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Flashcards in Small Ruminants Study Questions Deck (54)
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1
Q

What CNS lesions have been described associated with border disease?

A

a. cerebellar hypoplasia
b. necrosis of external granular layer

aka “Hairy Shaker”

2
Q

What are the most common manifestations of CAE in goats? Of visna-maedi in sheep?

A
  • Goats: proliferative arthritis, bilateral carpal joints- proliferative synovium, mononuclear cell infiltrate, carpal hyogroma, enchephalitis, mastitis
  • Sheep: multifocal interstitial pneumonia (Ovine progressive pneumonia: OPP), wasting
3
Q

What is the most serious poxvirus infection of domestic species?

A

Sheeppox

4
Q

What are the neoplastic cells in a thymoma?

A

Epithelial cells

5
Q

What is the cause of orf? What are the characteristic histologic lesions?

A
  • Orf virus: parapoxvirus
  • Proliferative epithelial lesions, ballooning degneration, intracytoplasmic inclusions
    first affects lips then muzzle
    proliferative lesions often develop a thick crust
6
Q

• What are the possible causes of goiter? (4)

A

◦ Iodine deficiency or excess
◦ Ingestion of goitrogens
◦ Genetic defects in enzymes involved in thyroid hormone biosynthesis
◦ Congenital: maternal thyroid hormone deficiency

7
Q

• What are the lesions associated with bluetongue infection in sheep?

A

Hemorrhage at the base of the pulmonary artery
• Will first see hyperemia of nasal and oral mucosa. Tongue may be cyanotic, congested, or edematous
• Hemorrhage of the rumen mucosa, coronary band, ulcers of the dental pad, etc.

8
Q

What is the main gross lesion associated with Oesophagostomum columbianum infection?

A

a. Intestinal serosal granulomas

appear as granulomas due to them encysting

9
Q

What is the cause of white muscle disease? What are the characteristic histologic lesions?

A
  • Vit E and Selenium deficiency
  • Degeneration and necrosis with mineralization, regeneration and fibrosis
  • Pale white streaks
10
Q

What is the pathogenesis of copper toxicosis?

A

ingestion of Cu in excess of carrier proteins capacity causes Cu to enter RBC, denature global and form heinz bodies. This causes hemolysis then hemoglobinemia/uria

11
Q

• What are the lesions of vibriosis in the placenta and in stillborn lambs? What are the causative agents of vibriosis?

A

◦ Placentitis: necrosis in cotyledons (friable, yellow), intercotyledonary areas are edematous.
◦ Autolyzed fetus with target lesions/necrosis in the liver
◦ Campylobacter fetus fetus or C. jejuni

12
Q

◦ What is the cause of caseous lymphadenitis?

A

• Corynebacterium pseudotuberculosis

- shearing wounds

13
Q

• What are the gross lesions of Mycoplasma capricolum spp. capripneumoniae infection of the lungs?

A

◦ Severe fibrinous pleuropneumonia (appears blue-grey)

◦ Foreign animal disease: Contagious caprine pleuropneumonia

14
Q

What is the gross lesion in the lungs associated with CAE/visna-maedi in goats and sheep?

A
  • Sheep more likely to get pneumonia: multifocal interstitial pneumonia (Ovine progressive pneumonia: OPP)
  • heavy, firm lungs that fail to collapse when thorax is opened, often worse in caudal lobes
15
Q

• What are the agents involved in chronic enzootic pneumonia in sheep? What does it cause?

A

Viral (PI-3, adenovirus, RSV, reovirus)
b. Bacteria (M. hemolytica, P. multocida, Chlamydophila, Bordatella parapertussis,
Mycoplasma ovipneumoniae)

16
Q

• What is the cause of enzootic abortion of ewes? What are the associated lesions?

A

◦ Chlamydophila abortus
◦ Exudative placentitis: necrotic, red-brown cotyledons, brown intercodtyledonary tissue thickened and covered in exudate
◦ Fetus: well preserved with few lesions or necrotic foci in liver and spleen

17
Q

What are the typical lesions of Foot and Mouth Disease in sheep and goats?

A

Vesicles of the mouth (commonly dental apd), feet (coronary band and interdigital), luminal pillars, prepuce, and vulva

18
Q

• What is the characteristic histologic lesion of Dermatophilus congolensis infection in sheep?

A

a. “lumpy wool”

b. Histo: alternating bands of keratin and inflammation, railroad track bacteria strands

19
Q

What are the characteristic histologic lesions of listeriosis in the CNS? What are outbreaks of listeriosis typically associated with? What are lesions in pregnant ruminants? In infected aborted lambs?

