Equine Vet & CVS

Question 1

what does stage 1 of a PPE involve

Answer 1

thorough clinical exam at rest to detect clinically apparent signs of injury, disease of physical abnormality (visual, palpation, manipulation)

exam of incisor teeth (age), eye, heart, lungs at rest

observe surroundings as well

Question 2

what does the cardiovascular exam involve

Answer 2

often healthy horse –> overt disease is rare (looking for abnormalities that might affect performance)

before (at rest), during and after exercise (recovery)

1. observation: (resp rate, effort, depth), peripheral vasculature
2. palpation: edema, peripheral perfusion (extremities warm)
3. pulse: rate, rhythm and quality
4. mucous membranes and capillary refill time
5. jugular veins

Question 3

what are the rules of cardiac auscultation

Answer 3

1. palpate both sides for apex beat
2. auscultate both sides
3. usually best to have forelimb cranial
4. have a systemic approach to encompass all valve areas

Question 4

outline the auscultation steps in the horse

Answer 4

1. palpate left apex beat
2. place stethoscope on this point
   - establish heart sounds, rate and rhythm
   - landmark for mitral valve –> move stethoscope radially around this point
3. then move stethoscope cm by cm in cranial/dorsal directioni
   - towards heart base and underneath triceps muscle for the outflow/semilunar valves (aortic and pulmonary)
   - perform radial scan
4. palpate apex beat on right side
5. auscultate as far cranial as possible (forelimb cranial, beneath triceps muscle)
6. tricuspid valve

Question 5

what are the normal heart sounds

Answer 5

S4 (lu): contraction of atria

S1 (lub): atrioventricular valve closure –> start of systole (S)

S2 (dup): aortic and pulmonary valves closure –> start of diastole (D)

S3 (de): end of rapid ventricular filling

Question 6

what is a second degree atrioventricular block

Answer 6

not clincally significant –> physiological arrhythmia

P waves (atria depolarization) not conducted to ventricles

rhythm regularly irregular

• dropped beat after every 2 or 3 normal contractions
• S4 may be heard in isolation
• rhythm should revert to normal with excitment or exercise
• can confirm with ECG - P wave visible with no associated QRS-T

Question 7

what is stage 2 of the PPE

Answer 7

walk and trot in hand

need firm level ground

turn sharply in both directions and back up

flexion tests and trot in circle on firm surface

Question 8

what is stage 3 of PPE

Answer 8

exercise phase

need large area

sufficient exercise to allow assessment of the horse (when it has an increased breathing effort and an increased heart rate)

walk, trot, canter and if appropriate gallop

unless a good reason should be ridden exercise

Question 9

what is stage 4 PPE

Answer 9

in stable

monitor cvs and resp system as return to resting levels

Question 10

what is stage 5 of PPE

Answer 10

second trot up

walk and trot in hand again –> looking for strains or injuries made evident by the exercise and rest stage

blood sample for storage

Question 11

what are additional investigations

Answer 11

radiographs

echocardiography

opthalmology

endoscopy

Question 12

what is 2 stage PPE

Answer 12

limited exam

stage 1: preliminary exam

stage 2: walk and trot in hand

can be performed but not ideal

owner needs to complete a disclaimer

Question 13

what is equine insurance coverage

Answer 13

vet fees

all risk mortality

loss of use

Question 14

what is the vets role in the pre-insurance exam

Answer 14

pre-insurance exam allows insurance company to assess risk and relate to level of cover –> pre-existing conditions usually will be excluded

Question 15

what is pre-insurance exam on a newly purchased horse

Answer 15

often use PPE form to obtain insurance

Question 16

what is pre-insurance exam on already in ownersup horse

Answer 16

depends on value

detailed exam - 5 stage (loss of use and vet fees)

limited exam - 2 stage (all-risks of mortality)

Question 17

what is all-risks of mortality insurance

Answer 17

insured value of horse paid: sudden death or destroyed on humane grounds (may be immediate, or after second opinion/consultation with insurance company)

Question 18

what is loss of use insurance

Answer 18

reimbursement if animal develops a permanent disability

requires diagnosis and treatment options (including those tried) –> usually requires non response to prolonged treatment (12 months), prognosis

often a second opinion is/has been obtained

once agreed and claim paid –> proof of destruction or retire horse (freeze brand)

