LUCRĂRI ŞTIINłIFICE MEDICINĂ VETERINARĂ VOL. XLIII (2), 2010 TIMIŞOARA
PULMONARY MORPHOPATHOLOGICAL CHANGES IN SWINE
INFECTIOUS PLEUROPNEUMONIA AND ASPECTS OF
HISTOPATHOLOGICAL DIAGNOSIS OF DISEASE
1
1
1
1
I. OLARIU-JURCA , M. COMAN , A. OLARIU-JURCA , A. STANCU , A.
1
2
LAZĂU , E. AVRAM
1
Faculty of Veterinary Medicine Timisoara, 300645, Calea Aradului No. 119,
Timisoara, Romania
2
DSVSA Satu-Mare
E-mail: olariu.jurca@fmvt.ro
Summary
From 112 bodies of pigs, aged 1.5-5 months, necropsied at the discipline of Legal
Medicine, between September 2008 in April 2009, 70 cases (62%), were
morphopathological diagnosed, with contagious pleuropneumonia.
Macroscopic and microscopic examination of lung parenchyma and the tracheobronchial and mediastinal lymphonodes were highlighted: 50 bodies with fibrinous pleuritis
and fibrino-hemorrhagic and/ or hemorrhagico-necrotic bronchopneumonia; fibroadhesive
pleuritis and fibrino-necrotic bronchopneumonia in 20 cases, in all cases were presented
serous inflammation of tracheo-bronchial and mediastinal lymph nodes.
Pulmonary lesions were identified in most cases in both lungs, affecting the face rib
of the diaphragmatic lobes, lesions that guide us in diagnosis.
Histopathological we noticed severe pulmonary vascular changes that favor
necrosis of lung parenchyma and appearance of sero-fibrinous or fibrino-hemorrhagic
exudate that floods affected areas.
In the alveolar lumen of the lung were present numerous oval or oblong
macrophages characteristic to swine infectious pleuropneumonia.
Key words: pig, infectious pleuropneumonia, pulmonary lesions
Pleuropneumonia caused by Actinobaccilus pleuropneumoniae is one of
the most serious, contagious and lethal respiratory disease that affects young
swine rose in intensive systems (2, 8, 11).
The lesions are located predominantly in the thoracic cavity and depend on
the disease form: in supraacute or acute evolution, lesions are represented by
serous or sero-fibrinous and/or fibrino-hemorrhagic exudates; hemorrhagic, fibrinohemorrhagic and hemorrhagico-necrotic bronchopneumonia, while in the subacute
and chronic evolution appears fibrinous or fibroadezive pleuropericarditis and
fibrino-necrotic bronchopneumonia (3, 5, 6, 10).
Lesions are quartered especially on the rib face of diaphragmatic lobes,
unilateral and / or bilateral, but also some cases present the inflammation of entire
lung parenchyma (10, 12).
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LUCRĂRI ŞTIINłIFICE MEDICINĂ VETERINARĂ VOL. XLIII (2), 2010, TIMIŞOARA
Materials and methods
Morphopathological research, macroscopic and microscopic exams, were
made following necropsy at the discipline of Forensic Medicine, from 112 bodies of
pigs, aged 1,5-5 months, from the farm with intensive growth in Timis County.
Following macroscopic examination of the lung, in 70 cases (62%) on the
costal face of diaphragmatic lobes, were noted lesions of hemorrhagic, fibrinohemorrhagic, hemorrhagico-necrotic and fibrino-necrotic bronchopneumonia. This
location of lesions guides us in diagnosis of swine infectious pleuropneumonia.
For histopathological confirmation of the necropsic diagnosis, we sampled
(tissue - 2 / 0, 5cm) of lymph nodes and tracheo-pulmonary lesions.
Samples were fixed in formaldehyde 10% soil, and then processed by
paraffin technique, sectioned at 6 µm and colored by the HEA method.
Histopathological samples obtained, were examined microscopically, with
increasing targets, interpreted and then the most characteristic lesions were microphotographed.
Results and discussions
At the external examination of the corpses we noted, in most cases, the
state of good maintenance, lack of skin elasticity, enoftalmy, skin cyanosis,
conjunctival and oral mucosa cyanosis.
