Pathology II Exam II Material Flashcards
Post-weaning multisystemic wasting syndrome (PMWS) is caused by Porcine Circovirus 2 (PCV-2) and results in generalized lymphadenopathy. Histologically, you will see lymphoid depletion with expansion of paracortical zones.
Which cell types are involved with infiltration of the paracortical zones?
Histiocytic cells and multinucleated giant cells (MNGC)
**Botryoid inclusion bodies are pathognomonic for this disease**
Which form of amyloidosis is most common in domestic animals?
Secondary (reactive) amyloidosis
Which virus is responsible for Infectious Canine Hepatitis [ICH]?
Canine adenovirus 1
What is most common sequela of hemopericardium?
Cardiac Tamponade
Extensive hemopericardium can interfere with the dilatation and contraction of the ventricles, causing cardiac tamponade
This fibrinous pericarditis presents in a cow along with an emphysematous myositis. What is the etiology?
Clostridium chauvoei
“Black Leg” Disease
What are the characteristic histological lesions associated with pyrrolizidine alkaloid toxicity?
Megalocytes
Megalocytes are hepatocytes with enlarged nuclei and increased cytoplasmic volume. They may be many times the size of normal hepatocytes
Clusters of variably-sized, intensely basophilic, intracytoplasmic botryoid inclusion bodies within histiocytes are pathognomonic for:
Postweaning Multisystemic Wasting Syndrome [PMWS] (Porcine Circovirus 2)
**pigs 5-12 weeks old are most commonly affected**
These multifocal to coalescing off-white raised nodules (granulomatous nephritis - dry form) in a cat are very characteristic of:
Feline Infectious Peritonitis
T/F: Most malignant tumors in the liver are metastatic from other organs
True
T/F: Hepatocellular carcinoma is a malignant neoplasm of hepatocytes
True
Hepatocellular carcinomas are most often seen in dogs, are irregularly shaped, and are not well-demarcated
The most likely cause of renal papillary necrosis in this horse is:
NSAID toxicity
NSAIDs inhibit prostaglandin synthesis, decrease production of PGE2, leading to loss of vasodilatory effect on arterioles in the region of the juxtamedullary nephrons. The result is ischemia and eventually papillary necrosis.
What is the most likely diagnosis in this cat?
Squamous cell carcinoma (SCC)
This multifocal granulomatous hepatitis (“target lesions”) in a turkey is most likely due to which organism?
Histomonas meleagridis
Condition is known as Histomoniasis or “Blackhead”
Etiologic Diagnosis?
Rhodococcal lymphadenitis
____________ results from damage to the air-blood barrier and plasma fluid leaks into the alveoli
Pulmonary edema
Pulmonary edema is often the cause of death in uremic animals
Twin pregnancy in ewes is commonly associated with which metabolic disease?
Ketosis
In pregnant & lactating animals, there is a continuous demand for glucose and amino acids and ketosis occurs when fat metabolism (occurs in response to increased energy demands) becomes excessive
Inflammation of the gall bladder is referred to as:
cholecystitis
Partial or complete thrombosis of the hepatic veins is known as ___________ syndrome
Budd-chiari syndrome
Budd-chiari syndrome is characterized by hepatomegaly, ascites, and abdominal pain. It is caused by thrombosis of the hepatic vein and the adjacent inferior vena cava
What is the characteristic target organ for Tularemia? Describe the pattern of necrosis that is typically associated with infection.
The target organ for Tularemia is the spleen.
Tularemia causes miliary necrotizing splenitis. Similar miliary necrosis may also be seen in the lymph nodes and the liver.
If you see splenic infarcts in a pig, which disease should you be concerned about?
Hog Cholera (Classical Swine Fever)
Classical Swine Fever is a reportable disease!
Which paraneoplastic syndrome is commonly associated with thymoma in cats?
Generalized exfoliative dermatitis
What is the main function of the exocrine pancreas?
production and secretion of digestive enzymes
In which 2 species is spenic volvulus most common?
Dogs and Pigs
In these species the spleen is attached loosely to the stomach by the gastrosplenic ligament.
Twisting occurs around this ligament, leading to obstuction of venous flow, and eventually congestion (and sometimes infarction)
Mulberry Heart Disease in pigs is most commonly caused by:
Vitamin E/Selenium Deficiency
Which parasite is known as the “barber pole worm?”
What is the biggest distinguishing factor for an animal infected with the barber-pole worm?
Haemonchus contortus
Haemonchus contortus feeds on blood and can cause anemia, hypoproteinemia, and bottle jaw
There are three morphological types of glomerulonephritis.
