PID SPOTs Flashcards
Is thymoma benign or malignant?
benign tumour of thymic epithelial cells. slow growing with low metastatic potential
What is the link between thymoma and hypercalcaemia ?
- 5% dogs with thyme a have hypercalcaemia
- this is an ionised hypercalcaemia (biologically active forms)
- hypercalcaemia of malignancy manifests as result of 3 pathological processes associated with neoplasia:
1. ) interference with 1 alpha- hydroxylase activity leading to unregulated conversion of calcidiol to active calcitriol and enhanced intestinal absorption of calcium
2. ) hyper secretion of PTHrP
3. ) heightened activity of IL-1, IL-6 and TNF which increase osteoclastic resorption, often without visible radiographic bone lesions.
What is the link between thymoma and myasthenia gravis ?
- 10-20% MG patients have thymoma
- 20-momma patient shave MG
- complex relationship, may involve:
1. ) general immune dysfunction and loss of self-tolerance
2. ) antigenic similarity between proteins of neuro filaments of the thymic myoid cells and the ACH-Rs
3. ) expression of an ACH-R by thymic myoid cells when challenged by a bacterium or virus - MG associated with thymic dz in dogs is usually generalised and acute
Why is there a link between FeLV and development of this type of tumour ?
Thymic lymphomas show FeLV pro viral insertion in the flit-1 locus
Describe the appearance of caseous lymphadenitis in sheep
- onion ring appearance of LNs/ internal organs d/t alternate layers of fibrosis and necrosis
Pathogenesis of caseous lymphadenitis
- chronic, recurring disease
- slowly enlarging, localised and non-painful abscess at point of entry into skin or regional LN
- spreads via blood or lymphatics
CS - caseous lymphadenitis
- initial infection may cause no CS OR:
- high fever
- anorexia
- anaemia
- cellulitis at infection site
- superficial abscesses enlarge and may rupture and discharge infectious pus
What would you expect if you saw something that appeared like caseous lymphadenitis but in a horse (as opposed to a sheep or goat)?
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What are the clinical syndromes associated with Johne’s Disease ?
name
What would you also suspect if you found chronic lymphadenitis in the bronchial lymph nodes of a cow ?
Mycobacterium bovis
Tx - SCC of tonsil with metastasis to regional LN
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Tx - intestinal adenocarcinoma with metastasis to mesenteric LNs
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Why is it important to consider Echinococcus granulosus (–>hydatid cyst) when an animal is coming into the UK under the Pet Travel Scheme ?
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T/F: Viruses that damage endothelial cells lead to petechial haemorrhages in various tissues and can cause infarction.
True
How do you prevent splenic infarcts in dogs d/t acute viral hepatitis?
vaccination?
Cause - caseous lymphadenitis
Corynebacterium pseudotuberculosis
When did caseous lymphadenitis (CLA) become established in the UK?
1991
CS - CLA
Abscessation of superficial LNs (cutaneous form) –> spread to Ls within chest and internal organs (visceral form). Sheep with superficial form may only show illness when abscess enlargement causes compression of airway.
Pathogenesis - CLA
Inoculated bacteria engulfed by phagocytic cells, proliferate intracellularly and spread via lymphatics to regional LNs. LN enlargement occurs through alternating necrosis and reformation of lesion capsule causing a distinctive laminated appearance of older lesions ‘onion rings’.
How does babesia divergens cause anaemia?
invades RBC, begins diving, eventually ruptures the cell
CS - Babesiosis
- pipestem diarrhoea
- anaemia
- haemoglobinuria
- increased temperature
- diarrhoea may cease after 36 hours and constipation ensues
- increased pulse rate
- abortion
- death (rare in UK babesiosis)
Transmission - Babesia divergens
Ixodes ricinus tick in the UK
How long does it take after infection with babesia for a cow to show CS?
2 weeks
In what type of cell does Leishmania multiply in?
Monocyte/ tissue macrophage
Dx - EIA
Serology - Coggin’s test (agar immunodiffusion)
Transmission - EIA
Vector-borne (blood-feeding insects) from infected animal biting a naive animal and inoculating it.
