Equine Flashcards
1
Q
What advice would you give to a horse owner who wants to breed their mare at foal heat?
A
- ideal for getting a foal asap
- however before 15 post partum uterus has not fully repaired and pregnancy rates are decreased
- delay foaling heat administer altrenogest x2 daily (progesterone) for 8 days then PG on day 9 which gives an embryo in the uterus by day 15.
- Or skip foal heat and short cycle with PG 5-6 days post ovulation
2
Q
An owner asks your advice on a mare that appears to be behaving erratically when in heat and asks if there is anything that you could do to help modify her behaviour. How would you respond to the owners concern?
A
Talk to the owner about his expectations of the mare (ei does he want to breed her in the future?) and his options
- Chemical (progestins) works within a day
- Surgical (ovariectomy)
- Immunological (GnRH vaccine)
- Other -> allow to get pregnant and abort after day 38 (unethical), marbles in urterus
3
Q
An owner telephones you in advance of the approaching breeding season and asks could you organise for her mare to be inseminated with shipped-cooled semen during the last week of October. Outline your approach to this case and how you might organise the mare to be in oestrus during the last week of October. What method could you use to induce ovulation in this mare?
A
- PG on second week of October
- PG on 3rd week of October
- hCG or deslorelin acetate on last week of October when >35mm follicle
OR
- Progestins for 15 days ending 3rd week of October
- hCG or deslorelin acetate on last week of October when >35mm follicle
4
Q
An owner telephones you on a Monday during November and asks if you could organise it so that their mare is in oestrus next week as they have booked their mare in for being serviced by a stallion next week. What would you suggest?
A
PGs over a few days prior to taking to stallion
5
Q
An owner telephones you on a Monday during November and asks if you could organise it so that their mare is in oestrus in 3 weeks as they have booked their mare in for being serviced by a stallion in 3 weeks time. What would you suggest?
A
- PG now (start of week 1)
- PG in 2 week time (start of week 2)
- hCG or deslorelin acetate in one week when >35mm follicle (if forced ovulation required)
OR
- Progestins for 2w
- PG on day 15
- Mare should be in estrus on week 3, hCG or deslorelin acetate may be admined if forced ovulation required)
6
Q
An owner has just purchased an 8-year old stock horse mare that she wishes to breed during the current breeding season. You advise her that a breeding soundness examination should be conducted on the mare, preferably when she is in oestrus. What could you recommend that would increase the probability that you could examine the mare when she is in oestrus during the next 2 weeks? Your advice could vary according to the owner’s facilities and budget.
A
PGs over a few days -> should be in estrus next week. Adjust if required
7
Q
Which one of the following products can be used to induce ovulation in mares with a 35 mm follicle within the ovary?
a. Cloprostenol
b. hCG (human chorionic gonadotrophin)
c. 17β-Oestradiol
d. eCG (equine chorionic gonadotrophin)
e. Altrenogest
f. Progesterone
A
b.hCG (human chorionic gonadotrophin)
8
Q
The most effective method to induce oestrous cycles in anoestrous mares is:
a. Administering altrenogestat 0.044 mg/kg for 14 days
b. Administering 3000 IU of human chorionic gonadotrophinIM once
c. Administering 100 µg of gonadotrophinreleasing hormone IM once
d. Exposing mares to 16 hours of light and 8 hours of darkness about 2 months before the oestrous cycles would normally commence.
e. Housing mares adjacent to a stallion for 2 months before oestrous cycle would normally commence.
A
d.Exposing mares to 16 hours of light and 8 hours of darkness about 2 months before the oestrous cycles would normally commence.
(actually better to increase hours of light gradually)
9
Q
- The manager of a Thoroughbred stud farm wants to start breeding mares as soon as possible during September. To increase the chances that mares will be cycling in September it would be best to:
a. Expose the mares to 8 hours of light and 16 hours of darkness about 2 months before oestrous cycles would normally commence.
b. Expose mares to 30 min of decreasing day length each week by enclosing them in darkened stables from 4 pm, about 2 months before oestrous cycles would normally commence.
c. Exposing mares to 16 hours of light and 8 hours of darkness about 2 months before the oestrous cycles would normally commence.
d. Administer a melatonin releasing implant to increase concentrations of prolactin within the blood of horses.
e. Administer a Cue-Mare device to all horses for 15 days during the last week of August.
A
c.Exposing mares to 16 hours of light and 8 hours of darkness about 2 months before the oestrous cycles would normally commence.
(actually better to increase hours of light gradually)
10
Q
What questions might you ask an owner who wishes to inseminate her mare with frozen semen?
