Special path Flashcards
1
Q
Myasthenia gravis
A
- disorder of neuromuscular impulse transmission
- inherited = animal born with too few acetylcholine receptors at neuromuscular junctions
- acquired = usually a primary lesion (thymoma), which produces acetylcholine receptor antibodies on post synaptic membrane
- no macro/micro lesions
- consequence = muscle weakness + atrophy, megaesophagus development
2
Q
hemangiosarcoma
A
- neoplasia of vascular endothelium
- primary = arises from heart, usually R auricle
- secondary = metastasis from spleen
- macro = red, bloody nodules
- common in GSD
- consequence = rupture leading to hemoperricardium and death from cardiac tamponade
3
Q
Edema disease
A
- disorder of rapidly growing, healthy feeder pigs being fed a high energy ration
- cause = E.coli, produces verotxoins
- pathogen: 1. dietary changes, 2. intestinal absorption of antitoxins, 3. fibrinoid necrosis of arteries and arterioles, 4. focal decrease in circulation through CNS -> infarct, 5. generalise edema
- extra neural lesions = swelling + transudation into body cavity
- organs affected = stomach, intestine
- micro = swine cerebral antipathy + neuronal necrosis
- consequence = 4- 8 weeks old piglet ie within 24 hrs
4
Q
black leg
A
- clostridium chauvoei
- pathogen: 1. spores ingested through intestinal tract, 2. disseminate through blood stream to skeletal muscles, 3. spores can remain latent/proliferative if bruising, 4. spores activate bacteria proliferate and produce toxins, 5. toxins cause capillary damage
- macro = gelatinous exudate, yellow, swollen, dark red
- micro = intramuscular blood + gas bubbles
- most common = acute death
5
Q
pyometra
A
- accumulation of pus within uterine walls
- cause = consequence of endometritis/metritis, E.coli (viscous brown exudate), strep (creamy yellow exudate)
- macro = necrotic areas with hemorrhagic areas
- micro = cystic endometrial hyperplasia
- consequence = widespread extramedullary hemaotpoiesis + immune complex glomerulopathy
6
Q
Hydrocephalus - pathogen
A
- accumulation of CSF within brain cavities (ventricular and subarachnoidal)
1. non absorptive CSF, pressure in ventricles increase
2. ventricles widen, ependyma is multi focally distrupted
3. compression of periventricular white matter
4. hydrostatic edema of white matter
5. degeneration + atrophy of myelin + axons -> loss of tissue
6. expansion of ventricles + compressive atrophy -> necrosis - most common in brachiocephalic/miniature breeds
- manifestation in 1st 3 months of life
7
Q
tuberculosis
A
- mycobacterium bovis
- aerogenic infection or PO calves
- multiply in macrophages + spreads via LN + resp
- hypersensitivity 3 -> granulomatous infalm
- pneumonia, lymphadenitis + pleuritis (pearl disease)
- granuloma = caseous necrosis + multinucleate giant cells, epithelia cells, macrophages, lymphocytes and fibroblasts
8
Q
hydrocephalus causes
A
- blockage of intervenrticular foramen (unilateral)
- blockage of both interventriclar (bilateral)
- blockage of mesencephalic duct (bilateral)
- blockage of lateral apertures of 4th ventricle (bilateral)
9
Q
types of hydrocephalus
A
communicating - congenital
= less common, communication between ventricular and subarachnoidal space
non communicating - congenital
= obstruction in ventricular system + opening of 4th ventricle
compensating - congenital
= secondary due to loss of lack of brain tissue
acquired = appears in developed brain tissue
non communicating - acquired
= injuries/obstruction, neoplasms and abscess, blockage of fluid
compensating - acquired
= secondary after losing neural tissue due to brain infarction or brain ageing
10
Q
paratuberculosis
A
- Johne’s disease
- causes = mycobacterium avian sap paratuberculosis
- macro = chronic segmental thickening of ileum, cecum and proximal colon.
