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Flashcards in Tarc LRS Path and Case Studies Deck (18)
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How is thymoma related to paraneoplastic syndromes?

> hypercalcaemia
- thymoma, T cell lymphoma and anal adenocarcinoma secrete PTH related peptide (unregulated) -> binds PTH-R and stimulates Ca release from mineral stores
> Myasthenia gravis
- as thymoma is neoplasm of epithelial cells, + and - selection of T cells in thymus is affected -> overproduction of autoreactice T cells producing AutoAb (in this case Ach-R targetted)


What infectious organism is thymic lymphoma commonly associated with? Why?

FeLV infects T cellls and thymocytes
- oncogenic retrovirus induces malignant transformation


Give 2 examples of chronic lymphadenitis

> granulomatous
- Johnes, Mycobacterium Avium Paratuberculosis (mesenteric LNs -> D+ and wt loss)
- TB, M. Bovis (bronchial LNs)


How can mycobacteria be demonstrated in a sample?

- stain for acid fast bacteria


Which species get Caseous Lymphadenitis? Clin signs and causitive agent?

- sheep and goats
- chronic recurring dz, slowly enlarging LNs are non-painful
- onion ring ppearance of LNs on PME (also in organs)
- may be no clin signs or pyrexia/cellulitis/anaemia/anorexia
- Corynebacterium pseudoTB


How do the common sites of lymphoma and SCC differ?

- lymphoma can afect tonsillar tissue and LNs
- SCC commonly affects tonsils then 2* mets to local LNs


Give 5 main dz of the spleen

> nodular hyperplasia
- benign, incidental finding at PM
- difficult to distinguish from neoplasia
> hydatid cysts
- echinococccus granulosus, IH sheep goats pigs, DefinitiveH dogs and carnivores
- beware dogs on PETS travel scheme who may have ingested cysts from meat in endemic areas, these will shed eggs
> splenic HS
- pdf GSD
- very malignant
> splenic lymphoma
- massie diffuse enlargement
- discrete areas of infarct w/haemorrhagic borders
> splenic infarcts
- seen in DOGS with acute viral hepatitis d/t adenovirus (CAV 1) prevention by VAX
- seen in PIGS with classical swine fever **NOTIFIABLE, CONTACT APHA**
(any viruses that affect endothelial cells -> pethichial haemorrhage and infarcts)


How is caseous lymphadenitis spread?

- shearing wounds
- fighting rams


How does corynebacterium hide from the immune system?

- intracellular bacteria
- capsule formation


Is corynebacterium sensitive to abx?

yes if they reach it


How can caseous lymphadenitis be prevented?

- esp shearing equpment
- quarantine new animals
- vaccines decreaseincidence but do not prevent all
eradication by testing for seropositivity in unvax flocks -> cull


Clinical signs of red water disease? Pahtogen?

> Babesia DIvergens (spread by Ixodes Ricinis)
- clinical signs 2w post infection
- anaemia d/t division of organisms within RBCs
- Hbg uria
- tachycardia
- abortion
- very rarely death
- pyrexia
- D+ for 36hrs then becoming constipation
- spread by ticks so only affected by tick ridden areas and if new farm is clean and not infected tick population


Tx babesia divergens?

- mild cases recover alone
- prophlyactic tx in cattle in risk areas
- no vax UK


CLinical signs of Leishmania Infantum?

- persistent ulcerated lesions esp nose and head


pathogenesis of leishmania

- multiplies in monocytes/tissue macrophages
- emerging sporadic dz d/t ^ travel dogs into endemic areas
- sandflly vector necessary for transmission so risk of spread within UK


CLinical signs EIA

- pale mms
- tachycardia
- pyrexia
- et loss
- lethargy
- ventral oedema
- anaemia and htrombocytopaenia on bloods


How is EIA confirmed?

Coggins test (agar immunodiffusion)


Likely source of infection of EIA?

vector borne by blood feeding insects from infected animal