BOD 2 & 3 Flashcards
Thymus’s default reaction to injury
atrophy
involution at sexual maturity normal, unless rodent or rabbit
- Grower/weaner pigs 6-16 wks with systemic infection/chronic wasting/failure to thrive
- On necropsy see lymphadenitis, thymic depletion
- Histo shows active granulomatous inflammation, lymphoid depletion
PCV-2 causing Thymitis (really only main clinical cause why you’d see thymitis)
2 types of thymic neoplasia and assoc’d signalments
- Thymic lymphosarcoma (T cells) - likely FeLV assoc’d if cat (+/- chylous effusion)
- Thymoma (epithelial cells) - adult goats
2 paraneoplastic syndromes for thymoma
Dogs - myasthenia gravis
Cats - feline exfoliative dermatitis
DDx’s for diffuse, gelatinous, bloody, splenomegaly
Splenic torsion
Barbiturates
Splenitis
DDx’s for nodular, gelatinous, bloody, splenomegaly
Hematoma
Hemangioma
Hemangiosarcoma
Acute splenic infarction
Primary sites for hemangiosarcoma
spleen liver right atrium bone marrow skin
How do you differentiate between African and Classical swine fever?
Classical - acute splenic infarcts
African - blood splenomegaly
DDx’s for diffuse, meaty, solid splenomegaly (bulges on cut)
Lymphosarcoma
Mastocytosis
Hyperplasia (d/t increased immune stim, phagocytosis, or hematoposesis
DDx’s for nodular, meaty, solid splenomegaly (bulges on cut)
- nodular lymphoid hyperpalsia (lymphoid follicle proliferation)
- neoplasm
- granuloma or abscess (septic bacterial, fungal, protozoal)
primary splenic neoplasms (causing nodular splenomegaly)
LSA - can cause diffuse or nodular
leiomyosarcoma, fibrosarcoma
Myelolipoma
neoplasms that commonly metastasize to the spleen
mammary carcinoma
squamous cell carcinoma
osteosarcoma
Causes of lymphadenitis
Classic or african swine fever - hemorrhagic necrotizing lymphadenitis
Corynebacterium pseutoTB - casesous lymphadenitis
Mycobacterium tuberculosis or bovis - granulomatous lymphadenitis
Peripheral, caseous lymphadenitis in a goat
Corynebacterium pseutoTB
fever + weight loss mild anemia stress leukogram Paraneoplastic hypercalcemia (d/t PTHrP) lymphadenopathy organomegaly - spleen or liver usually
Clin signs of LSA in dog (B cell most often)
what virus causes LSA in adult cattle
BLV - bov leukosis virus (Retrovirus)
where is the multicentric location of LSA in cattle
HURLS - heart, uterus, retro-orbital/renal, lymph nodes, spinal cord/stomach
what disease state often predisposes dogs/cats for lymphangectasia (dilated lymph vessels)? rum?
d/c - PLE, chronic lymphangitis
rum - Johne’s dz
what causes serous atrophy of bone marrow adipose
negative E balance
Infectious causes of aplastic anemia
CPV-2, feline panleukopenia, FeLV, Rickettsia, Ehrlichia
why are young livestock at increased risk of septicemia –> physitis or osteomyelitis
decreased or failed passive transfer
Sequestrum and involucrum MOA
trauma/hypoxia –> bone necrosis –> foreign body reaction, lytic/exudate pocket
2 pathologies of non-infectious osteomyelitis in young dogs
Panosteitis - medullary fibrosis, shifting leg lameness Metaphyseal osteopathy (or hypertrophic osteodystrophy) - double physis on rads, progressive lameness
4 types of metabolic bone disease (all d/t Ca/P imbalance)
Osteoporosis
Osteomalacia
Rickets
Fibrous osteodystrophy
What causes osteomalacia (defective mineralization of bone)
vit d deficiency (decreased Ca, P absorption) Phosphorus deficiency (or Ca or both)
MOA of rickets
- Vit D or P deficiency –> defective mineralization of osteoid in the physis (how differs from osteomalacia), juveniles only –> deformities
- get metaphyseal flaring, rachitic rosary
Fibrous osteodystrophy MOA
Primary hyperparathyroidism (rare) or Secondary " " (renal dz or nutritional issue) --> High PTH --> excess Ca release from bone --> replacement fibrosis - soft spongy bones, rubber jaw
How does renal dz cause secondary hyperparathyroidism (thus, fibrous osteodystrophy)
Decreased excretion of P = high P, low Ca = increased PTH secretion = more Ca mobilized from bone
How does nutrition cause secondary hyperparathyroidism (thus, fibrous osteodystrophy)
high P, low Ca, low Vit D = increased PTH secretion = more Ca mobilized from bone
e.g. carn on meat diet, Pig/EQ on grain/bran diets, lack of UVB in reptiles
Osteochondrodysplasia
abnormal endochondrial ossification –> defective cartilage development –> (disproportionate) dwarf stature or uncontrolled growth (e.g. daschhounds)
What is the most common primary bone tumor in domestics?
