what is the most likely diagnosis for cardiac tamponade in a stallion?

a. aortic rupture

b. trauma

c. hemangiosarcoma

d. valvular insufficiency

e. pericarditis

1. concentric hypertrophy of LV

2. fibrous endocardial thickening

3. post stenotic dilation

4. focal myocardial necrosis/fibrosis

5. heart failure when LV can't compensate

cattle-pasteurellosis, blackleg, coliform septicemias

pigs- Glasser's, strep, pasteurellosis, enzootic mycoplasmal pneumonia, salmonellosis

horses-strep

birds-psittacosis

what tumor type originates from cells in close association with nerves which function to initiate adjustments in the autonomic nervous system in response to changes in CO2, pH, O2?

a. insulinoma

b. perithyroidal ganglioneuroma

c. chemodectoma

d. neuroendocrine bronchial adenocarcinoma

e. pheochromocytoma

which layer of the adrenal cortex secretes glucocorticoids (non-human)?

a. zona glomerulosa

b. zona fasciculata

c. zona reticularis

d. all of the above

e. b and c

atherosclerosis in dogs in exclusively associated with what condition

a. hypoparathyroidism

b. DM

c. insulinoma

d. Cushing's

e. hypothyroidism

which of the following is true about Addison's disease?

a. associated with calcinosis cutis

b. high serum potassium and low serum sodium

c. tachycardia

d. b and c

e. all of the above

b. hi serum K, low Na

(bradycardia due to hi K, NOT tachycardia)

• polypeptide (stored in secretory granules) (e.g. TRH, ACTH, ADH, TSH, calcitonin, insulin, glucagon)
• steroid
• amino acid derivatives (e.g. thyroid)

acromegaly,

excess growth hormone -insulin resistant diabetes -exaggerated skin folds -increased interdigital and interdental spaces -“big boned”

• neurohypophysis- oxytocin and ADH
• adenohypophysis -
• pars distalis- GH, LH, LTH, prolactin, FSSH, TSH, ACTH 
• pars intermedia-ACTH in the dog 
• pars tuberalis-supporting capillary network

• nutritional (dogs, cats, birds, reptiles, primates) low calcium/hi phosphorus diets, inadeq vit D in new world primates. stim parathyroid glands, hyperplasia, increase PTH

• renal (dogs) chronic renal disease-->failure to excrete P and retain Ca; failure of kidney to metabolize Vit D--> hypocalcemia-->increased PTH-->fibrous osteodystrophy--> eventually still low serum Ca and hi P , (insoluble calcium phosphate)

-persistent hyper Ca/hypo P

-parathyroid chief cells will be atrophied

-thyroid C cells will be hyperplastic

-removal of tumor returns values to normal, but recurrence of hypercalcemia with regrowth of the tumor

what three tumors are associated with pseudohyperparathyroidism?

• anal sac apocrine gland acenocarcinoma (NOT perianal gland adenoma/adenocarcinoma)
• lymphosarcoma
• mammary gland adenocarcinoma

• selective deposition of amyloid in the islets resulting in degeneration of beta and alpha cells. not all cats with islet amyloid will have DM
• vacuolar degeneration of beta and alpha cells due to glycogen accumulation assoc with long term insulin resistance and exhaustion of insuling producing cells

adenoma=insulinoma

adenocarcinoma-most common and usually in right lobe

• DM-due to hyperglycemia (weak pelvic limb, reduced spinal reflexes and muscle mass, plantigrade stance of pelvic limbs in cats)
• hypothyroidism-(LMN sings, megaesophagus, cranial nerve deficits, laryngeal paralysis)
• hypoadrenocorticism(megaesophagus)
• insulinoma

deeply located muscles which function to maintian posture are composed mostly of what fiber type?

a. Type 1

b. Type 2A

c. Type 2B

d. satellite fibers

e. mitochondrial fibers

flat bones of the skull develop by the process of what?