A
How old is the mare? Can we do a breeding soundness exam? Any history of infertility? Has she been cycling regularly and recently? When are you looking at getting this done? Has the mare had previous foals? Previous AIs? With frozen semen? Which stallion are you planning to AI to and has he had good semen quality in the past?
11
Q
What advice will you give an owner regarding the likely success of AI’ing with frozen semen?
A
There are lower conception rates with frozen semen (20-60%) in comparison to fresh and multiple services may be required.
12
Q
You examine the mare, see evidence of uterine oedema with a 37 mm follicle present in one ovary. What will be your strategy to optimise the chance of conception occurring in this mare with frozen-thawed semen if you are provided with one dose of semen?
A
Induce with hCG or deslorelin 8am day 1, and scan at 24h (8am day 2). if ovulation does not appear imminent scan every 6h (2pm, 8pm (ew)) and deposit semen when ovulation appears imminent or has been detected.
13
Q
You examine the mare, see evidence of uterine oedema with a 37 mm follicle present in one ovary. What will be your strategy to optimise the chance of conception occurring in this mare with frozen-thawed semen if you are provided with two doses of semen?
A
Induce with hCG or deslorelin 5pm day 1, and inseminate at 24h (5pm day 2) and 40 h (9am day 3)
14
Q
Describe how you would manage a mare that is to be inseminated with chilled semen given that it will take 24 hours for semen to arrive on the property where the horse that is to be inseminated is located, at what stage of follicular development will you order the semen?
A
As you administer hCG or Deslorelin w/ >35mm follicle if confident of 24h wait. If unsure and have ability to store, order at 35mm or just less and admin hCG/Deslorelin when semen arrives
15
Q
If you aim to use hCG to induce ovulation will you inject it before the semen arrives or after the semen arrives?
A
Before, assuming you are moderately confident that the semen will come on time.
16
Q
What is the minimum diameter of the preovulatory follicle before you will induce ovulation.
A
> 35mm
17
Q
Deslorelin and hCG are hormonal agents that can be used to induce ovulation in mares. Describe the mechanism of action of these hormonal agents. What is the average interval to ovulation for each of these hormones when administered to a mare with a preovulatory follicle with a diamter of >35 mm.
A
hCG - LH like effects, ovulation 36h +/- 17h
Deslorelin - GnRH agonist (stimulates LH release), ovulation 32 - 48 h
18
Q
Describe the process of embryo transfer in the mare. In your description describe a treatment regime for preparing recipient mares. On what day of the cycle will you aim to transfer an embryo to recipient mares?
A
Synchronise ovulation between donor and recipient mares -> Breed donor mare -> flush uterus of donor mare to retrieve embryo (d6-8) -> wash and evaluate embryo -> load into transfer straw -> transfer to uterus of recipient
19
Q
If the recipient ovulates one day earlier than the donor mare can she still be used as a recipient?
A
Yes, recipient mares can ovulate between 1 day prior after 3 days after donor mare.
20
Q
What would be your suggestions for selecting recipient mares for an ET program?
A
Between 3 and 10 years of age. Maiden mares or have produced 1 or 2 foals. Good body weight, cycling.
OR progestin treated ovariectomised mares/anovulatory mares
21
Q
What is the normal dose of fresh, chilled semen that is used to AI mares?
A
> 500 million normal, progressively motile sperm
22
Q
What is the normal dose of frozen-thawed semen that is used for AI in mares?
A
> 300 million normal, progressively motile sperm
23
Q
Describe the process of collection and preparation of semen for cooled transport.
A
- must test neg for venereal diseases
- Tease stallion, allow to mount phantom and insert penis into lubricated artificial vagina kept at at temp 42-48 degrees C with disposable lining and collection vial.
- Extend with 1:1 to 1:3 semen to extender (contains buffers, energy, proteins and antibiotics)
- Dilute raw sperm to conc of 25 - 50 million sperm/mL , final dose of >500 million normal, progressively motile sperm so 1 billion for shipment
- Cool to 20 degrees quickly, then to 5 degrees slowly, then maintain temp.
24
Q
Embryos are normally collected from the uterus of a donor mare:
a. 2 to 4 days following ovulation
b. 6 to 8 days following ovulation
c. 10 to 12 days following ovulation
d. 14 to 16 days following ovulation
e. 18 to 20 days following ovulation
A
b. 6 to 8 days following ovulation
25
Equitainers and coolant storage and transport systems are used in the Equine AI industry to transport cooled semen. What is the optimum temperature that freshly collected equine semen should be cooled to in order to optimise its longevity when transporting fresh chilled semen.? How long will each device keep semen at this temperature for? When the semen arrives when should it be deposited into the mare?