Osteosarcoma
(malignant mesenchymal tumor of osteoblasts
produces osteoid)
Osteosarcoma behavior
Osteolytic - destroys cortical bone, stimulates reactive woven bone, inflamm around site
Highly invasive but doesn’t cross joints/articular surfaces
often metastasizes to lungs early
Eburnation
subchondral bone exposed through cartilage
How does synovium respond to injury?
inflammation
villous hyperplasia of synoviocytes
Pannus (fibroplasia over areas of eburnation)
immune-mediated polyarthritis is what type of hypersensitivity
type 3
focal areas of abnormal thickening of cartilage from failed ENOS of epiphysis is…? what can it progress to?
Osteochondrosis osteochondrosis dessicans (thick cartilage --> hypoxia --> necrosis, fragmentation of cartilage --> subchondral bone exposed, weakened --> subchondral cyst --> cavitating defect)
Who is especially prone to subchondral bone cysts
EQ
Which is an acute annulus rupture - hansen type I or type II IVDD?
type 1
What is the one bacterial spp that grows well in muscle (anerobic conditions)
Clostridium
C. chauvei causes true black leg in rum
What is the fatal lesion of black leg?
necrosis of cardiac muscle
severe extertion –> lactic acid buildup –> myonecrosis causes what 2 diseases?
Tying-up in EQ (EQ exertional rhabdomyolysis)
Capture myopathy in wildlife (–> death by cardiac necrosis)
malignant hyperthermia in pigs - MOA
genetic receptor mutation + stress –> ungregulated, prolonged Ca channels open –> sustained muscle contractions –> lactic acidosis, hyperthermia, death
what deficiency can cause a nutritional myopathy?
Vit E/Se - b/c not there to scavenge free radicals –
> muscle damage/necrosis
CNS/brain trauma usually results in what?
Herniation —> ischemic or hemorrhagic stroke
Common MOA for atherosclerotic thrombosis
Hypothyroid or high fat diet —> hypercholesterolemia —> plaque build up and thrombosis
4 types of cerebral edema
Vasogenic - vascular injury, most severe, fluid accum in white matter
Cytotoxic - intracellular accum d/t ionic change
Interstitial - periventricular white matter d/t increased ventricular p
Osmotic - protein loss in GI, kidney, or skin
Wallerian degeneration
White matter lesion
Axonal change, then Macrophages eat degraded myelin leaving digestion chambers
See in type 2 Hansen spinal cord dz
Feline ischemic encephalopathy often d/t
Cuterebra larvae migration causing focal cerebrovascular dz
PEM
Softening of cerebrocortical grey matter
Usually a thiamine deficiency, excess thiaminases (in fish), heat, sulfur compounds
Diagnose at necropsy w/ woods lamp
Thiamine deficiency, sulfur or lead tox, and salt tox all affect grey or white matter of the brain?
Grey
Circling disease is caused by who? Where are lesions seen?
Listeria monocytogenes Brain stem (also abortive, ocular, systemic infec besides nervous lesions)
How would you differentiate morbilivirus (canine distemper) from rabies on histo of neuro tissue?
