VME 4906 Test 3

Reasons for hierarchal organization

reduced aggression, increased cohesion, priority access to resources

subgroups

friends

dominant horse

often older, foal may learn dominance, less anxiety if there is a dominant mare

Neurohormonal response

release of ACTH, cortisol, epinephrine and norepinephrine, increased O2 & glucose to brain & skeletal muscle

Sleep

- lying down

- REM: 1-2 hrs/day

Positive vocal communication

nicker, whinny

Negative vocal communication

squeal

Odor Communication

scent marking, flehmen

Submission

lip flap, lip snap, chewing, licking lips

+ interactions

standing closely, mutual grooming

- interactions

squealing, biting, kicking , pinned ears, rolling eyes

Body language

observe from distance, head & body position, movement/resting

Ear position

both forward (Good), different positions, back (bad), helicopter (neutral)

Eyes

raise head for distance seeing, lower head for close up seeing, quiet vs worried vs anxious

Lips/Nose

flared nostrils or pinched, pulled back lips vs floppy, grinding teeth (anxious), tongue sucking (self soothing)

Flehmen response

transfer of pheromones to vomeronasal organ

Tail

Relaxed, swishing, clamped, high over back

What breed are stereotypies most common

Thouroughbred or warmbloods, passed through familial lines

Causes of sterotypes

lack of social contact, weaning, lack of turnout, not enough foraging, stress

Cribbing

- grab solid object, arch neck, pull object, grunt

- destructive

- hypertrophied neck muscle

- increased risk of temporohyoid osteoarthropathy

- increased risk of colic: epiploic foramen entrapment, increased Mitra abdominal pressure

Cribbing detterents

- cribbing straps

- rings

- muzzle

- cover surface

- modified fosell: neurectomy of ventral branches (84.4% effective)

Pawing

- in the stall, when tied, in trailer

- anxiety/fear, pain, learned, sereotypy

- damages stall, ground, foot, shoe & limb

Weaving

- lateral swaying movement of forequarters

Stall Walking

- repetitive tracing of route

- 2% of stabled horses

- decreased risk when horses have social contact

- onset 1 year

- occurs when frustrated locomotor, anticipation

- treatment: environment modification( turnout, exercise, mirror, toys), group weaning, diet modification (forage), slow feeders

Self mutilation

- stomping, biting, kicking, striking, rubbing

- +/- vocalization

- more common in stallions (2%)

- treatment: physical restraint, social modification, decrease olfactory stimulation, nutrition, exercise, tranquilizers

Type 1 self mutilation

normal response to physical discomfort

- GI, urogenital, musculoskeletal pain

Type 2 self mutiliation

self directed internal aggression

- stallions, geldings target themselves

Type 3 self mutilation

receptive stereotypy

Head Shaking

- recurrent, intermittent, involuntary

- ridden, handled, turn out

- 60% only in spring & summer: UV light, air quality, exercise

-diagnostics: video, diary, physical exam

- etiology: trigeminal nerve stimulation

- rule out: ear infection, protozoal myeloencephalitis, dental disease, iridium cyst, guttural pouch disease

- management: bitless bridle

- treat: nose net, UV eye protection, acupuncture

-drugs: antihistamines, herbal, dexamethasone, pulse therapy, ant GnRH vaccine

-surgical: block first, infraorbital neurectomy

-prognosis: 40% stabilize, 40% vary in season, 20% deteriorate

T/F: In wild horse herd behavior, the alpha male/stallion is generally in the lead directing where the herd moves.

False

The physiological response to the "fight or flight" hormones includes many characteristics EXCEPT:

increased blood flow to all organ systems

T/F: Horses can sleep standing up and thus do not need to ever lay down in a recumbent position

False

Which behavior would you expect to see in regards to submission in horses?

Licking lips

When entering a stall a normal, relaxed head position would be:

at or slightly above the withers

- stallions

- younger more than older

Flehmen response

T/F: There are a variety of strategies employed to try to decrease or eliminate cribbing in a horse, but time (how long a horse has been cribbing) is the biggest factor that influences success of a strategy

True

Nasofacial irritation or pain related to the trigeminal nerve is thought to be related to which stereotypic behavior

head shaking

T/F: Dexamethasone pulse therapy is really the most effective drug treatment for head shaking