Cooled to 4-6 degrees. Equitainer will maintain temp for 48h, cheaper coolant storage and transport system will maintain temp for 24h. Immediately deposited into the mare
26
Pregnancy rates following a single AI in mares can be similar to or even greater than following natural service. Explain why pregnancy rates following AI might be greater in some mares compared with natural service.
Reduces the number of pathogens that may be transmitted during natural service as well as contamination of mares. It prevents over use of a stallion and for sub fertile stallions to be optimally used. Minimal contamination breeding techniques can be implemented.
27
You examine an 8 year old mare in March 2009 with a history of not being observed in oestrus since the start of the breeding season in 2008. The mare is in good body condition. Rectal examination findings include a 7 cm diameter right ovary and a 3 cm diameter left ovary with no palpable follicles. On ultrasound examination of the right ovary you observe a multiloculated appearance with multiple anechoic structures that vary in size. The left ovary appears uniformly solid in appearance with only a few small follicles present. You take a blood sample for analysis for hormone concentrations. Concentrations of inhibin are 1.03 ng/mL and testosterone is 44.1 pg/mL. What is the most likely diagnosis? Explain why the left ovary is smaller than the right ovary. What treatment would you recommend and what is the possibility that the mare will return to oestrus in the future?
Granulosa Theca Cell Tumour. The large ovary has the tumor, the smally ovary is little due to high inhibin levels produce by the tumor. Remove larger, tumorous ovary qnd mare should return to estrus in 6-8 months.
28
You are presented with a 6 year old, pony mare that owners wish to breed but have never observed in heat. Outline your approach to investigating this case. List the potential causes of anoestrous in this mare.
Obtain the mares breeding history ("never been on heat") and preform breeding soundness exam. Consider endoscopy and sample for chromosome analysis. Consider if the issue is structural, functional or infectious/inflammatory in nature? Causes of anoestrus including seasonal anoestrus (unlikely here as its year round), nutritional anoestrus, disease, pituitary abnormality (eg cushings), ovarian tumors, chromosomal abnormalities, silent heat, prolonged dioestrus, dioetrus ovulation, pyometra, pregnancy/pseudopregnancy etc
29
List the expected foaling rates in mares with a: Grade I, IIA, IIB and III uterus as determined by endometrial biopsy.
```
Grade 1 (normal/mild, focal inflam/fibrosis) -> 80 - 90%
Grade 2A (mild-moderate inflammation and/or multifocal fibrosis with 1-3 layers of fibroblasts surrounding glands or 50 - 80%
Grade 2B (moderate inflammation and/or multifocal to diffuse fibrosis with 4 or more layers of fibroblasts surrounding glands or 2-4 fibrotic nests per 5mm linear field) - 10-50%
Grade 3 (severe inflammation and/or diffuse fibrosis with 5 or more fibrotic nests per 5mm linear field) -
```
30
An 18 year old mare is presented for examination having been diagnosed pregnant 50 days after mating in the previous year but failed to deliver a foal within the normal gestation period. On examination the uterus feels palpably larger than normal and hyperechoic masses with anechoic shadows below the masses are evident. There are at least 3 masses present about 3 cm in diameter. What could cause the abnormality noted?
retained fetal bones from a previous pregnancy
31
Based on age alone, what is the likelihood that an 18 year old mare will be able to deliver a foal?
~40%
32
From what age will less than 10% of mares produce live foals?
25
33
You conduct a breeding soundness examination on an 19 year old warm blood mare that the owners want to inseminate with frozen semen. The mare appears to be cycling, has reasonable conformation that will not require any correction. Uterine culture results are negative and the uterine biopsy report classifies the uterus as a Grade III endometrium. The mare has previously foaled at the age of 14, and 16 years of age. What would you say to the owner?
-19 year old mare has a less than 40% chance of delivering a live foal based on age alone
-Grade 3 endometrium reduces chances to less than 10%.
-using frozen semen also decreases chance of getting a live foal.
"While its totally up to you, the odds aren't in our favour, I would suggest inseminating a younger mare with the frozen semen and perhaps just putting this older mare into the paddock with a stallion and cross your fingers - minimizing cost due to relatively low chances of getting pregnant. We can treat the inflammation to increase your chances, but fibrosis is permanent."
34
You are examining a mare for pregnancy 18 days after breeding and detect two adjacent, cyst-like structures within the uterus of the mare on ultrasound examination. How would you differentiate cyst(s) from embryonic vesicles?
Cysts are often not spherical, may have an irregular outline and are consistent in size and position. Checking history and reassessing in a few days to see if there is movement/growth.