Rabies - intracytoplasmic inclusions only
Distemper - intranuclear and intracytoplasmic inclusions
Viruses that cause cerebellar hypoplasia in utero
Canine parvo
Feline panleukopenia
BVD, CSF
An adenoma of the adenohypophysis (ant pituitary) wiould cause what dz state?
Pituitary dependent Cushings (hyperadrenocorticism) - a secondary hyperfunc
Excess ACTH = adrenal cortical hyperplasia = excess cortisol
Adenoma of pars intermida of adenohypophysis (ant pit) in EQ causes
PPID from excess ACTH, clip, etc
PTH causes an increase in what? Where does it act.
?
Calcium, vit D3
Kidneys (increase P secretion, Ca retention), bone, GI (Ca resorp)
Vitamin D increases what?
Calcium, Phosphorus
A parathyroid adenoma would show what on bloodwork?
Increased PTH, Ca
Low P
Normal or increased vit D
Increased ALP
End stage renal failure causing secondary hyperparathyroidism would show what bloodwork?
High PTH, P
Nx or low vit D, iCa
Adrenals: what does each zone produce
Glomerulosa - mineralocorticoids (aldosterone)
Fasiculata - glucocorticoids (cortisol)
Reticularis - androgens, estrogens, progesterone
Common consequence of addisons dz
Pituitary nodular hyperplasia
No negative feedback from cortisol (b/c adrenals are atrophied) = hyperplasia of pituitary to secrete more ACTH
Ferrets and adrenal tumors
Hx of gonadectomy at 5-6 wks = no neg fedback = excess LH, zona reticularis hypertrophy
May also have active insulinoma - see adrenal dz + hyperinsulin/hypoglycemia
Function of glucagon
Hypoglycemia = glucagon inhibits insluin, stims glu release from liver and fat
Chronic/recurrent pancreatitis/ EPI or congenital islet hypoplasia can both cause what?
Diabetes mellitus
Two diseases of the guttural pouch
Empyema - strep zooepidemicus
Mycosis - aspergillosis
Who commonly gets otitis externa d/t ear conformation
Brachycephalics
Herding breeds, goldens, pomeranians, cocker spaniels
Moist environ —> secondaru bact infect, dermatitis
Secondary causes of otitis externa
Staph, proteus, pseudomonas, e coli
Malassezia, candida yeast
BACT AND YEAST ARE NOT PRIMARY CAUSES OF OE
Aural inflammatory polyps in cats is common with what kind of ear inflam?
Chronic otitis media
Lens injury results in
Cataracts - opacification of the lens
Sudden loss of vision is likely d/t
Retinal detachment
Leading cause of enucleation in dogs. Second?
Glaucoma (from sustained increased IOP)
Melanoma
common disease of intact older queens/bitches
CEM (cystic endometrial hyperplasia)
Progesterone primed endometrium –> CEM –> pyometra
MOA for pizzle rot in rams
High protein diet –> excess urea in urine where C. renale turns it into ammonia –> injury to local area
Bacteria plays a role in mummification or maceration?
maceration
sample trifecta for diagnosing abortion cases
placental, fetus, maternal serum
Mass in the oral cavity
melanoma unless proven otherwise
next likely: SCC, fibrosarcoma
how does bloat cause death?
asphyxiation, compression of caudal vena cava –> hypovolemic shock
MOA of grain overload? sequelae?
grain drops rumen pH –> rumen acidosis –> bact overload –> liver abscesses –> bacterial embolism –> pulmonary a. hemorrhage (f. necrophorum)
Is LDA or RDA more fatal in cows?
RDA
6 causes of red urine
IMHA, blister beetles, copper tox in sheep, blood parasites, bacillary hemoglobinuria, lepto
3 DDX’s for vasculitis in pigs
Erysipelothrix, salmonella septicemia, pcv-2
Who needs a deep skin scraping? Demodex or sarcoptes
demodex
what nutritional disorder causes hyperkeratosis of skin
vit A and zinc deficiency
cancers that can cause hypercalcemia of malignancy
AGASACA (makes PTHrP)
T cell lymphome
multiple myeloma
occasionally carcinomas
EQ sarcoids (most common horse skin tumor) caused by what?
bov papilloma virus