Circulatory Disorders of Ruminants Flashcards Preview

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Flashcards in Circulatory Disorders of Ruminants Deck (62):
1

Heart rate of a lactating dairy cow is?

RR 60-80

2

Tachycardia - 6 causes

Centrally - Cortico-stimulation - catecholamine
Peripherally Increased demand (lactating, eating etc)
Decrease in blood volume
Severe anemia
Decreased cardiac function
Arrhythmia

3

Bradycardia - 7 causes

Hypoglycemia
Decrease in catecholamines
Conserve energy
Vagal stimulation
Hyper/Hypokalemia (if severe causing A/V block)
Increased intra-cranial pressure
Arterial pressure is less than the inter-cranial pressure

4

Heart rate or rhythm doesn't fit it what do you do?

ECG

5

Shock - name 7 types

Hypo-perfusion
Cardiogenic
Hypo-volemic
Toxic (micovascular failure)
Endotoxic (bacterial toxins on the heart)
Septic (septicaemia with affect on organs & vasculature)
Neurogenic (intense stimulus - emotions, vagal, CNS trauma)

6

Leptospirosis - 5 types

Aerobic motile spirochete
Hardjo (host adapted), pomona (non-host adapted), gryppotyphosa, itcterohemorrhagica, canicola

7

Host adapted Lepto - causes what?

Repro problems, chronic persistent infections

8

Non-host adapted Lepto - causes what?

acute infection in accidental hosts

9

Epidemiology of Lepto

warm & wet
skin abrasions & mucus membranes
Urine, uterine fluids, spread venerially
After recovery can still shed

10

Leptospirosis - pathogenesis

Enters abrasion
Multiplies in blood
Liver/spleen brain
blood vessels/liver damage
Proximal tubules of kidneys/placenta/fetus damage
Recover? antibodies remove everything but eye, uterus & renal system

11

Leptospirosis - acute

calves < 1 month
high mortality (sudden death)
pyrexia, depression, anorexia, petichea, acute hemolytic anemia, hemoglobinurea, super anemic, tachycardic, have shock
(usually caused by pomona)
direct damage to the micro-circulation - blood loss - tachycardia, less O2 carrying --> tachycardia, peripheral vasoconstriction --> edema (damaged blood vessels, hypoxia, cell death, tachypnea & dyspnea

12

Leptospirosis - sheep

rare, but often sudden death

13

Leptospirosis - adult cattle

Usually hardjo

14

Initial infection of Leptospirosis - adult

pyrexia, anarexia, agalactia & stiffness
Recnet in intro? mastitis Agalactia, abortions a few weeks later
Sequelae - persists in repro tract, infertility (fetal infection, but also placentitis) & transmitted venereally
Mastitis - without gland inflammation - possible

15

Leptospirosis - diagnosis

Culture, but only do this in acute cases (pomona)
Dark field microscopy
PCR - don't tell you the serovar
Serology - can look at a rising titre, but hard to know if the herd is endemic

16

Leptospirosis - prevention

vaccine - server specific
reduces shedding as well
Can do as young as 4 weeks, repeat every 6-12 months, doesn't prevent abortions or renal shedding
Control - hard to identify carriers, can try to control shedding & spreading & have good hygiene

17

Cold water hemoglobinurea

Happens when you drink a whole lot of cold water - intravascular hemolysis - usually in calves (rumen is buffer). Usually after a period of water deprivation

18

Cold water hemoglobinurea - pathogenesis

Absorb water, decreases, blood electrolytes, decreases osmotic pressure,
RBC are the most fragile at 5 months
occurs within 1 hour of ingestion
tachycardia due to relative O2 deprivation
cell death, vasodilation, edema (pulmonary, brain, death)

19

Copper poisoning

Acute hemolysis because of chronic copper poisoning
Either primary (lot at once, or chronic) or secondary (plant, toxic)

20

Copper poisoning - pathogenesis (acute/chronic)

Acute - actual chemical damage to the GI mucosa, causing protein to coagulate causing coagulation necrosis, fluid loss, shock & death
Chronic - poorly understood - no clinical signs until critical levels in liver, liver necrosis - releases copper, oxidizes blood cells, methemoglobinemia, heinz bodies, hemolysis
PCV can decrease in 48 hours seriously

21

Copper poisoning - clinical signs

acute - GI issues, diarrhea, dysentary & jaundice, shock, abdominal pain
chronic- pale, jaundice, low appetite, tachycardia, depressed, tachypnea, maybe neurosigns later, anemia, methemoglobinemia, hypoxia & dyspnea

22

Copper poisoning - clinical path

anemia, hemoglobinemia/urea, methemiglobinemia/urea
high copper, high liver enzymes

23

Copper poisoning - treatment

don't stress
give a chelator - molybdenum to get the copper out.
(if suspected)

24

Copper poisoning - prevention

keep copper low in feed, or if you know about their molybdenum intake, you can give a little more

25

Heart failure - right or left?

right

26

Right-sided heart failure

Increase in heart right, decrease in appetite, exercise tolerance
Ventral edema, jugular distension, jugular pulse, extremities cool, elbows abducted

27

Left-sided heart failure - rare

Tachycardia, etc similar to right
Increase in pulmonary pressure, probably won't have many respiratory signs, unless pulmonary edema (frothing at the nares etc)
First sign - might be right sided heart failure

28

Treatment

poor prognosis, probably already permanent damange, could try diuretics

29

Arrhythmias

Heart disease usually, supra ventricular dysrhythmias rare, but usually a/fib cattle do get normal sinus arrhythmia.

