Exam 1 Flashcards
What are the 5 physiologic adaptations of the equine athlete
- Large maximal aerobic capacity
- Large intramuscular glycogen stores
- High volume of intramuscular mitochondria
- Splenic contraction
- Gait efficiency
What is the benefit of having max aerobic capacity in the athletic horse
It increases cardiac output, stroke volume and hemoglobin concentration which enhances the oxygenation of blood in the lung and supports a high metabolic rate
Why would you want an increased hemoglobin concentration
Because it increases the oxygen carrying capacity of blood
What fuels music contraction at high intensity (anaerobic) exercise
Glycogen
When does fatty acid oxidation became limited and carbohydrate stores recruited
At 40 - 60% VO2 max
What does vo2 max mean
The max oxygen the body uses during exercise
What is utilized when carbohydrate stores are used for oxygenation (which is why athletic horses have an advantage)
Glycogen
Oxidative capacity of the muscle is directly proportional to
The number of mitochondria per unit of muscle
What provides energy for muscle contraction und is critical for aerobic contraction
Mitochondria
Compare the amount of mitochondria in equine muscles to cow muscles
Equine muscle have 2x the amount of mitochondria than cattle due to work differences
What’s more efficient - aerobic metabolism or anaerobic metabolism
Aerobic metabolism
When does splenic contraction occur in horses
Before and during exercise
What is the benefit of splenic contraction
Increases circulating red cell mass (hemoglobin) without increasing plasma volume and increases oxygen carrying capacity of blood (by 50%)
What is critical for equine athletes muscle perfusion and performance during exercise
Splenic contraction because of the increased red cells and increased o2 carrying capacity
What gives the horse the ability to have a catapult like gait and decreases the size of the muscle
Stored elastic energy in muscles and muscle tendon units
Gait efficiency in horses allow for more work with less
Less muscle mass due to stored elastic energy
What is it called when thoroughbreds race long distances over brush like obstacles
Steeplechase
What type of injuries are often seen in steeple chase racing
High speed casualties and repetitive injuries from multiple compression cycles - seen often in thoroughbreds
Where are the injuries likely to be when galloping in races like steeplechases
Fetlock and carpus injuries common - max hyper per extension of carpus and fetlock particularly the right front because the right front bears all the weight
What horse breed does more of the trotting and pacing and why
Standardbreds - more heavily muscled, longer bodies, not as tall
Compare racing injuries between thoroughbreds and Standardbreds
Injuries usually less severe in Standardbreds compared to thoroughbreds because Standardbreds use a 2 beat gait, meaning less rotational forces that reduce the risk of overload injuries like the right front overweight bearing of the gallop done by thoroughbreds
What is the benefit of the 2 beat gaits done by standardbred trotters and pacers
More equal distribution of load which reduces the risk of overload injury, catastophic injuries, and long bone pathologies
What is a breakdown injury
Traumatic disruption of the suspensory apparatus
Slab or chip fractures happen usually at the -
Carpus
Stress fractures in race horses usually happen -
The pelvis
Soft tissue injury like superficial flexor tendanino ours because of what
Hyperextension of the fetlock and carpus like in thoroughbreds who are galloping and hyperextending
What is often second career injuries
Osteoarthritis
Dorsal metacarpal disease is also called
Bucked shins
What would you be thinking about if a pacer / trotter breaks his gait
Trey might be in pain or have a subtle lameness
What event is described as executing specific movements in a predetermined order and being judged based on rumor, collection, etc
Dressage
What type of horses perform dressage and what gait do they use
Any breed but usually warmbloods, walk, trots or canters but no gallops
What event types requires a lot of hind end engagement todo things like a canter pirouette
Dressage
What is the most common injury in dressage horses
Suspensory ligament desmitis (a soft tissue injury)
Where do dressage horses commonly get osteoarthritis
Hocks, fetlocks, coffins, cervical spine
Show jumpers are judged based on - and
Speed and accuracy
Snow hunters are judged based on - and -
Rhythm and quality of jumping style
Which horses are most often jumpers
Warmbloods and thoroughbreds
What forces affect jumpers
Vertical forces during takeoff and ground reaction forces on landing - increase as height increases
What limb bears the majority of the load when jumpers land
The trailing limb