35
List 5 abnormalities that could be encountered on vaginal examination in the mare.
Abnormal conformation, persistent hyment, lacerations, adhesions, vaginal bleeding
36
An owner telephones you and seeks your advice after seeing blood on the vulva of her 10 year old mare. What questions would you ask the owner? What are the potential causes of the appearance of blood on the vulva of a mare?
Has the mare foaled or been breed recently suggesting traumatic bleeding? Is she pregnant suggesting placental separation has occurs and foaling/abortion is imminent? Could also be varicose vessels or remnants of hymen.
37
An owner becomes concerned when she notices a pink membrane protruding into the vulva of her maiden mare. The mare has never been bred. What is the most likely diagnosis and how did the problem develop? How would you treat this condition?
Persistent hymen - can be incised if breeding is required, milky fluid may escape. If vagina is also hypoplastic suspect developemental abnormality which may cause infertility etc
38
What is meant by the term “anovulatory follicle” in the equine?
Anovulatory follicles are follicles which reach ovulatory size during oestrus but do not ovulate and can persist for 3-7 weeks. Initially on ultrasound you see small echogenic spots within a large anechoic follicle. Fribrin bands may be seen. Intrafollicular haemorrhage may occur. They are sensitive to PGF2a five days after formation.
39
Describe the ultrasound appearance of an anovulatory follicle in a mare? What other structures may they resemble?
Initially on ultrasound you see small echogenic spots within a large anechoic follicle. Fribrin bands may be seen. May resembler GTCT
40
Following formation of an anovulatory follicle what can you do to try to shorten the interoestrus interval?
PGF2a 5 days after formation
41
Define persistent mating induced endometritis in the mare.
Persistent mating-induced endometritis is defined as retention of > 2cm depth of fluid in the uterus > 18h after breeding - detected via ultrasound.
42
What causes persistent mating induced endometritis?
caused by a reduced ability to clear fluid from the uterus providing a favorable environment for bacterial growth. The main predisposing factor is defective myometrial mechanical activity.
43
How do you treat persistent mating induced endometritis?
Treatment includes sexual rest, minimum contamination breeding techniques, limit breeding to once per oestrus, uterine lavage (4h to 4d after breeding), use ofecbolics to stimulate uterine contraction (oxytocin, PGF2a), intrauterine antibiotics, exercise & teasing post lavage
44
You examine a mare for the purpose of pregnancy diagnosis 16 days after being mated. You fail to see an embryonic vesicle with transrectal ultrasonography but do see fluid within the uterine lumen. The diameter of the fluid is measured and found to be 4 cm in diameter at its greatest diameter. The fluid is noticed to contain traces of hyperechoic particles on ultrasound examination. What would you advise the client to do?
The mare is suffering from persistent mating induced endometritis which decreases fertility. I would advise treatment of sexual rest, use of ecbolics to stimulate uterine contraction (oxytocin, PGF2a), intrauterine antibiotics and exercise & teasing post lavage. When controlled, use minimum contamination breeding techniques and limit breeding to once per oestrus. Uterine lavage may be done 4h to 4d after breeding.
45
Discuss the diagnosis of endometritis in mares
Cytology, culture and biopsy are all used to assist with diagnosis of endometritis with biopsy being the definitive test.
46
If a mare is introduced into a stud carrying Taylorella equigenitalis and is mated with a stallion that subsequently is used to breed a number of other mares at the stud, what might you expect to see in the way of symptoms in mares that contract the disease during mating?
Mares acutely will see signs of endometritis with discharge 1-14 days after mating. May be mucopurulent and large amounts. Chronically there may be no symptoms.
47
Would you bother to inform the Department of Primary Industries if you suspect that an outbreak of CEM (Taylorella equigenitalis) might be occurring?
Yes - Australia is free from Taylorella so it is notifiable.
48
Suggest a treatment plan for attempting to eradicate the Taylorella infection from the stud?
Intrauterine infusion of penicillin as well as topical treatment of clitorial fossa, clitoris and clitoral sinuses with an antibiotic to which Taylorella is susceptible daily for 5 days. Topically treat Stallion with soap, water, chlorhex and antibiotic creams. Fossa glandis, urethral fossa and prepuce should be packed with antibiotic ointment every day for 5 days. Mares must test negative on at least 3 cultures 3 or so days apart to be declared clear. Clitoral sinusectomy could be considered in cases of residual infection.
49
What are some of the factors that you should consider when deciding on how to use a particular antibiotic for intrauterine therapy for endometritis?
The organisms need to be susceptible to the antibiotic and the antibiotic must be suitable for intreuterine use. Buffering etc may be needed to decrease irritation.
