Equine Medicine

What does colic mean

abdominal pain

What can colic range from (in terms of pain)

mild and self-limiting (gas) to life threatening and grave (intestinal obstruction/torsion)

What does founder mean

lay term for “laminitis”

What does laminitis (founder) mean and what is it caused by

• inflammation and subsequent separation of the laminae of the hoof

• Causes: carbohydrate overload, excess weight bearing, endotoxemia, high temp, anything that offsets the laminae that hold the coffin bone

• hallmark clinical sign is severe lameness with bounding digital pulses. P3 rotation or sinking can result from laminar separation

  • P3 is the coffin bone

  • usually, the horse will be leaning back on their heels to relieve pressure on their toes

What does the term “off” mean

lame

• giving to pressure on a painful limb, quick step

What does tube worm mean

administering dewormer by means of a nasogastric tube

• used so the horse won’t spit it up

What does the term “float” mean

Manually or mechanically filing off the sharp points of teeth

• horses have hypsodont teeth: teeth that keep growing

• sharp edges buccal: superior, lingual inferior

• clinical signs when the teeth are way too long are dropping feed/losing weight due to not eating

What does the term “arm” mean

rectal exam

• reasons: pregnancy and colic

• horses’ rectum are easy to tear

  • flip sleeve inside out and use lots of tube

  • gently palpate

  • don’t want to see blood

What does the term “cut” mean

castrate

What does the term “tying up” mean

myositis/muscle stiffness

• happens after working too hard or diet change

Leading a horse

• always use a lead rope attached to horse halter

• never grasps the halter itself

  • provides no options if horse were to startle

• do NOT coil end of lead rope around your hand

  • loops could tighten

  • fold it back and forth and grasp middle of folds

• never wrap lead rope or any other line attached to a horse around any part of your body

  • avoids being dragged

• don’t allow horse you’re leading to touch noses w/ unfamiliar horse

  • can lead the horses to bite or strike another (also applies when you’re mounted)

  • disease transmission

Tying a horse

• tie horse “eye high and no longer than your arm”: tie knot should be at least as high as horse’s eye, and distance from knot to halter should be no more than length of your arm

  • tie only to safe, solid object, using a quick-release knot or breakaway string

  • keep fingers out of loops as you tie knot

  • tie only w/ halter and lead, never w/ bridle reins

Maneuvering around horse

• stand near should or next to hindquarters

• do NOT stand directly in front of or directly behind a horse when grooming his hand or brushing or braiding his tail

• walking behind a horse, go either:

  • close enough to brush against him, keeping 1 hand on his rump as you pass around

    • where a kick would have no real force

  • far enough away to be well out of kicking range

• avoid ducking under tie rope

  • might cause horse to pull back, and you’d be X-treme vulnerable to injury if he did

• never kneel or sit on ground when working on distal limbs

  • remain squatting, so you can jump away in even he startles

  • be mindful of all 4 feet

Trailering a horse

• never fight w/ a reluctant horse to get him into a trailer

  • seek professional help and retraining, if necessary

• once a horse is in trailer, close back door or ramp before you hitch him to trailer tie

• unloading: untie horse before opening back of trailer so he doesn’t begin to back out on his own and hit end of rope, causing him to panic and pull back

Turning horse loose

• when turning out a horse or pony for exercise or returning him to his paddock or pasture, always turn his head back toward gate

• step through gate yourself before slipping halter

  • avoid his heels in case he kicks them up in delight at freedom

Feeding treats to horses

• offer carrot or apple chunks from palm of flattened hand to avoid being accidentally nipped

• put treats in a bucket before offering them

Paying attention to horses

• stay calm, focused, alert at all times

• be aware of surroundings

• be mindful of possible spooks

• listen to horse

Mucous membranes in horses (physical exam)

• pink/moist

• CRT < 3 secs

• above superior incisors

Skin turgor (physical exam)

pinch skin above eye or lateral neck

• not as reliable as mucous membrane

Lung sounds (physical exam)

auscultate all lung fields

• clear air movement sounds

• barely audible

• if we hear crackle, wheezing, or effort, this is abnormal

Borborygmi (physical exam)

gastrointestinal sounds/gurgle sounds of abdomen

• all 4 abdominal quadrants

  • cecum on right side and small intestine on left

• regular/consistent

  • not hyper or hypo motile

Temperature (equine vitals)

98-101F

• mild variation depending on ambient temp, activity, anxiety, etc

• rectal thermometer

Heart rate (equine vitals)

40 bpm

• 28-44 bpm

• auscultate: place stethoscope on left thorax at elbow

• feel pulse: submandibular

Respiration (equine vitals)

8-12 breaths per min

• auscultate: place stethoscope on thorax

• visualize: movement of thorax and abdomen

Digital pulses (equine vitals)

• palmar/ plantar digital vein-artery-nerve bundle

  • artery will pulse

• palmar/plantar axial/abaxial aspects of metacarpal-phalangeal joints

• should be faint or absent (otherwise think laminitis, joint infection)

  • really strong pulse → bad

• hoof should feel cooler than body

  • hot hoof wall → bad

What are the core vaccinations for horse

• WN/EWT: West Nile Virus Vaccine

• RV: rabies vaccine

What are the risk-based vaccinations for horses

• Flu/Rhino

• Strangles

• EHV: equine herpes vaccine

• EVA: equine arteritis vaccine

• Leptospirosis

  • transmitted through urine so if there’s a lot of rain/standing water, this vaccine is def needed

• Potomac Horse Fever

• Botulism

Venipuncture- IV (horses)

Jugular groove (vein)

• brachiocephalicus

• sternomandibularis

• jugular stays superficial

• jugular vein is v close to carotid artery which goes from heart to brain

Injections- IM (horses)

