AHPS Horses Flashcards
At what age are horses usually weaned?
6 months
What does the brand on the left shoulder represent?
The stud brand
What does the brand on the right shoulder represent?
Top = drop number i.e the number foal this was for that season Bottom = The year the horse was born. If january foal, this would be the number from the previous year.
What are the five current important issues for the horse industry?
Infectious disease threats
Environmental issues such as drought and urban expansion reducing the amount of possible horse land
Animal welfare e.g jumps racing, disposal of horses post race, feral horses
Medication control of horses in sports
Human OHS when handling horses
What are the three important infectious diseases that are a threat to AU horse industry?
African Horse Sickness
Equine influenza * most important *
Vesicular stomatitis
Who regulates the import of horses to AU?
The Australian Quarantine and Inspection Service (AQIS)
What quarantine measures are imposed on imported horses to AU?
Held for 2 weeks in country of origin
Held for a further 2 weeks here
Which country is exempt from tough quarantine regulations for horse transit into / from AU?
NZ
What kind of protection does the Hendra virus vaccine provide?
Against horse-horse and horse-human infection. It does not prevent the horse from becoming infected in the first place. ?
What does AUSVETPLAN do?
Guide the control and management of an outbreak of the diseases that are added to it.
What causes thumps? What is it
Irregular spasming of the diaphragm as a result of electrolyte disturbances due to fluid loss. usually via excessive sweating
What is the inter-oestrus interval of a mare?
~21 days
How long does oestrus occur for?
5 days
What occurs in dioestrous?
The CL persists and secrete progesterone. The mare is not receptive to a male at this time
When does a mare ovulate?
24-48h after oestrus finishes
When do most mares naturally start to cycle again?
Late September/ early October
When does the foal heat occur?
Average about 10 days after parturition.
What methods are available to serve a mare again soon after birthing, but not during the foal heat?
Daily progestagen supplementation
Prostaglandin dose during dioestrous after foal heat to short cycle mare into next heat
Under what conditions are foals born before August 1 permitted to race with the foals from that year?
If the dam was served after Sept 1 of the previous year
What is the Standardbred birthday in AU?
September 1
How long might you expose a mare to lights before September to encourage oestrous?
Up to 10 weeks
What are some of the signs that a mare is in heat?
Carry tail raised
Repeatedly evert the clitoris from the clitoral fossa (winking)
Frequent voiding of small amounts of urine
Stand close to another mare/horse
Flaccid, moist, open cervix
Oedematous endometrial folds detected with ultrasound
What diameter are follicles usually before they rupture?
4.5 cm
What is the typical follicle growth rate?
3-5 mm/ day
A mare is observed to have a 3.5cm follicle. What should the manager do?
Give Ovuplant and breed the next day. Sperm can survive for a couple of days in the genital tract.
When would Ovuplant be indicated? When would you breed after giving it?
When the follicle is >3cm
Induces ovulation within 48h in most cases
Breed the following day
When is the first ultrasound ? What are you looking for?
Day 10 - 14 post ovulation.
Looking for evidence of a pregnancy.
Twins may be evident and it is possible to crush one at this stage.
What is the significance of twin detection post day 16?
One may be safely manually ablated only if the conceptuses are in separate uterine horns
What percentage of twin pregnancies revert to a single after day 40?
60 - 80%
How can you terminate both pregnancies if twins post day 40?
Injection of prostaglandin.
If you can get to it before day 35, the mare will cycle again and you might still get a foal that season.
When is the second ultrasound? What is it looking for?
Day 25 - 28 post ovulation.
- reassess viability - heart beat should be present
- ensure twin is gone if you crushed it
When is the third ultrasound? What is its purpose?
Day 40 - to confirm a single pregnant. Stud fee usually due.
From which time can you determine the sex of the foetus?
Day 60 - 70
What event occurs at day 35? What significance is this to the breeder?
Endometrial cups start to form and produce pregnant mare serum gonadotrophin (PMSG)/ eCG (equine chorionic gonadotrophin)
Once these have formed, the mare will not return to cycling if she loses her pregnancy, as they continue to secrete hormone irrespectively.
At what times should EHV1 vaccination occur?
5th, 7th and 9th months of pregnancy
What vaccinations should a pregnant mare receive, and when?
Tetanus and Strangles booster 4 weeks before foal due
What event marks the end of stage 1 of labour?
Rupture of the chorioallantoic membrane
What is the shiny white foetal membrane?
The amnion
What is the time range for passage of the foetal membranes in horses?
3-4 hours, though within 30 - 90 minutes is best
What are the important three milestones in a foals first few hours?
On feet within 1 hour
Suckling within 2 hours
Urinating and defecating shortly after
What is a good rate of suckling for the first few weeks?
7/hour in the first week of life
2-3/hour thereafter
What is an appropriate SG for colostrum?
> 1.060
How long until colostrum is replaced by normal milk?
About 5h
When should you first evaluate success of passive transfer?
24h old
When to worm?
Every 2 - 3 months
Should worm the mare before foaling to protect the foal
When to vaccinate?
At 3 - 4 months as this is when maternal abs start to wane
What is a possible vaccination protocol for a new foal
3 months: tetanus + strangles
3 months and 2 weeks: strangles
4 months: Hendra + tetanus
4 months and 3 weeks: Hendra
When are boosters due?
Tetanus due every 5 years though recommended annually
Strangles and Hendra boosters biannually
When do horses reach sexual maturity? When are fillies and colts usually separated?
Around 18 - 24 months
At weaning
How much colostrum does a newborn require?
At least 10% of its bodyweight
What can you use if horse milk replacer is unavailable?
Sheep , goat and cow milk replacers are all okay.
A 3.8cm follicle is observed. What should the manager do?
Breed today
What value constitutes a fail of passive transfer?
<400mg/dl
What value constitutes a partial fail of passive transfer?
400 - 800 mg/dl
What value constitutes a success of passive transfer?
> 800mg/dl
Which hormones are high when a horse ovulates?
Oestrodiol, Leutenising hormone