Question 19

what does high metabolic rate require for the air to muscle transport of oxygen

Answer 19

oxidation of carbohydrate mainly glycogen

Question 20

what does the horse muscle contain

Answer 20

high volume of mitochondria

large stores of glycogen

lots of energy for contraction and a high oxidative (aerobic) capacity (VO2max)

Question 21

what is VO2max

Answer 21

maximum rate of oxygen consumption

Question 22

what is the horse VO2max

Answer 22

180-200 ml O2/kg/min

Question 23

why does the horse have such a high VO2max

Answer 23

1. resp system: large lung capacity/gas exchange surface area
2. CVS: efficient circulation to deliver oxygen to tissues, high max cardiac outoput, high oxygen carrying capacity (high Hb concentration, splenic contraction at start of exercise increases PCV)

Question 24

what needs to occur to be able to work at max capacity (6)

Answer 24

1. high maximal aerobic capacity
2. large intramuscular stores of glycogen
3. high mitochondrial volume in muscle
4. ability to increase oxygen-carrying capacity of blood by splenic contraction
5. efficiency of gait: muscular work of galloping halved by elastic storage of energy in muscle and tendon units
6. efficient thermoregulation: need to dissipate heat generated

Question 25

what are 3 areas of poor performance

Answer 25

1. decrease in performance level: not performing as expected, previously performed well 2. exercise intolerance: marked decrease in performance level, not capable of training at previous level 3. unable to compete at expected level: unproven horse, breeding would suggest should be good, trains well but poor in competition

Question 26

what are factors limiting performance

Answer 26

1. genetic 2. training 3. intrinsic factors 4. extrinsic factors (raining, hard ground, etc)

Question 27

how is poor performance investigated

Answer 27

1. history and general physical exam 2. evaluation of musculoskeletal system 3. laboratory screening 4. evaluation resp system (endoscopy, resp sampling) 5. evaluation of cvs (ECG, echocardiography) 6. exercise testing (field or treadmill) 7. post exercise evaluation

Question 28

what is dorsal displacement of soft palate (DDSP)

Answer 28

ex. 2 year old TB okay in training, during last race was competing well but 2/3 into race pulled up making loud gurgling noise normal URT endoscopy at rest dynamic overground --\> **free border of soft palate slip from beneath the epiglottis, obstructs breathing esp during expiration**

Question 29

what is inflammatory airway disease

Answer 29

mild to moderate equine asthma impairement of pulmonary function/gas exchange diagnosed on bronchoalveolar lavage fluid (BALF) cytology --\> increased nucleated cell counts and/or proportions of inflammatory cells principally neutrophils but also mast cells and eosinophils

Question 30

what is a CVS issue that may decrease performance

Answer 30

irregularly, irregular heart rhythm variable intensity of heart sounds, with no S4 audible arterial pulse varies in intensity sometimes with a pulse deficit

Question 31

what is recurrent exertional rhabdomyolysis (RER) and how is it diagnosed

Answer 31

occasionally stiff post exercise exercise test --\> blood sample before 30 mins of light exercise and then at 4 and 24 hours see an increase in creatinine kinase (CK) and aspartate aminotransferase (AST) post exercise --\> problems with muscle metabolism muscle biopsy --\> striated muscle cells damaged releasing muscle enzymes in blood and myoglobin

Question 32

what is hock osteoarthritis and how is it diagnosed

Answer 32

dragging hindlimbs over jumps/refusing jumps lame hindlimbs but can be toe dragging/shortened stride on both hindlimbs lameness improve with intro of local anaesthetic into tarsometatarsal joints hock radiographs --\> osteoarthritis identified associated with tarsometatarsal and distal intertarsal joints degenerative joint disease (hock arthritis, or bone spavin)

Question 33

what is equine gastric ulceration syndrome (EGUS) and how is it diagnosed

Answer 33

gastroscopy squamous mucosa ulceration seen due to lack of fibre in diet to buffer acid, large amounts of concentrates --\> rapid gastric emptying and increased acidity acid splashing during exercise sustained high speed work --\> impaired blood flow to mucosa and therefore healing ulceration causes pain + discomfort