Mounting problems Erection failure

Reproductive Disorders of the Stallion Flashcards by Michelle Chan

Semen collection and evaluation

 2 ejaculates one hour apart
 Total number of
spermatozoa/ejaculate
 Total number of normal
progressively motile spermatozoa
should be at least 1 billion in the
second ejaculate

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Cryptorchidism

• Testes should be in the
scrotum at birth
• Breed predisposition
• Treatment
 Improve testicular descent???
– hCG
– GnRH
 Castration
– Eliminated from breeding in
several countries (Not in the
USA)

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Differential diagnosis between cryptorchid and

gelding with stallion behavior

Endocrine
• Testosterone before after
hCG stimulation test
• hCG: 6000-10000 IU IV
• Testosterone increase 2
to 3 fold after 2 hours
• Estrogen
• Anti-Mullerian Hormone
Transabdominal or
transrectal ultrasonography
• Normal development of
accessory sex glands
• Presence intraabdominal
testis

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Penile lesions: Balanitis / Balanoposthitis

• Viral
 Coital exanthema (EHV-3)
• Smegma accumulation
 Bacterial / fungal
complications
• Parasitic
 Summer sores (Habronema
larvae)

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Treatment of parasitic balanitis

 Diagnosis (biopsy)
 Topical treatment
 Prevention:
– Fly control
– hygiene
– Ivermectins

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Neoplasia

• Type of neoplasia

 Squamous cell carcinomas
 Melanomas
 Other
– Cutaneous lyphosarcoma
– Sarcoids

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dx of neoplasia; tx

• Diagnosis
 History
 Lesions
 Histopathology
• Treatment
 SCC: early 5 F-U, cisplatin
 Melanoma: vaccines?
 Surgery: reefing, phalectomy

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Paralysis of the penis - causes

 Damage to sacral nerves
 Infectious diseases: EHV-l, Rabies,
Streptococcal- associated purpura
hemorrhagica
 Phenothiazine-base tranquilizers
(propionyl promazine)
 Exhaustion
 Starvation
 Following trauma

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clinical signs of penis paralysis

 Flaccid penis, edema, excoriation

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treatment of penis paralysis

 Medical/physical management if
early detection, penile amputation if
too late

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Poor libido

• No response to an
estrous mare after a
period of 10 minutes
• No secondary behaviors
• Donkey may take a lot
longer
• Consider learning
problems in young
stallions or stallions
retired from performance

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Aggressive behavior- Self-mutilation

• Flank-biting (abdomen, flank or hind limb while kicking and/or striking out
vocalizing in sharp squeals or barking grunts)
• Rule out
 Painful conditions
 Behavioral problems

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Aggressive behavior- Self-mutilation - management

 Address pain
 Physical device treatments to reduce self-mutilation
 Provide motivation for a substitute behavior or a strong distraction
 Diet change (grass and grass hay only without any grain or richer forage)
 Long-acting tranquilizers such as fluphenazine may be effective
 Tricyclic anti-depressants such as imipramine and clomipramine have
been found clinically useful
 Nutritional supplement l-tryptophan, the precursor of serotonin, has been
clinically effective in reducing self-mutilation
 Progesterone treatment (affects fertility)
 Odor masking preparations

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Impotentia coeundi

Mounting problems

* Erection failure

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Erection failure

• Erection: a complex
process
• Look for painful lesions
on glans penis
• Abnormal vasculature
 Compromised blood flow
to the cavernosum body
• Penile deviation
 Old lesions of “Stallion
rings”

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Impotentia generandi

• Ejaculatory disorders
 Ejaculation failure
 Incomplete ejaculation
 Retrograde ejaculation (rare)
 Premature ejaculation (rare)
 Urospermia
 Spermastasis (occluded or plugged ampullae
syndrome)
• Poor semen quality
 Azoospermia/oligozoospermia
 Teratozoospermia

Aids to facilitate ejaculation

• Enhance sexual arousal
• Remove or reduce cause of pain or discomfort
• Increase stimulation of the penis: hot compress at the
base of the penis
• Enhance sexual arousal (GnRH, Diazepam)
• Lower ejaculatory threshold (Imipramine)
• Induce ejaculation

50% of ejaculatory

disorders are atributed to what?

musculoskeletal problems 
• Osteoartritis
• Neurologic diseases
• Sore back
• Rhabdomyolysis
• Laminitis
• Aorto-iliac thrombosis

Management of stallions with musculoskeletal

disease

• Control pain
• Enhance sexual
arousal
• Ex-copula ejaculation
• Accommodate for
musculoskeletal
deficiencies
• One-mount rule
 Find proper handling to
achieve ejaculation with
a single mount

• Azoospermia

 Complete testicular degeneration
 Orchitis
 Testicular hypoplasia
 Epididymal blockage (bilateral)

• Oligozoospermia

 Testicular degeneration
 Incomplete ejaculation (sperm
accumulator)
 Retrograde ejaculation

Azoospermia / Oligozoospermia due to testicular

degeneration - factors

 Age
 Anabolic steroids
 Altrenogest
 Testicular trauma/infections
 Fever

testicular

degeneration clinical findings

 Small testes / asymmetry
 Increase spheroids in
ejaculate
 Increased sperm
abnormalities
 Low motility

Sperm Agglutination/accumulation: Diagnosis

• Very high concentration
• Presence of epithelial cells
• Clumping
• Transrectal ultrasonography
 Enlarged ampula of the vas
deferens

“Plugged or occuluded ampullae”: Treatment

``` • Ampullae massage • Oxytocin, PGF2 alpha before breeding • Frequent ejaculation  1 x to 2 x per day for 10 days ```

Hemospermia

``` Glans penis  Surface of the penis  Urethra – Urethritis – Urethral rents  Internal genitalia – Seminal vesiculitis • Timing of bloody discharge • Quantity • Diagnosis  Clinical evaluation  Transrectal ultrasonography  Endoscopic evaluation of the urethra and accessory sex glands ```

Hemospermia - Treatment

``` • Antimicrobials • Sexual rest • Urinary antiseptics • Sub-Ischial urethrotomy • Management during the breeding season  Fractionated ejaculate  Collection into extender  Chemical ejaculation?? ```

Urospermia clinical signs

``` Clinical signs – Large volume ejaculate – Change in color – Urine odor – Sediment – Poor motility ```

Urospermia dx

``` •Diagnosis –Evident (odor color) – Azostix® – Determination of creatinine (>2g/dl) –Urea (>30 mg/dl) ```

urospermia causes

``` – Cauda equine neuritis – EHV-1 – Sorghum and sudan grass – Severe pain – Urolithiasis – Generalized neoplasia ```

Urospermia - Treatment

• Diuretics: Furosemide (250 mg IV) (Lowe, E.V.J. 2001, Thoroughbred stallion) • Catheterization of the bladder and imipramine (Turner et al 1995) • No improvement with furosemide or imipramine in 3 cases (Sepulveda et al, Reprod. Dom. Anim 1999) • Management: Fractionation of ejaculate, “washing” • Flavoxate hydrochloride (bladder wall relaxation) • Bethanechol chloride (improves coordination of the bladder sphincter and detrusor function)

Seminal vesiculitis (Pyospermia)

``` • Infertility  Normal breeding behavior or reluctance to breed  Poor semen quality • Straining and posturing after breeding • Inflammatory cells in ejaculate, +/- microscopic hemospermia ```

Seminal vesiculitis Dx/Tx

``` • Culture: Catheterization and massage • Treatment • Direct flushing • Antibiotic infusion • Systemic antibiotics • NSAIDs • Management:  Minimum contamination breeding  AI (direct collection in extender, fractionate ```