50
Outline an “ideal” timeline for when pregnancy diagnosis should be performed in mares
Day 12-16: Initial ultrasound, evaluate for twins
Day 25-30: Second utrasound. Check for heartbeat and twins.
Day 45-60: Third ultrasound to confirm heartbeat and viability of pregnancy.
Can increase frequency if any concerns for example, twins.
51
How do you explain the existence of twins on Day 25 when you only diagnosed a singleton pregnancy on Day 12?
Embryos are motile before day 16 and hence it can be difficult to find both mobile vesicles. They also may have been superimposed etc.
52
Outline the options for treatment of unilaterally fixed twins at day 25 and the likely success rate with the different options that are available.
May attempt to separate and crush one but not recommended - leave them as success rate may only be similar to natural reduction rate.
53
What would be your ideal choice for early pregnancy diagnosis in the mare to enable a high probability of detecting twins during the mobility phase?
Rectal untrasonography before day 16
54
When do embryonic vesicles become fixed in mares?
~ day 16
55
The owner chooses to leave the twins intact. You return on Day 32 and find that both twins are still present and unilaterally fixed. What advice would you now give to the owner?
Still probably best to leave and monitor. Can manage at >60 days by cervical dislocation or repeated trauma. Alternatively recycle by injecting PG and then rebreed.
56
A mare is mated once on 30/1/12 and is subsequently diagnosed as pregnant 14 days later using transrectalultrasonography. What is her expected foaling date?
A mares gestation is ~ 11 months (320d to 370d) so it is expected that the mare will foal about the 30th of December or so. Attempting to be more accurate is moderately useless due to variation between pregnancies. Maybe a new years baby!
57
Outline your management plan for a mare diagnosed with hydropsallantois at 7 months of gestation. What is the prognosis for future fertility in the mare if she has an uneventful recovery? Is it likely to reoccur in the mare at the next pregnancy?
Abortion should be induced as foetuses are often non-viable. IV fluids should be given and birth should be assisted. It is unlikely to reoccur and fertility should be fine in the future if recovery was uneventful.
58
With live born twins, one twin is often smaller than the other. What is the cause of a difference in the size of twins at birth?
Likely that there is interference in contact between the endometrium and trophoblast of one of the embrionic vesicles, causing nutrient deprivation to one of the fetuses.
59
Are twins likely to be dizygotic or monozygotic in the mare?
Dizygotic. Monozygotic twins are very rare in the mare.
60
What is the approximate likelihood that a mare will give birth to live twin foals that survive to 2 weeks of age
Less than 15%
61
What signs might indicate that an abortion was due to torsion of the umbilical cord?
The umbilical cord may appear severely twisted and congested/haemorrhagic. Measuring it to be more than a certain length also points towards torsion of the umbilical chord.
62
What questions would you ask an owner whose horse has aborted at 200 days gestation,
Reproductive history
-Has this mare had previous pregnancies?
-Has this mare had previous abortions?
-Were all previous pregnancies 'normal'? eg. size of foal etc
Clinical signs before and after abortion
-Did you notice anything strange before the abortion?
-Was there any blood coming from the vulva before the abortion?
-How has the mare been since the abortion?
Recent changes
-Has there been any recent introductions?
-Have they been vaccinated recently? When? With what?
-Have any of the mares been unwell lately? Of there food? Lethargic? Respiratory signs? When? For how long?
-Have any of the mares been transported lately? When? To/from where?
Housing/environment
-Stabled or paddocked? Always?
-Hows the weather been?
-Have they been moved recently? When? From where?
Sources of food and water
-What are they fed? How often? How much?
-Where is there source of water?
63
How would you examine the placenta and foetus of an aborted mare? What specimens would you collect from the mare and the aborted foal and placenta?
Check for any obvious abnormalities, that the placenta is intact and the umbilical cord is not severely twisted. Weigh the foetus and placenta. Assess the foetal size and degree of autolysis. A small foetus may suggest chronic disease, while a normally sized foetus suggests a more acute process. Check for a cervical star thickening suggesting an ascending infection.
Collect specimens - entire placenta and foetus is best, as well as blood/serum from the dam and if possible foetal serum.
64
What advice would you give to the owners of a mare who has aborted while you await for results on the samples that you submit to the laboratory.
Consider quarantining the dam and if possible disinfect contaminated areas. Split in contact mares up as much as facilities allow to decrease chance of an 'abortion storm'. Consider EHV-1 vaccine. Revise all advice when laboratory results are received.
