Lecture 6

Question 1

What two parasite strategies do you need in horses

Answer 1

Parasite control for first year of life

Parasite control for horses over 18 months

Question 2

Goals of program for first year of life

Answer 2

Limit parasite burdens until young horses develop immunity

Question 3

Goal of program for adults over 18 months

Answer 3

Minimize disease without inducing resistance to parasiticides

Question 4

Major internal parasites

Answer 4

Small strongyles
Large strongyles
Anoplocephala perfoliata
Ascarids

Question 5

Minor internal parasites

Answer 5

Gastrophilus intestinalis (bots)
Habronema, drashcia (stomach worms)
Oxyuris equi (pinworms)
Strongyloides westeri (thread worms)
Dictyocaulus (lungworms)

Question 6

What is the most important parasite to manage in adult horses

Answer 6

Small strongyles/ cyathstomes

Question 7

Prepatent period of small strongyles

Answer 7

5 weeks minimum

Question 8

Describe small strongyles life cycle

Answer 8

Larvae migrate to cecum/colon for 4-6 weeks and encyst where they can live for months to years (mature and encysted doesn’t cause disease unless all encyst at the same time then it causes severe colitis)

Question 9

Describe large strongyles

Answer 9

Migrate through abdominal tissues and live in lumen of the gut

Long prepatent period (6 months)

Clinical signs- colic, poor growth, weight loss

Very well controlled now with ivermectin

Question 10

Major parasite concern for young horses

Answer 10

Parascaris equorum (roundworms)
Adult horses develop immunity but deadly for young foals
Eggs persist in environment for years

Question 11

Round worms life cycle

Answer 11

Lives in small intestine and migrates to lymphatics, liver, lungs, pharynx, and back to small intestine (about a month for migration but takes over two months to shed eggs)

Question 12

Clinical signs of roundworm infection (ascarids)

Answer 12

Coughing, diarrhea, colic, pot belly, rough hair coat, weight loss

**remember cannot be diagnosed prior to 80-90 days of infection by fecal float

Question 13

What drugs have ascarids become resistant to

Answer 13

Ivermectin
Moxidectin
Pyrantel

Question 14

Control of ascarids

Answer 14

Perform FECRT when possible

Deworm at 60 days of age and very frequently until 8-12 months

Question 15

Describe tapeworms

Answer 15

Anoplocephala perfoliata
Live at ileo-cecal valve and cause spasmodic colic, intussusceptions, ileal impactions
Shed intermittently so have to do multiple fecals

Question 16

Treatment of tapeworms

Answer 16

Praziquantel

Pyrantel

Question 17

When should you deworm for tapeworms

Answer 17

Foals- prior to weaning

Adults- 1 to 2 times/ year

Question 18

Describe botflies

Answer 18

Gastrophilus intestinalis

Little clinical disease

Question 19

Treatment for botflies

Answer 19

Ivermectin or moxidectin

Remove eggs from legs

Question 20

Describe stomach worms

Answer 20

Habronema, draschia
Transmitted by stable flies
No significant internal damage
Cutaneous infections- granulomas on eyes, sheath, ventral midline
Treat with ivermectin and steroid

Question 21

Describe oxyuris equi

Answer 21

Pinworms
Live in small colon
Cements eggs to skin of anus and horses get very itchy and rub tail
Prepatent period- 3.5 to 5 months
Difficult to find on fecal float usually diagnosed based on clinical signs

Question 22

What parasite causes diarrhea in foals 5 days- 4 months

Answer 22

Strongyloides westeri (threadworms)

Question 23

Describe threadworms

Answer 23

Foals are infected via milk from dam
Resides in small intestine
Foals develop immunity quickly
Prepatent period is 5-7 days

Question 24

Treatment for strongyloides westeri

Answer 24

Treat mares in late gestation with macrocyclic lactones

Treat foals as needed

Question 25

Describe lungworms

Answer 25

Dictyocaulus Donkeys can harbor infection with no CS and expose horses Horses show cough and decreased performance Treat with ivermectin

Question 26

How to diagnose lungworms

Answer 26

Baermans test

Question 27

Which parasites are a concern for juvenile horses

Answer 27

Ascarids- main concern Strongyloides Small and large strongyles

Question 28

Refugia

Answer 28

Maintain population of parasites that do not receive drugs to keep resistance down

Question 29

How to combat resistance

Answer 29

Use FECRT to determine effectiveness of drugs Treat horses with FEC Treat during peak transmission season

Question 30

When should you treat based of FEC

Answer 30

Less than 200= do not treat 200-500= may treat Greater than 500= treat

Question 31

When will you worry about resistance in pyrantel and BNZ? | Macrocyclic lactones?

Answer 31

Pyrantel and BNZ= less than 90% Macrocyclic lactones= less than 98%

Question 32

When should you treat for worms based on season

Answer 32

Spring and fall- good climate for parasites

Question 33

What is the expected egg reappearance period? What is it for specific drugs?

Answer 33

Interval between treatment and resumption of FEC greater than 200 ``` BZM= 4 weeks Pyrantel= 4 weeks Ivermectin= 8 weeks Moxidectin= 12 weeks ```

Question 34

What is key with foals?

Answer 34

Prevention!

Question 35

Describe normal neonate behavior

Answer 35

Sternal recumbency- 2 minutes Suckle reflex- 30 min Standing- 60 min Nursing- 2 hours

Question 36

What is the 1-2-3 rule

Answer 36

1 hour to stand 2 hours to nurse 3 hours to pass the placenta

Question 37

When should the foal be examined

Answer 37

First 12-24 hours of life

Question 38

Describe temp in foals

Answer 38

Normal- 99 to 102 Hypothermia is common in sick neonates Unable to adequately cool in very hot climates

Question 39

Describe foal heart

Answer 39

After birth- 40 to 80 bpm and increases to 100 to 120 during 1 week Often have murmur that naturally resolves- PDA, innocent flow murmurs, ventricular septal defects

Question 40

What is dr mallicotes favorite thing to look at on foals

Answer 40

MM

Question 41

Describe resp

Answer 41

``` Transitioning from fluid filled to air filled lung Increase in minute ventilation Decrease from 80 to 30 bpm Inspiratory and expiratory crackles Normal is 30-40 bpm ```

Question 42

What should you use for umbilical care in horse

Answer 42

Not iodine because its inflammatory! | Dip with chlorohexidine

Question 43

Enemas

Answer 43

Give in first few hours of life | Clients should NOT give repeat enemas

Question 44

Colostrum

Answer 44

Foals need 2 liters in 24 hours | First two hours of life are most critical because gut starts closing after that

Question 45

When should you measure IgG and what does it mean

Answer 45

Measure at 12-24 hours | If less than 800, consider transfusion. If less than 400, definite transfusion

Question 46

What vx/ antimicrobials should you use on foals

Answer 46

Tetanus antitoxin if mare was not properly vaccinated | Give abx if there is a non-observed birth and history of sepsis or if there is a history of problems on the farm