1. General Age

   Breed
   Weight/BCS
   Vaccinations
   Medications
   Usual management routine such as housing/feeding Current use

2. Reproductive history
   Covered mares before?

   Had semen collection before?

   Previous injuries to scrotum/penis? 

1. General clinical examination

2. Lameness examination

3. Look for evidence of heritable defects 

1. Scrotum with testicles (and visible epididymides)

2. Penis within inner and outer prepuce–check urethral fossa for ‘bean’ of

   smegma

3. Consider if internal examination per rectum is required

4. Evaluation of libido and mating ability

5. Evaluation of semen quality

Review anatomy of the ductus deferens, ampullae ,seminal vesicles, prostate and bulbourethral glands, as well as detailed anatomy of the testicles and scrotum 

Any inflammation or swelling will raise the temperature of the testicles and adversely affect spermatogenesis. It will take approximately two months after the lesion resolves before the animal will produce normal ejaculates. Generalized pyrexia can also have this effect.

A. Acute trauma: usually from a kick from a mare/field companion Use anti-inflammatory measures urgently

(icepack, NSAIDs, antibiotics, gentle massage)
Intrascrotal haemorrhage will lead to permanent testicular damage due to the insulating properties of the resultant fibrous tissue. Surgical removal of the organised blood clot or hemi- castration can be performed in an attempt to save the unaffected testis.

B. Hydrocoele: Abnormal collection of fluid between visceral/parietal vaginal tunics Usually not painful

Can accompany scrotal oedema
May self-resolve, esp with gentle exercise, could be drained if not resolving and if unilateral and persistent, remove affected testis and tunics to save contralateral testis from heat-induced degeneration

C. Haematocoele: Usually following trauma – treat as trauma/hydrocele
D. Scrotal oedema: May be due to local trauma or systemic disease, eg

hypoalbuminaemia – treat underlying condition 

Congenital
Possibly hereditary
Not uncommon in stallions (3%)
Usually associated with an underdeveloped epididymis 

Major cause of subfertility/infertility
May be due to:

(i) old age
(ii) excess heat
(iii) trauma
(iv) toxins
(v) anabolic steroid use (vi) radiation exposure

Both conditions can present as: Unilateral or bilateral

Soft or firm consistency
Oligo- or azoospermic
Round premature germ cells in ejaculate Libido usually normal

History is important in differentiating between these two conditions. Unlike testicular hypoplasia, degeneration may be reversible, but may take several months for semen to return to normal. Treatment with GnRH has been tried but remains controversial.

Because it takes approximately 60 days from development of sperm from spermatogonia until ejaculation, it is possible for acute testicular degeneration to be present and yet the ejaculate can be fairly satisfactory. It may take 2-6 weeks for the infertility to become apparent. 

Extensive necrosis can lead to loss of testicular function

Diagnosis: Ultrasonography
Treatment: If haemorrhage contained within tunica albuginea, adhesions may not occur. If haemorrhage is massive - hemicastration
Prophylactic antibiotics 

Usually greater than 270o to stop blood flow. If only 180o is a developmental abnormality which does not affect fertility
Diagnosis: Presents as acute colic. Affected testicle may be enlarged and hot or cold depending on duration. Surgery required. 

Primary orchitis rare
Affected testis hot, swollen, tense and acutely painful
Fever and scrotal oedema are common
Stiffened hindlimb gait
Followed by ischaemic necrosis and abscess formation Adhesions commonly develop
Treatment: Antibiotics, NSAIDs, hydrotherapy
Prompt removal of a unilaterally affected testis may save the contralateral testis

Seminomas and teratomas most common 

Heritable? - probably, but no good studies performed. Animal may present as castrated. Stallion-like behaviour can be dangerous.