The picture below shows a thickening of the basement membrane. What type of glomerulonephritis is pictured?
Membranous glomerulonephritis
Identify the developmental pancreatic abnormality associated with small nodules in the duodenum, small bowel, spleen, liver, gall bladder, and mesentery:
Ectopic Pancreas
This is an incidental finding, occasionally seen in dogs. The ectopic tissue is of normal integrity and presumably functional.
Which bursal infection induces neoplastic proliferation of B-lymphocytes?
Lymphoid Leukosis (Avian Leukosis Virus)
**rarely induces changes in nerves, skin, or iris as seen in Marek’s disease**
T/F: Thymic lymphomas rarely metastasize
False
Thymomas rarely metastasize
In which site(s) do we see lymphoma in chickens with Marek’s Disease?
Kidney and Skin
What is the common name for this presentation in a pig?
Mulberry Heart Disease
(caused by Vitamin E/Se deficiency)
What is the most likely etiology for the valvular endocarditis pictured below in the heart of a pig?
Erysipelothrix rhusiopathiae
(Streptococcus suis could be another differential diagnosis)
In which species is dilated cardiomyopathy most commonly seen?
Dogs
Is this an example of an acute or chronic renal infarct?
chronic
Note the area of fibrosis
Which bacterial organism is responsible for Tularemia?
Francisella tularensis
Tularemia is also called Rabbit Fever, Deer Fly Fever, and Ohara’s Disease
Black Disease (infectious necrotic hepatitis) is caused by which bacterial organism?
Clostridium novyi type B
The cortical hemorrhage seen in this kidney is likely the result of which viral infection?
Herpesvirus
What are Gamna-Gandy bodies composed of?
bilirubin, hemosiderin, and calcium
Gamna-Gandy bodies are also referred to as siderotic plaques. They are often present in older dogs and are likely sequalae to previous hemorrhages induced by trauma of the spleen
_________ is a term often used to desribe kidneys that are severely affected by chronic inflammation and fibrosis
End-Stage Kidney
From which cell type do hemangiosarcomas originate?
endothelial cells
What is the main reservoir for Tularemia?
Wild Rabbits
(also carried by rodents)
A malignant tumor of striated muscle is termed:
rhabdomyosarcoma
T/F: Pancreatic nodular hyperplasia is a common incidental finding in old dogs, cats, and cattle
True
There is no clinical significance to the lesions, but they must be distinguished from neoplasms of the endocrine and exocrine pancreas
T/F: Cysticercosis in humans results from the ingestion of cysticerci
False
Cysticercosis in humans (including neurocysticersosis) results from the ingestion of _*Taenia* eggs_, not from ingestion of cysticerci
Which bacterial organism causes Bacillary hemoglobinuria?
Clostridium haemolyticum
Bacillary hemoglobinuria is a disease of cattle and sheep, occurs when the liver is injured, and is caused by Clostridium haemolyticum, which produces a B toxin.
Toxins (particularly phospholipase C) induce hepatocellular necrosis and intravascular hemolysis with anemia and hemoglobinuria. Grossly, a single large area of necrosis is seen in the liver
It is important to distinguish congenital portosystemic shunts from acquired portosystemic shunts.
Acquired shunts are typically a result of:
chronic portal hypertension
Acquired shunts have multiple, thin walled and tortuous blood vessels, and evidence of liver disease
What is the most likely diagnosis for this acute necrotizing and suppurative myocarditis in a cow?
Histophilus somni
A tumor of the nerve sheath is referred to as a:
Shwanomma
Shwanommas are tumors of the nerve sheath, are developed from Schwann cells, and are typically benign.
What is the most common malignant tumor of the canine spleen?
hemangiosarcoma
Pancreatic calculi consist mainly of:
**calcium carbonate **and calcium phosphate
Which nephrotoxic plant causes tubular degeneration and peri-renal edema in pigs and cattle?
Pigweed (Amaranthus retroflexus)
The hyperkeratosis of this foot pad is a manifestation of liver dysfunction. What is the name of this condition?
Hepatocutaneous syndrome
aka Superficial Necrolytic Dermatitis
Which stain is used to histologically confirm amyloidosis in formalin-fixed, paraffin embedded samples?
Congo Red
What is the etiological agent for **Contagious Ecthyma **in sheep?
Parapoxvirus
**this is a zoonotic disease**
What would your top two differentials be for this cat with granulomatous nephritis?
