Tarc LRS Path and Case Studies Flashcards
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?
biosecurity
- 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