A

Suppurative encephalitis of the brainstem: microabcesses, sometimes within foci of microgliosis
Outbreaks: feeding silage that has been improperly stored
Pregnant: last trimester abortion as listeria localizes to uterus/placenta
Exudative placentitis with necrosis of cotyledons
If close to term: metritis, septicemia, dystocia, necrotic/necrosuppurative foci in liver (also spleen, lung, kidney, heart, adrenal, brain)
Autolysis of fetus which is expelled around 5 days after death
necrosuppurative hepatitis

20
Q

What are predisposing factors for vaginal prolapse?

A

a. Increased intraabdominal pressure
i. Overconditioning
ii. Rumen distention
iii. Recumbency

b. Tail docking too short

21
Q

What are the clinicopathologic abnormalities expected with Haemonchus contortus infection?

A

Anemia and hypoproteinema

22
Q

What is most often the major clinical manifestation of caprine arthritis-encephalitis virus in affected goat herds?

A

Arthritis in adults

23
Q

What are the histologic lesions of scrapie?

A

Vaculation of neurons

a. Abnormal accumulation of prion (PrPSc

24
Q

Where in the lung are Muellerius capillaris lesions located? Dictyocaulus filaria?

A
  • Muellerius capillaris: nodules on the dorsocaudal lung surface
  • Dictyocaulus filaria: within the airways
25
Q

• What are common bacterial causes of mastitis in sheep and goats?

A

Staph aureus, M. hemolytica, C. pseudotuberculosis, T. pyogenes, M. agalactiae

26
Q

What is the main lesion associated with pseudopregnancy?

A

Hydrometra

27
Q

Where are cysts from Taenia (Cysticercus) ovis typically located? From Coenurus cerebralis (Taenia multiceps)? From Echinococcus granulosus? From Cysticercus tenuicollis (Taenia hydatigena)?

A
  • Taenia (Cysticercus) ovis: heart and skeletal muscles
    contains 1 thing inside cyst
  • Coenurus cerebralis (Taenia multiceps): brain, sometimes spinal cord
    contains multiple brood capsules inside
  • Echinococcus granulosus: liver or lung
    hydatid cysts
  • tenuicollis (Taenia hydatigena): encyst in peritoneum in the abdominal cavity
28
Q

What is the typical appearance of placentitis associated with Toxoplasma gondii?

A

Affects the cotyledonary area only and causes mineralization

29
Q

• Why are ruminants susceptible to pituitary abscesses?

A

◦ Pituitary gland is surrounded by extensive vascular meshwork (rete miracle) which makes them susceptible to hematogenous infections in the region of the pituitary
◦ Trueperella puogenes is a common cause

30
Q

• What are the gross lesions of Mannheimia hemolytica infection of the lungs?

A

Fibrinous pleuropneumonia

31
Q

What causes black disease? What is the pathogenesis of this disease?

A
  • Clostridium novae
  • Damage from migrating lifer flukes provides anaerobic environment for germination of spores resulting in bacteria that produce toxins; lead to toxemia and hemolysis
32
Q

• What is the cause of ovine pulmonary adenocarcinoma?

A

• a. Jaagsietke sheep retrovirus, ovine pulmonary adenocarcinoma virus (OPAV)
b. incubation 2yr
c. sheep>goats
• multiple grey to tan regions in the lungs

33
Q

What are the lesions associated with polioencephalomalacia?

A
  • Acute death: cerebral edema
  • Depression/laminar palor of grey matter, increased intracranial pressure resulting in the herniation of the cerebellum, pale yellow and soft grey matter
  • caused by Thiamine deficiency/abnormalities, sulfur compounds, or water deprivation/salt toxicity
34
Q

• What is the cause of Johne’s disease? Where are the lesions most often located in sheep and goats?

A

◦ Mycobacterium avid ss. paratuberculosis: causes chronic wasting with granulomatous enteritis (without diarrhea)
◦ ileum, cecum, and colon affected

35
Q

What are the gross lesions associated with sheeppox? Goatpox?

A

a. Sheeppox:
i. umbilicated cutaneous vesicles containing little fluid–>pustules covered w/ thin crust
ii. proliferative dermatitis
iii. nodular lung lesions w/ caseous necrosis
b. Goatpox: nodular lesions affecting sparsely haired regions (cheeks, nostrils, eyelids, udder, vulva, scrotum, prepuce, ventral surface of tail, medial thighs

36
Q

What is the pathogenesis of frothy bloat? Feedlot bloat?

A
  • Frothy bloat: feeding high soluble protein, especially legumes, alfalfa, and clover
  • Secondary tympany: physical or functional problem with gas eructation
  • Increased pressure on diaphragm hinders respiration and cardiac function and compression of the caudal vena cava, abdominal viscera
37
Q

What are typical signs of coccidiosis in sheep and goats? What ages are typically affected?

