Exam 1 Path II Flashcards
Which of the following is more likely to develop neoplastic alimentary tract disease?
- a. dogs and cats
- b. ruminants and pigs
- c. horses
dogs and cats
Which of the following is more likely to develop infectious alimentary tract disease that are poorly controlled by vaccination?
- a. dogs and cats
- b. ruminants and pigs
- c. horses
ruminants and pigs
Which of the following is more likely to develop intestinal displacement?
- a. dogs and cats
- b. ruminants and pigs
- c. horses
horses– colic
Portals of pathogen entry into the GI tract?
- (1) Ingestion (*most common*)
- (2) Coughed up and swallowed
- (3) Systemic hematogenous route
- (4) Migration through the body (ie. parasites)
Cleft Palate (Palatoschisis)
Common in calves Central defect in the midline fusion of the palatine shelves resulting in communication b/w the oral and nasal cavity.
Tongue may protrude through the abdnormalities
Causes of Palatoschisis and Cheiloschisis?
- often a genetic disorder
- toxins = ingestion of Veratrum californicum and other teratogenic plants like lupines, poison hemlock in cattle and sheep
- maternal exposure to drugs during pregnancy
- griseofulvin in queens and mares
- steroids in primates
Common sequela of Palatoschisis?
(1) aspiration pneumonia due to the communication b/w the cavities (2) starvation (unable to generate suction to suckle)
Malocclusion
Congenital abnormalities of the oral cavity. Failure to the upper and lower incisors to interdigitate properly. May result in difficulties in the prehension and mastication of food. Brachygnathia – shorter lower jaw Prognathia – protrusion of the lower jaw
Brachygnathia
Brachygnathia – shorter lower jaw
Prognathia
Prognathia – protrusion of the lower jaw
Other names for Cleft Lip ?
“Harelip” Cheiloschisis
Dental Attrition
loss of tooth structure by mastication
The degree of tooth wear depends on the tooth, the animal species and the types of food.
Abnormal wearing is MOST COMMON in herbivores results in “step mouth”
Peridontal disease
Resident bacterial films and the acid and enzymes they produce to enamel, gingival and periodontal ligamental damage
See:
–Dental Plaques
–Dental calculus (tartar & mineralized dental plaque)
–Decrease alveolar bone and gingival recession and loss of teeth
Wooden Tongue Etiology?
Actinobacillus ligniersesii - gram neg rod primarily in cattle, occasionally in swine and sheep
Thrush (Candidia albicans)
Often is observed in young animals (especially if on long-term antibiotic treatment) or in animals with underlying debilitating diseases see yellow/white plaques on mucosal surface that are the hyphae/yeast of the Candidia
What are lingual lesions manifestations of? (ulcerative and necrotizing glossitis)
–renal failure –viral disease (BVD, FMD) Other Etiology: Infectious agents, trauma, chemical injury, auto-immune, idiopathic
Lymphoplasmacytic Gingivitis & stomatitis is common in:
cats that are FeLV or FIV positive. FCV can also be involved. See Infected gums and mucous membranes
Feline chronic gingivo-stomatitis (FCGS)
Feline chronic gingivo-stomatitis (FCGS) Cinical signs: oral pain, dysphagia, ptyalism and weight loss. Etiology: unclear. Dental plaque, FCV, and immune-mediated mechanisms appear to be involved. FCGS is also common in FIV positive cats.
Chronic ulcerative (lympho-plasmacytic) paradental stomatitis
Chronic ulcerative (lympho-plasmacytic) paradental stomatitis Most common in older dogs Etiology unclear but associated with chronicperiodontal disease and immunosuppresion. Looks similar to feline lymphoplasmacytic gingivitis
Common cause of vesicular stomatitis in cats?
Calciviral infection
Reportable/Foreign Vesicular Stomatis (4 disease) and host?
–Foot and Mouth Disease (Picornavirus) – Ruminants, pigs (cloven hoofed animals) NOT HORSES –Vesicular Stomatitis (Rhabdovirus) – Ruminants, pigs and horses (only one in horses) –Vesicular Exanthema of Swine (Calicivirus) – ONLY PIGS –Swine Vesicular Disease (Enterovirus) – ONLY PIGS
Foot and Mouth Disease Pathogenesis
Viral ingestion/inhalation–> pharynx –> viremia –>oral mucosa & epidermal sites (oral cavity and coronary bands –> lesions develop in areas subjected to mechanical injury –>vesicle à ulcer/erosion –> sloughing
Clinical Signs of Foot and Mouth Disease
Vesicular Stomitits
drooling saliva (ptyalism), lameness due to coronary band lesions, sloughing of the hoof, lesion in areas susceptible to mechanical injury.
Tiger Heart- acute myocardial degeneration and necrosis (pale stripes) that cause high death in young animals
Vesicular Exanthema
Vesicular Stomitits only in pigs
caused by calcivirus
Vesicular/Ulcer lesions on nose, face and feet
What is the name of this? What are 3 etiolgy? Pathogenesis?
Erosive-Ulcerative Stomatitides
(1) dogs and cats with renal disease
(2) BVD in cattle (subtle lesions)
(3) MCF in cows (more severe)
NO vesicle formation.
Due to presence of vasculitis that leads to damage of the surface epithelium and exposure of the lamina propria.
What is this called? what is the etiology and outcome?
Tiger Heart
acute myocardial degeneration and necrosis (pale stripes) that causes high mortality in young animals
Seen in Foot and Mouth Disease
Disease name? Etiology? Description? Histology?
Bovine Papular stomatitis
Etiology: Parapoxvirus
Papules on the nares, muzzle, oral cavity.
Usually present in immunosuppressed individuals.
Appear as “Coin-Shaped papules and Ulcers”, the virus is closely related to pseudocowpox virus that causes “milker’s nodule in humans (hands)”.
See proliferation/raised epithelium due to hyperplasia of keratinocytes.
See ballooning degeneration and eosinophilic intracytoplasmic inclusion bodies
Names? Etiology? Complications? Host?
Oral Necrobacillosis
Fusobacterium necrophorum (filamentous bacteria part of normal flora)
in calf, sheep and pigs
“Calf Diptera” – ulcerative/necrotizing inflammation in oral cavities, pharynx and laryngitis
Complication- problems eating and aspiration pneumonia due to necrotic exudates
What is the expected etiology of Feline eosinophilic granuloma? Why do they think this?
Etiology believed to be immune mediated hypersensitivity due to response to corticosteroid therapy
What breed is gingival hyperplasia most common in?
Boxers
What is an Epulis and what is its prognosis?
Tumor of the periodontal ligament– type stroma
Fibromatous and ossifying epulis are benign.= GOOD PROGNOSIS
Treat surgically
Histological- proliferation of periodontal epithelium embedded into fibroblast stroma
Acanthomatous ameloblastoma
(previously known as acanthomatous epulis)
locally aggressive and often recur after excision – poor prognosis
behaves like squamous cell carcinoma (except this tumor does not metastasize)
Canine oral papillomatosis
Papilomavirus-induced papilliform or cauliflower-type lesions (“warts”) in the lips and oral mucosa
It is transmissible and usually affects animals younger than 1 year-old.
Lesions regress spontaneously and immunity is long-lasting.
Verrucous lesion composed of thick keratinized stratified squamous epithelium covering a pedunculate connective tissue core.
Oral Melanomas
Most Common Species? Prognosis? Predisposions?
Most common in dogs.
Poor prognosis. Around 90% of oral melanomas in dogs are malignant – see pulmonary metastases
Predisposing factors: Smaller breed and oral pigmentation
May lose pigmentation =amelanotic
Where are Squamous cell carcinomas common in cats and dogs?
Tonsils and tongue
Primary congenital megaesophagus
Cause? Location? Complications? Species most common in?
Caused by persistant right aortic arch (PRAA) primarily in dogs (German Shepards are predisposed)
Occurs when the right aortic arch develops instead of the left. This leads to the ligamentum arteriosum forming a vascular ring around the esophagus, causing compression.
The dilitation will be located directly cranial to the heart.
Side effects: weight loss, accumulation of feed, regurgitation, aspiration pneumonia
Secondary Acquired Megaesophagus
3 main causes? Location?
Causes:
(1) Idiopathic
(2) Maniestation of myasthenia gravis- immune mediated destruction of ACh receptors causes relaxation of the esophagus
(3) Polymiositis
Location: immediatly cranial to the stomach
Choke
Cause? 2 Common locations? Consequence?
Cause: Due to obstruction (potatoes, apples, corn cobs)
Location: where impaired dilatation due to hard structures
(1) Dorsal to the larynx
(2) Thoracic Inlet
Consequence:
(1) Impaired eating and drinking
(2) Compression necrosis
Reflux Esophagitis
Reflux of gastric acid causes chemical burns on the distal/aboral esophagus.
Most common cause of esophageal erosion and ulcers.
Common in pigs due to the high incidence of gastric ulcers that damges the esophageal portion of the stomachc and leads to an increase in reflux.
What is this? What causes it?
Erosive-ulcerative esophagitis due to BVD (pestivirus)
See multiple variable sized and shaped ulcers.
Lesion are also seen in the oral cavity and sometime the intestines.
Spirocerca lupi esophagitis
Spirocerca enters the stomach mucosa –> travel through the aorta to the esophagus
Causes caseous granulomatous esophagitis that usually has communication with the lumen so that eggs can be released.
May lead to malignant neoplastic transformation causing the formation of mainly osteosarcomas and fibrosarcomas.
Common in dogs in the caribbean
Ruminal Tympany or Bloat
Primary vs. secondary?