= lepromatous form - prominent mucosal folds
= tuberculoid form - caveating granulomas
= arteriosclerosis
11
Q
canine distemper
A
- cause = morbillivirus
- pathogen: 1. transmitted to puppies in bodily fluids + invades upper resp tract and conjunctiva. 2. spreads to regional L.N + causes viremia, 3. infects almost all cells of body, particularly epi cells, 4. decrease immune response, decrease cytokine production nd predisposition for 2bact infection
- macro = diffuse interstitial pneumonia, necrotising, bronchiolitis + pneumocyte type 2 hyperplasia
- mico = eosinophilic inclusion in epi cells
- consequence = 2ary bacterial infection - bordetella bronchiseptica enamel hypoplasia, hyperkeratosis of nose and foot pads
12
Q
Sertoli cell tumour
A
- macro = well-circumscribed, firm white lobulated by fivbrous bands mass
- micro = abundant fivbrous tissue, intratubular/diffuse arrangement of Sertoli cells
- 1/3 of these tumours have a feminising effect - alopecia + hyperplasia or metaplasia of prostate
13
Q
GDV
A
- large- deep chested dog breeds = acute GDV
- simple gastric dilation = young pups + overeating
- predisposition = distending gas, fluid/feed obstruction of pylorus
- repeated dilation = stretching + relaxation of gastrohepatic ligament -> gastric rotation
- XS gas/obstruction -> dilation -> rotation of mesenteric axis -> compress of diaphragm , vena cava and portal vein s-> cardiac output and perfusion to abdomen viscera -> shock
- severe abdo distension, 180-360 degrees
- consequence = stomach rupture and death
14
Q
splenomegaly
A
- causes = blood accumulation, increase MMS cell number, lymphoid hyperplasia, inflammation and neoplasia
uniform splenomegaly = - bloody spleen (hyperemic) -> congestion; torsion, euthanasia by barbiturates,
- meaty (nonhyperemic) -> phagocytosis, deposti disease + cell proliferation
nodular splenomegaly - uneven contraction, hematoma, haemangiosarcoma
- splenic nodules with firm consistency = nodular hyperplasia, abscess, chronic granuloma
15
Q
infectious canine hepatitis
A
- causes = canine adenovirus 1
1. exposure orally by urine/infected dogs
2. causes viremia, multiplies in tonsils + spreads via L.N
3. virus has a tropism for hepatocytes, vascular Endo + renal epi - macro = haemorrhage in organs + seroa, enlarged friable liver + hyperaemic tonsils + LN, gall bladder wall edema and corneal edema
- micro = smaller, centrilobular necrosis, large, intranuclearl inclusions. Endothelial damage + haemorrhage
16
Q
vesicle
A
- fluid filled cavity within/beneath the epidermis less than 1cm in diameter
- cause = viral infections, pemphigus follia cells/vulvaris, thermal burns
- vesicle greater than 1cm = bulla
17
Q
exocytosis
A
mechanism of exiting a cell from basolateral surface
18
Q
hepatocellular steatosis
A
- excessive lipid within hepatocytes
- causes = incorrect nutrition ->increase feed starvation of fat animals, toxins, ketosis
pathogen - increase dietary intake of fat + carbs, increased esterification + fat mobilisation, decrease oxidation + decrease secretion of lipoproteins - macro = enlarged, yellow liver
- micro = swollen hepatocyte contain numerous vacuoles
- consequence = significance depends on cause, severity + duration. hepatocellular necrosis, fatty cysts, liver rupture which can lead to haemoabdo
19
Q
leydig cell tumour
A
- interstitial cell tumour of testes
- most common testifcular tumour in dogs
- almost always benign
- macro = spherical, well -demarcaated tan- organ coloured mass with areas of haemorrhage
- micro - finely encapsulated, cells in sheets or small groups, abundant vacuolated cytoplasm
20
Q
seminonoma
A
- germ cell neoplasm
- macro= homogenous, white- pink grey firm mass, fine fibrous trabeculae
- micro = intratubular/diffuse, large round neoplasic cells with little cytoplasm. high mitotic rate
- locally invasive but rarely metastatic
21
Q
mastitis
A
inflammation of mammary gland
cause -= strep, strap, ecology, mycoplasma Bovis
22
Q
urolithiasis
A
- presence of stones or calculi in urinary collecting system
- renal pelvis = nephroliths, ureter = urethroliths, urinary bladder = urocystolith/urethrea = urethrolith
