Lymphatic disease Flashcards
What are the types of BLS?
Sporadic- generalized lymphadenopathy, thymic, skin/cutaneous
Endemic/enzootic- BLV associated form
Is calf/juvenile BLS associated with BLV infection?
No
What age animals develop calf/juvenile BLS?
Birth to 6 months old
What clinical signs are associated with calf/juvenile BLS?
Lymphadenopathy, bloat, dyspnea, depression, weight loss, weakness, sudden onset
How does calf/juvenile BLS progress?
Rapid progression after clinical signs
How is calf/juvenile BLS diagnosed?
PE and hematology or on necropsy
What is the age of onset for thymic/adolescent BLS?
6 months to 2 years
Is thymic/adolescent BLS associated with BLV infection?
No
What are the clinical signs associated with thymic/adolescent BLS?
Signs secondary to space occupying lesions in neck and thorax- dyspnea, brisket enlargement, loss of body condition, bloat
What is the prognosis for thymic/adolescent BLS?
Poor- fatal, often secondary to bloat
How is thymic/adolescent BLS diagnosed?
Cytology or biopsy of mass
What is the age of onset of skin/cutaneous BLS?
1-3 years, may onset and then regress then re-appear
Is skin/cutaneous BLS associated with BLV infection?
No
What clinical signs are associated with skin/cutaneous BLS?
Diffuse, cutaneous lesions- may be ulcerated/painful, other signs depend on location
How is skin/cutaneous BLS diagnosed?
Skin biopsy
What is the age of onset of adult BLV-associated BLS?
4-8 years
What are the predilection sites of adult BLV-associated BLS?
Heart (right atrium), uterus, lymph nodes, abomasum, spinal cord, retrobulbar
What are the clinical signs associated with adult BLV-associated BLS?
Dependent on site-
Heart failure, abortion/embryo loss, bloat, weight loss, melena, outflow obstruction, ataxia, recumbency, proptosis
How is adult BLV-associated BLS diagnosed?
Histopathology- biopsy > FNA > core biopsy
CSF can be used but is not sensitive
Hard to diagnose ante-mortem
How is adult BLV-associated BLS treated?
Supportive care, salvage, euthanasia
What percentage of BLV infected animals develop BLS?
<5%
What type of virus is BLV?
Oncogenic type C retrovirus affecting B cells
What are transmission risks for BLV?
Iatrogenic spread (needles, dehorners, palpation sleeves, etc.), vertical transmission in utero, milk/colostrum
Describe the three outcomes of BLV infection
Subclinical- stays subclinical throughout life, might have slight production losses
Persistent lymphocytosis
Lymphosarcoma- uncommon, possible that genetics influence susceptibility
How is BLV diagnosed?
ELISA +/- PCR
What is the causative agent of caseous lymphadenitis?
Corynebacterium pseudotuberculosis
Why is Corynebacterium pseudotuberculosis such a dangerous bacteria?
Survives well in soil (for months), migrates from wounds and forms abscesses at lymph nodes, contains exotoxins and survives in macrophages
How is Corynebacterium pseudotuberculosis spread?
Wounds (shearing injuries), inhalation
Describe the external form of caseous lymphadenitis
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
Describe the internal form of caseous lymphadenitis
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
Describe the vaccine for caseous lymphadenitis
Made for sheep, moderately efficacious at limiting spread, vaccinated animals will test positive on SHI, has negative effects for goats (fever, ataxia, convulsions, etc.)