Why would a horse with neck pain be a bad jumper
The rely on their neck for balance
Where are the common injuries with jumpers
Higher up where muscle turns into tendon - most common is superficial and deep digital flexor tendinitis
Where do jumpers tend to get osteoarthritis
Neck, hocks, coffin, stifle, fetlocks
What event type sees a lot of issues with pain - for example foot, back and sacroiliac pain
Jumpers
79% of injuries during an event occur on the - course
Cross country course -where the jump over natural solid obstacles
what are the 3 courses in eventing
Dressage, showjumping and cross country
What are 3 important qualities for an eventing horse to have and succeed
Cardiovascular fitness , stamina and endurance
Which horse breeds are western performance horses commonly
Quarter horses and paints
Describe the common look of western pleasure horses
Big bodies, heavily muscled, tiny feet
High speed, lateral movement, high end stressors describes what event type
Western performance horses
Why are there so many hind end stressors in wester performance horses
Sliding stops, quick spins and turns
What is the most common soft tissue injury in western performance horses
Stifles - CCL and meniscus
What are common injuries within the bone that affects western performance horses
Acute avulsion fractures of plantar process of P2 due to sliding stops and proximal P2 chip fractures
What horse breeds often participate in endurance races
Arabian horses
- And - are most important in Arabian horses because of the long distances they have to travel over multiple days
Fitness and cardiovascular health
What is the most common injury seen in endurance horses
Metabolic injuries - dehydration, electrolyte loss, tying up
What is the terrible triad and which event horses experience it
Hock pain , foot soreness, and back pain experienced by endurance horses (Arabians)
What are genetic disorders in performance horses that can be affected by nutrition
HYPP, PSSM , equine metabolic syndrome
What are the 3 phases of the performance exam
Conformation, static /musculoskeletal, dynamic
Conformation of the horse should be evaluated with respect to that
Use of the horse
What is the thirds rule in the conformation part of the performance exam
Drop a vertical line from withers to the ground and then the sacroiliac to the ground to determine any asymmetries , the size of hindquarters, length of the neck to the back
How can you tell if a horse has a base narrow conformation
If you look at its limbs and drop a line down through the carpus, fetlock, pastern, etc and most of the limb is on the inside then it is a base narrow conformation
Which horses often have a base narrow conformation
Quarter horses because they are heavily muscled in their chests
If a horse is very straight in conformation from their hock to the hoof , what are you worried abat
Suspensory ligament problems (proximal suspensory dermatitis - psd)
What hock (straight hock) angle increases a horses risk for psd - proximal suspensory dermatitis
> 150 - 160 degrees
Sway back / thoracic lordosis is often seen in - horses
Aging horses - so if seen in young horses indicates a weak back
What is a very important thing to do in phase 2 of the performance exam (the static part)
Palpate the muscle separate from the bone - symmetry, pain , focal spasm
Where do you assess muscle during the performance exam
Cervical, thoracic, lumbar and pelvic regions
Why should you manipulate the axial skeleton motion during your static exam
To check range of motion, can they bend the neck, raise or lower it is there pain
What can you use to measure joint range of motion
Goniometry - can be used as a screening tool when rehabbing to assess ROM and symmetry
Define mechanical nociceptive threshold
Minimum pressure required to induce a pain response
What can you use to measure mechanical nociceptive threshold
Pressure algometer
What is part of the dynamic exam part of the performance exams
Evaluate in a straight line, circle, flexion tests to assess pain, stride lengths, etc.
What does a grade 4 lameness indicate
Lameness obvious at a walk
What does a lameness grade 3 indicate
Lameness obvious and consistent at a trot
What does aloneness grade 2 mean
Lameness apparent under certain circumstances - circling, under saddle,etc.
What on cause a slapping gait that t is obvious at a walk
Fibrotic myopathy - scar tissue over the semimembranosus and semitrndinosis
The weight of a rider can exacerbate _
Axial skeletal lameness
What could white hairs on the back of a horse indicate
Chronic sores from poor saddle fit which can eventually lead to scar tissue then chronic muscle pain
What do gait analysis system do
Objectively evaluate motion and identify asymmemy in sound or lame horse
What does kinetics study
Study of the forces that act on the body