Therio- Stallion Repro Dz's

drraythe's version from 2016-04-29 14:32

intro + Impotentia coeundi

Question Answer
basic reasons there might be Impotentia coeundi? (list for reading)Pain (musculoskeletal or back pain), Penile trauma, Neoplasia, Habronemiasis, Coital exanthema (EHV-3)
basic reasons there might be Impotentia generandi? (list for reading) Cryptorchidism, Inguinal/scrotal herniation, Torsion of the spermatic cord, Orchitis, Scrotal trauma, Testicular degeneration, Testicular atrophy, Blocked ampulla, Tear in the pelvic urethra
what are the two major viral venereal diseases?Coital exanthema (EHV-3), Equine Viral Arteritis (EVA)
what are the three major bacterial venereal diseases?Contagious Equine Metritis (CEM- Taylorella equigenitalis), Pseudomonas, Klebsiella
what is the main protozoal venereal dz of horses?Dourine (Trypanosoma equiperdum)
what's Impotentia coeundi?problem with the act of sex, not generating the things capable of fertilization
what are some common causes of penile trauma?Cuts after breeding, Kick from mare, Penetrating object from bedding, Others: stallion ring, castration, etc…
how do you treat cases of penile trauma?Stall rest, Elevate --> Replace the penis in the sheath (if possible) & put in retention stitches (or apply sling/belly wrap to suspend penis), Lubricate, Cold water hydrotherapy 2-4x/day, Diuretics, NSAIDs, corticosteroids, AB’s, Sexual rest
what are the chronic effects of penile trauma?May get scar tissue formation resulting in phimosis or paraphimosis
what is Paraphimosis?inability of the horse to retract the protruded penis into the preputial cavity (trauma, exhaustion, ...)
what is Phimosis?inability of the horse to protrude its penis from the preputial orifice or preputial ring
what is Priapism?persistent erection without sexual stimulation (most often following phenothiazines) can lead to paraphimosis and paralysis. AVOID ACEPROMAZINE IN STALLIONS
priapism is usually caused by what and results in what problems?usually cause by phenothiazines (DONT GIVE STALLIONS ACEPROMAZINE) and can lead to paraphimosis and paralysis
how common are penile neoplasias?Penile neoplasia form up to 10% of equine tumors
4 most common types of neoplasias?Squamous Cell Carcinoma, Sarcoid, Melanoma (greys), Papilloma (benign on the genitalia of young horses, disappears with acquired immunity against the virus)
what does SSC look like? what are the DDx?DDx: Habronema, Sarcoid
Habronemiasis--> aka? what causes this? DDx?aka summer sores, caused by migration of Habronema larvae. DDx SCC
how do you dx and tx habronemiasis?dx: bx. tx: Fly prevention/ Sexual rest/ Systemic & topical anthelmintics (ivermectin etc)