Testicles may be retained high in inguinal area or abdominal cavity. Diagnosis: If <3 years of age or a donkey do an hCG stimulation test (basal blood sample, administer hCG IV, 2nd blood sample after 30- 60 mins - look for elevation in testosterone)

If >3 years of age do oestrone sulphate assay.
Treatment: removal by laparotomy / laparoscopy.
NB: Anorchidism/monorchidism/polyorchidism: very rare indeed 

EPIDIDYMIS 

1. Epididymitis: Very rare in the stallion, usually associated with orchitis Chronic epididymitis leads to obstruction of the epididymis

   Leads to pressure degeneration in testes

2. Sperm granuloma: Spermatozoa crossing into local blood vessels following

trauma. Specific anti-sperm antibodies produced and granuloma forms 

A. Blocked ampullae:
Spermiostasis. High or low sperm numbers in semen. Often many

detached heads and low motility
Ampullae feel swollen and tense on palpation
Epididymal tail prominent secondary to blockage
Treated by massage and frequent ejaculation
Oxytocin (10-20 iu) may be administered prior to ejaculation. 

1. Persistent frenulum (congenital)

2. Scarring between penis and prepuce (acquired)

   - both of the above present as penile deviation and may require surgery

C. Phimosis: congenital or acquired constriction of preputial orifice–may require surgery 

A. Paraphimosis/priapism:
1. After phenothiazine or other sedative use 2. Following preputial trauma
3. With chronic grass sickness/botulism

Impairs venous and lymphatic drainage. Within hours penis and prepuce become oedematous. If left untreated cellulitis, necrosis, gangrene can develop requiring removal of the penis

Treatment: Support the penis manually, such as with tights
Reduce oedema - hydrotherapy, NSAIDs, diuretics, massage

B.

C.

Haematoma (ruptured penis)

Often follows kick from a mare at breeding.
Misuse of Artificial Vagina (AV) equipment can cause haemotoma. Haemorrhage from superficial vessels in dorsum of penis
Rapid swelling
Can result in paraphimosis
Treat as for paraphimosis

Balanoposthitis

Balanitis = inflammation of the glans penis Posthitis = inflammation of the prepuce Uncommon in the stallion 

Balanoposthitis 

Balanitis = inflammation of the glans penis Posthitis = inflammation of the prepuce Uncommon in the stallion

The preputial cavity contains a wide variety of microorganisms. Trauma can allow introduction of infection into deeper tissues. Results in swelling, inflammation, pain and preputial discharge.

Consider:

1.

2.

3.

Coital exanthema (EHV-3): pox-like lesions on penis

venereally transmitted self-limiting
complete resolution in 3-5 weeks

Venereal pathogens: A pure growth of Pseudomonas aeruginosa, Klebsiella pneumoniae (capsule types 5, 1 and 2), or Taylorella equigenitalis from swabs is considered abnormal and they should be reported to DEFRA

Other bacteria or fungi: A normal population of bacteria live in the sheath so sheaths should not be over-cleaned or secondary fungal infections may overgrow. 

1. Fibropapilloma: Rare
   Usually regress spontaneously in 1-6 months

2. Squamous cell carcinoma Not uncommon

   Ulcerate and bleed at breeding
   Eventually metastasise
   Diagnosis: Histological examination of biopsy

   Treatment: Cryosurgery for early lesions, anti-neoplastic chemotherapeutics, local excision, in severe cases reefing (circumcision) phallectomy may be necessary

3. Melanomata
   May be surgically removed

4. Viral papillomata
   Will self resolve

5. Sarcoids – refer to sarcoid notes 

Libido is largely genetic but environmental influences play an important role.

1. Nutrition: too thin or too fat

2. Systemic diseases

3. Age

4. Management:

harsh handling
poor restraint of mount animal
improper footing
mount animal not in oestrus or wrong height AV too hot or too cold
low ceiling
overuse

5. Psychic factors:  can result from a previous painful experience, overuse, excessive discipline.

6. Musculoskeletal: especially if it involves the hindquarters, eg spavin

7. Hormonal factors: impotent stallions tend to have lower blood concentrations of LH and

   oestradiol whereas concentrations of testosterone are normal. 

Ejaculatory dysfunction  

 relatively common in stallions

1. a)  Often presents as stallion with good libido and normal copulatory behaviour.

2. b)  May appear to ejaculate (tail flags, urethral pulsations) but does not.