Ruminal Tympany or Bloat= Over distention of the rumena dn reticulum by gases produced during fermentation
- Primary - associated with new diets of highly fermentable products that cause the formation of stable foam
-
Secondary- due to physical obstruction of the esophagus that prevents eructation of gas
- Obstruction can be due to vagus indigestion, esophageal papillomas, and lymphosarcomas that cause lymphanditis
Clinical signs of Ruminal Tympany
- Distended left abdomen and paralumbar fossa.
- (pregnancy causes right side distention)
- Respiratory signs due to increase pressure on the thoracic cavity
- Cranial congestion due to pressure on blood vessels
- Frothy ruminal content (primary bloat)
- Decreased/Acidic ruminal pH (primary bloar)
- Bloat Line at the thoracic inlet
Traumatic Reticulitis
Traumatic reticulitis/ “hardwear disease”
Caused by ingestion of sharp objects (bovine lips prevent them from being very discriminat when eating) that then enter the reticulum. During rumination, the contractions of the reticulum causes perforation of the object into the reticulum wall.
If severe, the forign object may also puncture the diaphram, pericardium (pericarditis & CHF), heart or lungs (pneumonia).
Animals appear in pain, be reluctant to more or stant on unlevel group to prevent any further pressure on the foreign object.
Magnets are sometimes fed to cattle to prevent reticulitis.
To check for traumatic reticulitits during necropsy you should feel between the diaphram and reticulum for any forign bodies or fibrin adhesions.
Chemical Ruminitis/ Lactic acidosis/ Grain Overload
Chemical Ruminitis
Common in feedloack cattle due to high carbohydrate diet that leads to an increase in fermentation in the rumen –> acidic pH–> damage and necrosis of the mucosa
See sloughing of the mucosa that exposes VERY RED, inflammatory submucosa with areas of necrosis, degeneration and pustules (compare to post-mortum ruminal sloughing)
Can treat by surgically removing ruminal contents and replacing them with a healthy ruminal contents from slaughtered animals.
If survive you will have development of Stellate ulcers and/or portal showering of bacteria
Stellate ulcers
Ruminal scars of animals that survive grain overload
What are complications of grain overload?
- Sudden death
- Portal showeing of bacteria - mucosal damage causes ruminal flora to enter the sytemic circulation via the portal vein. See hepatic abcesses and necrosis
- Fibrinonecrotising ruminitis
- Secondary mycotic ruminitis (picture)
- Stellate ulcers
What is this? What species does it commonly occur in?
GDV- Gastric Dilatation volvulus
Occurs in dogs and sows after they eat/drink large amounts and then excersise
K9 Clinical signs: progressive abdominal distention, non-productive retching, hypersalivation and restlessness.
Stomach looks dilated, red, swollen and friable.
Spleen may be displace to the right side due to the gastrosplenic ligament.
Surgical emergency! if wait to long you can have venous infarction –> necrosis–> intraluminal hemorrhage.
Abomasal displacement
Species? Right vs. Left? Clinical signs?
Occurs most often in post-parturient dairy cows and calves
Left-sided is most common: generally non-fatal due to only partial obstruction of abomasal flow
Right-sided: Represent ~15% of the abomasal displacement. 20% of these result in abomasal volvulus.
Clinical Signs: abdominal pain, elevated heart rate, anorexia, dehydration, depressed peristalsis with lack of feces and abomasal tympany (high-pitch ping elicited by percussion).
What is this? When does it occur? How do you tell it is not post-mortem change? How do you prevent it?
Gastric Impaction/Rupture
Occurs in horses due:
(1) intestinal obstruction (ilius) –> adynamic (paralytic) or mechincal ileus that inhibits bowel motility and gastric emptying. ** MOST COMMON**
(2) high grain diet with large amounts of water– due to exspansion
(3) Chronic diaphramatic hernia - may see gastric contents within the thoracic cavity
(4) Persimmon ingestion
Prevention
Horses are unable to vomit, so if a horse is colicing you should pass a nasogastric tube to releive the pressure.
How to tell it is ante-mortem: Hemorrage!
Where do gastric ulcers typically occur in pigs? What are the clinical signs? What is a common cause?
Gastric ulcers in pigs typically occur in the esophageal portion of the stomach (was covered by stratified squamous epithelium).
Clinical signs: due to chronic internal bleeding there is melena & anemia (white pigs will look very pale). In severe cases, the ulcer may perferate –> peritonitis –> death
Cause: Finely ground feeds stimulate excessive Cl production in the stomach. High wheat compenents in feed also plays a role.
What is the etiology of gastric ulcers in horses? where do they commonly occur in foals?
Etiology: stress, immunosuppression, highly fermentable diets, NSAIDs, ideopathic
In young horses: near margo plicatus & ideopathic
NSAID induced gastric ulcers in horses
Why does it occur?
Often occurs after using NSAIDs in colic patients. Colic patients are typically dehydrated, thus even normal doses of NSAIDs can cause issues.
Occurs due to NSAIDs reducing prostoglandins that become PGE2 & PCl1- which have a protective role.
May also see intestinal ulcerations.
Why do dogs with cutaneous mast cell tumors develop gastric ulcers?
Mast cell tumors cause the release of histamine into the blood. Histamine binds to receptors on parietal cells and causes them to increase HCl secretion
If severe, dogs may develop perforated gastroduodenal ulcer that can lead to fatal peritonitis.
What is this? Which species does it commonly occur in? Where and Why does it occur?
Gastric Inflammation of a Pig in the fundus region of the stomach
Occurs secodnary to endotoxemia or bacterial sepsis (salmonellosis is most common, e.coli, glassers disease) that causes gastric venous infarction.
Gastric mucosa will be dark red and may have fibrin exudate and an increase of mucous production.
This occasionally is seen in ruminants and horses
Gastric Inflammation
Where and why does is most commonly occur in pigs?
In the fundus of the stomach
Secondary to bacterial sepsis - ie salmonellosis
What would cause this swollen and red cut section of the stomach mucosa to have a gritty consistency and whitish color?
Uremic gastritis in small animal patient with renal failure
Gritty consistancy and whitish color is due to diffuse mineralization.
Diffuse mineralization can be seen as diffuse black dots on histology with a Von-Kossa staining.
Uremia lead to vascular lesions that cause damage to the mucosa of the stomach and intestines.
Clinical signs of uremic gastritis include chronic vomitting and diarrhea.
May also see ulcerative glossitis in renal failure patients
What causes Bacterial gastritis/abomasitis?
AKA Braxy (bradshot)
Clostridium septicum causes Bacterial gastritis/abomasitis - Braxy (Bradshot)
Clostridium septicum is a gas producing bacteria, thus it will present as fiable, edematous, hemorragic necrotising and emphysematous gastritis
Occurs after ingestion of frozen food that contain the bacteria and cause mucosal damage.
What is this lesion? What is the pathogenesis?
Mycotic gastritis/abomasitis caused by angio-invasive fungi (Aspergillus, Absidia, Rhizopus, Mucor spp. etc.) that have a predilection to blood vessels and cause mycotic vasculitis/perivasculitis and thrombosis that result in round focal areas of ischemia.
Multifocal lesions are necrohemorragic and typically covered with a fribinonecrotic exudate mixed with fungal hyphae
Common sequel of long-term antibiotic therapy, immunosuppresion, debilitating conditions (sepsis) and grain overload.
Can confirm fungal hyphae around blood vessels via GMS stain.
What is going on with this horse? what is the clinical signifigance?
Parasitic gastritis due to Gasterophilus nasalis and intestinalis = Bot fly larvae
Gasterophilus nasalis is located close to the intestines
G. intestinalis is close to the esophageal portion of the stomach
NO CLINICAL SIGNIFIGANCE- even in severe infestation
What is this abnormality in the abomasum? Etiology?
Proliferative (hyperplastic) abomasitis due to Ostertagia spp.
“Moroccan leather” appearance
What is this large nodule near the margo plicatus of a horse?
Draschia megastoma (nematode) brood pouch causing a Granulomatous gastritis.
Will be able to find nematode within…
What parasite will most likely cause bottle jaw and pale mucous membranes in sheep and goats? Why do you see these clinical signs?
Trichostongylid nematode Haemonchus contortus“Barber pole worm”
Severe parasitic abomasitis results in chronic blood loss –> anemia & hypoproteinemia & melena
What is the most common gastric tumor in horses? Where is it commonly located?
Gastric squamous cell carcinoma
Arises in the esophageal portion of the stomach. It may looked depressed or proliferative, may be surrounded by digested blood.
It is locally aggressive and will penetrate and invade all muscle layers of the stomach wall and then cause peritoneal carcinomatosis via transcoelomic transplantation.
Clinical signs: weight loss and internal bleeding (anemia & melena)
One of the most common tumors in horses in general.
What are the large ulcerative nodules seen in the stomach of this horse?
What species can these occur in?
What do you have to differentiate this from in horses?
Gastric Lymphosarcoma
Occurs in ANY species!
Have to differentiate from Drashia.
Lymphosarcomas are located everywhere and will have a solid appearance and no presence of parasites.
Ulcers seen in esophageal portion of the stomach of the picture is probably due to the stress of the animal having a tumor.
What is a common cause of gastric lymphosarcoma in older cows?
Bovine Leukemoa virus = Enzootic Leukosis
Enlarged lymph nodes and multicentric lymphosarcoma.
Abomasum folds will be thickened and nodular. On a cut surface there is presence of a solid pale-tan tissue.
Mass in the submucosal causes compression of blood vessels –> ischemia –> necrosis.
May have ulceration and see melena.
What is Atresia coli?
Atresia coli is the most common segmental anomaly of the intestines in domestic animals.
Range from stenosis (incomplete occlusion of the intestinal lumen) to atresia (complete occlusion/ obliteration of the intestinal lumen).
Due to ischemia of gut during fetal development.
Autosomal recessive trait in hosteins calves
Will be unable to deficate and have abdominal distension due to megacolon.
What is atresia ani?