65
A cream coloured discharge is noticed from the vulva of a mare that was diagnosed as being pregnant on rectal examination at 6 weeks of gestation. She is currently about 100 days of gestation. On rectal examination a pregnancy was still palpable and a foetal heartbeat evident. The veterinarian suspects that there is a degree of endometritis present and wants to implement treatment to attempt to preserve the pregnancy. What would you recommend?
The aim of treating placentitis is to maintain the pregnancy until the foetus is sufficently mature to be viable post birth as well as antimicrobial treatment. Good antibiotic choices include trimethoprim sulfadiazine (PO), potassium penicillin + Gentamicin (IV) and ceftiofur (IM). Altrenogest can be used to assist in maintaining the pregnancy.
66
A horse owner asks you to examine her mare who is at 300 days of gestation but is showing signs of enlargement of the mammary gland (see photograph). Outline your approach to this case and how you might evaluate if the pregnancy is progressing normally.
Ultrasound to assess placental thickness, foetal heart rate etc.
67
What signs may indicate that a mare is suffering from placentitis?
Vulvar discharge, placental thickening (>12mm), increased cellularity of allantoic and amniotic fluid, foetal tachycardia, fluid acummulation between chorion and uterus,
68
If you diagnose placentitis what treatment would you recommend? Once you start treatment how will you monitor the response to treatment?
The aim of treating placentitis is to maintain the pregnancy until the foetus is sufficently mature to be viable post birth as well as antimicrobial treatment. Good antibiotic choices include trimethoprim sulfadiazine (PO), potassium penicillin + Gentamicin (IV) and ceftiofur (IM). Altrenogest can be used to assist in maintaining the pregnancy.
Monitor foetal heart rate, CTUP and Ca milk concentrations.
69
Termination of pregnancy in a pregnant mare at 25 days of gestation would be best achieved with:
a) Administration of altrenogest at a dose rate of 0.022 mg/kg, orally once daily for 2 consecutive days
b) Administration of human chorionic gonadotrophin at a dose rate of 3000 IU intravenously
c) Administration of a deslorelin (Ovulplant) implant subcutaneously with removal of the implant within 48 hours
d) Administration of cloprostenol intramuscularly at a dose rate of 250 µg/450 kg
e) Administration of oxytocin at a dose rate of 20 IU intravenously
f) Administration of dexamethasone intramuscularly at a dose rate of 30 mg
d) Administration of cloprostenol intramuscularly at a dose rate of 250 µg/450 kg (PGF2a analogue)
70
An owner of a mare has taken time off work to stay up at night to monitor her mare foaling. They explain that the mare was bred 11 months ago and she is overdue to foal. They have been off work for a week, feel exhausted and must return to work. They are concerned that the foal may be dead, or if alive it may become too large for the mare to give birth on her own. They ask if you could come and induce their mare to foal. How would you approach this case?
The normal gestation of a horse can be up to 12months, so there is a fair chance she is perfectly fine. I would check mating and due dates, previous gestation lengths and any history of pregnancy issues. I would assess pregnancy status and foal viability, as well as orientation of the foetus. Examination of the udder and determination of milk concentration of CaCO3. I would suggest not inducing the foal (unless there is medical reason to found in my examination) and suggest monitoring systems, to get some sleep and let nature take over. You are more likely to have a healthy foal if you don't induce early.
71
An owner calls you at 10 pm to say that her mare foaled normally at 7 pm but that the placenta is still hanging from the vulva of the mare? What advice would you give to the owner, when would you plan to attend the case and what treatment would you recommend?
Don't try to manually remove it, tie it up if possible to avoid mare standing on it. Attend now - administer oxytocin with saline over 30 - 60. Administer TMS and check back in the morning. If still retained in the morning, readminister oxytocin + saline. Give some time, and then attempt burns technique.
72
In order for a stallion to pass a breeding soundness examination they must ejaculate a minimum of how many morphologically normal, progressively motile sperm in each of 2 ejaculates collected 1 hour apart at any time during the year?
a. 300 million
b. 500 million
c. 1 billion
d. 2 billion
e. 5 billion
c.1 billion
73
Following a routine breeding soundness examination of a stallion you classify the stallion as a questionable prospective breeder because the total number of progressively motile and normal spermatozoa within both ejaculates was 920 and 850 million sperm, respectively. All other components of the BSE are normal. You suggest to the owner that the stallion should be retested to determine if semen quality over time improves, remains unchanged or deteriorates further. After what period of time would you recommend that the stallion be retested?
a. 30 days
b. 60 days
c. 90 days
d. 120 days
e. 150 days
b.60 days
74
What is the purposes of a BSE in a stallion?
- To assess cause of infertility/subfertility
- To determine prognosis for future prognosis
- Estimate size of a stallion's book
- Determine if a stallion has mental and physical attributes necessary to deliver semen containing enough viable spermatazoa (free from infection) to the mares reproductive tract.