a. reversal lines

b. proliferation

c. intramembranous ossification

d. endochondral ossification 

e. hypertrophy

blood vessels from the metaphysis invade into the advancing growth plate bringing with them what type of cell that forms bone on the cartilage spicules?

a. osteoblasts

b. osteocytes

c. osteoclasts

d. megakaryocytes

e. a and b

equine botulism can lead to what complication?

a. aspiration pneumonia

b. hepatic abscesses

c. COPD

d. foundering

e. b and d

growth

throughout life

alter gross shape of the bone

fibrous osteodystrophy

"big head"

crandiomandibular osteopathy

unmineralized collagenous matrix of bone

inadequate mineralization

a tumor as an osteosarcoma

1. resting cartilage zone: inactive
2. proliferating cartilage zone: interstitial growth within growth plate
3. maturing/hypertrophic cartilage zone: cells making matrix and beginning to degenerate
4. calcified cartilage zone: cartilagenous septa are invaded by blood vessels which bring osteoblasts and allows mineralization to begin
5. primary spongiosa: bone deposited on outer surfaces of cartilagenous spicules

lack of dietary Ca, Vit D, P, P/Ca imbalance

accumulation of osteoid

blood vessels don't invade inadequately mineralized collagen/cartilage, resulting in persistence of unmineralized cartilage within metaphysis. 

lack of vitamin C in species that lack enzyme L-gulonolactone oxidase. 

blood vessels weak due to poor quality collagen cannot sustain osteogenesis and hemorrhage and result in diminshed metaphyseal bone formation

outer fibrous (structure, protection)

inner osteogenic layer

osteoclasts

Howship's lacunae

osteoporosis can be due to:

who gets osteogenesis imperfecta?

what is it?

Holsteins, dogs

small fragile trabeculae

osteopetrosis is autosomal________,

and is the failure of ________ resulting in _______

recessive

osteoclasts

filling of medullaty cavity with excessive bone

what is the growth retardation lattice?

what is a common cause?

• enlargement of ends of long bones and costochondral junctions (enlarged joints)
• valgus deformity
• soft bones

• increase in size and disorganization in the zone of hypertrophic cartilage
• defective calcification
• excess osteoid
• marrow fibrosis

fibrous osteodystrophy

continuous action of parathyroid hormone pulling calcium from bone either bc there is a tumor producing excess parathyroid hromone or in an attempt to raise the serum Ca or restore normal P/Ca ratio due to poor nutrition

what is HOP-hypertrophic “pulmonary” osteo(arthro)pathy?

• proliferative bone condition assoc with a space occupying thoracic or abdominal mass lesion. inciting cause is usually a tumor by can be infec/inflam.
• hallmark path is chronic prolif of new bone beneath periostium, not involving joint surfaces. 
• severing the vagus nerve can be curative

• young large breed dogs, less than 1 yr.  
• swollen, painful, hot joint (or near joint) metaphysis. 
• radiographically, there is a double line. parallel lines
• will outgrow it, but need to get them non-weight bearing, otherwise, will slip their physis

• transient inflammatory disease
• pain, lameness, inflammatory
• large breed dogs, german sheps,
• woven tissue density around nutrient foramen, with a minor inflam component

• hereditary (small breed, westies, etc) or spontaneous.
• also bull mastiffs.
• proliferative bone.
• reversal lines.
• aggressive remodeling

inflammation of the marrow spaces. chronic and disfiguring due to lack of drainage and persistence of infectious agents in necrotic bone

can be caused by bacteria (most common), also viral, fungal, protozoal

• young animals
• affects numerous bones and mis-interpreted as tumor
• radio-opaque cartilage and bone nodules that may disrupt movement
• hallmark path lesion is well-differentiated cartilage cap subtended by endochondral ossification
• lesions will close when growth ends

osteosarcoma

large breeds

metastasize to lungs quickly

• synovial membrane: hypertrophy, pannus
• articular cartilage: fibrillation
• bone: myxomatous degeneration, pseudocyts, eburnation, proliferation

• large breed dogs
• dysplasia of articular-epiphyseal complex with cartilage thinning and disorganization with fibrosis and possible collapse of subchondral bone. 

synovial cell sarcoma

biphasic tumors epithelial and spindle.

