- 1 -
Post Mortem Pathology /
Bovine Diseases
/
Dr. Saevan Saad Al-Mahmood
1. ACTINOBACILLOSIS
Definition
Infectious disease caused by bacteria named
Actinobacillus lignieresii
is
responsible for the
wooden tongue
disease characterized by the presence of
granulomas with pus containing small, hard yellow to white granules known as
sulfur granules
.
Clinical signs
Mainly affects tongue lymph nodes of the head and neck. The characteristic
lesion is a granuloma of the tongue, with discharge of pus to the exterior. Infection
usually begins as an acute inflammation with sudden onset of inability to eat or
drink for several days, drooling saliva, rapid loss of condition, painful and
swollen tongue nodules and ulcers on the tongue. Animals may occasionally die
from starvation and thirst in the acute stages of the disease. As the infection
becomes chronic, fibrous tissue is deposited and the tongue becomes shrunken
and immobile and eating is difficult
Post-mortem findings
Animals will often be in poor condition with granulomatous lesions
containing pus seen in and around the mouth. There are ulcers up to 1 cm in
diameter. Encapsulated abscesses found in local lymph nodes. In chronic cases
there is fibrous connective tissue proliferation and hardening and distortion of the
tongue.
Differential diagnosis
1-Actinomyces bovis.
2-Staphylococci spp.
3-Streptococci spp.
4-Corynebacterium pyogenes.
- 2 -
Post Mortem Pathology /
Bovine Diseases
/
Dr. Saevan Saad Al-Mahmood
2. ANAPLASMOSIS
Definition
A fever disease caused
Anaplasma marginale
and
Anaplasma centrale
. It is
characterized by initial high fever and progressive anemia then death.
Clinical signs
1- Sudden increasing temperatures.
2- Anemia, weakness and respiratory distress.
3- Jaundice and frequently a marked loss of condition.
4- Urine is often brown due to the presence of bile pigments.
5- Severely affected animals die.
Post-mortem findings
Gross pathology findings are due to anemia and resulting anoxia. These
include pale and often jaundiced tissues, watery blood and an enlarged spleen
with a soft reddish-brown pulp, liver is also enlarged, yellow-brown in color.
Differential diagnosis
1-Babesiosis.
2-Leptospirosis.
3-Bacillary haemaglobinuria.
4-Rapeseed poisoning.
5-Eperythrozoonosis.
6-Chronic copper poisoning.
- 3 -
Post Mortem Pathology /
Bovine Diseases
/
Dr. Saevan Saad Al-Mahmood
3. CONTAGIOUS BOVINE PLEUROPNEUMONIA
Definition
Is an acute, sub-acute or chronic respiratory disease of cattle caused by a
Mycoplasma called
Mycoplasma mycoides mycoides
.
Clinical signs
1- Acute form: Fever (41.5°C), loss of appetite, and depression, rapid abdominal
respiration, epistaxis, purulent or mucoid nasal discharges progressing to
coughing and chest pain, sometimes abortions and stillbirths.
2- Sub-acute and Chronic form: Slight rise in temperature, loss of condition,
respiratory problems.
Post-mortem findings
1- Acute cases: severe pneumonia with copious (up to 30L) yellow exudates. One
or both lungs may be completely consolidated with a characteristic ‘
marbled’
appearance
. Affected areas are pink to dark red, swollen with a firm
consistency.
2- Sub-acute and Chronic cases: necrotic lung tissue becomes encapsulated.
Pleural adhesions are common.
Differential diagnosis
- In the Acute form:
1-Pleuropneumonia and bronchopneumonia.
2-East Coast Fever.
3-Traumatic pericarditis.
- In the Sub-acute and chronic form:
1-Hydatid cyst.
2-Actinobacillosis.
3-Tuberculosis.
4-Bovine farcy.
- 4 -
Post Mortem Pathology /
Bovine Diseases
/
Dr. Saevan Saad Al-Mahmood
4. MALIGNANT CATARRHAL FEVER (MCF)
Definition
Acute disease of bovine caused by two virus
alcephaline hepesvirus (AHV-
1)
or
ovine herpesvirus-2 (OvHV-2)
this
disease characterized by fever, high
mortality and catarrhal inflammation.