Impotentia generandi

Question Answer
when do testicles usually descend in stallions?Testes normally in scrotum between 30 days before and 10 days after birth
how common is cryptorchidism, and is it usually uni or bilateral?Cryptorchidism is seen in 5-8% of foals and is most frequently unilateral
what is a rig?cryptorchid stallion
how might you be able to dx cryptorchidism with a rectal palpation?find the inguinal ring and feel for the spermatic cord running through it
cryptorchidism--> hormone assay dx--> Basal Testosterone levels of a NORMAL stallion?0.5 to 1ng/ml
cryptorchidism--> hormone assay dx--> Basal Testosterone levels of a GELDING?0.05 to 0.1ng/ml
how do you do a hCG stimulation test to dx a cryptorchid?(remember that hCG has LH like effects) Take blood sample before hCG administration. Administer hCG 10,000 IU IV or IM (Chorulon®). Take blood samples at 30 min intervals for up to 3h after hCG administration (if only 1 sample then take at 3h after hCG). Normal and cryptorchid stallions should have a marked increase in testosterone in response to hCG
what other hormone can you measure aside from testosterone to try to determine if you have a cryptorchid?Antimullerian Hormone (AMH) (cryptorchid will have high levels of this, even higher than stallion)
5 main DDx for a swollen scrotum?Inguinal hernia, Hydrocele (Pitting oedema – usually lack of exercise), Torsion of the spermatic cord, Orchitis, Trauma
is inguinal/scrotal herniation congenital or acquired?could be either
clinical signs of inguinal/scrotal herniation?Colicky – especially if strangulated. Swollen scrotum. Pain on palpation of scrotum. May be able to reduce herniated intestines
dx and tx of inguinal/scrotal herniation?Dx: U/S. Tx: Sx
Torsion of the spermatic cord most commonly occurs in what type of testes?Common with retained cryptorchid testis but may occur intra-scrotal
which degrees are common in torsion of the spermatic cord?Can be 180° or 360° torsion
what is the major problem caused by torsion of the spermatic cord?ischemic damage
clinical signs of spermatic cord torsion?*180° torsion sometimes have no clinical signs!! Will see: COLIC!!!!, Swelling & pain of scrotum, NB!! check Orientation of the testis
how do you tx spermatic cord torsion?Hemi-orchidectomy if long standing… want to protect spermatogenesis in contralateral testis. Sx and pexy
what does testicular (spermatic cord) torsion look like on U/S?
what is the major concern with scrotal trauma?Requires QUICK & AGGRESSIVE TREATMENT to prevent permanent damage to fertility due to compromised thermoregulation
how do you treat scrotal trauma?NSAIDs, AB’s (depending on cause); hydrotherapy. Consider hemiorchidectomy to preserve the other testis
what are some nasty chronic changes which can happen due to scrotal trauma? (4)(1) Exposure of body to spermatozoa results in anti-sperm antibody formation (2) Spermatic granuloma (3) Testicular degeneration/atrophy (4) Sub/Infertility
Testicular degeneration/atrophy is usually due to...Usually due to some sort of insult to testes (Eg. Hydrocele due to neoplasia/trauma; following orchitis or trauma to testes)
what are the testes like in Testicular degeneration?Testes become softer than normal
what are the testes like in Testicular atrophy?Usually unilateral, Affected testis smaller and more fibrotic (Eg. Chronic orchitis)
testicular degen vs atrophy- which is SOFTER testes?degen
testicular degen vs atrophy- which is usually unilateral?atrophy
what is Azoospermia?Complete absence of spermatozoa in the ejaculate
what are 6 major reasons for azoospermia? (and the top two?)Incomplete ejaculation, Plugged ampullae, Testicular degeneration, Retrograde ejaculation, Congenital hypoplasia of epididymii, Genetical abnormalities (trisomy)
when do you usually see blocked ampulla? how is it usually dx?Usually at the beginning of the breeding season.....dx when Hx of mares not falling pregnant after covering, and semen eval reveals Azoospermia/oligospermia
how do you go about Treatment of plugged ampullae? (4 things)Repeated semen collection, PGF, Oxytocin, Manual massage per rectum
what is preventative tx you can do for plugge ampullae?continue to collect semen on regular basis
what is Spermiostasis like following blocked ampulla?Initially only few dead spermatozoa (loose heads) in the ejaculate--> When passage is restored, first very high concentration of dead spermatozoa (loose heads and some other abnormalities).--> May take several days of daily semen collection to resume normal quality spermatozoa and establish normal DSO.
clinical signs of tear in pelvic urethra?Blood in ejaculate (hemospermia) No other clinical signs
why do we care about blood in ejaculate (hemospermia) aside from the problem causing it?Affects fertility of ejaculate
how do you diagnose a tear in the pelvic urethra?Appearance of blood in ejaculate, Endoscopy, Usually tear in pelvic urethra