1.      degen with regen

2.      degen and necrosis with some regen

3.      degen and necrosis with fibrosis

1.      intact basal lamina or sarcolemmal tube for scaffolding

2.      satellite cells (aka proliferating myoblasts)

dehydration-->  nuclear material erupts dorsally into vertebral canal housing spinal cord.

very painful

complete the table:

       type 1                      type 2A                     type 2B

metab

speed

# of mitos

ATPASE

function 

                type 1                  type 2A                type 2B                                

metab           oxi                 oxi/glycolytic        glycolytic        

speed        slow                      fast                      fast

# of mitos    lots                     moderate               few

ATPASE        low                     moderate               high

function   postural                   rapid act         rapid act

• vacuolar degen-intracytoplasmic vacuoles
• hyaline degen-glassy eosinophilic cytoplasm without striations

1.      striations lost

2.      macs and PMNs enter tissue

3.      satellite cells enlarge and divide

4.      satellite cells move to center of myofiber “nuclear rowing” is key sign

5.      later cross striations reappear

1. transection of radial nerve in HBC

2. left cricoarytenoideius dorsalis due to left recurrent laryngeal derve damage

what are the common bac causes of abscesses  (KNOW!)

•  strep zooepidemicus (horses)
• Arcanobacterium pyogenes (cattle and sheep)        
• cornyebacterium pseudotuberculosis (horse, sheep, goat)

o   perfringens

o   chauvoei

o   septicum

o   novyi

Black leg. Clostridium chauvoei

ingested, dormant in skeletal muscle, trauma, exotoxins 

• toxin halts release of Ach at NMJ
• dogs/cats not very susceptible (rodent eaters)
• soil and GI tract spores
• irreversible damage presynaptic axon terminals
• horses susceptible, dysphagia and tongue weakness can cause aspiration pneumonia

• hyperkalemic periodic paralysis quarterhorses,
• autosomal dominant recurrent weakness 
• muscle fasciculations 
• hyperkalemia ONLY during episodes

-↑CK and AST

What is the #1 plant cause of toxic myopathy in cattle?most common cause of segmental necrosis of myofibers (esp in diaphragm) in pigs

HYPP (autosomal dominant)

Duchenne's muscular dystrophy (X-linked)

fainting goats (autosomal dominant)

defect in dystrophin

X-linked

repeated bouts of necrosis and regeneration of skeletal muscle varies from early death to survival with resp failrue due to seevere diaphragmatic myonecrosis

immune mediated

Ab against Ach receptors on skeletal muscle

self-tolerance

thymomas can initiate a loss of tolerance to Ach receptors

what is the mech for fainting goats?

what are the serum CK and AST levels?

autosomal dominant

chloride channel in skeletal muscle defect

serum CK and AST normal (no leaking

• feed additive used in cattle and poultry as coccidiostatic to improve growth
• horses extremely sensitive, pale muscles, myonecrosis.
• ionophores form lipid soluble dipolar reversible complexes with cations

eosinophilic myositis

german sheps with difficulty eating

acute disease with swollen temporalis and masseter

chronic disease with atrophic masticatory muscles

Ab agains IIM myosin 

young to young adult quarterhorses

strep equi equi

circulating immune complexes

rhadomyolysis

1.      Purpura hemorrhagica-horses

2.      viral-horses, cats

3.      canine polymyositis

4.      masticatory muscle myositis (dogs)

5.      extraocular muscle myositisi (dogs)

6.      acquired myasthenia gravis (dogs/cats) 

E. coli

cattle

• ↑K, ↓K in urine
•   ↓Na, ↑Na in urine
•   ↓Cl, ↑Cl in urine
•   hypovolemia
•  bradycardia