At the internal examination, in the thoracic cavity we noted an appreciable
amount of sero-hemorrhagic exudates (500 ml) with rare floaters of fibrin.
Macroscopic, the lungs were increased in volume, with rounded edges and
tense pleura.
In 50 cases, aged 1.5-5 month, on the rib face of the diaphragmatic lobes,
the inspection and the section revealed numerous red-cherry, dry, compact areas
covered by an yellowish gray membrane and fibrinous exudates, fibrinohemorrhagic pleuro-bronchopneumonia.
In 20 cases, in both lungs, predominant on the face rib of diaphragmatic
lobes, were observed blackish red areas surrounded by a gray-white belt of
fibroconjuctival reaction. Section of affected area revealed color, aspect and
consistence changes (birch color, dry aspect and increased consistence).
Docimasia were positive.
Between parietal pleura and serous thoracic cavity were present adherent
membrane strongly anchored to the wall rib.
Microscopic examination revealed: pulmonary alveolar necrosis nearby
dilatated lymphatic vessels (Fig. 1); heads- looking cells in the lumen of alveoli
necrosis (Fig. 20; fibrino-hemorrhagic exudates in the lumen of pulmonary alveoli
and interstitium (perilobular) (Fig. 3); peeling respiratory epithelium; hypertrophied
pleura (Fig. 4); capillares of the alveolar septa were more dilated by conglutinate
platelets, red blood cells, granulocytes, neutrophils and microtrombosis (Fig. 5).
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LUCRĂRI ŞTIINłIFICE MEDICINĂ VETERINARĂ VOL. XLIII (2), 2010 TIMIŞOARA
These vascular changes favor local necrosis of pulmonary tissue, and flood
affected areas with sero-fibrinous and fibrino-necrotic exudates (Fig. 6). These
modified structural aspects, reported in the literature as characteristic to swine
infectious pleuropneumonia, are common in acute and subacute evolution of
disease and translated by fibrino-hemorrhagic and hemorrhagico-necrotic
bronchopneumonia (1, 4, 9).
Elongated/ellipsoidal shape of alveolar macrophages is due to exotoxins
action produced by Actinobacillus pleuropneumoniae and represents clear evidence
of histopahological diagnosis in swine infectious pleuropneumonia (2, 10, 12).
Fig. 1. Pulmonary alveolar necrosis
nearby dilatated lymphatic vessels.
HEA. x 100
Fig. 2. Heads-looking cells in the lumen
of alveoli necrosis. HEA x 400
Fig. 3. Fibrino- hemorrhagic exudates
in the lumen of pulmonary alveoli and
alveoli necrosis. HEA x 100
Fig. 4. Hypertrophied pleura, dilatated
lymphatic vessels and alveoli necrosis.
HEA x 100
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LUCRĂRI ŞTIINłIFICE MEDICINĂ VETERINARĂ VOL. XLIII (2), 2010, TIMIŞOARA
Fig. 5. Intravascular microtrombosis,
pulmonary alveolar necrosis and
alveolar emphysema. HEA x 100
Fig. 6. Fibrino-necrotic exudates in the
lumen of pulmonary alveoli. HEA x 100
Conclusions
Swine
infectious
pleuropneumonia
were
macroscopically
and
microscopically diagnosed, at 70 pigs (62%) aged 1.5-5 months from 112 corpses
necropsied at the Forensic Discipline.
In 50 cases the disease was acute or supracute and gross lesions
identified were represented by fibrinous and/ or fibrino-hemorrhagic pleuritis,
hemorrhagic and hemorrhagic–necrotic bronchopneumonia and serous tracheo
and mediastinal lymph nodes. Pleuritis and/or fibroadhesive pleuropericarditis and
fibrino-necrotic bronchopneumonia were observed in 20 cases of subacute and
chronic evolution.
Histopathological lesions observed were: hypertrophied pleura covered by
a cellular fibrin exudate; alveolar necrosis nearby lymph vessels dilated by the
accumulation of fibrin, blood elements and limph- monocytes; pulmonary alveoli
overloaded with heads-looking cells and fibrino-hemorrhagic exudates; respiratory
epithelium peeling, sharp demarcation of the lung lobes by a rich gap infiltrated with
a cellular fibrin exudate.
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