75
When would you undertake a BSE?
- At the start of the breeding season to check for any problems and to estimate the stallions proper mating load.
- If subfertility/infertility is suspected
- If abnormal sexual behaviour develops
- Before sale
- If disease/injury may have affected the reproductive system
- Before semen is frozen
76
List the components of a BSE of a stallion.
```
History - General and Reproductive
ID
Physical examination
Collect blood samples to test for equine infection anaemia or equine viral arteritis if necessary
Swabs
- Pre-wash penile shaft
- Pre wash fossa glandis
- Pre wash prepucial fold
- Post wash urethra
- Post ejaculate urethra
Evaluate breeding behaviour and libido
Examine testicles and measure
Examine accessory sex glands and inguinal rings per rectum
Collect 2 semen samples, 1h apart
Semen evaluation with longevity testing
```
77
What is the diagnostic value of a hCG stimulation test in a stallion with poor fertility?
A two to three fold increase in T indicates presence of testicular tissue
78
What is the diagnostic value of the concentration of alkaline phosphatase in the semen of a stallion?
If the semen contains less than 100 IU/L of alkaline phosphatase then is shows a mechanical blockage or failure to ejaculate. Between 100 and 1000 IU/L show partial blockage, partial ejaculate or testicular/epididymal pathology. If greater than 1000 IU?L the sample contains fluid from the testes and epididymis
79
Explain what is meant by daily sperm output in relation to a stallion and what is it used for? What is the value of calculating and estimating daily sperm output in a stallion?
Daily sperm output refers to the total number of sperm that a stallion can ejaculate per day after depletion of epididymal sperm reserves, allowing an estimation of the number of mares a stallion can breed on a daily basis. Can be found after depleting once per day for 10 days or twice daily for 5-7 day. Can be estimated using testicle size. If actual
80
Outline the physiological control of reproductive function in the stallion
GnRH stimulate AP to release FSH and LH. FSH causes the seritoli cell to release androgen binding potein and LH acts on leydig cells to release testosterone. ABH binds testosterone and enhances spermatogenisis. Testosterone is converted to dihydrotestosterone and estrogen. Serotoli cells produce inhibin.
81
What is the normal total scrotal width of a stallion?
>80mm
82
What is the normal percentage of progressively motile sperm in a fertile stallion?
>60 %
83
What is the normal pH of equine sperm?
7-7.7
84
How many progressively motile, normal sperm should be present in a fertile stallion's sperm.
>1 billion
85
Low concentrations of alkaline phosphatase in a sample of semen collected from a stallion can indicate:
a. A normal sample of semen as concentrations of alkaline phosphatase are normally low in semen collected from stallions with normal fertility
b. Blockage of sperm outflow from the epididymis
c. The presence of seminal vesiculitis
d. The presence of blood in the semen (haemospermia)
e. The presence of testicular degeneration
f. Failure to ejaculate fluid from the epididymis
f.Failure to ejaculate fluid from the epididymis
86
A Thoroughbred stallion has been imported from the UK for the current breeding season. He was imported in September, passed through quarrantine and began breeding mares in early November. The stallion has bred 6 mares so far by natural service. None of the mares were diagnosed pregnant when pregnancy diagnosis was performed 13 to 18 days following the last service. Outline your approach to investigating the potential fertility of this stallion.
History of stallion and mares - mares may be the issue rather than the stallion
Consider the possibility that stress may cause subfertility - may continue to be for ~60 after stressor (importation, quarentine and transportation)
BSE including full physical exam, blood tests, evaluate sexual behaviour and libido, swabs, inspect and measure testes, rectally examine accessory sex glands and inguinal ring, collection of 2 samples of semen 1h apart for assessment.
87
During the winter months mares normally experience a period of anoestrous. As such they do not experience ovulatorycycles. Without artificial manipulation mares are essentially infertile during this period. With your knowledge of the reproductive physiology and seasonality of reproduction in stallions would you expect that a stallion would be fertile during winter and able to provide semen for the purposes of cryopreservation? What differences would you expect in a stallion’s ejaculate collected in July compared to December?
In winter, libido may be reduced along with semen volume, number of sperm and total scrotal width. However, if a stallion can produce enough progressively motile normal spermatozoa for cyropreservation during winter, than it may be frozen.
88
Explain how a stallion with progressive motility of sperm in his ejaculate of 60% could be less fertile than a stallion with a progressive motility of sperm in his ejaculate of 40%.