3. c)  May ejaculate after several breeding attempts.

Causes (i) psychogenic: may try diazepam use
(ii) organic: damage to the dorsal nerve of the penis

malfunction of the ANS
blocked ejaculatory ducts
retrograde ejaculation (semen -> bladder) 

1. Urospermia in stallions: Urination during ejaculation – aetiology unknown, may be due to neurological dysfunction or urinary incontinence. Will

   affect fertility. Encourage urination pre-breeding.

2. Haemospermia: May be secondary to infection of the tract, trauma,

   neoplasia or bladder calculi. Will affect fertility. Urethral endoscopy

   may assist in diagnosis.

3. Morphological abnormalities:

   1. Primary (associated with spermatogenesis):

   (i) head/acrosome defects
   (ii) bent mid-pieces
   (iii) proximal cytoplasmic droplets (iv) tail stump defects

   2. Secondary (acquired in duct system)

   (i) distal cytoplasmic droplets

   (ii) kinked tails

   3. Tertiary (in-vitro damage)

   (i) detached heads (ii) kinked tails 

Teasing programmes: used on stud farms to assess when mares in oestrus

Requirements: A good teaser stallion (often a small pony)
A tease system suited to the farm's management

An experienced observer and recorder

Mares should be teased every other day during the breeding season. This not only determines when mares need to be bred but is a good method of detecting early pregnancy loss. 

Intact male horse with the following characteristics:

1. Good libido
2. Vocal
3. Easy to handle

4. Not easily frustrated - it is wise to allow the teaser stallion to breed about once a week 

1. The stallion is brought to the door of the mare's box.
2. The mare is restrained in stocks and the stallion is brought to her side.
3. The mares are group housed and the stallion is brought to their fence.
4. The stallion is placed in a small, well-constructed enclosure within the mare's pasture. 5. The mare is brought to the door of the stallion's box.
6. The stallion teases the mare over a teasing board. 

Preparation of the stallion for breeding 

The stallion should be fitted with a breeding bridle and bit or a headcollar with a chain through the mouth or over the nose.

Tease the stallion until he achieves full erection.
Rinse the penis with warm water and dry it with a soft paper towel. Occasionally the penis will need to be washed with a mild soap.
Avoid repeated use of antiseptics that can alter the natural flora of the penis and make it susceptible to Klebsiella or Pseudomonas infections.
The stallion should tease the mare to determine her readiness for breeding. The stallion is then allowed to mount the mare. Watch for tail flagging and pulsations at the base of the penis during ejaculation. After the horse dismounts the penis may again be rinsed with warm water. 

Preparation of the mare for breeding 

Wrap tail with bandage or disposable plastic bag. Wash the perineal region three times with mild soap or antiseptic solution. Rinse and dry. 

Restraint of mare for hand-breeding 

Adequately tease mare
Use bridle or headcollar and chain over nose
Can use twitch or tie foreleg up if uncertain of mare Some farms use breeding hobbles 

Artificial Vagina

1. Must be clean and dry (if necessary wash with non-residual soap and rinse well)

2. Soak for 20 min in 70% alcohol

3. Hang up to dry

4. Rinse with distilled water, dry.

5. Fill with water so internal surface is 45oC

6. Use non-spermicidal lubricant 

Missouri AV  

inexpensive, light, easy to use, can apply extra glans pressure manually. 

Colorado AV 

expensive, heavy, maintains temperature well 

May use a ‘dummy’ mare or an ovarictomised mare, ideally treated with oestradiol (but no longer available in UK).
Some stallions can be trained to collect from the ground. 

Semen 

Should be filtered to remove gel fraction
Protect from cold shock, UV light, excessive agitation

Evaluate:

motility (total and progressive)
volume
concentration

morphology (periodically through season)

Extend: 

1:1 or 1:2 for routine use or preferably to 50 million progressively motile sperm/ml for slow-cool shipped semen

Non-fat dry skim milk glucose extender: Consists of non-fat dry milk, glucose, sterile distilled water and antibiotics.

Mares should be inseminated with a minimum of 500 million progressively motile, morphologically normal sperm. Use insemination volumes under 50 ml. 