Feline Infectious Peritonitis [FIP] and Lymphosarcoma
(the image is FIP)
This disorder has been associated with generation of free radicals and Vitamin E/Selenium deficiency, and is one of the most common causes of massive hepatic necrosis in pigs
Hepatosis dietetica
Name the congenital disorder characterized by blood from the portal vein bypassing the liver and draining into the posterior vena cava:
Congenital Portosystemic Shunt
A liver that is bypassed by a congenital shunt is very small because it has been deprived of primary perfusion by portal hepatotrophic factors (such as insulin, glucagon, and amino acids)
T/F: *Fascioloides magna *matures in bile ducts, resulting in chronic fibrosing cholangitis
False!
Fasciola hepatica matures in bile ducts, causing chronic fibrosing cholangitis.
Fascioloides magna resides in cysts within the liver parenchyma
Which cells are primarily targeted in the case of Feline Immunodeficiency Virus [FIV]?
T lymphocytes
Specifically CD4+ T-lymphocytes
T/F: “White-spotted kidney” is common in young cattle and is usually an incidental finding
True
Presumed to be some residual lesions of E. coli bacteremia in the first few weeks of life
The bone marrow hyperplasia in this horse is most likely due to which viral disease?
Equine Infectious Anemia [EIA]
Which organism is responsible for Jowl Abscess in swine?
Streptococcus porcinus
This thrombus at the bifurcation of the abdominal aorta and the external iliac arteries in cats is commonly referred to as:
Saddle Thrombus
Brisket edema is caused by _____-sided congestive heart failure (CHF)
Brisket edema is caused by right-sided congestive heart failure (CHF)
The tubular degeneration and peri-renal edema in this pig is likely the result of which nephrotoxic plant?
Pigweed (Amaranthus retroflexus)
What is the most common hematopoietic neoplasm in the cat?
Lymphoma
good job.
Suppurative glomerulitis is caused by:
bacteremia
What is the most likely etiology associated with pyogranulomatous lymphadenitis in a horse?
Rhodococcus equi
If a cow presented with this presentation of interstitial nephritis, what would be your top differential diagnosis?
E. coli septicemia (White Spotted Kidney)
Is the lymph node moist in acute or chronic lymphadenitis?
Acute Lymphadenitis
Juvenile pancreatic atrophy affects young dogs (6-12 months) and is most common in which canine breed?
German Shepherd
Which canine breeds are at increased risk of developing histiocytic sarcoma?
- Bernese mountain dogs
- Rottweilers
- Flat-coated retriever dogs
- Golden retrievers
(If you see the spleen and you’re not given a breed, a good differential would be bacteremia)
Which stain would be appropriate to use on a frozen section of liver tissue to confirm hepatic lipidosis?
Oil Red O
Oil Red O is a lipid stain and is only useful on frozen tissue sections or fresh smears
This pyogranulomatous bronchopneumonia is a classic presentation associated with which etiological agent?
Rhodococcus equi
What is the most common and most potent alfatoxin?
B1
Alfatoxins are ingested in moldy feed (corn, peanuts, cottonseed) and converted to toxic intermediates in hepatocytes. This is more common in warm humid temperatures
In cases of chronic injury, regeneration can result in hepatocellular nodular regeneration, fibrosis, and impaired blood and bile flow. This condition is commonly known as:
cirrhosis
Cirrhosis is characterized by nodular regeneration and post-necrotic scarring. This change corresponds to end-stage of many chronic liver diseases and the liver is usually reduced in size
T/F: Kidneys are typically shrunken and granular in cases of chronic glomerulonephritis
True
Which bacterial organism is responsible for Tyzzer’s Disease?
Clostridium piliforme
What is the etiologic agent for Yersiniosis? Describe the pattern of necrosis associated with infection.
Yersinia pseudotuberculosis
Miliary splenic necrosis is seen. Similar miliary necrosis may also be seen in the lymph nodes and liver.
What is the most consistent gross lesion found in birds affected by Marek’s Disease?
Enlargement of Peripheral Nerve Trunks
This multifocal necrotic hepatitis and colitis occurs in foals, calves, kittens, and puppies. It is caused by Clostridium piliforme. What is the name of the disease?
Tyzzer’s Disease
Caseous lymphadenitis is caused by which bacterial organism?
Corynebacterium pseudotuberculosis
Name the parasite that matures in bile ducts, causing chronic fibrosing cholangitis
Fasciola hepatica
Accumulation of copper is not readily visible with H&E staining. Which special stain is used to demonstrate copper within hepatocytes?
Rhodanine stain
What are the most common plant genera associated with pyrrolizidine alkaloids?
Senecio, Crotalaria, Tichodesma, Heliotropium
pyrrolizidine alkaloid hepatotoxicity results in the presence of megalocytes
In congenital megaesophagus as a result of persistent right aortic arch (PRAA), a vascular ring forms around the esophagus and trachea, preventing full dilation of the esophagus.