False

History of patient

- signalment

- health history, vaccines, deworming

- normal diet, appetite

- turnout & work schedule

- current medications/supplements

- previous treatment

Observation for physical exam

- outside stall

-assess respiratory rate and effort

- assess husbandry/housing practices

Head & Neck exam

- symmetry

- observe cornea, sclera, conjunt

- mucous membrane, normal: pink

- capillary refill time: <2s

- percuss sinus

- palpate lymphnodes

- assess jugular fill

- muscle symmetry

- inspect skin

Thorax (chest) exam

- ausculate lungs, count RR, normal=8-20

- ausculate heart, count HR, normal=20-40 bpm

- left valves: pulmonic, aortic, mitral

- right valves: tricuspid

Front/Hind Limbs exam

- palpate for heat, swelling

- palpate hooves for heat, joint swelling, changes to coronary band

- lift feet, look at soles

- palpate for digital pulses, prominent=problem

Abdoment exam

- ausculate for GI motility

- left upper, left lower, right upper, right lower

Tail exam

- rectal temp, normal=99-101.5

- palpate tail, inspect tail head for masses

- walk horse in circle

Body weight

use scale or estimate based on body condition score

After the signalment for a horse is taken, what is the next thing done

Assess the horse standing outside the stall

The sclera around the eyes of a horse can sometimes give you a hint about ______ in a horse

systemic problems

The jugular vein should fill in about

5 seconds

There are a few hear murmurs that are indicative of a defect in the horse. You can hear these _____

only on the right side of the horse

T/F: A lot of horses that are extremely ill have an extremely low body temp

False

T/F: The nociceptive system is also considered one of the sensory systems

True

Tissues from left to right within auditory system

Pinna, tympanic membrane, ossicles, cochlea

Which color cones are not included in horse Vision

red

Horse pupil shape

oval, image C

Which of the listed cranial nerves specifically responds to touch?

trigeminal

Vomeronasal organ associated with:

olfaction, reproduction, hierarchy of other horses

Within the auditory system, the first tissue where sound causes an impact or change due to vibrations is

tympanic membrane

T/F: In addition to the lens, the shape of a horse's eye, which is round rather than oval, is thought to help with focusing the light entering the eye

False

Which of the following characteristic is NOT part of horses vision

Trichromatic

T/F: concentrated along a horse's muzzle they have vibrissae, special whiskers, that are highly responsive to touch within a blood sinus

True

Sensory system of a horse

consists of sensory receptors, neural pathways, parts involved in perception

How many muscles in Pinna?

10

Range of hearing

55-3500 Hz

oval shape of eye, rectangular pupil is good for what

focusing light

Vision perception

65 degree binocular front, 350 degrees monocular around

Dichromatic or Trichromatic

dichromatic vision

Somatosensory

- free nerve endings

- vibrissae= trigeminal nerve to brain

Where are mechanoreceptors located?

concentrated in muzzle

Type 2 taste buds

sweet, bitter, umani, G protein coupled receptors

Type 3 taste buds

sour salty, ion receptors

taste buds

spindle shaped with microvilli, basal cells, all taste buds have all cell types

tongue has fungiform, foliate, circumvallate papillae

Which cranial nerve for front of tongue

7

which cranial nerve for root of tongue

9 & 10

which cranial nerve for larynx of tongue

10

factors of being an herbivore

- bitter to avoid toxic plants

- prefer sweet & salty

- avoid sour

Flavor

depends on taste, smell, texture, chemesthesis

Main olfactory epithelium (MOE)

synapses olfactory bulb

vomeronasal organ (VNO)

synapses on accessory olfactory bulb to amygdala, reproduction

Natural uses of olfactory sense

mates/rivals, avoid predators, assess food

Distant communication

sight, sound, smell

Close communication

touch

Vestibular system

semi circular canals, crystals move hairs & maintains balance

Thermoreceptors

- warm & cold free nerve endings

cool receptors

- located cornea, tongue, bladder, facial skin

- aid in taste/flavor

- blinking

Nociceptive system

noxious stimuli (pain)

- receptors detect stimuli above certain thresholds

- mostly in skin, joints, not as conc. internally

large eyes

improve achromatic rod vision in dim light

endoparasite

infection

ectoparasite

infestation

definitive host

final

intermediate host

will leave

prepatent

inside host before eggs in feces

patent

eggs released into environments

Helminths

trematodes, cestodes, nematodes

Protozoans

flagellates, amoeba, apicomplexans

Arthropods

fleas, ticks, mosquitos, lice

Fecal flotation

- 1g or more of feces

- solution specific gravity must be less than parasite specific gravity

McMasters Test

at least 25 eggs/slide, not sensitive enough to pick up less accurately, 4g of species

- egg # does not correlate with # adults in animal

- best if raw egg counts btwn 2 chambers within 25-50% each other

Fecal Egg Count Reduction Test (FECRT)

each animal weighed and treated

- test 2nd time after 14 days