfonamides could lower death rate, but at discontinuation of the treatment, the disease could recur. Sulfonamides are appropriate for treatment, but they inhibit egg-laying. possibly be spread from sinuses to adjacent air-filled skull bones with subsequent necrosis and onset of neurological signs (opisthotonus and torticolis). The diagnosis is made on the basis of disease history, clinical signs, the lesions and the results of bacteriological studies. Fowl cholera should be differentiated from acute E. coli septicaemia, erysipeloid, fowl typhoid etc. The immunization of birds at the age of 8 -12 weeks gives very promising results. Many antibiotics and sulfonamides could lower death rate, but at discontinuation of the treatment, the disease could recur. Sulfonamides are appropriate for treatment, but they inhibit egg-laying. 80. 81. possibly be spread from sinuses to adjacent air-filled skull bones with subsequent necrosis and onset of neurological signs (opisthotonus and torticolis). The diagnosis is made on the basis of disease history, clinical signs, the lesions and the results of bacteriological studies. Fowl cholera should be differentiated from acute E. coli septicaemia, erysipeloid, fowl typhoid etc. The immunization of birds at the age of 8 -12 weeks gives very promising results. Many antibiotics and sulfonamides could lower death rate, but at discontinuation of the treatment, the disease could recur. Sulfonamides are appropriate for treatment, but they inhibit egg-laying.

Bacterial Diseases PARATYPHOID INFECTIONS

Bacterial Diseases

PARATYPHOID INFECTIONS

Fig. 1. Congestion (overfilling of blood vessels with red blood cells) of the liver as an initial manifestation of E. coli septicaemia in a broiler chicken. H/E, Bar = 40 µm. 53. Fowl paratyphoid is an acute or chronic disease in domestic fowl and many other avian or mammalian species, caused by some motile Salmonella serotypes that are not host-specific. The highest morbidity and death rates are usually observed during the first 2 weeks after hatching. The chickens are drowsy, with eyes closed, ruffled feathers and grouped near the sources of heat.
 
Diarrhoea, dehydration and pasted down appearance around the vent are observed. Pathoana-tomically, marked catarrhal haemorrhagic enteritis is observed. Often the caeca are filled with gelatinous, fibrinous, cheese-like exudate. This is a finding, characteristic for salmonellosis, but it is not specific for any of serotypes. 54. Diarrhoea, dehydration and pasted down appearance around the vent are observed. Pathoana-tomically, marked catarrhal haemorrhagic enteritis is observed. Often the caeca are filled with gelatinous, fibrinous, cheese-like exudate. This is a finding, characteristic for salmonellosis, but it is not specific for any of serotypes.
 
The inflammatory fibrinous exudate in caeca often forms casts with the shape of mucosal folds. The aetiological agents are about 10 - 15 Salmonella serotypes and the most common isolates are S. Enteritidis and 5. Typhimurium. Most fowl paratyphoid organisms contain an endotoxin, responsible for their pathogenic effects. 55. The inflammatory fibrinous exudate in caeca often forms casts with the shape of mucosal folds. The aetiological agents are about 10 - 15 Salmonella serotypes and the most common isolates are S. Enteritidis and 5. Typhimurium. Most fowl paratyphoid organisms contain an endotoxin, responsible for their pathogenic effects.
 
 Sometimes, necrotic foci in the liver are discovered. The infection of small chickens occurs by penetration of microorganisms into the egg after faecal contamination. The transmission of agents could be done also by a contaminated source of animal protein (meat and bone meal etc.). The rodents are a significant reservoir of paratyphoid microorganisms. The treatment inhibits but does not eradicate the infection. The appropriate treatment minimizes the death rate until the birds develop immunity. 56. . Sometimes, necrotic foci in the liver are discovered. The infection of small chickens occurs by penetration of microorganisms into the egg after faecal contamination. The transmission of agents could be done also by a contaminated source of animal protein (meat and bone meal etc.). The rodents are a significant reservoir of paratyphoid microorganisms. The treatment inhibits but does not eradicate the infection. The appropriate treatment minimizes the death rate until the birds develop immunity.
 
 P. aeruginosa infection via a contaminated injectable Marek's vaccine. About 24h after the vaccination, nervous signs are appearing: incoordination, ataxia, unilateral lameness (if the vaccination is manual). Automatically vaccinated chickens exhibit subcutaneous oedemas in the region of the neck, sometimes involving the head. 57. . P. aeruginosa infection via a contaminated injectable Marek's vaccine. About 24h after the vaccination, nervous signs are appearing: incoordination, ataxia, unilateral lameness (if the vaccination is manual). Automatically vaccinated chickens exhibit subcutaneous oedemas in the region of the neck, sometimes involving the head.
 