Which three structures form the vascular ring?
aorta, pulmonary artery, and ductus arteriosus
Though it’s hard to tell from the sexy look she’s giving you, this sheep is suffering from chronic liver damage and hepatogenous photosensitization.
Which mycotoxin is most likely to blame?
Sporidesmin
Sporidesmin is a mycotoxin from the fungus Pithomyces chartarum, found on dead ryegrass in warm climates
T/F: Alsike Clover toxicity results in megalocytosis
No!
Megalocytosis is NOT associated with Alsike Clover toxicity. Megalocytosis is associated with pyrrolizidine alkaloid toxicity.
What is the main cell type that is targeted in Marek’s Disease?
T-lymphocytes
Marek’s disease is due to viral infection (Gallid herpesvirus-2) and induces lymphoma specifically for chickens!
The image below shows hemopericardium in a dog. What is the most likely cause in this case?
ruptured atrial hemangiosarcoma
Rupture of the wall of the right atrium after invasion by hemangiosarcoma
Which four cardiac abnormalities are associated with Tetralogy of Fallot?
- Overriding aorta: coming out over intraventricular septum instead of left ventricle
- Pulmonary stenosis: narrowing of the pulmonary valve
- Ventricular septal defect: working against pressure due to stenosis
- Right ventricular hypertrophy
Tetralogy of Fallot is a complicated cardiac anomaly characterized by these 4 lesions. TOF is inherited in Keeshond dogs and is frequent in English bulldogs
______-sided heart failure causes portal vein and hepatic congestion
Right-sided heart failure causes portal vein and hepatic congestion, commonly known as ‘Nutmeg Liver’
The reticulated pattern is due to zonal necrosis
The image shows glomerular and medullary amyloidosis. Which stain has been used in the image?
Lugol’s Iodine
Which bacterial organism is most commonly the cause of embolic nephritis?
Actinobacillus equuli
Normal kidneys in abnormal locations are referred to as:
Ectopic Kidneys
Ectopic kidneys are predisposing factors for ureter obstruction and development of hydronephrosis
Is fat necrosis associated with acute or chronic pancreatitis?
Acute Pancreatitis
Which morphologic type of glomerulonephritis is characterized by thickening of the basement membrane, but no increase in cellularity?
Membranous glomerulonephritis
In dogs, chronic pancreatitis is usually due to repeated mild episodes of acute pancreatitis. Describe the characteristics of chronic pancreatitis:
Chronic pacreatitis is characterized by fibrosis, parenchymal atrophy, and chronic inflammation
There are three morphological types of glomerulonephritis.
Notice the increased cellularity in the image. What type of glomerulonephritis is pictured?
Proliferative glomerulonephritis
In which dog breeds would you most likely see Tetralogy of Fallot?
Keeshonds and English bulldogs
Tetralogy of Fallot is inherited in Keeshonds and is frequently seen in English bulldogs
These hydatid cysts are most likely the result of which parasitic organism?
Echinococcus granulosus
The cysts are caused by the larval stages of the organism.
**Taenia hydatigena may also cause these types of cysts**
Valvular endocardiosis is an age-related disease in middle-aged to old dogs characterized by degeneration of valvular collagen. Which canine breed is particularly susceptible to developing this disease?
Cavalier King Charles Spaniel
‘Milk spots’ in this pig liver are most likely due to which parasitic organism?
Ascaris suum
Migration of other parasitic larvae can cause similar changes. The white spots are multiple areas of fibrosis following migration of larvae through the liver
Which canine breeds are predisposed to persistent right aortic arch (PRAA)?
German Shepherds, Irish Setters, and Great Danes
The lymphoid organ found only in birds is ______________ and it is populated mainly by ________ cells
The lymphoid organ found only in birds is the Bursa of Fabricious and it is populated mainly by B-lymphocytes
Which special stain is used for diagnosis of Tyzzer’s Disease?
Warthin-Starry stain
Warthin-Starry is a silver stain. Diagnosis of Tyzzer’s disease is done by demonstrating bundles of large, long bacilli in hepatocytes (in a ‘pick-up sticks’ formation)
Inflammation of the lymph nodes is known as:
Lymphadenitis
Inflammation of the renal pelvis and renal parenchyma is referred to as:
Pyelonephritis
Unlike other forms of nephritis, the lesions of pyelonephritis are not necessarily symmetrical
(pictured below: unilateral pyelonephritis in a cat)
T/F: All lymphomas are viral-induced
False
NOT all lymphomas are viral-induced
These pinpoint off-white spots in the liver of a horse are indicative of which viral infection
Equine Herpesvirus 1
Pictured below is hepatic tissue. Based on this image, what would be your diagnosis?
