Equine Vet & CVS Flashcards
what does stage 1 of a PPE involve
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
what does the cardiovascular exam involve
often healthy horse –> overt disease is rare (looking for abnormalities that might affect performance)
before (at rest), during and after exercise (recovery)
- observation: (resp rate, effort, depth), peripheral vasculature
- palpation: edema, peripheral perfusion (extremities warm)
- pulse: rate, rhythm and quality
- mucous membranes and capillary refill time
- jugular veins
what are the rules of cardiac auscultation
- palpate both sides for apex beat
- auscultate both sides
- usually best to have forelimb cranial
- have a systemic approach to encompass all valve areas
outline the auscultation steps in the horse
- palpate left apex beat
- place stethoscope on this point
- establish heart sounds, rate and rhythm
- landmark for mitral valve –> move stethoscope radially around this point - 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 - palpate apex beat on right side
- auscultate as far cranial as possible (forelimb cranial, beneath triceps muscle)
- tricuspid valve
what are the normal heart sounds
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
what is a second degree atrioventricular block
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
what is stage 2 of the PPE
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
what is stage 3 of PPE
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
what is stage 4 PPE
in stable
monitor cvs and resp system as return to resting levels
what is stage 5 of PPE
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
what are additional investigations
radiographs
echocardiography
opthalmology
endoscopy
what is 2 stage PPE
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
what is equine insurance coverage
vet fees
all risk mortality
loss of use
what is the vets role in the pre-insurance exam
pre-insurance exam allows insurance company to assess risk and relate to level of cover –> pre-existing conditions usually will be excluded
what is pre-insurance exam on a newly purchased horse
often use PPE form to obtain insurance
what is pre-insurance exam on already in ownersup horse
depends on value
detailed exam - 5 stage (loss of use and vet fees)
limited exam - 2 stage (all-risks of mortality)
what is all-risks of mortality insurance
insured value of horse paid: sudden death or destroyed on humane grounds (may be immediate, or after second opinion/consultation with insurance company)
what is loss of use insurance
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)
what does high metabolic rate require for the air to muscle transport of oxygen
oxidation of carbohydrate mainly glycogen
what does the horse muscle contain
high volume of mitochondria
large stores of glycogen
lots of energy for contraction and a high oxidative (aerobic) capacity (VO2max)
what is VO2max
maximum rate of oxygen consumption
what is the horse VO2max
180-200 ml O2/kg/min
why does the horse have such a high VO2max
- resp system: large lung capacity/gas exchange surface area
- 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)
what needs to occur to be able to work at max capacity (6)
- high maximal aerobic capacity
- large intramuscular stores of glycogen
- high mitochondrial volume in muscle
- ability to increase oxygen-carrying capacity of blood by splenic contraction
- efficiency of gait: muscular work of galloping halved by elastic storage of energy in muscle and tendon units
- efficient thermoregulation: need to dissipate heat generated
what are 3 areas of poor performance
- decrease in performance level: not performing as expected, previously performed well
- exercise intolerance: marked decrease in performance level, not capable of training at previous level
- unable to compete at expected level: unproven horse, breeding would suggest should be good, trains well but poor in competition
what are factors limiting performance
- genetic
- training
- intrinsic factors
- extrinsic factors (raining, hard ground, etc)
how is poor performance investigated
- history and general physical exam
- evaluation of musculoskeletal system
- laboratory screening
- evaluation resp system (endoscopy, resp sampling)
- evaluation of cvs (ECG, echocardiography)
- exercise testing (field or treadmill)
- post exercise evaluation
what is dorsal displacement of soft palate (DDSP)
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
what is inflammatory airway disease
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
what is a CVS issue that may decrease performance
irregularly, irregular heart rhythm
variable intensity of heart sounds, with no S4 audible
arterial pulse varies in intensity sometimes with a pulse deficit
what is recurrent exertional rhabdomyolysis (RER) and how is it diagnosed
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
what is hock osteoarthritis and how is it diagnosed
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)
what is equine gastric ulceration syndrome (EGUS) and how is it diagnosed
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