- form when familial, congenital and pathophysiology factors occur together and cause precipitation of excretory metabolites which form grossly visible stones
- predisposing = decreased water, pH, cystitis
- consequence = obstruction of traumatic injury, infection
- mini schnauzers = struvite
23
Q
osteogenesis imperfecta
A
- inherited CT disorder
- cause = mutation in COLL1 gene
- consequence = bone fractures, joint laxity, blue sclera
- macro = decreased trabecular bone, delay in compaction of cortical bone + dental fractures
- micro = evidence of fractures and disorganised dentin
- calves, lambs, kittens and puppies
24
Q
pseudorabies
A
- Aujesky’s disease/ match itch
- cause = said herpes virus 1
1. virus enters thru upper respiratory tract, tonsils
2. replicates + enters sensory nerve ends
3. transported to trigemeninal ganglia + bulbous olfactoria
4. enters brain - glycoproteins on surface of virus allows binding + entry into cells
- macro = leptomeningeal congestion
- micro = non purulent menegoencephalomyelitis
- consequence = fatal in piglets
- lesions outside CNS in pigs, in resp system, lymphoid, digestive and reproductive
25
Q
osteosarcoma
A
- malignant neoplasms of unknown origin
- cats + dogs, usually older + giant
- metaphysics of long bones
- characteristics = rapid growth, painful + aggressive
- class = simple, compound or pleomoprhic
- based on location = central, juxtacortical/ periosteal
- macro = grey-white mass containing variable amounts of mineralised bone. Random areas of hemorrhage
26
Q
bloat
A
- over-distension of rumen + reticulum with gas of fermentation
primary = legume, dietary or frothy bloat - legumes -> release chloroplasts particles -> rumen microbes colonise particles + degrade protein -> gas bubbles trapped + stable foam is fornmed. Organic acids + salivary bicarbonates -> CO2. Luminal fermentation + acid prod -> low pH
- legumes + fine particles -> decrease salivary secretion -> increase viscosity of rumen contents -> foam -> physical blockage of cardia
secondary = physical obstruction/stenosis of oesophagus - signs + lesion = abd distension, animal dead + rolled ono back, lots of frothy rumen content
27
Q
juvenile pancreatic atrophy of dogs
A
- GSDs 6-12m
- complex inheritance - multiple genes and environmental factors
- prob atrophy driven by autoimmune disease (lymphocytic pancreatitis)
- signs = maldigestion, rapid weight loss despite huge appetite
- macro = small pancreas, visible loss of parenchynma
- micro = islands of normal exocrine pancreatic tissue usually remains but otherwise tissue is markedly depleted
28
Q
infectious/ contagious ecthyma of sheep
A
- parapoxvirus
- lips, oral mucosa, eyelids and feet
- abrasions -> infections -> lesions characteristics for poxvirus
- high morbidity, low mortality but weight loss
29
Q
Cushing;s
A
- cortisol excess - adult dogs, infrequent in cats + rare in other domestic animals
- cause = functional neoplasm, ACTH secreting adenoma of pituitary gland, iatrogenic XS of corticosteroids
- function disorders = increased appetite, weakened + atrophies muscles of extremities and abdomen
- hepatomegaly, skin lesions
30
Q
acantholysis
A
- disruption of intercellular junctions between keratinocytes of epidermis
- cause: immune mediated, exfoliative toxins from staph
1. damage of transmembrane glycoproteins, splitting of extracellular core of desmosomes
2. desmosome plaque dissolve + intermediate filament retract - micro= varies depending on location. Vesicles/ pustules, free-floating keratinocytes
31
Q
parvovirus enteritis
A
- feline and canine forms
1. virus replicates in lymphoid tissue, cause lymphoid depletion, crypt cell destruction
macro - hyperaemic intestine with serositis, SI maybe fluid-filled + hemorrhagic - micro = basophilic intranuclear inclusions bodies in enterocytes, necrosis of crypt epi cells, permanent villous distortion + atrophy
- consequence = hemorrhagic diarrhoea + death from shock
- secondary bacterial infection with endotoxemia
32
Q
mast cell tumour
A
- dogs, cats, pigs + cattle
- malignant
- cell of origin: CT or mucosal mast cells
- most common in dogs - back of body + scrotum
- can look like inflammation due to degranulation + release of mediators
- micro = eosinophilic, flame figures, toluidine blue = mast cells are purplet