The stallion with a motility of 60% may produce a lower number of total sperm. eg. 60% of 10 is 6, 40% of 20 is 8. More important than percentage of motile sperm is the number of normal progressively motile sperm in an ejaculate
89
What is the preferred dilution ratio for equine semen?
At minimum 1:3, 1:4 or 1:5 is preferred.
90
Outline some of the physical causes of reduced libido in stallions
Penile lesions, musculoskeletal problems causing pain eg back issues, lameness.
91
Outline some of the behavioural causes of reduced libido in stallions
Previous bad experiences (excessive discipline, aversion to handler etc), unreceptive or hostile mares, overuse, overuse as teaser, mare preference, unstable collection dummy, changes in environment
92
Should you administer testosterone to increase libido in stallion?
NO - feeds back and decreases LH and spermatogenisis
93
What is paraphimosis?
The inability to retract the penis back into the prepuce.
94
How would you treat paraphimosis?
```
- Reduce swelling, inflammation and pain
NSAIDs, opioids
Hydrotherapy
Support wrap
Mild exercise
Unilateral castration may be indicated
- Return penis and and prolapsed prepuce to the prepuce if possible or support penis
purse string suture of prepuce
if prolapse unable to be reduced, support with wrap of some kind
- Control infection
topical antibiotics
possibly systemic antibiotics
Tetnus
- Isolate from mares
```
95
How might the failure to be able to retract the penis and proximal prepuce exacerbate paraphimosis?
Venous and lymphatic drainage may be impaired which exacerbates swelling, may cause ulceration etc and chronically desensitization of the penis.
96
Healing ulcers were observed on the penis of a stallion. What is the likely cause of the lesions? Is it likely to be contagious and spread to mares during natural mating or AI? What treatment would you recommend for this stallion?
Equine herpes virus 3 which is contagious via natural mating and AI. Treatment includes sexual rest until the lesions are healed, strict hygiene measures, antibiotic ointment to reduce secondary bacterial infections.
97
List six (6) potential causes of scrotal swelling. What diagnostic methods would you use to differentiate the conditions?
- Trauma/wound
- Varicocoele -> dilation of veins of pampiniform plexus and those draining the cremaster muscle. Diagnose on ultrasound
- Hydrocoele -> serous fluid accumulation between visceral and parietal layers of vaginal tunic. Diagnose on untrasound and aspiration of fluid
- Haematocoele -> blood accumulation within vaginal tunic. Diagnose on ultrasound
- Torsion of spermatic chord -> twisting 180 or more degrees. Diagnose on palpation and clinical signs
- Inguinal hernia -> intestine into scrotum, diagnose on ultrasound, abdominal palpation via rectum etc
- Neoplasia
- Insect bite
- Orchitis/epididymitis
98
True or false: The most common cause of testicular neoplasia in stallions is a Sertolicell tumour.
False, it is a Seminoma
99
True of false: Most testicular tumours in stallions are benign.
True
100
What is the name given to the condition in which blood appears in the semen?
Haemospermia
101
What are some of the potential causes of haemospermia?
Lacerations, bacterial urethritis, seminal vesiculitis, habronemiasis, neoplasia, epididymitis, EHV3
102
What diagnostic aids could you use to help determine the cause of haemospermia?
Physical examination, endoscopy to examine urethra, rectal palpation to check for semenal vesiculitis, culture semen
103
In a case of idiopathic haemospermia what would you recommend to the client?
Sexual rest, antibiotics and extenders &/or fractionalization
104
Outline your approach to investigating a stallion whose fertility is declining. If this is associated with testicular degeneration for which no treatment is possible outline how you might manage the stallion to improve the fertility of mares which he serves.
Collect a thorough history and search for evidence that fertility is actually declining and do a BSE & repeat. Do endocrinological testing, a testicular biopsy and monitor fertility data over time. To manage low fertility, manage mating load, aim for one (well timed) breeding per cycle with minimum contamination breeding techniques. Use young, fertile mares.
105
A stallion is presented for a BSE. Two attempts are made to collect semen from the stallion during the examination. On both occasions the stallion mounts a teaser mare, penetrates the artificial vagina but following dismount the artificial vagina contains a small volume of fluid that does not appear to contain sperm cells. Outline your approach to determining the cause of not obtaining any spermatozoa during the collection procedure.
History - Previous BSE, semen evaluations and fertility
Physical examination
Palpate testes
Examine penis
Check AV for suitability
Try a different teaser mare
Did an ejaculation actually occur? Pulsing urethra or alkaline phosphatase concentration
106
Define the meaning of Oligospermia and Azoospermia
Ogliospermia - Low numbers of sperm in ejaculate
| Azoospermia - Absence of sperm in ejaculate