Clinical signs
The acute form is called
Head and eyes form
and include high fever (40-
42°c) and anorexia, weakness, erosion of the buccal mucosa, adenopathy,
purulent nasal discharge, dyspnea, keratoconjonctivitis with progressive opacity
of the cornea and ophthalmic, encephalitis with neurological disorders.
The per-acute form is called the
intestinal form
, it is marked by a liquid and
hemorrhagic diarrhea. The ophthalmic signs are milder and the death occurs in 1-
3 days.
Post-mortem findings
Hemorrhage and erythema in the mouth, nasal cavities and pharynx, erosion
of cheek, longitudinal shallow erosions on the esophagus, liver is swollen,
petechial hemorrhage in the brain and meninges.
Differential diagnosis
1-Bovine Virus Diarrhea/Mucosal Disease.
2-IBR.
3-Rinderpest.
4-Pneumonic pasteurellosis.
5-Photosensitive dermatitis.
- 5 -
Post Mortem Pathology /
Bovine Diseases
/
Dr. Saevan Saad Al-Mahmood
5. RINDERPEST
Definition
Also known as
cattle plague
, it’s an acute highly contagious disease of cattle
caused by a
Morbillivirus
. In its acute form it is characterized by inflammation
and necrosis of mucous membranes and a very high mortality rate.
Clinical signs
Sudden onset of fever (41.5 °C), depression and loss of appetite, congestion
of the visible mucosal surfaces, watery discharges from the eyes and nose, loss
of milk production in dairy animals, necrotic lesions on mucous membranes of
the mouth nostrils, diarrhea starts about two days after appearance of mucosal
lesions. Feces are profuse, dark, fetid and may contain mucus, blood and necrotic
mucosa.
Post-mortem findings
1-Dehydrated carcass with fecal staining of the legs.
2-Erosions of the mucosa in the mouth, pharynx and esophagus.
3-Mucopurulent nasal exudate.
4-Congestion, edema and erosion of the abomasa mucosa.
5-Necrotic Payer’s patches with severe congestion, ulceration and
hemorrhages in the large intestine ‘
tiger striping
’ hemorrhages of the
longitudinal folds of the large intestine.
Differential diagnosis
1-Mucosal disease.
2-Malignant catarrhal fever.
3-Infectious bovine rhinotracheitis.
4-Foot-and-mouth disease.
5-Vesicular stomatitis.
6-Paratuberculosis.
7-Arsenic poisoning.
- 6 -
Post Mortem Pathology /
Bovine Diseases
/
Dr. Saevan Saad Al-Mahmood
6. THEILERIOSIS
Definition
This parasite cause serious disease of Bovidae due to the infection by the
protozoa:
1-
Theileria parva
causing
East Coast Fever
(ECF)
2-
Theileria annulata
causing
Tropical Theileriosis
or
Mediterranean Coast Fever
(MCF)
Clinical signs
Augmentation of lymph nodes, high fever and anorexia, drop in milk yield,
nasal and ocular discharge, dyspnea, diarrhea, emaciation, weakness and
recumbency. The skin is thicker and covered with cutaneous ulcers with petechial
hemorrhage and abortion are commonly observed.
Post-mortem findings
Massive pulmonary edema, hyperemia, emphysema, enlargement of lymph
nodes and spleen, ulceration of the abomasum and intestines.
Differential diagnosis
1-Babesiosis.
2-Anaplasmosis.
3-Trypanosomis.
4-MCF.
- 7 -
Post Mortem Pathology /
Bovine Diseases
/
Dr. Saevan Saad Al-Mahmood
7. BOVINE TUBERCULOSIS (BTB)
Definition
A highly contagious chronic disease of cattle caused by
Mycobacterium
bovis
and associated with progressive emaciation and tubercle (granuloma)
formation involving most usually the respiratory system but also other organs
with great economic importance to the livestock industry and humans as zoonotic
disease.
Clinical signs
In the early stages, there are no clinical signs. In advanced stages cattle have
fluctuating temperature, anorexia and loss of body condition, enlarged lymph
nodes, persistent cough progressing to dyspnea and increases respiratory rate.