30

Atrial Fibrillation

Lose coordinated electrical activity of the atria (sometimes you get AV node ventricular activity)
On ECG, no p-waves, irregular base line (as in f waves) undulating baseline… every once in a while, normal random QRS
Occurs especially with atrial enlargement
Can occur spontaneously with sub-acute or chronic GI disease
If persistent, heart disease or heart failure
Always clinically relevant (toxemia, severe electrolyte imbalances, myocardial abnormalities)

31

Endocarditis

Valvular or non-vavluar
A. pyogenes, e.coli or alpho-hemolytic strep

32

Endocarditis - pathogenesis

Disturbed blood flow -> damage to endocardium -> platelet adhesion/fibrin clumps -> bacteria can colonize if circulating

33

Endocarditis - Predisposing factors

valvular regurg/stenosis, heart disease, none

34

Endocarditis - clinical finding

poor doing weight loss, shifting lamens associated with arthritis, fluctuating fever goes away with antibiotics, may or may not have a heart murmur
Usually tricuspid on the atrial surface
Lungs showered, will get cough
Lots of these? pulmonary hypertension, after load increases, right volume overload
Left - renal/myocardial infarcts, maybe septic arthritis

35

Endocarditis - clinical pathology

neutrophilia (with or without left shift)
anemia
hyperfibrinogenima
Hypergloblinimia

36

Endocarditis - post mortem

vegetative growths that distort the valves
Examine the chordae & the rest of the endocardium (hard to culture)
Other lesions consistent with embolization & abscess

37

Endocarditis - treatment

ideally culture first
Start with broad spectrum
Change to what culture says
Continue for more than 14 days

38

Cardiomyopathy - what kind is in bovine?

DCM
Inherited - red gene in Holsteins
Diffuse myocardial fibrosis association
Clinical signs = right heart failure

39

DCM - diagnosis

R/O other causes of right heart failure
See the clinical signs like this in an otherwise healthy animal
Congestive heart failure and extensive myocardial fibrosis

40

Myocarditis

Bacterial - h. somni, a. pyogenes, clostridia
Viral - FMD, bluetongue

41

Myocardial degeneration

Toxin (ionophore, bacterial toxemia, gosseypole)
Nutrition (vitamin e & selenium deficiency, excessive molybdenum or sulphates)

42

Myocarditis/Myocardial degeneration

Sudden death
Chronic - heart failure, arrhythmias
Vitamin e/selenium -> die when exercised

43

Myocarditis/Myocardial degeneration - clin path

Can look at CK
Tropanin 1
Otherwise underlying cause

44

Myocarditis/Myocardial degeneration - treatment

Remove/treat underlying cause
Rest, decrease stress
Anti-inflammatories in myocarditis
Don't treat with anti-arrhytmias

45

Myocarditis/Myocardial degeneration - PM

don't see much histo
Can see a streatked pallor on the myocardium if vitamin/E/selenium
Myocarditis abscess - may see these, patchy though, not diffuse

46

Pericardial disease (TRP)

In ruminants usually, pericarditis (TRP in cows)
Sheeps/goats/calves - sequelae of septicemia
Hardware ingested, decreased everything, venous engorgement, elbows are abducted
Undulating disease

47

Friction rubs

Important to differentiate from a murmur. These can vary from beat-to-beat and in timing with relation to the beats. (both character & intensity)
Can disappear with the appearance of effusion

48

Triad of diagnostic clinical signs for pericardial disease

Muffled heart sounds
Weak rapid pulse
Venous engorgement
(Can do U/S, ECG, large & small alternating QRSs, pericardio-centesis)
Can see fibrin, thickened pericardium, purulence, may see FB. Reticulum communication possible

49

Pericardial disease - treatment

antibiotics
drain pericardial sac
Remove FB by surgery

50

Pericardial disease - sequelae

Fibrin --> fibrosis, constrictive pericarditis

51

High mountain disease

Chronic heart failure in cows living in high altitude.
Low atmospheric oxygen
Alveolar hypoxia
Pulmonary vasoconstriction/hypertension
right heart failure
Cor pulmonale

52

High mountain disease - animals affected

Holsteins (tunica media is more sensitive) predisposed, sheep & goats pretty resistant
introduced animals

53

High mountain disease - pathogenesis

Low O2
Myocardial damage
Need to slowly adapt them.

54

High mountain disease - PM

CHF, concentric right ventricular hypertrophy

55

Congenital heart disease

Variable incidence, can be simple or complex
Simple - VSD
ASD/PD are less common
Complex - rare (tetraology of fallow), persistent truncus arteriosis etc)

56

Congenital heart disease - Clinical significance

Consider the direction of the shunt
Possible extra-cardiac effect could alter cardiac function (e.g. pulmonary hypertension)

57

Left-to-right shunts

Increase the workload of both the chambers (left more than right)
Decrease the cardiovascular functional capacity
Cause failure to thrive

58

Right-to-left-shunt

similar to L-to-R, but even worse because of hypoxemia

59

Congenital heart disease - Clinical signs

variable - from asymptomatic, to gradually progressive to severe/immediate (exercise intolerance) - resp distress
(can do blood gasses, grave prognosis)

60

Simple VSD

Loudest very forward on the right

61

Complex VSD

Loudest on the left

62

PDA in ruminants is simple or complex

Complex in ruminants