Atresia ani = imperforate anus
Females may be able to survive this condition longer if they form a concomitant recto-vaginal fistula.
Will have distended megacolon –> abdominal distenstion
What breed is lethal white syndrome most prevelent in?
American Paint Horses
What is wrong with this calf?
Lethal White Syndrome / Congenital Colonic Aganglionosis
Autosomal recessive genetic disorder in which completely/mostly white horses will lack of myenteric and submucosal parasympathetic ganglia in the wall of the ileum, cecum and colon. Leading to intestinal immotility and colic shortly after birth.
Grossly on necropsy the large colon and cecum will be reduced in size and you will not see any parasympatheitc ganglion.
Foal is unable to eliminate the “first feces”/Meconium that contains sloughed cells and other contents –> colic.
What is this? What is is composed of?
Entrolith
Composed of concentric lamellae of magnesium, ammonium phosphate (struvite) deposit around a “nucleus” foreign body such as a nail, wire etc.
Vary in size, some may weight up to 10 kg.
What is a Trichobezoar?
Trichobezoar= Hair ball!!
Found in cats, dogs and cattle. Can cause obstruction.
Not as heavy as enteroliths.
What is a Phytobezoars?
Phytobezoars= plant material impregnated with some phosphate salts
May be found in the colon of horses.
If mixed with hair it is referred to as phytotrichobezoars
In which species are Ascarid impactions most severe in?
Pigs and Foals
May cause obstruction
What is this? What is the most common cause?
Rectal Stricture in pig due to salmonellosis (S. typhimurium)
Salmonella causes vasculitis of the cranial hemorrhoidal artery –> ischemia –> helaing by fibrosis –> stricture and stenosis.
Pig will also have abdominal pain and distention due to megacolon.
What is a common cause o Rectal stricture in pigs?
Salmonella typhimurium
Internal vs. external hernia
Internal hernia: Displacement of intestine through a normal or abnormal foramina within the abdominal cavity (rare).
Examples: incarceration (entrapment) of loops of the intestine within the slit-like epiploic foramen, or a rent (tear) in the omentum or mesentery.
External hernia: Displacement of loops of intestine, omentum and occasionally other viscera (hernial contents) outside the abdominal cavity.
Displaced contents are inside of a pouch (hernial sac, formed by the peritoneum and the skin) which protrudes through the hernial ring - an opening in the abdominal wall which could be acquired or natural (e.g.: vaginal ring of the inguinal canal).
What is eventration?
Eventration= When displaced abdominal contents are not covered by parietal peritoneum or skin the lesion.
What is happening here? causes?
Diaphramatic Hernia
Due to trauma or congenital (loose diaphramatic hiatus)
Will se respiratory sigsn and hear abdominal sounds within the thorax,
What is incarceration of a hernia?
Incarceration= fixation of loop of intestine within the hernia.
Can lead to venous infarction, sepsis and death
What is happening to this horses left colon? sequel?
Torsion!
Wrapping of the intestines around itself.
Sequel= venous infarction –> congestion –> necrosis –> endotoxemia –> septic shock
What is intestinal volvulus?
torsion of a piece of intestines along its mesenteric axis
Segment will be dark red due to congestion, as well as edematous and friable.
What are the arrows pointing to?
Pedunculated lipoma
Benign tumor of adipose tissue that arises from the mesentery.
Tumors may have a stalk/peducle attached to them that can twist around section of intestions.
Common in old horses.
If necrosis of the center of a large lipoma there will be dystrophic mineralization and the lipomas will become heavy and more likely to twist around intestines.
Intussescipiens
Vs.
Intussesceptum
Intussescipiens- portion “eating” the other section of intestine. Outside
Intussesceptum- smaller portion within another section of the bowel. Inside.
What are some predisposing factors to intussusception?
Enteritis –> increased peristaltic activity
Parasite infestation
Ideopathic!
What do you call inflammation of the cecum?
typhlitis
What are typical signs of inflammation of the intestines?
diarrhoea which leads to dehydration, acidosis,
malabsorption, hypoproteinemia, electrolyte imbalance.
Can have portal showering of bacteria & fatal endotoxic shock
What lesions will you see in animals with BVD (Pestivirus)?
Payer patch necrosis & areas of subtle ulceration in the oral cavity, forestomach and intestines.
May be mild or subclinical.
Mucosal disease (most severe form) occurs commonly in persistantly infected (immunotolerant) animals that develop/obtain a cytopathic strain of the virus.
Affected animals are usually 6-12 months of age.
Malignant Catarrhal Fever
MCF infects a variety of ruminant (bison, cervids) and sheep in the USA.
Low morbitity, high mortality
Produces fibrino-necrotizing vasculitis with prominant perivascular infiltrates on many organs and tissues (ex. kidney)
Also damages lymph node tissies.
Vasculitis will lead to erosion and ulceration in the oral cavity, Gi tract and on the coronary bands.
Enteric Coronaviral Infection
Transmissible gastro-enteritis (TGE) in pigs and common cause of neonatal diarrha in calves (w/ rotovirus and cryptosporidium).
Causes severe villous atrophy/blunting of the tios and sides of the villi
Gross: intestinal wall will be very thin (due to villous atropy) and you will see fluid and gas as the intestinal contents.
Enteric rotoviral infection
Causes diarrhea in young animals (all species)
Causes damage to surface/tip enterocyes resulting in variable degreems of strophy
Subclinical infections are common in piglets.
Parvovirus enteritis
Caused by CPV-2 and Feline Panleucopenia virus.
Targets fast resplicating cells in the intestinal crypts cells and bone marrow (in Feline form)
Serosal surfaces will look granular and red.
Causes Segmental fibrino-hemorrhagic enteritis, necrosis of peyers patches, and issues associated with bone marrow suppresion (in cats)
May see unique regenerative changes in the remaining crypt cells or intranuclear inclusions.
FeLV in older cats will produce similar enteritis lesions.
What is wrong with this cat?
FIP -very important cat disease
Two forms: (can have both)
(1) Wet form: peritoneal and thoracic perfusion due to vasculitis
(2) Dry form- solid puogranulomatous lesion due to vasculutis
Will commonly see gray plaques on the surface of the intestines, liver and spleen. Also in alignment with the blood vessels of the cortex of the kidney
What is wrong with a cat with a kidney that looks like this?
FIP
maybe lymphosarcoma
Name me four types of E.coli (from chart in lecture 3A)
Enterotoxigenic colibacillosis= Secretory diarrhea (enterotoxininduced) in Neonatal pigs, calves and lambs
Septicemic colibacillosis=Failure of passive transfer of maternal antibodies in Neonatal calves, pigs, foals. Enteritis is not common –sudden death or subacute & chronic disease (meningitis, polyarthritis etc)
Post- weaning colibacillosis= Similar to enterotoxigenic colibacillosis with secretory diarrhea & mild or no lesions
Weaner pigs Attaching & Effacing - attached to surface enterocytes and cause villus atrophy. Some may not produce toxins. In Pigs, dogs –less common in other animals.
What is probably wrong with this pig?
Edema disease (enterotoxemic colibacillosis)
Caused by strains of E. coli that produce the edema toxin that cause endothelial cell injury in arterioles resulting
in fluid loss and edema.
It is most common in pigs a few weeks after weaning.
Will see diffuse edema, specifically a swollen face, periorbital edema and edema of the mesentery of the spiral colon.
Affected animals may exhibit focal bilaterally symmetric encephalomalacia (Cerebrospinal angiopathy of swine) after the acute phase due to blood vessel damage that leads to cerebral edema and degenerative changes.
What is the most common cause of clostridial enterotoxemia?
Clostridium perfringens Type D
See severe hemorrhagic lesions in the intestines
Which animals are most commonly affected by clostridial enterotoxemia?
young, best nourished animals in the group
What toxin of C. perfringes type D causes focal symmetrical encephalomalacia (FSE) in sheep?
Angiotoxin/Epsilon toxin
toxin has predilection for blood vessels within the brain
(Will also see severe hemorrhagic enteritis)
What C. perfringens causes clostridial enteritis in chickens?
Type A (& C)
Lesion are similar to Type D= necrohemorragic enteritis
Will see layer of gram negative bacilli on surface layer of intestines in histology.
Tyzzer’s Disease
Clostridium piliforme
Main target is liver, but lesion also on intestines (port of entry) and heart
Colitis X
Clostridium perfringens typa A & Clostridium difficile
Fibrinonecrotizing Typhlocholitis in horses
Result of dysbacteriosis ( associated with antibiotic therapy or dietary change) leadin to proliferation of toxigenic clostridia
Salmonellosis
ALL species are pathogenic
Disease range from enterocolitis to septicemis
Causes ulcerative & fibrinonecrotizing enterocolitis
Intestinal contents will be malodorous and contain mucus, fibrin and occasionally blood (feces: “septic tank odor”).
Mucosa will be thickened (edema), friable, with areas of hemorrage and necrosis with fibrin and mucous on surface
Stress factors play a role
Zoonotic and nosocomial (common in horse hospitals)
Complications of disease:
embolic mycotic pneumonia (multifocal necrohemorragic with red margins due to secondary angioinvasive fungi)
Rectal strictures –> megacolon
Horse
Fibrino-necrotizing entero-colitis
DDx: Salmonellosis or Colitis X
Embolic mycotic pneumonia
Sequel of Salmonellosis
Due to opportunistic angiovasive fungi from intestinal contents
Pig
Button Ulcers
DDx: Chronic Salmonellosis -or- Hog Cholera (CSF)
Can lead to rectal stictures –> megacolon
Pig
Lawsonia intracellularis
Porcine Proliferative Enteropathy (PPE)
Common in the enterocytes of the ilium** and late jejunum of weaner and young pigs.
Intestines will have “garden hose appearance” due to the mark thickening
May become proliferative hemorrhagic enteropathy in older animals= intestinal contents will be blood. High mortality, low morbidity.
