Lymphoid Disease in Ruminants Flashcards Preview

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Flashcards in Lymphoid Disease in Ruminants Deck (24)
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1
Q

Caseous Lymphadenitis

A

Sheep & goats
Gram +ve facultative anaerobe & facultative intracellular bacillus
Corynebacterium pseudoteburculosis
(nitrate -/+ biotypes)
Nitrate +ve one is associated with ulcerative lymphangitis in horses & cattle

2
Q

Caseous Lymphadenitis - pathogenesis

A

outer cell wall = lipid layer
Resists phagocytic killing
Phospholipase D - exotoxin, cytotoxin, partial hemolysin, causes local inflammation & necrosis
Causes lymphatic thrombosis
Penetrates the skin
Leukocytes phagocytose the bacteria (survive)
Go to lymph node & multiply
cells die, release, lymphogenous & hematogenous spread

3
Q

Caseous Lymphadenitis - transmission

A

Need to have a contaminated environment (e.g. wounds after fighting or shearing, traumatized oral/mucous membranes)
can be aerosol - pulmonary abscessation

4
Q

Caseous Lymphadenitis - in environment

A

Doesn’t multiply in the environment but survives for weeks to months
e.g. shaded areas, wooded bedding

5
Q

Caseous Lymphadenitis - prevalence

A

Prevalence increase with age
Clnical cases are sporadic
Subclinical common
goats&raquo_space; sheep

6
Q

Caseous Lymphadenitis - clinical signs

A

SUperficial lymph node abscesses in head & neck
Visceral lymph nodes - weight loss anorexia, depression
Sheep lamelated - goats pasty & green-y

7
Q

Caseous Lymphadenitis - diagnosis

A

clinical signs, cytology & culture of abscesses
elisa, serology
(CBC unreliable)

8
Q

Caseous Lymphadenitis - PM

A

Abcessed lymph nodes

Peripheral or visearl lymph nodes OR abscesses in lung parenchyma

9
Q

Caseous Lymphadenitis - treatment

A

no a/b
drain abscesses, but may cause transmission
no yet reliable vaccine
irradicate infected animals

10
Q

Leukosis

A

A. enzootic bovine leukosis or B. sporadic

11
Q

Enzootic Leukosis bovine leukosis

A

bovine leukaemia virus
any tissue affected
once clinical, fatal

12
Q

Enzootic Leukosis bovine leukosis

A

macrophages & lymphocytes in a pro-viral form

antibodies produced but not effective to the virus

13
Q

Enzootic Leukosis bovine leukosis - Factors affecting prevalence

A
age
level of infection in the herd
status of the dam
genetics
concurrent disease or stress
14
Q

Enzootic Leukosis bovine leukosis - transmission

A

mostly horizontal, blood

15
Q

Enzootic Leukosis bovine leukosis - clin path

A

lymphocytosis in 30% of seropositives
Lymphoma is <5% of seropositives
Latent period

16
Q

A. Enzootic Leukosis bovine leukosis 1. persistant lymphocytosis

A

Persistant lymphocytosis - sublicinical lymphoproliferative state (pre-lymphosarcoma) tumour associated antigen in the circulating cells

17
Q

Enzootic Leukosis bovine leukosis 2. multi-centric lymphoma

A

greater than 2 years old, sporadically
depends on cli
Lymph node, retrobulbar, abomasal, heart, meninges, etc.

18
Q

A. Enzootic Leukosis bovine leukosis 1. persistant lymphocytosis

A

CBC for cell count etc

19
Q

Enzootic Leukosis bovine leukosis 2. multi-centric lymphoma

A

lymph nodes are unreliable (don’t test those
Do a post mortem & serology)
Aged serology - high sensitivity/specificity, but you may get false negatives & false positives
Can use RAA/Virus isolation/PCR

20
Q

Enzootic Leukosis bovine leukosis - control

A

Can attempt eradication for control

21
Q

sporadic bovine leukosis (name 3)

A

Juvenile multi-centril lymphoma
Cutaneous lymphoma
Thymic lymphoma

22
Q

Juvenile multi-centril lymphoma

A

Cavles under 6 months
sudden onset, rapid course of disease
weight loss, depression, lymphadenopathy or variable signs depending on organs
If bone marrow infiltrates - anemia leukaemia

23
Q

Cutaneous lymphoma

A

Dermal lesions, back hind limbs & perineum
May become multi centric lymphoma
Occurs in animals 1-3 years old
lesions are 1-3 cm with a necrotic centre
May regress & reoccur

24
Q

Thymic lymphoma

A

6 months to 2 years old
Clinical signs associated with a mediastinal mass
Venous obstruction edema, jugular distension, thoracic fluid –> interfere with ventilation