 The overlying skin is often macerated and the down-fallen and easily detached with the superficial epidermal layer. Most commonly, the Pseudomonas infection originates from hatcheries. 58. The overlying skin is often macerated and the down-fallen and easily detached with the superficial epidermal layer. Most commonly, the Pseudomonas infection originates from hatcheries.
 
Subcutaneously, serous or haemorrhagic oedemas are detected. P. aeruginosa is a motile. Gram-negative, non-sporing rod. The microorganism is an aerobe, grows on ordinary bacteriological media and produces a green pigment composed by fluorescein & pyocyanin that has a characteristic fruity odour. 59. Subcutaneously, serous or haemorrhagic oedemas are detected. P. aeruginosa is a motile. Gram-negative, non-sporing rod. The microorganism is an aerobe, grows on ordinary bacteriological media and produces a green pigment composed by fluorescein & pyocyanin that has a characteristic fruity odour.
 
A subcutaneous haemorrhagic oedema in the region of the neck about the site of MD vaccine application.  P. aeruginosa is widely distributed in the soil, water and the environment. The high humidity favours its development. Susceptible avian species are chickens, turkeys, pheasants, ducks, goose, ostriches and exotic birds. 60. A subcutaneous haemorrhagic oedema in the region of the neck about the site of MD vaccine application. P. aeruginosa is widely distributed in the soil, water and the environment. The high humidity favours its development. Susceptible avian species are chickens, turkeys, pheasants, ducks, goose, ostriches and exotic birds.
 
Sometimes, subcutaneous haemorrhages in the muscles are present 61. Sometimes, subcutaneous haemorrhages in the muscles are present
 
In the liver, hyperaemia, subcapsular haemorrhages and dystrophy are detected. 62 In the liver, hyperaemia, subcapsular haemorrhages and dystrophy are detected.
 
Acute septicaemic P. aeruginosa infection.  Serofibrinous inflammation of serous membranes in the pleuroperitoneal cavity (aerosacculitis, pericarditis, and perihepatitis) is detected. The lesions strongly resemble (imitate) these observed in E. coli septicaemia 63.Acute septicaemic P. aeruginosa infection. Serofibrinous inflammation of serous membranes in the pleuroperitoneal cavity (aerosacculitis, pericarditis, and perihepatitis) is detected. The lesions strongly resemble (imitate) these observed in E. coli septicaemia
 
Local P. aeruginosa infections.  They are encountered secondary to septicaemia or independently. Pododermatitis and inflamed footpad are usually observed in broilers at the age of 7 -14 days. 64. Local P. aeruginosa infections. They are encountered secondary to septicaemia or independently. Pododermatitis and inflamed footpad are usually observed in broilers at the age of 7 -14 days.
 
Other local forms of P. aeruginosa infection are conjunctivites and consequent keratites and panophthalmrtes 65. Other local forms of P. aeruginosa infection are conjunctivites and consequent keratites and panophthalmrtes
 
Arthrrtes and periarthrites are encountered in broilers as well as in growing birds. Tibiotarsal joints are most commonly affected. The skin and the mucous coats are the entrance door of the infection. The prevention is based upon detection and elimination of the causative agent. The strict hygiene in hatcheries and throughout the injection of birds is essential for the prevention of Pseudomonas infection. The test of isolates1 sensitivity is of most importance for the treatment, because the microorganism is resistant to a high number of antimicrobial drugs. Arthrrtes and periarthrites are encountered in broilers as well as in growing birds. Tibiotarsal joints are most commonly affected. The skin and the mucous coats are the entrance door of the infection. The prevention is based upon detection and elimination of the causative agent. The strict hygiene in hatcheries and throughout the injection of birds is essential for the prevention of Pseudomonas infection. The test of isolates1 sensitivity is of most importance for the treatment, because the microorganism is resistant to a high number of antimicrobial drugs. 66. 67. Arthrrtes and periarthrites are encountered in broilers as well as in growing birds. Tibiotarsal joints are most commonly affected. The skin and the mucous coats are the entrance door of the infection. The prevention is based upon detection and elimination of the causative agent. The strict hygiene in hatcheries and throughout the injection of birds is essential for the prevention of Pseudomonas infection. The test of isolates1 sensitivity is of most importance for the treatment, because the microorganism is resistant to a high number of antimicrobial drugs.