Hepatic lipidosis
Note the diffuse cytoplasmic accumulation of lipid within the hepatocytes throughout the liver
Name the main preformed toxin present in blue-green algae
Microcystin
The skin of the eyelids, snout, and submandibular area of this pig are edematous as a result of production of a toxin by which bacterial organism?
Escherichia coli
This disease is known as Edema Disease or enterotoxemic colibacillosis, an infection that is specific for pigs. Bacterial endotoxin (verotoxin) causes endothelial cell injury in arterioles, resulting in fluid loss and edema.
One of the more significant changes associated with this disease is edema of the spiral colon (pictured below).
In cattle, Anthrax is a cause of splenomegaly. Would this spleen be hard or soft upon palpation?
Soft!
Dark red to black, soft spleen. This is an example of ‘bloody spleen’
What is a common sequela to ventricular septal defect (VSD) due to force of contraction in the left ventricle pushing into the right ventricle?
“Jet Lesions”
A jet lesion is a raised, rough, firm streak of endocardial fibrosis resulting from long-term trauma by a jet of blood leaking through the damages valve in the closed position
What is the most common paraneoplastic syndrome of thymoma in dogs?
Myasthenia gravis (resulting in megaesophagus)
T/F: There is a cutaneous form of Marek’s Disease
True
Abnormal and permanent dilation of the renal pelvis and calyces with progressive atrophy of the renal parenchyma is known as:
hydronephrosis
Yellow discoloration of tissues due to hyperbilirubinemia is called:
Icterus
Congenital malformation that results from a fusion of the cranial or caudal poles of the kidneys:
Horseshoe kidney
What should be your top differential diagnosis in the case of a protein-losing nephropathy?
Glomerular amyloidosis
Presence of focal areas in the liver in which sinusoids are dilated and filled with blood is referred to as:
Telangiectasis
Telangiectasis is common in cattle and old cats, and doesn’t really seem to have any clinical significance
In which species is hypertrophic cardiomyopathy most commonly seen?
Cats
(look for marked thickening of the left ventricular walls)
Multifocal interstitial nephritis is common in young cattle. What is another name for this presentation?
White Spotted Kidney
White spotted kidney is presumed to be some residual lesions of E. coli bacteremia in the first few weeks of life.
Following the bacteremia, the bacteria localize in the renal interstitial capillaries, migrate through the vascular endothelium, persist in the interstital spaces, and migrate via the lateral intercellular junctions to reach the tubular lumina
T/F: Hepatocellular adenoma is a malignant neoplasm of hepatocytes
False
Hepatocellular adenoma is a _benign_ neoplasm of hepatocytes
What is the name of this post-mortem change?
Bile imbibition
This proliferative cholangitis in a rabbit is most likely due to which protozoal organism?
Eimeria stiedae
Diffuse splenic enlargement is termed:
splenomegaly
Splenic rupture is fairly common, especially in dogs, and is most commonly caused by:
trauma
Canine fibrohystiocytic nodules look very similar to nodular hyperplasia, but may progress to form:
malignant fibrous histiocytoma
A tumor of the aortic body at the base of the heart is termed:
chemodectoma
These skin lesions on a pig are extremely characteristic of infection by which bacterial organism?
Erysipelothrix rhusiopathiae
T/F: The lymph node may be congested and edematous in the case of chronic lymphadenitis
False
Congestion and edema are common in acute lymphadenitis, not chronic
T/F: The lymph node may be necrotic and fibrotic in the case of chronic lymphadenitis
True
Is a pale cortex and medulla characteristic of acute or chronic lymphadenitis?
Chronic lymphadenitis
A pig presents with diffuse severe splenic congestion. What is your top differential?
African Swine Fever
(If this was a cow, Anthrax should be high on your list)
This proliferative ileitis in a pig is caused by:
Lawsonia intracellularis
Swine Dysentery is caused by:
Brachyspira hyodysenteriae
The disease affects mainly pigs 8-14 weeks old and is characterized by large bowel diarrhea with mucous and blood in the feces
What feline condition may cause the lesion evident in the image?
- Hyperthyroidism
- Hypertrophic cardiomyopathy
- Diabetes mellitus
- Subaortic stenosis
- Systemic hypertension
Hypertrophic cardiomyopathy [HCM]
This is an aortic thromboembolism secondary to feline hypertrophic cardiomyopathy (HCM), the most common heart disease of cats.
