Gross Pathology of Cattle- cardiovascular

Question 1

Where does a ventricular septal defect usually occur?

Answer 1

Perimembranous portion of septum

Question 2

What are the components of the tetralogy of Fallot?

Answer 2

Ventricular septal defect
Overriding aorta
Pulmonic stenosis
Compensatory right ventricular hypertrophy

Question 3

What bony structure is in the cow heart?

Answer 3

Os cordis

Question 4

What does white muscle disease cause (gross findings)

Answer 4

Necrosis, replacement fibrosis of myocardium, and calcification

Question 5

Most frequent sites (in heart) of white muscle disease lesions?

Answer 5

Left ventricular papillary muscles
Subendocardial myocardium
Subepicardial myocardium

Question 6

What causes Foot and Mouth Disease?

Answer 6

Bovine aphthovirus (picornaviridae)

Question 7

What does bovine aphthovirus cause, grossly in young animals? (up to 2 weeks)

Answer 7

Myocardial necrosis, leading to tiger-striping of the heart, same in skeletal muscle

Question 8

Cause of blackleg?

Answer 8

Clostridium chauvoei

Question 9

What causes multiple abscesses in myocardium (especially the papillary muscle)?

Answer 9

Histophilus somni

Question 10

Five syndromes of histophilus somni

Answer 10

1. Myocarditis
2. Pleuropneumonia
3. Thrombotic encephalomeningitis
4. Metritis
5. Suppurative arthritis

Question 11

Differentials for suppurative myocarditis (3)

Answer 11

Streptococcus bovis*
Staphylococcus aureus
Coliforms

Question 12

What causes myocardial necrosis with no mineral or fibrosis?

Answer 12

Myocardial toxins

Question 13

Name two categories of toxins that cause simple myocardial necrosis

Answer 13

1. Ionophores (coccidiostats)- alters Na-K pump system, flooding myocytes with Ca
2. Plants- senna plants, white snakeroot, gossypol

Question 14

What causes patchy granulomatous, eosinophilic myocarditis?

Answer 14

Hairy vetch (Vicia villosa)

Question 15

What organ, other than the heart, is affected by hairy vetch (Vicia villosa) toxicity?

Answer 15

Kidney

Question 16

Proliferative lesion on valves

Answer 16

Vegetative valvular endocarditis

Question 17

What causes valvular endocarditis?

Answer 17

Staph, strep, coliforms
Trueperella pyogenes
Bartonella bovis if aortic valve

Question 18

Causes of subendocardial mineralization (not white muscle)

Answer 18

Granulomatous inflammation (Johne’s disease)
Plant ingestion- Cestrum diurnum, Trisetum flavescens, and Solanum glaucophyllum (contain Vitamin D analog, causes metastatic calcification)

Question 19

Parasitic myocarditis is caused by

Answer 19

Cysticercus bovis (Taenia saginata is adult)

Question 20

Where else can cysticercus bovis reside?

Answer 20

Masseter muscle

Question 21

An incidental finding of focal edema and fibrosis that may look like a parasite or infarct

Answer 21

Myocardial lymphangectasia

Question 22

Two neoplasias of the myocardium

Answer 22

1. Lymphoma (BLV)
2. Neurofibroma or schwannoma

Question 23

Pathogenesis of altitude disease

Answer 23

Low oxygen levels–>vasoconstriction within pulmonary arteries–>pulmonary hypertension–>increased preload–>right heart failure and ventral edema, globoid heart