Use silver stain to see bacteria.
Swine dysentery
Swine Dysentry (Spirochetal colitis)
Caused by Brachyspira hyodysenteriae
Affect pigs 8-24 wks (low incidence in USA)
Large bowel diarrhea with mucus and blood in feces
Will had edema/thickening of the wall, ulceration, hemorrage, fibrin, mucous (bacteria induces goblet cell hyperplasia) within the large intestines.
Rhodococcus equi
- Causes an enterocolitis in young horses
- Virulent factors allow the bacteria to survive within the cytoplasm of macrophages and cause chronic disease
- Typically R. Equi is associated with suppurative pyogranulomatous pneumonia in foals.
- The enteric lesions are ulcerative and pyogranulomatous and are associated with prominent regional lymphadenitis.
- Also, causes osteomyelitis in horses
Foal
Pyogranulomatous lymphadenitis, R. equi
Foal
Rhodoccocus equi pyogranulomatous pneumonia
Cow, Older then 19 months
Johne’s Disease (Mycobacterium avium paratuberculosis)
Chronic disease of rumunants
Characterized by D, emationation and hypoproteinemia.
Usually occurs in animal older than 19 months
Low morbidity
Lesions are most likely in the ileocecal area= cerebriform appearance due to granulomatous inflammation (M0 are the main component). Also found in the lieum, cecuma and proximal colon.
Acid fast stain will confirm diagnosis
Sheep typcally have subtle lessions but will exhibit prominant/thickened lymphatic vessels due to pyogranulomatous lymphangitis
Sheep/Goat
Johnes Diseas
Sheep typcally have subtle intestinal lessions but will exhibit prominant/thickened lymphatic vessels due to pyogranulomatous lymphangitis
Boxer (dog) colon
Granulomatous Colitis due to special strain of E. coli
Genetic component
See multifocal ulcerative lesions of the colon that may have raised borders due to the pyogranulomatous reaction.
Will see macrophages containing gram negative bacteria in the lamina propria.
Clinical signs: diarrhea, sometimes bloody –> ematiation
Cryptosporidiosis
Causes diarrhea in calve. Usually associated with other etiology (corona, rotovirus)
Will see protozoal organism (basophilic blebs) on the apical surface of the enterocyte
causes a reduced absorptive surface –> diarrhea
ZOONOTIC!!!!!
Goat and sheeps
Coccidial enteritis
In sheep and goats, it causes hyperplasia of the mucosa –> grey raised nodules
Coccidial enteritis
Coccidia parasitize epithelial cellls of the intestines–> deaht of cells –> necrophemorrhagic enteritis.
Clinical Signs: bloody diarrhea, loss of condition, hypoproteinemia.
Proliferative enteritis in goats and sheep.
Male parasites will be blue, and females will be red on stain.
Ancylostoma caninum & Uncinaria stenocephala
Canine Hookworms
Blood sucking parasites that cause significant anemia and hypoproteinemia in puppies
Larvae may be found in colostrum.
Horse
ANOPLOCEPHALA PERFOLITIA
Cause issues at the ileocecal valve –> ilial hypertrophy –> colic
Trichuris spp.
Whipworm
Parasitize the cecum and colon of domestic animals.
Most infections are subclinical
Severe infections may lead to bloody diarrhea, weight loss, dehydration and anemia.
Pig. DDx? Which is most common?
“Milk spot liver”= fibrosis of the conntective tissue capsule and periportal fibrosis.
Etiology: *Ascaris suum & renal worm (Stephanurus dentatus)
Ascaris suum is most common
Stephanurus dentatus is common in free-range pigs in St. Kitts.
Intestinal tumors are most common in which species?
Dogs and cats
Most primary tumors are carcinomas
What are most primary tumors in the intestines?
Carcinomas
What is the most common form of neoplasm in cats?
Lymphosarcoma (LSA)
The alimentary form of LSA has the highest incidence in cats.
Where do most lymphosarcomas of the intestines arise from? what is the exception
Lymphosarcomas in the intestines are usual manifestation of multicentric lymphosarcomas.
The exceptions may be in cats, in which the alimentary form of lymphosarcomas are primarily from the intestines.
what is the largest visceral organ?
LIVER
How much cardiac output does the liver recieve? how is it divided?
25% cardiac output
67% portal vein / 33% hepatic artery
Why woudl you want to know the % body weight the liver is?
In necropsy, to determine if the liver size is abnormal.
Carnivores 3-4% body weight
Omnivores 2% body weight
Herbivores 1% body weight
(NO NOT MEMORIZE %)
What is in the portal triad?
Bile ductules (3-4)
Branches of portal vein
Hepatic artery
Nerves and lymphatics
How does blood flow travel in the liver?
portal triad –> central
toxic injury near portal triad
hypoxic injury near central vein
What direction does the bile flow in the liver?
central vein –> portal triad bile ducts
What are the other names of the 3 Liver Zones? Where are they located?
Zone 1 or centroacinar (periportal) surrounds the portal triads
Zone 2 or midzone is the intermediate or midlobular area
Zone 3 or periacinar (centrilobular) surrounds the central veins
What cell makes up 80% of the liver mass?
Hepatocytes!
Kuffer cells
regional macrophages
participate in immune and regenerative response
Stellate/ Lipocyte/ Ito cells
produce and maintain entracellular matric and store vitamin A
Ito cells play role in fibrosis (drug target)
7 functions of the liver?
- Bilirubin metabolism
- Bile acid metabolism
- Carbohydrate metabolism
- Lipid metabolism
- Xenobiotic metabolism
- Protein synthesis
- Immune function
How much injury can a liver have before there are obvious clinical signs? What are ways to catch liver injury early?
Clinical signs appear after approximately 75% of the parenchyma is injured
Liver enzymes (AST, ALT, LDH, alkaline phosphatase, gammaglutamyl transpeptidase) can be elevated early; thus they are commonly used as biomarkers of liver injury
Portals of entry of injurous agents to the liver?
- Hematogenous
- Retrograde through biliary and pancreatic ducts
- Direct extension through the liver capsule (example: trauma through the abdominal wall, rib cage, lumen of the gastrointestinal tract)
6 Mechanism of Liver Injury?
- Metabolic bioactivation of chemicals to reactive species
- Stimulation of autoimmunity
- Stimulation of apoptosis
- Disruption of calcium homeostasis
- Canalicular injury
- Mitochondrial injury
5 different responses to liver injury?
- Atrophy (whole organ, individual cell)
- Hypertrophy and hyperplasia
- Regeneration of parenchyma
- Replacement by fibrosis
- Biliary hyperplasia
What are 4 causes of liver atropy?
Increased catabolism /Decrease anabolism (ie portal shunt)
Decreased blood flow
Decreased bile flow
Pressure
What % of liver can regenerate within a week!
60%
What are liver stem cells called? what can they differentiate into?
Oval (stem) cells can differentiate into hepatocytes or bile duct epithelium
What is required for liver regeneration?
- Intact framework (reticulum fibers)
- Good blood supply
- Patent bile ducts
What is a regenerative nodule?
Hepatocellular regeneration due to sustained or repetitive hepatocellular injury is often nodular.
Histolofically looks like an unorganized cluster of cells, lacks a capsule.
Surrounding area in pucture also has bile duct hyperplasia due to response to injury
What happens during liver fibrosis?
- Increased amount of connective tissue within the liver
- Ito (stellate) cells also proliferate
• Significance is dependent upon effects on normal hepatic function and type of collagen (removal and remodelling)
dog
End stage liver / Liver Cirrhosis
In cases of chronic injury, regeneration can result in hepatocellular nodular proliferation/regeneration with fibrosis (post-necrotic scarring) between nodules and impaired blood and bile flow.
Liver usually reduced in size
Severe bilary hyperplasia
Horse
Capsular fibrosis/perihepatitis in horses (incidental lesion)
Due to: Resolution of peritonitis, Parasitic migration, friction
• Also known as “perihepatitis filamentosa”
Cattle or horse
Focal areas of pale discoloration
Adjacent to mesenteric attachment= incidental
Seen occasionally in cattle and horses
What causes liver rupture? What are the common sequelas?
Rupture etiology: Trauma or Enarged Liver
Sequela: death due to hemoperitoneum -or- healing by spider web fibrosis (picture)
Liver post-mortem changes
Occur rapidly- especially if hot environment
Pale, irregular foci
Greenish black discoloration near the intestine
Emphysema
Liver autolysis will make your histology slides crappy
What are the three tpes of LIVER DEGENERATION AND
NECROSIS- PATTERNS?
- Random (Single cell, Multifocal, Piecemeal necrosis)
- Zonal
- Massive
describe the pattern of necrosis/degeneration
Random, multifocal liver necrosis
Size: Etiology: Infections= bacterial (pig salmonellosis), viral (equine herpes), parasitic.
Describe! What is a Common cause?
Centrilobular or Zone 3/ periacinar necrosis
commonly due to hypoxia
Decribe the type of liver necrosis? How common is this?
Midzonal/Zone 2 necrosis
Very rare. Seen in yellow fever.
Describe! What is a common etiology?
Periportal necrosis
Common Etiology= toxic
Massive hepatic necrosis
necrosis that involved entire lobule or contiguous lobules
can be caused by hepatosis dietica in swine (vit E/ selenium deficiency)
Hepatosis dietetica
***KNOW THIS****
Associated with Vitamine E/Selenium deficency and generation of free radicals.
One of the most common causes of massive hepatic necrosis.
May see jaundice and complete necroisis of nodule (seperated by prominant CT)
Calf
Congenital cyst
Developmental abnormality
Congenital bilary cyst
Due to abnormal development of bile ductules - cyst will have a thin wall, lined by a single layer of bilary epithelium
Usually an incidental finding
CONGENITAL POLYCYSTIC LIVER DISEASE
Multiple cysts are located in the liver and kidney. Can cause pressure necrosis of the surrounding parenchyma.
