Lymphatic disease

Question 1

What are the types of BLS?

Answer 1

Sporadic- generalized lymphadenopathy, thymic, skin/cutaneous
Endemic/enzootic- BLV associated form

Question 2

Is calf/juvenile BLS associated with BLV infection?

Answer 2

No

Question 3

What age animals develop calf/juvenile BLS?

Answer 3

Birth to 6 months old

Question 4

What clinical signs are associated with calf/juvenile BLS?

Answer 4

Lymphadenopathy, bloat, dyspnea, depression, weight loss, weakness, sudden onset

Question 5

How does calf/juvenile BLS progress?

Answer 5

Rapid progression after clinical signs

Question 6

How is calf/juvenile BLS diagnosed?

Answer 6

PE and hematology or on necropsy

Question 7

What is the age of onset for thymic/adolescent BLS?

Answer 7

6 months to 2 years

Question 8

Is thymic/adolescent BLS associated with BLV infection?

Answer 8

No

Question 9

What are the clinical signs associated with thymic/adolescent BLS?

Answer 9

Signs secondary to space occupying lesions in neck and thorax- dyspnea, brisket enlargement, loss of body condition, bloat

Question 10

What is the prognosis for thymic/adolescent BLS?

Answer 10

Poor- fatal, often secondary to bloat

Question 11

How is thymic/adolescent BLS diagnosed?

Answer 11

Cytology or biopsy of mass

Question 12

What is the age of onset of skin/cutaneous BLS?

Answer 12

1-3 years, may onset and then regress then re-appear

Question 13

Is skin/cutaneous BLS associated with BLV infection?

Answer 13

No

Question 14

What clinical signs are associated with skin/cutaneous BLS?

Answer 14

Diffuse, cutaneous lesions- may be ulcerated/painful, other signs depend on location

Question 15

How is skin/cutaneous BLS diagnosed?

Answer 15

Skin biopsy

Question 16

What is the age of onset of adult BLV-associated BLS?

Answer 16

4-8 years

Question 17

What are the predilection sites of adult BLV-associated BLS?

Answer 17

Heart (right atrium), uterus, lymph nodes, abomasum, spinal cord, retrobulbar

Question 18

What are the clinical signs associated with adult BLV-associated BLS?

Answer 18

Dependent on site-
Heart failure, abortion/embryo loss, bloat, weight loss, melena, outflow obstruction, ataxia, recumbency, proptosis

Question 19

How is adult BLV-associated BLS diagnosed?

Answer 19

Histopathology- biopsy > FNA > core biopsy
CSF can be used but is not sensitive
Hard to diagnose ante-mortem

Question 20

How is adult BLV-associated BLS treated?

Answer 20

Supportive care, salvage, euthanasia

Question 21

What percentage of BLV infected animals develop BLS?

Answer 21

<5%

Question 22

What type of virus is BLV?

Answer 22

Oncogenic type C retrovirus affecting B cells

Question 23

What are transmission risks for BLV?

Answer 23

Iatrogenic spread (needles, dehorners, palpation sleeves, etc.), vertical transmission in utero, milk/colostrum

Question 24

Describe the three outcomes of BLV infection

Answer 24

Subclinical- stays subclinical throughout life, might have slight production losses
Persistent lymphocytosis
Lymphosarcoma- uncommon, possible that genetics influence susceptibility

Question 25

How is BLV diagnosed?

Answer 25

ELISA +/- PCR

Question 26

What is the causative agent of caseous lymphadenitis?

Answer 26

Corynebacterium pseudotuberculosis

Question 27

Why is Corynebacterium pseudotuberculosis such a dangerous bacteria?

Answer 27

Survives well in soil (for months), migrates from wounds and forms abscesses at lymph nodes, contains exotoxins and survives in macrophages

Question 28

How is Corynebacterium pseudotuberculosis spread?

Answer 28

Wounds (shearing injuries), inhalation

Question 29

Describe the external form of caseous lymphadenitis

Answer 29

Abscessation around head/neck with various LNs possibly infected, non-painful, thick purulent discharge, common in goats, causes life-long infection, diagnosed by gram stain of pus (gram positive) Treat by removing abscess, can use procaine penicillin or tulathromycin but culling recommended

Question 30

Describe the internal form of caseous lymphadenitis

Answer 30

Abscessation of internal lymph nodes and abdominal organs (liver, kidney, lungs, udder, spinal cord, nuchal ligament), causes non-specific signs- weight loss, inappetence, respiratory signs, usually happens in sheep, diagnose with SHI and clinical signs No treatment, culling recommended

Question 31

Describe the vaccine for caseous lymphadenitis

Answer 31

Made for sheep, moderately efficacious at limiting spread, vaccinated animals will test positive on SHI, has negative effects for goats (fever, ataxia, convulsions, etc.)