Venereal dzs

Question Answer
Coital exanthema is caused by what?EHV-3
how is Coital exanthema spread?Venereally transmitted & by fomites
how does Coital exanthema present?External genital infection! Initially vesicles on external genitalia of stallions & mares--> Then pustules, ulcers and crusts. May cause pain during coitus. Non-infectious once ulcers have healed – cause depigmented areas. Immunity short lived – reinfection
if you see depigmented areas on the external genitals, what might you think?Coital exanthema ( EHV-3)
treatment for coital exanthemia?sexual rest and hygiene
Equine Viral Arteritis (EVA)--> where does this like to live geographically?Endemic in Europe – Reportable in the US
how is Equine Viral Arteritis (EVA) transmitted? By aerosols from acutely infected horses, ****Venereally from carrier stallions, Via chilled/frozen semen (AI), Indirect transmission by fomites, feces, urine, vaginal secretions etc
how environmentally stable is equine viral arteritis?The virus is heat sensitive but is able to persist at freezing temperatures
how do the majority of cases present for EVA?The majority of cases are subclinical or inapparent
what are the major clinical signs of EVA?signs of resp dz: Fever, depression, anorexia, leukopenia, Rhinitis, conjunctivitis, Urticaria; Edema of limbs, ventrum, periorbital region, scrotum, Abortion—associated with ‘abortion storms'
who is a carrier for EVA?Mares, geldings & immature colts rapidly rid themselves of the disease & develop immunity--> Only stallions develop a carrier status
why are only stallions carriers for EVA?Testosterone-dependent virus, Survives in ampulla, with a Variable duration (years or lifelong)
how do chronic carries shed EVA?Shed through semen in chronic carriers, but not through the respiratory tract.
how can you eliminate EVA (unique, not with drugs)since TESTOSTERONE DEPENDANT, you can eliminate the virus by Suppressing testosterone for ≥ 6 weeks (GNRH??)
2 ways to dx EVA?(1) Virus isolation include whole blood, nasopharyngeal swabs, semen, conjunctival swabs, fetal or placental tissues/fluids (2) Serology (paired samples)
is there a vx for EVA?YES! At-risk stallions re-vaccinated annually
what is something that is a problem with the VX for EVA vx, and how do we try to circumvent this problem?Currently it is not possible to differentiate vaccinated from natural infection via serology which has implications regarding breeding shed access and export. So, Stallions are screened serologically before primary vaccination. CERTIFICATION OF NON CARRIER STATE.
what causes Contagious Equine Metritis?Caused by bacterium Taylorella equigenitalis
what economical impact does contageous equine metritis have?Countries that don’t have CEM WILL NOT IMPORT YOUR HORSES!!! REPORTABLE IN THE US!
CEM---> Strict import quarantine & testing requirements--> where do you take swabs, and what do you do with them?3 swabs taken from urethra, urethral fossa & lamina interna. In charcoal Amies media to reach lab within 48h. Sent for culture (OIE recognised) or PCR. Test breeding in USA
how is CEM spread?Transmitted venereally & by FOMITES
what are the clinical signs of CEM in STALLIONS?***inapparent carriers
what are the clinical signs of CEM in MARES?transient endometritis post-breeding (Will usually clear themselves and develop transient immunity-- May (25%) become carriers)
which is only males are carriers?EVA- bc testosterone dependent
*what are the 3 places swabs are taken from for CEM in STALLiONS?Swabs taken from urethra, urethral fossa & lamina interna
*what are the 3 places swabs are taken from for CEM in MARES?Swabs taken from clitoral sinus, clitoral fossa & endometrium
what medium is a CEM swab added to?In charcoal amies medium
do you want to ship CEM swabs on ice? how quick should it get to the lab?yes on ice, to lab within 48 hrs
how do you treat stallions for CEM?Daily scrubbing of penis with chlorhexidine & application of nitrofurazone or silver sulphadiazine ointment for 5-7 days. Application of dry-cow intramammary ointment into urethral fossa/sinus
when and how do you follow-up-test for CEM?One week after initiation of treatment the stallion is swabbed for isolation of Taylorella equigenitalis for 3 consecutive weeks.
what is "Test breeding" and where is this required?required in the states, where a Stallion test bred to 2 mares--> Mares swabbed (clitoral sinus, clitoral fossa & endometrium) 3 times – sent for culture. Following negative results, stallion can resume breeding
Pseudomonas aeruginosa /Klebsiella pneumoniae--> how are these spread?Can be spread venereally to mares during coitus
Pseudomonas aeruginosa /Klebsiella pneumoniae--> how do these affect the mare?Can cause endometritis
what usually causes Pseudomonas aeruginosa /Klebsiella pneumoniae to become a problem for stallions?Overgrowth of these bacteria usually due to mismanagement of stallion during breeding (Eg. Overzealous washing of penis with disinfectants)
Dx of Pseudomonas aeruginosa /Klebsiella pneumoniae?Swab indicating pure growth – need to capsule type to determine if pathogenic or not
Dourine is caused by?Trypanosoma equiperdum (REPORTABLE in the US)
clinical signs of Dourine?Edematous swelling of genitalia, Mucopurulent urethral discharge, 2-10cm urticarial cutaneous plaques (“silver dollar” plaques). Progression emaciation, penile paralysis
2 ways to dx dourine?(1) Complement fixation test (2) Isolation of trypanosomes in urethral exudate, blood or urticarial plaques
tx for dourine?Generally impractical, euthanasia
reportable in the US?EVA, Contagious Equine Metritis, Dourine