Cair terriers, West Highland white terries, and Persian cats are predisposed.
May result in mortality due to liver or renal failure. NOT incidental (compared to incidental bilary cysts)
What breed are predisposed to develop congenital polycystic liver disease?
Cair terriers
West Highland white terries
Persian cats
Diaphramatic hernia of the liver
Congenital abnormality due to missing part of the diaphram or a very thin wall of the diaphram.
(could also be traumatic)
In the liver, which circulatory disturbance is most likely to occur?
a. congestion
b. infarction
c. ischemia
CONGESTION
Infarction/ischemia are rare due to high collateral circulation and double circulation (arterial and portal vein)
What gross characteristics would you see in ACUTE liver congestion?
Slight enlargement of the liver
Prominant reticular pattern- due to congestion of centrilobular areas
What would you grossly see in CHRONIC passive congestion?
“nutmeg liver” - due to right sided heart failure (picture)
Reticular pattern due to zonal congestion
Histological appearance of chronic passive congestion of the liver?
Congestion around central veins
Hepatocytes around portal areas are often unremarkable
Midzonal fatty change is occasionally seen
What is the Budd-Chiaria syndrome?
**NEED TO KNOW THIS**
Budd-Chiaria syndrome= hepatomegaly, ascites, and abdominal pain.
It is caused by thrombosis of the hepatic vein and the adjacent inferior vena cava.
Probable causes of thrombosis include conditions producing thrombotic tendencies or sluggish flow such as myeloproliferative disorders, infections, trauma and
neoplasia.
Gross appearance of congenital portosystemic shunts?
Blood within the portal venous system bypass the liver and drain into the posterior vena cava, or the azygous vein.
Gross:
- Hepatic encephalopathy and ascites are seen in congenital cases in dogs and cats.
- Decrease size fo the liver because it has been deprived of primary perfusion by portal hepatotrophic factors such as insulin, glucagon and amino acids.
Histological appearance of congenital portosystemic shunts?
Small hepatocytes
Portal veins are small/abscent in small portal triads
Multiple, more prominant, hepatic arterioles
Acquired shunts in liver
Acquired shunts have multiple, thin walled and tortuous blood vessels and evidence of liver disease
Due to chronic portal hypertension..
Telangiectasis
Telangiectasis
Definition: presence of focal areas in which sinusoids are dilated and filled with blood.
Gross appearance: irregular, circumscribed, dark-red foci of cavernous ectasia of sinusoids.
Common in: cattle and old cats
Clinical Signifigance: NONE!
Histologically: Dilation of sinusoids
Bovine
Telangiectasis= focal areas of silated sinusoids within the liver
NO clinical significance
Also commonly seen in older cats (picture)
Which species commonly get Telangiectasis?
Cattle and older cats
No clinical signifigance. Focal dilitation of the sinusoids of the liver. Grossly appear as irregular dark red foci.
5 Mechanism of Hepatic Lipidosis?
-
Excessive entry of fatty acids into the liver
- consequence of (1) excessive dietary intake of fat or (2) increased mobilization of fat from adipose tissue due to increased demand (lactation, starvation, and endocrine abnormalities).
- Decreased oxidation of fatty acids within hepatocytes.
- Increased esterification of fatty acids to triglycerides.
-
Decreased apoprotein synthesis
- subsequent decreased production and export of lipoprotein from hepatocytes.
- Impaired secretion of lipoprotein from the liver
Gross appearance of hepatic lipidosis?
Enlarged
heavy
uniform light yellow or orange
cuts with ease
greasy
rounded edges
smooth surface
tissue will float in water or fixative
Mdx & Disease name of the liver on the right
Mdx: Diffuse hepatic lipidosis
Condition: Hepatic lipidosis
What stains can you use to confrim hepatic lipidosis?
*** NEED TO KNOW***
(1) Oil red O - have to do a frozen stain, normal processing will wash fat out of cells.
(2) Osmium tetroxide- binds to lipids and keeps them within cells. Prevents washing out during normal processing. Lipids will appear black. VERY BAD FOR THE ENVIRONMENT
What is the significance of hepatic lipidosis?
Depends on the cause, severity and duration.
- Lesion is reversible in mild cases
- could lead to hepatic necrosis, fatty cysts, fat embolism and liver rupture with internal hemorrhage.
- Fatty livers are also more susceptible to toxic damage and traumatic injury.
What conditions are characterized by fatty liver?
- Physiological Fatty Liver ( late pregnancy, peak lactation, dietary excess, TWINE PREGNANCY IN EWES)
- Fasting in obese animals
- Bovine fatty liver syndrome- occurs in obese dairy cattle a few days after parturition when another event causes them to go off feed.
- Feline fatty liver syndrome- poorly defined/ideopathic. In either obese or anorexic cats. Causes icterus, hepatic failure and hepatic encephalopathy (picture)
- Equine hyperlipemia - occurs in obese ponies od shetland breed. Pathogenesis unknown. See pale discoleration and rounded edges of liver
- Endocrine disorders
- Toxic and anoxic injury
Equine hyperlipemia
Common in obese Shetland breed ponies
Unknown pathogenesis
**Pale discoloration and rounded edges**
What are two common endocrine disorders that cause hepatic lipidosis?
diabetes mellitus and hypothyroidism.
The increased lipolysis results in increased access of fatty acids, coinciding with shortage of ATP (due to reduced glucose availability), concluding with reduction in lipoprotein synthesis.
Fatty degeneration
Accumulation of fat within cells arising as a consequence of cellular injury is called fatty degeneration.
Injury to hepatocytes can lead to accumulation of fat because of decreased formation and/or export of lipoproteins by hepatocytes and decreased oxidation of fatty acids within hepatocytes
What 3 conditions lead to an excess storage of glycogen in hepatocytes?
Diabetes mellitus
Hyperadrenocorticism (steroid induced hepatopathy)
Glycogen storage diseases
Why does Excessive levels of endogenous or exogenous glucocorticoids cause extensive swelling of hepatocytes?
Glucocorticoids induce glycogen synthetase and enhance hepatic storage of glycogen –> excess accumulation –> swelling
What will you see grossly and histologically with steroid induced hepatopathy?
Gross: Enlarged, pale liver due to swollen hepatocytes (particularly in the midzonal areas)
- Differential diagnosis is hepatic lipidosis/ fatty change; thus a special stain (PAS stain) should be used to distinguish these two conditions.
Histologically: “feathery” cytoplasm. Glycogen accumulation around a centrally located nucleus. Enlarged cells. Confirm with PAS stain
Which breeds are predisposed to hepatic amyloidosis?
Abyssinian cats
Siamese cats
Chinese Shar-Pei dogs
Where does amyloid accumulate in the liver?
Space of Disse
When/Why does hepatic amyloid occur in animals?
Hepatic amyloidosis usually occurs as a consequence of prolonged antigenic stimulation such as chronic infection or repeated inoculations of an antigen.
Special stains for: Amyloid, Glycogen, Lipids & Copper
Amyloid: Congo Red
Glycogen: PAS
Lipid: Oil Red O
Copper: Rhodanine or Rubeanic acid
What liver condition commonly occurs when an ewe has a twin pregnancy?
** KNOW THIS***
Ketosis
5 causes of Cu toxicosis/Cu accumulation in the liver?
- Dietary excess in ruminants
- Grazing on pasture low in molybdenum (common in ovine)
- Hepatic (cholestatic) disease (accumulates in bile –> injury)
- Chronic liver disease
- Hereditary disorders (Bedlington and West Highland terriers, Dalmatians , cats, LEC rats)
What breeds are predisposed to copper toxicosis?
Bedlington and West Highland terriers
Dalmatians.
Also reported in cats
Long Evans Cinnamon (LEC) rats are human model for Wilson’s disease
What is the Rhodaine stain used for?
Copper
How do agents that cause hepatitis reach the liver?
Hematogenous/ blood-borne route (most common)
Ascending route: reaching the liver by ascending the biliary system
Direct extension from the peritoneum
Cholangiohepatitis
inflammation of bile ductules and liver parenchyma
Etiology? Edx?
Etiologic diagnosis: Parasitic hepatitis.
Etiologic agent: Fascioloides magna
What is a likely cause of this in a young animal/fetus? What will you see on histology?
HERPES VIRUS
Discrete off-white foci are seen in young animals and fetuses with Herpes viruses.
Necrotic hepatocytes often contain intranuclear inclusion bodies (INIB) and are surrounded by inflammatory cells.
Agents include:
- Bovine Herpes virus 1: Infectious Bovine Rhinotracheitis (IBR)
- Equine Herpes virus 1: Equine Viral Rhinopneumonitis (EVR)
- Canine herpes virus 1
- Pseudorabies in pigs.
What disease will cause:
gall bladder edema
corneal edema “blue eye” in survivors
enlarge, congested and friable liver
serosal petechia, ecchymosis and paint-brush hemorrhages
Canine adenovirus 1= Infectious canine hepatitis (ICH)
AKA Rubarth’s disease, Fox encephalitis, Hepatitis contagiosa canis
Highly contagious peracute disease
See intranuclear inclusion bodies
Pathogenesis: Oral exposure to urine → tonsilitis → viremia → virus has tropism for hepatocytes, vascular endothelium, renal epithelium, and mesothelium
Clinical signs: peracute onset, with vomiting, diarrhea, petechia in mucosal surfaces, hemorrhagic diathesis (=excessive bleeding)
What are the histological features of ICH?
- *Periacinar individual cell necrosis** of hepatocytes
- *Intranuclear basophilic inclusion bodie**s in hepatocytes, endothelial cells, biliary epithelium and Kupfer cells
- *Endothelial damage** in various organs
- *Minimal inflammation** (peracute)
Which disease will cause dish rag liver in horses?