Post-mortem findings
Mycobacterium bovis mainly enters the body via the respiratory tract or the
alimentary tract, with the former being the most common. In the lungs localized
bronchiolitis is followed by ‘
tubercle’
, formation which is abscess with necrotic
focus and caseation and sometimes calcification surrounded by a fibrous capsule.
Tubercles have a yellowish appearance, and a caseous, caseo-calcareous or
calcified consistency. Post-mortem finding vary from single small focus usually
in the lung to numerous, sometimes confluent lesions in several organs. Tubercles
may be found in bronchial, mediastina, retropharyngeal and portal lymph nodes.
Lesions in the lungs, liver, spleen, body cavities can be found in advanced cases.
Differential diagnosis
1-Contagious Bovine Pleuropneumonia.
2-Bacterial pneumonia caused by Corynebacterium pyogenes.
3-Inhalation pneumonia.
4-Traumatic pericarditis.
5-Chronic aberrant liver fluke infestation.
- 8 -
Post Mortem Pathology /
Bovine Diseases
/
Dr. Saevan Saad Al-Mahmood
8. LISTERIOSIS
Definition
Opportunistic bacterial disease caused by
Listeria monocytogenes
. It affects
a large range of animal species and is a severe zoonosis.
Clinical signs
1-Fever, anorexia.
2-Conjunctivitis.
3-Opisthotonos and paralysis.
4-Facial paralysis with salivation.
5-Involuntary circling movements
6-Coma then death.
7-Pregnant cow with late abortion is common with mastitis.
8-Septicaemia may occur in young animals.
Post-mortem findings
Encephalitis with congestion of meninges. Septicemia and small necrotic
foci on liver, hemorrhagic gastroenteritis.
Differential diagnosis
1-Rabies.
2-Coenurosis.
3-Lead poisoning.
3-Bovine Spongiform Encephalopathy.
4-Ketosis in cattle.
- 9 -
Post Mortem Pathology /
Bovine Diseases
/
Dr. Saevan Saad Al-Mahmood
9. LEPTOSPIROSIS
Definition
A zoonotic disease caused by a bacteria
Leptospira borgpetersenii
, its
spread by animal urine contaminating the environment.
Clinical signs
General signs of the disease include fever, anorexia, depression, anemia, and
dyspnea. With more specific signs are abortions, stillbirths and weak newborns,
drop in milk yield and mastitis, icterus (jaundice), hemoglobinuria and
conjunctivitis.
Post-mortem findings
1-Icterus.
2-Hemoglobinuria.
3-Submucosal hemorrhages.
4-Kidneys are swollen, congested with hemorrhages.
5-Lymph nodes are swollen and multifocal petechial and ecchymotic
hemorrhagic.
6-Mummified fetus.
Differential diagnosis
1-Babesiosis.
2-Anaplasmosis.
3-Post-parturient hemoglobinuria.
- 10 -
Post Mortem Pathology /
Bovine Diseases
/
Dr. Saevan Saad Al-Mahmood
10. ACTINOMYCES
Definition
Chronic infectious diseases caused by
Actinomyces bovis
its most common
in cattle and known as
actinomycosis
or
lumpy jaw
and the classic lesion is
confined to the mandible
(Splendore-Hoeppli).
Clinical signs
A. bovis is probably an obligate parasite of the oropharyngeal mucosa in a
number of animal species, and most infections involve the oral tissues. A. bovis
may invade bone directly though the periosteum, but osteomyelitis usually
develops from periodontitis, presumably via lymphatic, which drain into the
mandibular bone.
Post-mortem findings
In bone the causative agent causes a chronic pyogranulomatous
inflammatory reaction and suppurative tracts penetrating the medullary spaces,
leading to multiple foci of bone resorption and proliferation.
Fistulae often discharge through the skin or mucous membranes. Periosteal
proliferation is excessive, and the bone may become enormously enlarged, with
destruction of the normal architecture of the mandible.
The teeth in the affected portion of the jaw become loose, lost, or buried in
granulation tissue. On cut surface, the affected mandible has a “honeycomb”
appearance with reactive bone surrounding pockets of inflammatory tissue.
Differential diagnosis
1- Actinobacillus.
2-Tuberculosis.
3- Nocardial Disease.
4- Sarcocytosis.