DMN 2 Final Review

What is the orad?

Proximal segment of the intestine (intussusceptum) that telescopes into another section

What is the aborad?

The distal segment of the intestine (intussuscipiens) that receives the telescoping segment

Most common site for intussusception in dogs and cats?

Ileocecal or ileocolic

Intussusception is associated with ______ in young animals

Enteritis

These breeds are predisposed to intussusception

German shepherds and Siamese cats

What is the main concern when mesenteric drag occurs?

Blood vessels are compressed → edema, hemorrhage, hypoxia, necrosis

Acute intussusception is what kind of obstruction?

Complete

Signs of acute intussusception:

Severe vomiting, melena/frank blood in feces, straining

Signs of chronic/partial intussusception:

Intermittent vomiting, weight loss, soft/ribbon like stool

Significance of palpating a “sausage shaped” mass

Indicates intussusception

The gold standard for diagnosing intussusception

Ultrasound of bulls-eye or target pattern

Torsion is less than a ____ degree twist whereas volvulus is a at least _____ degrees and up to _____ degrees with GDV

180

180

270

Gastric dilation volvulus is most common in what types of dogs?

Deep chested

Obstruction due to volvulus/torsion can cause:

elevated lactic acid (vascular compromise)

metabolic acidosis (anaerobic metabolism)

dehydration (fluid sequestration/reduced renal perfusion)

How does simple gastric dilation differ from GDV

Only includes distension of the stomach (no rotation) and can resolve on its own

What is a factor that makes dogs more susceptible to GDV

Middle to older age

What part of the stomach is most susceptible to decreased perfusion and eventually ischemic necrosis

Fundus

Why does tachycardia occur with GDV

Congestion of gastric/splenic vasculature causes decreased venous return (hypotension) so catecholamines are released to increase HR and therefore BP

What is the effect of reperfusion injury following surgical repositioning of stomach/spleen

Endothelial damage by ROS, DIC, and SIRs (systemic inflammatory response = widespread inflammation)

How is gastric volvulus differentiated from torsion using radiography?

Location of pylorus in volvulus is dorsal and left

What does a “reverse C” or “double bubble” of the stomach indicate on a radiograph?

GDV from pylorus moving dorsal and left

Most common type of colic is?

Spasmodic

Both _____ colic and ______ colic have increased borborygmi but differ in treatment (on farm vs in clinic)

spasmodic colic(treat on farm)

Enteritis colic (treat in clinic)

How should obstruction/impaction colic be treated?

On farm via nasogastric intubation of water or IV if severe

A horse is found rolling and looking at abdomen, is BAR, HR is 64bpm, RR WRI, increased borborygmi, no reflux, and good response to pain relief. What type of colic?

Spasmodic colic

A horse is anorexic, depressed, pawing at ground, HR of 52 bpm, tacky MM, increased borborygmi upper quadrants and lower right but decreased borborygmi lower left quadrant. Good response to pain relief with no reflux. What type of colic?

Impaction, likely at pelvic flexure

What does palpation of “doughy” intestines in left ventral quadrant of a horse indicate?

Impaction at pelvic flexure

If a horse has reflux and you suspect some type of strangulating colic, where is the issue likely occurring?

Small intestine

If a horse has no reflux but you suspect strangulating colic, where is the issue likely occurring?

Large intestine

Why is it important to give pain relief to horses with any type of colic?

Otherwise they are at risk of developing ileus (pain = more sympathetic and less parasympathetic activity = gastric stasis)

What do you do if you palpate small intestinal loops (no taeniae) in horses?

Straight to surgery (strangulating colic)

What are the 3 responses to hepatic necrosis?

Regeneration, fibrosis, biliary hyperplasia

Portals of entry into liver:

Penetrating trauma

Hematogenous spread (portal circulation)

Retrograde biliary infection (ascending)

Kupffer cells are _______ of the liver and pit cells are _____ of the liver; both are found in ______

macrophages

lymphocytes

sinusoids

Blood-borne infectious agents cause a _____ pattern of hepatocellular necrosis

random/embolic/multifocal

Hepatotoxicities and hypoxic injury cause a _____ pattern of hepatocellular necrosis

zonal

Zonal hepatocellular necrosis causes a _____ pattern that can be viewed grossly

enhanced lobular

Approx ____ of hepatic parenchyma can be removed before function is impaired and regeneration can occur within ______

75%

days to weeks

What determines if healing in the liver occurs by regeneration or by scarring?

If some hepatocytes in the lobule survive the lobule will regenerate, if the whole lobule is destroyed then scarring will occur

Stellate/Ito cells are found within ________ and produce _____, which is significant when fibrosis occurs

the space of Disse (between hepatocyte and sinusoid)

collagen/ECM

What is the significance of nodular regeneration in the liver?

Occurs with chronic/repeated injury and indicated cirrhosis/end-stage liver failure

What is the most common cause of nonspecific reactive hepatitis?

gastrointestinal disease (infiltration of portal tracts by mononuclear infiltrates)

Lymphocytic cholangitis is ________ and occurs mostly in _____

immune mediated

cats

What are the steps of neoplasia progression?

Initiation

Promotion

Progression

Presentation of a solitary well demarcated mass involving the entire hepatic lobule could be diagnosed as?

Hepatocellular carcinoma

Cholangiocellular adenomas are most common in?

cats

What is the gross presentation of a metastatic malignant melanoma on the liver?