Equine serum hepatitis aka Theiler’s disease
Caused by Pegivirus (used to be ideopathic)
Disease usually occurs 1-2 months after injection with a biological products of equine serum origin e.g. pregnant mare serum or tetanus antitoxin, but can occur without any such inoculation.
Clinical signs are acute even though liver lesions may appear older.
Characterized by icterus, ascites, petechiae, and hepatic encephalopathy due to severe hepatic fatty degeneration and some necrosis, cholestasis, mononuclear infiltration and slight fibrosis and regeneration.
What disease will result in a single large area of necrosis seen in a liver (picture) as well as intravascular anemia and hemoglobinuria in cattle and sheep?
Bacillary hemoglobinuris
Caused by Clostridium haemolyticum which produces a B toxin.
Occurs in cattle and sheep when the liver is injured.
(ie. Migrating liver flukes create an anaerobic environment for latent spores of the organism to germinate and elaborate the toxins.)
Which disease will causes small and numerous areas of liver necrosis and dark coloration of skin?
Black disease/ Infectious necrotic hepatitis
caused by Clostridium novyi type B
Dark discoloration of skin is due to severe sub-q venous congestion
lesions of fluke infestions or migration through the liver are also associated with it
Tyzzer’s Disease
Caused by Clostridium piliforme (previously known as Bacillus piliformis)
.It causes multifocal necrotic hepatitis and colitis.
Diagnosis is done by demonstrating bundles of large, long bacilli in hepatocytes stained with silver (Warthin-Starry) stain.
Seen especially in rodents and immunocompromised or very young animals (foals, calves, kittens, puppies)
Liver of young animal
Tyzzers disease- Clostridium piliforme
Diagnosis is done by demonstrating bundles of large,
long bacilli in hepatocytes stained with silver (Warthin-Starry) stain.
Leptospirosis
Disease characterized by jaundice
Pathogenesis varies according to serotype of Leptospira sp..
Lesions are often due to ischemic injury following hemolytic anemia.
Cholestasis has also been implicated as a cause of icterus
Leptospira grippotyphosa has also been associated with chronic active hepatitis in dogs.
Demonstrate lepto via silver stain (warthin starry)
Liver abcesses are due to….
hematogenous infection or secondary to omphalophlebitis
seen in cattle as a complication of chemical rumenitis or traumatic reticulitis.
Abscesses may be few or many and are usually caused by mixed bacterial flora including Fusobacterium necrophorus, Trueperella pyogenes (formerly known as Arcanobacter pyogenes), Streptococci and Staphylococci.
The left lobe is more frequently affected.
Use NAG- neoplasia, abcess or granuloma
What is the significance of liver abcesses?
Could be incidental finding at abattoir or necropsy
May heal, become encapsulated and sterile
May cause focal adhesive peritonitis, or diaphragmatic adhesions (photo)
May break into hepatic vein or vena cava and cause thrombophlebitis, endocarditis, pulmonary abscesses or massive endotoxic shock
Generalized infection in young animals
Toxemia if numerous.
Causes o granulomatous hepatitis?
Occurs secondary to fungal infections (Blastomycosis, Histoplasmosis),
bacterial diseases such as tuberculosis (confirm via acid fast stain)
Mycotic infection of the liver
Usually seconday to mycotic ruminitis in cattle or part of a systemic mycosis
Have red rim, but no campule
Etiology:
Aspergillus fumigatus and other Zygomycetes in ruminants
Histoplasma capsulatum
Cryptococcus neoformans
Coccidioides immitis
Sporothrix schenckii
Fasciola hepatica
Larvae migrate through the liver and matureflukes reside within the bile ducts
Prominennt areas of bile duct, due to inflammation and fibrosis, may look like cords.
Causes chronic fibrosing cholangitis
Pipe stem liver
Fasciola hepatic
causing chronic fibrosing cholangitis that looks like cords
Etiology?
Hydatid cysts/ intermediate stage of Ecchinococcus granulosus
Dog is the definitive host.
Rabbit. What is wrong with the right liver?
** IMPORTANT***
Proliferative cholangitis
Etiology: Eimeria stiedae
Gross appearance: multiple, raised, off-white nodules scattered throughout the liver
Etiology? Mdx? Disease name?
Etiology: Histomonas meleagridis
Disease name: Black head
Pathogenesis associated to Heterakis gallinarum
MDX: Multifocal granulomatous hepatitis (“target lesion”) and Diffuse granulomatous typhilits
What will ingestion of Blue-green algae cause?
It is a hepatotoxic plant. Microcystin is the main preformed toxin.
It blooms in late summer or early fall
Lesion include:
- *Acute hemorrhagic gastro-enteritis**
- *Acute centrilobular to massive hepatic necrosis**
- *Chronic liver disease** in survivors
What are the main lesions you will see in Pyrrolizidine alkaloid toxicity on gross and histology?
Pyrrolizidine alkaloid toxicity- due to alkaloids being convered to toxic pyrrolic esters by the liver p450 system,
Common in cattle, horses, pigs, goats, sheep
Gross: Hepatopathy
- Acute: periacinar necrosis
- Hepatic veno-occlusive disease
- Chronic with fibrosis (most common form)
****Histology******
- Portal fibrosis*
- Biliary hyperplasia*
- Megalocytosis** (toxin is antimitotic)
- Absent parenchymal regeneration
Alsike Clover
Toxin plant in north america
Causes Chronic liver disease and photodynamic dermatitis
Histology: Fibrosis, bile duct hyperplasia, & portal hepatitis
NO megalocytosis
4 Common Mycotoxins
A. Aflatoxins- B1 is most common and potent (carcinogen). Chronic > Acute
B. Sporidesmin- toxic to bile duct epithelium –> cholangiohepatits. Photosensitization & facial edema in sheep
C. Phomopsin- grows on lupins, chronic liver damage in herbivores
D. Poisonous mushrooms- dogs, fatal acute periacinar to massive hepatocellular necrosis
copper toxicosis is common in _______\_
Sheep
Cu accumulates in liver lysosomes and is release as a consequence of stress–> lipid peroxidation and massive hepatic necrosis
4 Hepatotoxic therapeutic drugs
• Trimethoprim-sulfonamide - Doberman pinschers
• Carprofen - especially Labrador retrievers
• Ivermectin - collies and shelties NO
• Anticonvulsants: primidone, phenytoin and phenobarbital
Hepatic Encephalopathy
Manifestation of liver dysfunction and failure –> depression, behavior changes, mania, convulsions, head pressing
Causes:
Acute liver disease- horse and ruminants
Portosystemic shunts - dogs and cats
Chronic liver disease - any animals
Pathogenesis:
Blood accumulation of neurotoxic substances bypassing the liver
Requires shunting of >10-15% of portal blood
Main toxic substance is ammonia
Ammonia bypasses the liver**→ increased levels reach the general circulation → go through the blood-brain barrier causing encephalopathy.
What causes elevations in bilirubin?
**KNOW THIS***
- Overproduction of bilirubin (prehepatic jaundice)
* Hemolysis - intra- or extra-vascular
- Overproduction of bilirubin (prehepatic jaundice)
- Decreased uptake, conjugation or secretion of bilirubin (hepatic jaundice)
- Severe hepatocellular injury
- Impairment of flow within canaliculi (intrahepatic cholestasis)
- Reduced outflow of bile in extrahepatic bile ducts and gallbladder (post hepatic jaundice)
- Mechanical obstruction of bile ducts (extrahepatic cholestasis) or gallbladder (cholelithiasis)
What are Metabolis Disturbances of Hepatic Failure?
-
Hemorrhagic diathesis or bleeding tendencies
• Impaired synthesis of clotting factors
• Reduced clearance of products of clotting cascade
• Impaired platelet function
• Impaired absorption of vitamin K
• Disseminated intravascular coagulation (DIC) -
Hypoalbuminemia
• Decreased synthesis in chronic liver disease
• Loss in ascites or via the gastrointestinal tract
What does this indicate?
Acquired portosystemic shunts
What should you suspect if a dogs paw ahs crusting erosions and scaling at the mucocutaneous junctions and footpads?
Hepatocutaneous syndrome (Superficial necrolytic dermatitis)
A rare cutaneous problem in liver disease in dogs
What are the 3 main causes of Photosensitization?
Photosensitization is due to activation of photodynamic pigments by UV light
-
Primary
St John’s wort (Hypericum perforatum)
Chlorpromazine
Phenothiazine -
Secondary (hepatogenous)
• Occurs in herbivores with impaired excretion of phylloerythrin
• Is the most common form -
Congenital
• Abnormal metabolism of heme –> Retention of porphyrins
What are non-neoplastic gorwth disturbances of the liver?
Hepatocellular nodular hyperplasia - age related change only in dogs
Regenerative nodules
Bile duct hyperplasia
Cholangioma
benign hepatic tumor of bile epithelium
common in cats
Most malignant tumors in the liver are ________
a. primary (from hepatocytes, bile duct or mesenchymal tissue)
b. seconday (other organs)
Secondary
Ruminant Liver. Benign or malignant?
Hepatocellular Adenoma= beinign neoplasm of hepatocytes
Seen in young ruminants s a single, non-encapsulates, red-brown nodule. It is composed of well differntiated hepatocytes and the portal arease are NOT seen in the neoplastic ares
Feline Liver.
Beinign or Malignany? What is is most common in? Gross? Histology?
Hepatocellular Carcinoma = Malignant
• Most often seen in dogs
Gross: solitary and involes entire lobe. Cut surface is multilobulated and grey-white to yellow brown
Histology: cells are arranfes in a trabecular pattern (3 or mor cells thick). Hepatocytes exhibit atypical and bizarre forms
Cholangiocellular adenoma vs. carcinoma
Cholangiocellular adenoma- Benign tumour arising from the bile ducts. Often cystic
Cholangiocellular carcinoma- Relatively common (described in all species)
• Multilobulated, firm, raised, with central areas of depression (umbilicated).