AI OF THE MARE (not permitted in racing TBs) 

1. Tail wrap

2. Empty rectum

3. Wash perineal region with povidone iodine scrub, dry

4. Semen is drawn into syringe (no silicone)

5. Use a disposable plastic insemination pipette

6. Wear a clean plastic sleeve and sterile glove

7. Use sterile non-spermicidal lubricant

8. The pipette is introduced into the uterus, covered by a hand and the semen is

   deposited in the uterine body for chilled semen, and as far up the correct uterine horn as possible with frozen semen (Deep Intrauterine Insemination) 

1. Mares can be bred by stallions which would otherwise be geographically inaccessible

2. Mares and foals not subjected to transport stress

3. Mares can remain in work

4. Mare owners save on transport costs

5. No risk of trauma to mare or stallion from each other

6. Lower risk of disease transmission 

1. More expensive

2. Success rates may be lower than with natural service

3. More veterinary intervention 

1. Natural service 48-72hrs

2. Chilled semen 12-48 hrs

3. Frozen semen 6-24 hrs 

Evaluate 3 things on each examination of mare: 

Size: usually develop from 20-25mm to 45-50mm before ovulation
Shape: remain round until approx 24hrs prior to ovulation, then flatten and ‘point’ Other factors: wall thickness, ‘snowflakes’
Softness: feel turgid until approx 24hrs prior to ovulation 

2. Grade 0: no oedema (in dioestrus) 

   Grade 1: minimal oedema
   Grade 2: mild-moderate oedema
   Grade 3: moderate oedema
   Grade 4: maximal oedema (+/- free fluid) 

2. Visual examination with speculum and torch Digital palpation
   Rectal palpation

3. If mare can be teased this is a bonus! 

Using chilled semen 

Best pregnancy rates achieved by inseminating mare within 24 hours prior to ovulation. Post- ovulation inseminations result in lower pregnancy rates and higher rates of early embryonic loss. 

Dominant follicle reaches 35-40mm EO grade 3 or 4
Cervix fully relaxed
Check no free fluid in uterus

Give induction agent (hCG or deslorelin) Order semen for arrival following day Scan mare to check not ovulated Inseminate semen

Save a few drops for examination 

Some studs advocate splitting the chilled dose into 2 portions to be inseminated 24 hours apart. Not generally recommended by equine fertility experts as semen survives better in mare’s isthmus than in chilled container. 

Using frozen semen 

Examine mare daily as for chilled AI but use deslorelin implant as induction agent to give a shorter likely ovulation interval. If implanted at 6pm, should ovulate the next but one day between 8am and 12pm – but ideally keep scanning in the meantime to monitor progress. Inseminate within 6 hours of ovulation – before or after is fine but because predicting ovulation time is very difficult, insemination usually takes place when CH seen. May consider fixed-time AI @36 and 48 hrs post-deslorelin if two doses semen available at no extra cost. 

Post-insemination examination: 

Scan mare at least 4 hrs after AI and on day following insemination to ensure:

1. CH present (note if 2x CH present twins possible)

2. No free fluid present 

Key points for AI: 

•   Plan!

•   Monitor carefully

•   Good hygiene

•   Careful handling of semen

•   Advise client re costs and success rates: approx. 40-50% per cycle for frozen AI, 50-60%

  per cycle for chilled AI, 60-70% per cycle for natural service 

0. PREGNANCY DIAGNOSIS 

0. Performed per rectum in the first few months. Be very careful to look for twins. Examine whole tract from one ovary to other and back again slowly, keeping whole uterus on screen at all times. Check body carefully. If the mare does not return to season as expected, be prepared to look again. Do not give a prostaglandin injection unless you are confident that there is no pregnancy.

   ‘Landmark’ days:

•   Day 11: 1cm vesicle

•   Day 15: 1.5cm vesicle

•   Day 17: Implantation

•   Day 21: Embryo appears ventrally

•   Day 24: Heartbeat seen

•   Day 35: eCG produced

•   Days 60-70: Sexing possible