A
  • Proliferative enteritis, +/- hemorrhagic
  • ill-thrift, diarrhea, weakness in young
  • Eimeria sp.
38
Q

What is the histologic lesion in the brain/spinal cord associated with CAE/visna-maedi in goats and sheep?

A
  • Goat: leukoencephalitis, leukomyelitis

- Kids typically get encephalomyelitis which causes paresis

39
Q

What is the nasal bot of sheep?

A

Oestrus ovis

Incidental/no CS

40
Q

What is the cause of enzootic nasal tumor?

A

Enzootic Nasal Tumor Virus (type D retrovirus)

41
Q

What is lipidosis in sheep most commonly associated with?

A

Pregnancy toxemia

More often in older ewes with multiple fetuses

42
Q

• What are the features of schistosomus reflexus? (3)

A

◦ Severe retroflexion of spinal column: hindlimb are adjacent to skull
◦ Ankylosis of limb joints
◦ Failure of closure of abdominal wall with eventuation

43
Q

What is a carpal hygroma? What disease is it associated with in goats?

A
  • Bursitis that does not typically communicate with the joint
  • CAE
44
Q

What are the characteristic lesions of enzootic ataxia?

A

a. Cavitation of white matter
b. Hypomyelination, demyelination
c. Hypopigmentation leukotrichia
- Caused by copper deficiency

45
Q

What is the pathogenesis of grain overload in ruminants?

A

Ingestion of excess grain/carbs decreases the pH due to VFA. A pH of less than or equal to 5 causes the death of most Gm- bacteria, allowing Gm+ bacteria, esp. Streptococcus bovid to proliferate and produce lactic acid. At pH of 4.5-5.5: Strep die and lactobacilli proliferate

46
Q

• What is the brain lesion associated with Clostridium perfringens type D? What are other gross lesions associated with this agent?

A
  • Focal symmetrical encephalomalacia of the basal ganglia, internal capsule, thalamus, substantial nigra
  • “Pulpy kidneys” due to rapid autolysis in lambs
47
Q

• What is a true hermaphrodite? A male pseudohermaphrodite? A female pseudohermaphrodite?

A

a. True hermaphrodite=having both male and female gonads (testes and ovaries
b. Male pseudohermaphrodite=male gonads but female external genitalia
c. Female pseudohermaphrodite=female gonads but male external genitalia

48
Q

• What gross and histologic lesions would you expect to find with tetanus?

A

• NONE! Can demonstrate toxin in the serum, but no post mortem lesions

49
Q

What are the typical gross and histologic lesions associated with Peste de Petits Ruminants virus?

A
  • Grossly:
    Serous to mucopurulent oculonasal discharge,
    Hemorrhagic colitis (almost always present),
    Fibrinonecrotic tracheitis,
    Bronchointerstitial pneumonia,
    Necrosis and erosions/ulcers of oral cavity, esophagus, rarely fore stomach
  • Histologically:
    bonchointerstitial pneumonia,
    lymphoid necrosis,
    Necrosis of epithelial cells and epithelial syncytial cells,
  • Intranuclear and intracytoplasmic inclusions
50
Q

How do typical lesions of bacterial mastitis in goats differ from infection with Mycoplasma agalactiae?

A

Typically involves one gland compared to M. agalactiae, which is bilateral
M. agalactiae is primarily in goats that become septicemic and often die. Survivors will have lesions in the eye, periarticular tissue, and active mammary glands

51
Q

• What are the lesions associated with Clostridium perfringens type C in lambs? In adult sheep?

A

a. Lambs: Necrohemorrhagic enteritis–> jejunum, ileum-lumen free blood
b. Adults: Patchy-diffuse reddening SI, jejunum ulcers, clear abominal fluid that clots
w/ air exposure (large volume)

52
Q

• What is the cause and what is the pathogenesis of pizzle rot?

A

a. Corynebacterium renale
b. hydrolysis of urea–>ammonia
c. irritation to penis, prepuce
d. higher incidence in wethers with long hair/wool around prepuce (Merino, Angora)”

53
Q

• What causes braxy? What are the gross lesions of braxy?

A

◦ Clostridium septicum
◦ Hemorrhagic abomasitis:

abomasa fold thickening, red, sometimes with hemorrhage or necrosis. Extensive submucosal edema and emphysema with multifocal necrosis.

54
Q

• What are the lesions associated with Brucella ovis in sheep?

A

a. granulomatous epididymitis + periochitis (fibrin, fluid)–>reduced fertility
b. NO ORCHITIS
c. placentitis: placental edema, multifocal-coalescing plaques in intercotyledonary areas
(leathery appearance)>cotyledon necrosis