Hemangiosarcoma are ________________\_ origin tumors that arise from the ______ _______
Hemangiosarcomas are mesenchymal origin tumors that arise from the right atrium
Animals die when the tumor ruptures
What are the steps required for a histology specimen
- Tissue Collection
- Fixation- 10% NBF at 10:1 NBF:tissue. Fixes at ~1 mm/hour for 24 hours
- Trimming- lesion & normal. All layers. ~3mm thickness
- Processing- replace water with wax. Alcohol –> xylene –> paraffin. 15 hours
- Embedding- create mold by putting in paraffin filled block then place on ice.
- Microtomy- rough trim before then cut into 2-10 um (4um)
- Staining- deparaffinize via xylene, alcohols and water befor staining
- Coverslipping
When using a microtomy, what thickness should you cut?
4um
Before processing, what thickness should you trim your tissue ?
~3mm thick
ensure it fits in the cassette without smushing it
What ate the 3 magic numbers for fixatives/fixing?
Use 10 % NBF
at 10:1 ratio of NBF:tissue
It fixes at a rate of ~1mm/hour, so ensure pieces are small
Have tissue in fixative for 24 hours. You may need to change out fixative if feces or blood within
Where do hematopoeitic cells originate in the embyro? during gestation?
embryo= yolk sac
gestation= liver, spleen –> bone marrow
How quickly are neutrophils produced in the bone marrow? platelets? RBC?
Neutrophils= hours
Platelets= days
RBC= months
Release of immature cells indicates bone marrow
________ or _________
Release of immature cells indicates bone marrow
stress or disease
Under normal circumstances only mature cells are
released into the systemic circulation
Hematopoiesis is controlled by soluble stimulatory
factors that include cytokines, hormones and growth
factors
What are 4 indications to examine the bone marrow?
- Unexplained cytopenias (any non‐regenerative anemia)
- Maturation defects or morphologic abnormalities in cells
- Potential myeloproliferative/lymphoproliferative disease
- Potential malignancies metastatic to marrow
True or False
Even though bone marrow is present in multiple sites it
responds as a single tissue unit.
a sample taken anywhere
is thought to be representative of the marrow as a whole.
True!!!
What are two types of evaluationd of bone marrow
aspirates (cytology)
Core biopsies (histology)- more invasive but you can see cell organization
What is wrong with this neonatal calf?
Nothing! The bone marrow is normally this color in neonates due to the bone marrow being active
Ex. normal 13 day old foal (picture below)
What is wrong with this goat/sheep? What is the cause? Where else will you see clinical signs?
Serous atropy of Fat
Due to starvation of cachexia (caused by disease, inflammation, diet, neoplasia, etc)
Also will see serous atropy of fat at the base of heart and around the kidney.
Common in sheeps and goats
May aslo see osteopenia (picture)
What are 3 common causes of bone marrow degeneration/necrpsos?
- Radiation
- Chemical, antineoplastic drugs
- Viral infections (parvovirus of feline panleukopenia, canine parvovirus, EIA virus etc.)
Since bone marrow cells are very active metabolically, a variety of insults can interfere with hematopoiesis. Bone marrow necrosis may result in pancytopenia.
[Parvoviruses- infect rapidly dividing cells. In-utero infection in cats causes cerebellar atrophy. Infects cardiomyocytes of puppies.]
What is the usual cause of this lesion?
Suppurative osteomyelitis is usually the result of bacterial infections.
Tissue will be rich in neutrophils and macrophages.
Septic osteomyelitis= comes from the blood (maybe originating from the umbilical cord/omphalitis)
What are common causes of diffuse granulomatous osteomyelitis? what may it result in?
Diffuse granulomatous osteomyelitis is usually the result of fungal infections, e.g.: histoplasmosis and coccidiodomycosis.
Osteomyelitis may result in Pancytopenia
Lesion will be rich in macrophages that may contain the causative agent .
Multifocal granulomatous osteomyelitis is seen in tuberculosis of birds(?)
Histoplasmosis can also manifest in other organs as a diffuse granulomatous uveitis, hepatitis and splenitis.
Cytauxzoonosis
Cytauxozoon felis – protozoa
Often fatal
Bobcats (Lynx rufus) are the reservoir
Two forms
- Schizogenous phase –> macrophages (enlarged and filled with parasite) –> systemic illness
- Erythrocytic phase –>anemia
What will you see in bone marrow hypoplasia/atropy?
- Decreased proliferative activity
- Usually characterized by increase in yellow marrow
- Often accompanies marrow degeneration.
- Sequel will depend on cell line(s) affected
Example: marrow damage secondary to feline panleukopenia virus infection.
Example: myelofibrosis (CT replaces precursors) in scirvey/Vitamin C deficiency
Pancytopenia may be the result of …
-
myelophthisis, the replacement of myeloid tissue by abnormal tissue:
- collagen‐rich fibrous connective tissue(myelofibrosis)
- malignant neoplasia
- abnormality of hematopoietic cells – aplastic anemia/pancytopenia (destruction of hematopoietic stem cells)
What will you see in bone marrow hyperplasia? pathogenesis?
One or multiple cell lines may be hyperplastic depending on the stimulus
Gross finding: Red marrow replacing yellow marrow (fat) at metaphysis and endosteal surface of diaphysis.
Pathogenesis: ↓cell numbers in blood caused by increased peripheral demand; or adequate numbers of hypofunctional cells in peripheral blood –> lead to ↑cell production in the marrow in response to poietns and
interleukins.
Example: Bovine Leukocyte Adhesion Deficiency (BLAD) syndrome - in people and dogs (Irish setters). Defect in migration of leukocytes.
horse w/ hyperplasia due to IHA (picture below)
What is wrong with this adult horse? common cause?
** NEED TO KNOW***
Bone marrow hyperplasia secondary to EIA
Causes of anemia in EIA (1) extravascular immune mediated hemolysis (2) decrease production (3) Inflammation
May see acute thrombocytopenia (due to immune mediated mechanism, they are innocent bystanders)
Horses are infected for life with EIA. They act as reservoirs. the disease can be transmitted by flies and mosquitoes.
Which primary neoplasia are most common in the bone marrow?
Lymphoproliferative (LYMPHOID) Disease
Marrow and/or extramedullary neoplastic transformation of a lymphoid cell line
- lymphoma (lymphosarcoma)
- lymphoid (lymphocytic) leukemia
- plasma cell tumors
Myeloproliferative (MYELOID) Disease are rarer.
What are the three types of Lymphoproliferative (LYMPHOID) Diseases?
- Lymphoid leukemia
- Lymphoma (Leukemic phase)
- Plasma cell neoplasia ( multiple myeloma & plasmacytoma)
What are the two types of myeloproliferative disease of the bone marrow?
Acute forms: rapidly fatal and tend to occur in younger animals, poorly differentiated cells, decrease number of circulating cells
Chronic forms: longer clinical course (indolent), neoplastic cells are relatively well‐differentiated, increase number of circulating cells
What are common features of both Myelo/Lymphoproliferative disease of the bone marrow?
- Anemia
- Hypercellular marrow
- Leukemic cells in peripheral circulation (especially if chronic)
- Megaloblastic alterations in erythroid cells
- Thrombocytopenia (not always present)
- Hepato/splenomegaly – Myelo/lymphoproliferative disease spreads early to involve the spleen and liver. Animals may present with splenomegaly and/or hepatomegaly
What would you call this abnormality? What is possible cause?
Hepatosplenomegaly
Due to myelo/lymphoproliferative disease (LSA) due to the early spread of these diseases to the spleen and liver
Also may see anemia, hypercellular bone marrow, leukemic cells in peripheral circulation, megaloblastic alterations in RBC etc.
What may be wrong with this cow?
Lymphoid leukemia or leukemic lymphoma
May see focal to multifocal whitish masses, that may be hard (picture below)
What are three types of plasma cell neoplasias?
- Multiple myeloma- malignant, from bone barrow, M protein, increase Ig secretion, punched out appearance, monoclonal gammopathy, hypercalcemia
- Cutaneous Plasmacytomas- benign
- Extramedullary Plasmacytoma - malignant, dogs, cats, horses, + amyloidosis
Multiple Myeloma
rare, malignant tumor of plasma cells that arise from the bone marrow
have increase secretion of Ig/Ig subunits ( M protein) - monoclonal gammopathy
“punched out” appearance of osteolytic lesions in 25-66% of cases. Starts in active marrow (vertebral bodies, flat bones, pelvis)
hypercalcemia due to osteolysis
Plasma cells will be enlarged, have perinuclear clearing, with nucleas pushed to the side due to increased cytoplasm.
Cutaneous vs. Extramedullary Plasmacytomas?
Cutaneous Plasmacytomas- Rare ‐ usually benign – skin or mucous membranes
Extramedullary Plasmacytoma- Rare – malignant – dogs, horses, cats; Amyloidosis is a feature
Both are types of plasma cell neoplasias
ddx?
Multiple Myeloma
“punched out” osteolytic lesions
What are 4 types of Histocytic neoplasias?
-
Histiocytic sarcoma - uncommon – malignant tumor of histiocytic (macrophage or dendritic cell) origin
- frequently in the dog (Rottweiler, Bernese mountain dog); rarely in cat
- disseminated form= “malignant histiocytosis”
-
Cutaneous histiocytosis and systemic histiocytosis
- nonneoplastic canine immunoregulatory disorders
- Canine cutaneous histiocytoma- benign – epidermal Langerhans cell origin. “top heavy” nodular lesions.
