Gross Pathology of Cattle- cardiovascular Flashcards
Where does a ventricular septal defect usually occur?
Perimembranous portion of septum
What are the components of the tetralogy of Fallot?
Ventricular septal defect
Overriding aorta
Pulmonic stenosis
Compensatory right ventricular hypertrophy
What bony structure is in the cow heart?
Os cordis
What does white muscle disease cause (gross findings)
Necrosis, replacement fibrosis of myocardium, and calcification
Most frequent sites (in heart) of white muscle disease lesions?
Left ventricular papillary muscles
Subendocardial myocardium
Subepicardial myocardium
What causes Foot and Mouth Disease?
Bovine aphthovirus (picornaviridae)
What does bovine aphthovirus cause, grossly in young animals? (up to 2 weeks)
Myocardial necrosis, leading to tiger-striping of the heart, same in skeletal muscle
Cause of blackleg?
Clostridium chauvoei
What causes multiple abscesses in myocardium (especially the papillary muscle)?
Histophilus somni
Five syndromes of histophilus somni
- Myocarditis
- Pleuropneumonia
- Thrombotic encephalomeningitis
- Metritis
- Suppurative arthritis
Differentials for suppurative myocarditis (3)
Streptococcus bovis*
Staphylococcus aureus
Coliforms
What causes myocardial necrosis with no mineral or fibrosis?
Myocardial toxins
Name two categories of toxins that cause simple myocardial necrosis
- Ionophores (coccidiostats)- alters Na-K pump system, flooding myocytes with Ca
- Plants- senna plants, white snakeroot, gossypol
What causes patchy granulomatous, eosinophilic myocarditis?
Hairy vetch (Vicia villosa)
What organ, other than the heart, is affected by hairy vetch (Vicia villosa) toxicity?
Kidney
Proliferative lesion on valves
Vegetative valvular endocarditis
What causes valvular endocarditis?
Staph, strep, coliforms
Trueperella pyogenes
Bartonella bovis if aortic valve
Causes of subendocardial mineralization (not white muscle)
Granulomatous inflammation (Johne’s disease)
Plant ingestion- Cestrum diurnum, Trisetum flavescens, and Solanum glaucophyllum (contain Vitamin D analog, causes metastatic calcification)
Parasitic myocarditis is caused by
Cysticercus bovis (Taenia saginata is adult)
Where else can cysticercus bovis reside?
Masseter muscle
An incidental finding of focal edema and fibrosis that may look like a parasite or infarct
Myocardial lymphangectasia
Two neoplasias of the myocardium
- Lymphoma (BLV)
- Neurofibroma or schwannoma
Pathogenesis of altitude disease
Low oxygen levels–>vasoconstriction within pulmonary arteries–>pulmonary hypertension–>increased preload–>right heart failure and ventral edema, globoid heart