Bacterial Diseases SALMONELLOSES

Bacterial Diseases

SALMONELLOSES

Pullorum disease is an acute systemic disease in chickens and turkey poults. The infection is trans¬mitted with eggs and is commonly characterized by a white diarrhoea and high death rate, whereas adult birds are asymptomatic earners. The morbidity and the mortality rates increase about the 7th - 10th day after hatching. The affected chickens appear somnolent, depressed and their growth is retarded. The feathers around the vent in many chickens is stained with diarrhoeic faeces or pasted with dry faeces. 36, 37. Pullorum disease is an acute systemic disease in chickens and turkey poults. The infection is trans¬mitted with eggs and is commonly characterized by a white diarrhoea and high death rate, whereas adult birds are asymptomatic earners. The morbidity and the mortality rates increase about the 7th - 10th day after hatching. The affected chickens appear somnolent, depressed and their growth is retarded. The feathers around the vent in many chickens is stained with diarrhoeic faeces or pasted with dry faeces. 36. 37. Pullorum disease is an acute systemic disease in chickens and turkey poults. The infection is trans¬mitted with eggs and is commonly characterized by a white diarrhoea and high death rate, whereas adult birds are asymptomatic earners. The morbidity and the mortality rates increase about the 7th - 10th day after hatching. The affected chickens appear somnolent, depressed and their growth is retarded. The feathers around the vent in many chickens is stained with diarrhoeic faeces or pasted with dry faeces.
 
The oedema of tibiotarsal joints is a frequent associated sign. Pullorum disease is widely distributed among all age groups of chickens and turkeys. The highest losses are in birds under the age of 4 weeks. 38. The oedema of tibiotarsal joints is a frequent associated sign. Pullorum disease is widely distributed among all age groups of chickens and turkeys. The highest losses are in birds under the age of 4 weeks.
 
The aetiological agent is S. pullorum, a non-motile Gram-negative microorganism. S. pullorum is very resistant under moderate climatic conditions and could survive for months. It could be killed by fumigation with formaldehyde of breeder eggs in the hatchery. Typical for this form are the greyish-whitish nodes in one or some of the following places: heart (39), lungs, liver, gizzard walls (40) and intestines, the peritoneum. The aetiological agent is S. pullorum, a non-motile Gram-negative microorganism. S. pullorum is very resistant under moderate climatic conditions and could survive for months. It could be killed by fumigation with formaldehyde of breeder eggs in the hatchery. Typical for this form are the greyish-whitish nodes in one or some of the following places: heart (39), lungs, liver, gizzard walls (40) and intestines, the peritoneum. 39. 40. The aetiological agent is S. pullorum, a non-motile Gram-negative microorganism. S. pullorum is very resistant under moderate climatic conditions and could survive for months. It could be killed by fumigation with formaldehyde of breeder eggs in the hatchery. Typical for this form are the greyish-whitish nodes in one or some of the following places: heart (39), lungs, liver, gizzard walls (40) and intestines, the peritoneum.
 
Sometimes, greyish-whitish milliary necroses are found out in the liver. S. pullorum is transmitted by infected eggs of layer hens that are carriers. Many hatched infected chickens spread the microorganism by a horizontal route to other birds via the gastrointestinal and the urinary tracts. Adult carrier birds also spread the agent through their excreta. Sometimes, greyish-whitish milliary necroses are found out in the liver. S. pullorum is transmitted by infected eggs of layer hens that are carriers. Many hatched infected chickens spread the microorganism by a horizontal route to other birds via the gastrointestinal and the urinary tracts. Adult carrier birds also spread the agent through their excreta.
 
 Ureters are often filled with urates. For confirmation of the diagnosis, 5. pullorum should be isolated and typed. Pullorum disease must be differentiated from other salmonelloses, E. coli infections, Aspergillus that produces similar pulmonary lesions. Staphylococcus aureus, causing arthrites etc. Sometimes, the pulmonary nodes resemble the tumours in Marek's disease. 42. Ureters are often filled with urates. For confirmation of the diagnosis, 5. pullorum should be isolated and typed. Pullorum disease must be differentiated from other salmonelloses, E. coli infections, Aspergillus that produces similar pulmonary lesions. Staphylococcus aureus, causing arthrites etc. Sometimes, the pulmonary nodes resemble the tumours in Marek's disease.
 