-
Feline progressive histiocytosis
• Initially indolent cutaneous neoplasm; probably of dendritic cell origin
________ syndrome= not clearly neoplastic maturation abnormalities of bone marrow cells characterized by ineffective and dysplastic hematopoises –> peripheral cytopenia of one or more cell lines
Myelodysplastic (MDS)
It is seen in cats infected with FeLV
Which animals normally have hemal nodes (prominent, small, dark red) in their lymph nodes?
Ruminants
______ lymph nodes have a inverted cortex and medulla
Porcine
What should you suspect if your lymph node had a red color? black? brown? green? orange?
Red= blood
Black = anthracosis/carbon, tatoo ink
Brown= melanin, parasite hematin, hemosiderin
Green= eosinophils, blue-green algae
Orange= paratuberculosis in sheep
Hemosiderosis: Brownish discoloration observed in lymph nodes draining areas of ________
hemorrhage
lymphoid tissue proliferation of the outer cortex = _____ hyperplasia
lymphoid proliferation of the inner cortex = _____/_____ hyperplasia
outer cortex=follicular hyperplasia
inner cortex= lymphocyte/diffuse hyperplasia
______ is a common term for a painful swollen lymph node
buboes (bubos)
What are DDx for focal areas of necrosis in lymph nodes of CATS
toxoplasmosis, salmonellosis, tularemia, yersiniosis,
Tyzzer’s disease, FIP
Diagnosis?
Foal has enlarged swollen lymph nodes ( only mandibular, pharyngeal, parotid) with some abscessation and fistulation
Strangles- Streptococcus equi ssp equi
________ __________ = Streptococcus equi ssp equi abscesses anywhere in the body other than the pharyngeal area
Bastard strangles
Sheep lymph node.
Top Disease? Etiology?
Caseous lymphadenitis
Corynebacterium pseudotuberculosis
See concentric “onion ring” lymph node & eosinophilic (green) pus becomes caseous with age
Top DDx for a cow with granulomatous lymphadenitis?
Mycobacterium bovis
Top DDx for pig with diffuse granulomatous (histocytic) lymphadenitis?
PMWS- Porcine Multisystemic Wasting Disease
Porcine Circovirus 2
Lymph node will be increased in size and have uneven color.
Will have B & T Cell depletion –> immunosuppresion
Botryoid intracytoplasmic inclusion in macrophages
______ are usually ill when lymphoma is diagnoses
Cats
(dogs are usually healthy)
Lymphosarcoma can be induced by _____ in cats and _______ in cattle
FeLV , BLV
Which anatomical classification of lymphomas is most common?
Multicentric
Alimentary lymphomas are common in _____
CATS
in animals, which has a better survival profile and response to treatment;
B-cell lymphomas –or–T-cell lymphomas?
B-cell lymphomas
True or False
Large cell lymphomas with high mitotic rates are slower to progress but response poorly to chemotherapy
FALSE
Small cell lymphomas with low mitotic rates are slower to progress but response poorly to chemotherapy
L_arge cell lymphomas_ with high mitotic rates rapidly progress but response well to chemotherapy
Malignant lymphomas (most common canine treated neoplasm) affects dog of what ages and breeds?
ALL ages and ALL breeds
Bovine lymph node.
Etiology/Disease?
BLV- bovine enzootic leukosis
The hemorrage and necrosis is characteristic of rapid growing tumors
Abomasum of young cow. Etiology/Disease?
enzootic leukosis (BLV) with abomasal involvement
__________ is the MOST COMMON reported malignency in pigs
*** KNOW THIS*****
Lymphoma
What would be my best diagnosis for the type of malignancy in this pig?
Lymphoma
It is the most common reported malignancy in pigs
Which species has the highest incidence of lymphoma?
CATS
Lymphoma is the most common hemopoietic neoplasm in cats
FUN FACT: Although it can be caused by FeLV, as FeLV infection rates has gone down the incidence of lymphoma has actually increased (mainly gastrointerstinal lymphomas)
Why are endoscopic biopsie for GI lymphomas not always diagnostic?
Different types of tumors are located in different areas of the GI tract. A single biopsy of one area will commonly miss the tumor.
Ex. B cell lymphomas are “further down” than T-cells, or are in the stomach.
Marek disease is most often in chickens _____ month of age
2-5
Leukemia virus of birds usually infects birds after the age of ____ months
6
True or False
Birds have lymph nodes
False- they dont have lymph nodes…
_________ disease causes cutaneous (nodules at base of feathers), ocular (“grey eye”) and diffuse (liver, spleen, etc) lymphocytic infiltrates/lymphoma. As well as peripheral neuritis (sciatic n.)
Marek’s (herpesvirus)
What disease in chickens will cause these clinical signs?
Marek’s disease (Herpesvirus)
lack of Ag stimulation, toxins, chemotherapy, infectious agents, ionizing radiation, malnutrition, cachexia, & aging cause what response in the spleen?
lymphoid atropy
storage of blood and contraction to expel reserve blood are important functions of what organ?
Spleen
Congestion, acute hyperemia, and acute hemolytic anemia are causes of a __________ spleen
bloody
Phagocytosis, proliferation of cells, and storage of material (ex. amyloid) are causes of a _________ spleen
meaty
Hematomas, incompletely contracted areas of spleen, acute splenic infarcts and vascular neoplasma (hemangiosarcoma) are causes of splenic ________ with a________ consistency
nodule , bloody
What are 6 causes of splenic nodules with a firm consistency?
- Splenic nodular hyperplasia
- Fibrohistiocytic nodules
- Primary neoplasms
- Secondary (metastatic) neoplasms
- Granulomas
- Abscesses
SCID (splenic hypoplasia), congenital accessory spleens and splenic fissures (horses) are all developmental anomalies that result in a ______ spleen
small
true or false
accessory spleens are functional
false
they lack the proper blood suppy
_________ ____________ are gray-white to yellow, hard dry encrustation on the capsule (usually on the margins) of the spleen that are most common in old dogs.
Siderotic plaques
What is present on this old dogs spleen?
Siderofibrosis of the splenic capsule (siderotic plaques/nodules, Gamma‐Gandy bodies).
Siderotic plaques are a _______ change, but may be a sequel of ________
aging/degenerative , hemorrhage
What is wrong with this old dogs spleen?
Hemosiderosis (degenerative lesion)
pigment make it look brown
Barbiturate-insuced splenomegaly is due to ________ ___________ _________
Acute passive congestion
Barbituates, gastrosplenic torsion/volvulus and right CHF cause ______ _______ _____ of the spleen
acute-passive congestion
Acute splenic infarction in pigs should alert you about the possibility of ____ _____ ______
Classical Swine Fever (hog Cholera)
____ _____ leads to seeding of the omentum and formation of numerous “accessory spleens” –> splenosis
Splenic rupture
Splenic hematoma
________ & _________ result in hyperplasic spenitis
Aleutian disease of mink and ferrets
Equine infectious anemia
Due to Chronic antigenic stimulation results in hyperplasia of the monocyte‐macrophage or lymphoid/ plasma cell population
Acute splenic hyperemia/spenitis with splenomegaly can be seen in a bovine with ______
Bacillus anthracis
large bacillus, forms short chains and is characterized by square ends and a distinct capsule.
What is going on with this spleen?
lymphoid hyperplasia
What is the etilogy of White‐grey miliary foci scattered throughout the splenic parenchyma. Causing a Necrotizing (or necrosuppurative) splenitis.
Francisella tularensis (Tularemia) - “rabbit fever”
Acute multifocal (milary) necrotizing hepatis and splenitis is characterisitc of ______ virus in raptors
Herpes
“herpes inclusion body disease (hepatosplenitits) of raptors”
Raptors get infected by consuming pigeons infected (often subclinically) with columbid herpesvirus (CoHV),
Multifocal granulomatous spenitis is characteristic of systemic ________ _______ in birds
Mycobacterium avium
What is wrong with this spleen? what is the clinical signifigance?
Nodular hyperplasia
Incidental - slow growing
likely an aging change, formed by a mixture of hyperplastic extramedullary hemopoietic cells, and are prone to rupture from trauma, resulting in hemoabdomen and exsanguination
Splenic _________ are benign, but are prone to rupture
hemangiona
Splenic ____________ are the most common neoplasm of the spleen
Hemangiosarcoma
(they are also commonly found on the skin)
Highlt metastaitc, invade the abdominal cavity.
White, multi-nodular, firm mass of the spleen is most likely a …
Lymphosarcoma
Cat
Histocytic sarcoma
Which 4 viruses cause thymic atophy
EHV-1
FeLV
BVD
Canine Distemper
SCID in arabian foals and Basset hounds causes thymic _________
hypoplasia
Thymus inflammation is very rare, but can occur in pigs with ______
PCV-2
What kind of neoplasm is this? what is the prognosis?
Thymic Lymphoma
Results in lung collaps, breathing difficulties and compression of vessels feeding the brain. Poor prognosis, hard to remove.
Myasthenia gravis (–>megaesophagus) in dogs and Generalized exfoliative dermatitis (head and pinna) of cat are paraneiplastic syndroms of ______
thymoma
What are 3 infections of the Bursa of Fabricius?
- Infectious bursal disease (birnavirus)- lymphoid depletion (3-6 weeks)
- Lymphoid leukosis (avian leukosis virus) - neoplastic proliferation of B-lymphocytes
- New castle disease (paramyxovirus)
Infectious birdal disease occurs in chickens________ weeks of age.
3-6 weeks
IBV is the most important disease of concentrated broiler producing areas of the US
Causes lymphoid depletion –> immunodeficiency due to the virus targeting pre-B lymphoctes.
Birds usually die of secondary infections.
This is caused by which disease?
Infectious bursal disease (IBD)
Other names of this condition: Gumboro disease, Avian infectious bursitis
Etiology: Avian bursal disease virus (Birnavirus)