Multifocal black masses

Hepatic lipidosis occurs from accumulation of _______

triglycerides

Low-density lipoproteins are formed from a complex of _____ with ______

triglycerides

apoproteins

The gross pathology of a liver undergoing hepatic lipidosis is:

swollen, yellow, and greasy with an enhanced lobular pattern

What animals does hepatosis dietetica occur in?

Young, rapidly growin pigs

What causes hepatosis dietetica and what is it characterized by?

Vitamin E or selenium deficiency

acute hepatic necrosis

White liver occurs due to a deficiency in _____ and is common in ____

cobalt

sheep

Why does cobalt deficiency lead to white liver disease?

Cobalt is needed to make B12 and B12 is needed to make RBCs

No cobalt = anemia = hypoxia and centrilobular hepatocellular necrosis

What is the histopathology of the liver with intrahepatic cholestasis?

Liver has diffuse yellow tracks (canaliculi have bilirubin build up)

Which protozoa cause embolic necrosis of the liver (hematogenous spread)?

toxoplasmosis and neosporosis

Intralesional tachyzoites are ______ shaped and bradyzoites are _____ shaped. Together they are indicative of a ______ infection of the liver

banana

round

protozoa

This nematode causes multifocal hepatic fibrosis and is referred to as “milk-spotted liver”

ascaris suum

Ascaris suum larvae infect the liver of which animal?

pigs

How can dirofilaria immitis effect the liver?

Block the vena cava, preventing venous return, engorging the liver with blood (congestion)

Fasciola hepatica is a liver fluke that infects:

cattle and sheep

Fasciola hepatica adults inhabit the _____ and release eggs into ____

biliary system

bile

Fasciola hepatica can allow for the proliferation of clostridium ____ and ____

haemolyticum

novyi

Clostridium haemolyticum causes _____ in ______

bacillary hemoglobinuria (intravascular hemolysis)

cattle

Clostridium novyi causes ________

infectious necrotic hepatitis

Echinococcus is a ______ that is ______ and infects the liver

cestode

zoonotic

______ is the most widespread zoonotic infection in the world

leptospirosis

Leptospirosis replicates in the ______ and is excreted in ______

liver (also kidney and spleen)

urine

Leptospirosis has toxins that cause ________ which leads to _____ necrosis in the liver and ______ icterus

intravascular hemolytic anemia

centrilobular ischemic

prehepatic

Tyzzer’s disease is caused by which bacteria?

Clostridium piliforme

Clostridium piliforme infects via the _____ route and spreads through the body via _____

oral

entero-hepatic circulation

Tyzzers disease is common in which animals?

Foals (1-6 weeks)

Clostiridium piliforme causes ______ necrosis surrounded by ______ and ______ cells in the liver

multifocal

neutrophil and mononuclear

Tyzzer’s disease causes embolic necrosis of the liver but it may also cause _____ and _____

colitis

myocarditis

Liver abscesses are ______ infections that are common in ______

polymicrobial

foals, neonate ruminants, feedlot cattle

Any type of damage to the _____ allows for translocation of bacteria into portal circulation, leading to _____ pattern of infection in liver (abcesses)

GIT

embolic

Polymicrobial infections are usually by _______ microbes and in cattle the most common type is _______

anaerobic

fusobacterium necrophorum

What are 2 predisposing factors for liver abscesses in feedlot cattle?

rumenitis and ruminal acidosis

Canine adenovirus -1 causes ________ in puppies

infectious canine hepatitis (ICH)

Canine adenovirus-1 can be diagnosed with visualization of ______ in hepatocytes or kupffer cells

large basophilic intranuclear viral inclusions (blue arrows)

Dogs with canine adenovirus-1 may develop ______ which is clinically referred to as ______

immune-complex uveitis

Blue eye

What is rift valley fever

vector borne zoonotic disease of ruminants that causes high mortality and hepatomegaly +embolic necrosis

These substances can accumulate inside hepatocytes

Copper, iron, glycogen, lipids

These substances can accumulate outside hepatocytes

Amyloid and bilirubin

Right-sided heart failure causes ______ in the caudal vena cava leading to ______ of the liver

elevated pressure

passive congestion

Passive congestion leads to hypoxia of ________ which results in enhanced lobular pattern (also called ______)

centrilobular zone

nutmeg liver

Congenital portosystemic shunts cause animals to be _______ and develop signs of ______ (neuro issues)

stunted

hepatic encephalopathy (hyperammonemia)

Animals with congenital PSSs will have ______ livers

small

Large breed dogs have ______ shunts

intrahepatic

Small breed dogs and cats have _____ shunts

extrahepatic

Animals with congenital PSS have abnormal ammonia metabolism leading to _____ deposition in the urinary bladder

ammonium biurate crystalluria

Congenital portal vein hypoplasia occurs in _____ and is also called ______

small breed dogs

hepatic microvascular dysplasia

Dogs with portal vein hypoplasia will have _____ and _____

microhepatica

ascites (portal vein hypertension)

Persistent portal hypertension can cause _____ and development of _______

ascites

acquired portosystemic shunts

The most common type of amyloidosis is _______ which is secondary to chronic inflammation

amyloid associated protein (AA)

Where does amyloid deposition occur in the liver?

Starts in space of Disse and extends into sinusoids

Amyloid is stained with ______

congo red

Hepatocellular copper accumulation leads to production of ______ which causes _____ necrosis

reactive oxygen species

centrilobular

Copper metabolism disorders are common in _______ due to a mutation in the _____ gene

Bedlington terriers

COMMD1

Copper is stained with

rhodanine