Acute fowl typhoid.  The outbreaks usually begin with a sharp decline in forage consumption and egg production. The fertilization and hatchability rates are considerably reduced. Diarrhoea appears. The death rate in acute fowl typhoid is high and varies between 10% and 90%. About 1/3 of chickens hatched from eggs from typhoid-infected flocks die. A characteristic lesion for acute fowl typhoid in adult birds is the enlarged and bronze greenish tint of liver. 43. Acute fowl typhoid. The outbreaks usually begin with a sharp decline in forage consumption and egg production. The fertilization and hatchability rates are considerably reduced. Diarrhoea appears. The death rate in acute fowl typhoid is high and varies between 10% and 90%. About 1/3 of chickens hatched from eggs from typhoid-infected flocks die. A characteristic lesion for acute fowl typhoid in adult birds is the enlarged and bronze greenish tint of liver.
 
. Acute fowl typhoid.  In some instances, the enlarged liver is mottled with multiple milliary necroses. The outbreaks are observed primarily in hens and turkeys, but the disease is sometimes encountered in other domestic or wild fowl. . 44. . Acute fowl typhoid. In some instances, the enlarged liver is mottled with multiple milliary necroses. The outbreaks are observed primarily in hens and turkeys, but the disease is sometimes encountered in other domestic or wild fowl.
 
Acute fowl typhoid.  In other cases, the size of liver necroses varies from milliary to spots with a diameter of 1 - 2 cm. Unlike pullorum disease, fowl typhoid is lasting for months. 45. Acute fowl typhoid. In other cases, the size of liver necroses varies from milliary to spots with a diameter of 1 - 2 cm. Unlike pullorum disease, fowl typhoid is lasting for months.
 
. Acute fowl typhoid.  The spleen is 2-3 times bigger, sometimes with greyish-whitish nodules prominating on the surface, representing hyperplasic follicles. 46. Acute fowl typhoid. The spleen is 2-3 times bigger, sometimes with greyish-whitish nodules prominating on the surface, representing hyperplasic follicles.
 
Acute fowl typhoid.  Often, enteritis, especially of the anterior part of small intestine, sometimes with ulcerations, is present. The aetiological agent is Salmonella gallinarum. This organism usually shares common antigens with 5. pullorum and the two microorganisms often give a cross-agglutination reaction. 47. Acute fowl typhoid. Often, enteritis, especially of the anterior part of small intestine, sometimes with ulcerations, is present. The aetiological agent is Salmonella gallinarum. This organism usually shares common antigens with 5. pullorum and the two microorganisms often give a cross-agglutination reaction.
 
Acute fowl typhoid.  More rarely, myocardial necroses due to Salmonella toxins are detected. The transmission of the infection by contaminated eggs is especially important. Moreover, the transmission of 5. gallinarum occurs mainly among growing or productive flocks and the death rate among adult birds is higher. 48. Acute fowl typhoid. More rarely, myocardial necroses due to Salmonella toxins are detected. The transmission of the infection by contaminated eggs is especially important. Moreover, the transmission of 5. gallinarum occurs mainly among growing or productive flocks and the death rate among adult birds is higher.
 
Acute fowl typhoid.  The lungs acquire a characteristic brown colour. Here, necroses and, following their organization, „sarcoma-like nodules 49. Acute fowl typhoid. The lungs acquire a characteristic brown colour. Here, necroses and, following their organization, „sarcoma-like nodules"
 
Chronic fowl typhoid.  The lesions are primarily in the gonads. The ovaries are affected by inflammatory and degenerative changes. 50. Chronic fowl typhoid. The lesions are primarily in the gonads. The ovaries are affected by inflammatory and degenerative changes.
 
Chronic fowl typhoid.  Frequently, affected follicles are deformed and appear like thick pendulating masses. Fowl typhoid should be differentiated from other salmonelloses, E. coli infections, Pasteurella spp. infections etc. If breeder flocks are proved to be carriers of the infection, their eggs should not be used for breeding. 51 Chronic fowl typhoid. Frequently, affected follicles are deformed and appear like thick pendulating masses. Fowl typhoid should be differentiated from other salmonelloses, E. coli infections, Pasteurella spp. infections etc. If breeder flocks are proved to be carriers of the infection, their eggs should not be used for breeding.
 
52. Chronic fowl typhoid. Sometimes, the going out of yolk from degenerated follicles results in fibrinous adhesive peritonitis. Taking into consideration that chemotherapy does not eliminate the carriership, the treatment of poultry infected with fowl typhoid or pullorum disease is not justified and is never recommended.