Horses Flashcards

Question

Horse Vision

Answer 1

Vision: wide field of vision and eyes see independently (monocular vision): cannot see directly in-front (forehead) or behind (tail)

Answer 2

14 Hz - 25 Hz (20Hz-20KHz): responds well to low tone commands: Don’t like high or shrill commands - Ears rotate 180º: 10 muscles (people 3 ear muscles)

Answer 3

Like salt and sweet. Dislike bitter and sour: - protective against poisonous plants and water

Answer 4

better sense of smell than people: use smell for **pheromone detection** (stallion) and **predator detection**. - Foals and mares bond through sense of smell

Answer 5

Horse rolls upper lip (expose sensitive membrane of lips and nose) to **detect unusual smell**. - Allows ‘scent’ to interact with vomeronasal organ (important in pheromone detection)

Answer 6

abdominal pain: many causes - Horse is listless or varying degrees of distress - Signs: curling lips, pawing, kicking at belly, lying down, rolling - Pulse rate elevated, sweating, pink to blue gums - Emergency in horses - Stats: 4.2 colic/ 100 horses: 11% are fatal

Answer 7

1. Colic by cuase 2. Colic by location

Answer 8

- **Digestive Colic**: too much feed or change in feed - **Spasmodic or gas colic**: eating too fast or toxin in feed - **Sand colic**: sand in feed - **Impaction colic**: not enough water - **Others**: ‘Intestinal accident’

Answer 9

- Gastric colic’ (gastric dilatation and rupture): stomach small (8-10 liters). - Stomach will rupture as fluids content increase -as horses can not vomit - Intestinal obstruction (fluid build up) or too much gas . Very common - Horse stomach rupture (Stomach Impaction): impacted with feed. Less common

Answer 10

Most common causes of colic: - obstruction - strangulation - intussusception - inflammation - volvulus (180º rotation around mesenteric axis) - ascarid impaction - cranial mesenteric arteritis (verminous arteritis) - Enteroliths and cecal impaction (many more)

Answer 11

A type of cholic that occurs in old horses - Fat gows on fiberous tissue - Starts swinging →Wraps around and strangles intestines - Must be surgicaly removed

Answer 12

- Mild exercise (walk or jog): gas colic - Pain meds (NSAIDS) - Stomach tube - Fluid rehydration - **Better feed and access to water** - Surgery - Deworm

Answer 13

- EIA: Acute – Chronic incidence of fever anemia (low RBC), edema and cachexia (wasting), jaundice, - **Many horses are asymptomatic** or only have mild clinical symptoms and thus are carriers - Virus: **lives in leukocytes for life** and in **plasma during periods of viremia** - Infects: different cell lineages: RBC , macrophage, monocytes, endothelial cells: leads to destruction - incubation period: 7-45 days

Answer 14

Reportible Disease - Retrovirus (RNA virus) - Lentivirus - Associated with high morbidity and mortality - Found worldwide Is considered a sporadic disease and incidence is low (CFIA, 2014) - Hot Spot: Northeast Alberta: Cold Lake region

Answer 15

- **Mechanical transmission**: Biting flies (Horse, Deer flies; painful), main method of transmission. - Local infection more likely than distant animals - **Other transmission**: contaminated equipment, milk, semen, in utero

Answer 16

Use Clinical signs (above slides) Tests: - Antibody tests Coggins test (AGID) and ELISA: Horses are seronegative for 2-3 weeks and thus the Coggins test usually doesn't work in early infection - Molecular tests: PCR: Good for testing foals to infected mares - Vaccine: none - Vaccine: 1975-1990 China developed vaccine, not recommended strategy (OIE, Govt. of Canada) - Terminate animal or permanently isolate for other equids (is this good to isolate)

Answer 17

Roaring/Wistling Horses - Exercise intolerance in horses - Left side is mainly affected. - Right side and bilateral nerves affected is uncommon - Left recurrent laryngeal nerve: **Due to extended length of left recurrent nerve travelling around aortic arch** (base of the heart) - Progressive loss in distal myelinated fibers that innervate that laryngeal muscles (left side) - Left arytenoid cartilage and left vocal fold (chord) becomes weak and can progress to paralysis. - **Arytenoid cartilage collapsed medial (into the tracheal lumen) and the vocal fold will not open.** - Reduced glottal cross-section area (airway area is smaller) **The greater the exercise greater the air resistance and the louder the ‘roaring’** - More exercise will further collapse the trachea and more difficulty breathing - Greater exercise intolerance and poorer horse performance - Most horses with laryngeal hemiplegia sound normal (no roaring) at rest

Answer 18

Treatments - Prosthetic laryngoplasty: best for performance horses- horses usually never reach potential - Laryngeal ventriculectomy: reduces roaring Complications: - Chronic cough - Aspiration of feed (aspiration pneumonia) - Implant failure/infection

Answer 19

1:7 horses will have an incidence of laminitis in its life-time

Answer 20

Founder: means to give away or collapse

Answer 21

Inflammation of structures attaching the hoof to the 3rd phalanx bone (coffin bone) - Failure or loss of attachment of the laminar basal epithelial cells of the epidermal laminae with dermal laminae - The 3rd phalanx rotates toward the sole of the foot and can penetrate through the sole: ‘Sinking’

Answer 22

1) Matrix molecules of the basement membrane and dermis breakdown by metalloproteinases 2) dysregulation of hemidesmosomes-adhesion molecules that used to attach epithelial cells to matrix molecules

Answer 23

1. Endocrine Disease: Cushing’s disease (Hyperadrenocorticism) or Equine Metabolic Syndrome: Possibility due too much insulin produced, this may injure laminae 2. **Excessive grain intake (common)** 3. **Grazing on pasture (grain overload)**: of high sugar content such as spring/fall growth (very common) 4. **Excessive or concussive exercise in adult horses (common)** 5. **Obesity** - risk increases greatly as body score increases (common) 6. Stress from disease or trauma: excessive bearing of weight on 1 leg - post injury to other limb(s)(common) 7. Use of corticosteroid drugs 8. walnut shavings in a load of bedding: 1% walnut in shaving in bedding will lead to laminitis 9. Small hooves or poor hoof quality 10. **Infections**: diarrhea (bacterial[salmonella], rickettsia [Potomac Horse fever], retained placenta, septicemia etc (sporadic)

Answer 24

- Clinical exam and history - Radiographs - Nerve blocks

Answer 25

- **Acute**: <3 days; hot hoofs, painful to walk, depressed, decrease appetite , prominent digital pulse: only severe incidence leads to 3rd phalanx rotation and sinking - **Subacute**:> 3 days, similar to symptoms and manifestation as acute laminitis - **Chronic**: intermittent periods of acute and subacute laminitis, will eventually lead to rotation and sinking of 3rd phalanx

Answer 26

<3 days; hot hoofs, painful to walk, depressed, decrease appetite , prominent digital pulse: only severe incidence leads to 3rd phalanx rotation and sinking

Answer 27

>3 days similar to symptoms and manifestation as acute laminitis - depressed - low appitite - prominent digital puls

Answer 28

**Intermittent periods of acute and subacute laminitis**, will eventually lead to rotation and sinking of 3rd phalanx