• Cervical

  • cervical vertebrae

  • scapula

  • nuchal ligament

• Rear

  • semimembranosus

  • semitendenosus

Layer 1: Wound Dressing (Bandaging)

should be non-stick

• if a wound is present, primary or contact layer should be a wound dressing

• appropriate dressing may vary depending on type of wound and stage of healing

  • most commonly used wound dressing is a sterile non-adherent gauze pad

Layer 2: Padding (Bandaging)

intermediate bandaging layer consists of soft, absorbent padding material to cushion and protect the limb, and to help evenly distribute pressure applied by bandage

• roll cotton

• sheet cotton

• combine cotton (knowns as Gamgee)

• commercial cotton or flannel “pillow” or quilted wraps

  • can be washed and reused

• smoothed w/ a cling gauze wrap

Layer 3: Bandage (Bandaging)

third and outermost bandaging layer consists of bandage itself, which secures other layers and provides compression

• flexible cohesive bandages “Vet Wrap”

  • 3M Vetrap

  • Powerflex

  • Co-Flex

• Reusable bandages w/ Velcro fasteners

  • fleece

  • cotton

  • polyester knit bandages w/

• 4 and 6 inches wide

  • narrower bandage can result in pressure points and general constriction of limb

On top of the layer 3 of the actual bandage, there’s a protective layer. What are 2 things that can used for the protective layer

• elasticon

  • holds bandage in place

  • prevents slipping

• duct tape

  • waterproof protection

8 principles of bandaging

1. begin w/ clean, dry legs and bandages

   1. trapped dirt and debris can cause skin irritation/wound irritation

   2. moisture can lead to a fungal infection

2. apply correct tension

   1. greatest challenge

   2. applied too loose, bandage will fail to provide adequate support, but may slip out of place or come undone

      1. create pressure points on back of leg that can cause damage to tendons (“bandage bow”)

   3. wrapped too tightly will impede circulation in limb and can also result in tendon injury

   4. ideal tension for a correctly applied leg bandage = snug

      1. tight enough to remain securely in place

      2. not too light restrict blood flow in limb

3. make wraps smooth and even

   1. bandage and padding underneath should lie flat and smooth

      1. no wrinkles, bunches, or ridges that could cause pressure points

   2. leg bandages wrapped in spiral pattern

   3. each wrap made around leg, should overlap preceding layer by about 50%

      1. ensure consistent, even distribution of pressure

4. provide adequate padding

   1. inadequate amt of padding → construction on limb, inhibiting blood flow and creating pressure points that can lead to injury

   2. layer of padding should be at least one inch in thickness in order to adequately cushion and protect leg

   3. always make sure there’s ~ inch of padding showing above and below bandage

5. wrap from front to back, outside to inside (counterclock on left legs, clockwise on right)

   1. ensures tension from bandage is applied to front of leg rather than on delicate tendons at back of leg

   2. horse ppl expect this

6. start wrap over bond at inside front of leg

   1. never start or finish wrap over tendons

      1. may cause damage or over joint as constant movement will loosen bandage and may cause it to bunch or unravel

      2. horse ppl expect this

7. standing bandages

   1. provide protection, mild support, and warmth to tendons and ligaments in horse’s lower leg

   2. wrap legs in pairs

8. check leg bandages frequently and re-bandage if necessary

   1. general rule

      1. standing bandages shouldn’t be worn for longer than 12 hrs at time

      2. wound bandages should usually be changed every day

Clinical Signs of Colic

• stoic, depressed

• laying down (up and down)

• inappetent

• bruxism (grinding teeth)

• biting at abdomen

• restlessness

• rolling excessively

  • abrasions over eyes and on hips

• violently thrasing

History taken while examining for colic

• when was last time horse appeared normal

• when did horse last eat

• what its usual diet

• when did it last defecate? what did stool look like

• has it colicked before

• are any other horses on property displaying similar signs

• reproductive status

• deworming history

• travel history

• history of dental care

• primary use of horse

• what meds have been administered recently

Physical Exam

• abnormal signs w/ colic

• Tacky MM

  • variety of colors like bright red, fuchsia, purple

  • toxic line = endotoxemia

• injected sclera (blood shot eyes)

• normothermic

• sweating

• tachycardia

• tachypnea (high respiration rate)

• decreased or absent GI sounds

Diagnostics (w/ colic)

• NG tube

  • esophagus is on left side and trachae is on right

  • you’ll smell and hear the correct side

• rectal palpation

• abdominocentesis

• abdominal ultrasound

• clinicopathologic analysis

• don’t do radiographs bc waste of time

Surgical candidate or not (assoc w/ colic)

• Stabilize

  • IV cath

  • IV fluids

  • Banamine/Bute

    • no banamine and dex together

  • butorphanol

  • xylazine

  • buscopan

  • NG tube

    • oil, epsom salt, H2O

  • walking

  • enema

• referral

Lameness Exam/ Grades

• evaluated at a trot

• Lameness on a scale from 0-5

  • 0= no lameness observed @ time of exam

  • 1= lameness difficult to observe and not consistent, regardless of circumstances

  • 2= lameness difficult to observe at walk and trot, but consistent under certain circumstances, such as trotting in a circle

  • 3= lameness consistently observable at a trot in all circumstances

  • 4= lameness apparent at a walk

  • 5= lameness w/ minimal (toe-touching) to non-weight bearing

Flexion Tests (for Lameness Exams)

holding leg in a flex for like 30 secs and let them trot after bc first 3 steps will be worst/show if there’s a prob

Nerve Blocks (Lameness Exams)

• Use carbocaine

• Start distal then work your way up the limb (with shot of carbocaine)

• you’ll know where the problem is when the lameness goes away

• Nerve block shot → wait ~ 10 mins → trot exam