Infertility & reproductive pathologies in male dogs Flashcards
Causes of reduced fertility. (10)
- Age
- Infections
- Blocage of the epididymis
- Retrograde ejaculation
- Diseases of the prostate
- Cystitis
- Endocrine disturbances
- Immune mediated
- Medical treatment as suprelorin, some antifungal, steroids
- Anatomical abnormalities (inherited/congenital)
After bad breeding management, what is the second most frequent cause of missing pregnancy in bitches, presented for
infertility.
reduced semen quality
Define the following:
Azoospermia =
Aspermia =
Teratospermia =
Asthenozoospermia =
Oligospermia =
Azoospermia = no sperm in the ejaculate
Aspermia = complete lack of semen with ejaculation (not to be confused with azoospermia, the lack of sperm cells in the semen)
Teratospermia = presence of sperm with abnormal morphology that affects fertility
Asthenozoospermia = sperm with low motility
Oligospermia = low sperm count
Fertility examination for the male dog should include: (6)
General clinical examination
Standard blood/urine/T4
Genital exam
* Palpation of the testis/epididymis
* Release of the penis behind the bulbus glandis
Digital rectal palpation of the prostate
Semen collection and evaluation
Ultrasound (testis, epididymis ,prostate, bladder)
Semen quality deteriorates as the dog gets older (breed dependent) → after what age?
6 years of age +/-
Often some degree of benign prostate hyperplasia (BPH) after 6 years of age → can effect semen quality.
Frozen semen to preserve valuable genes → has to be done when
the dog is still young to get the best freezing result.
Orchitis/epididymitis
Acute?
Chronic?
Pathogenesis?
Usually occurs in young dogs (2-4 years).
Acute:
❖ Pain, swelling, fever, hindleg lameness, scrotal edema, purulent discharge
Chronic:
❖ Non-painful enlargement of the scrotum (soft or very firm)
❖ Sometimes atrophy of the unaffected testis
Pathogenesis:
infection or autoimmune destruction
❖ Retrograde infection from the prostate or lower urinary tract
❖ Hematogenous spread
❖ Penetrating wounds
❖ Brucella Canis, E.Coli, Strep spp, Staph spp
Chronic inflammation, normally results in testicular/epididymal degeneration and fibrosis.
Diagnosis of Orchitis/epididymitis. (4)
Clinical symptoms (size, temp, pain, firmness of testes)
Fine needle aspirate for
- Cytology
- Culture (anaerobic, aerobic and mycoplasma)
-ALL dogs presented with scrotal enlargement should be tested for Brucella Canis (RSAT/AGID or culture from semen)
Ultrasound- differentiation of structures that are not palpable.
Treatment of orchitis/epididymitis.
Antibiotics alone only for acute infections when the blood/testis-barrier is not intact.
NSAIDs
Removal of the affected testis also if bilateral.
For valuable stud dogs → remove the affected testis as fast as possible in
combination with antibiotics (always antibiogram) → decreases the risk of
changes in the contralateral testis.
Describe Retrograde ejaculation.
The semen is delivered in the bladder instead of through the urethra.
If azospermia → always take an urine sample just after the collection.
neurologic problem
urolith
inflammation in the sphincter muscle
trauma
prostate hyperplasia
Therapy: Propanolamine ( propalin)→ sympathomimetic
Signs of Brucella in males. (4)
Orchitis/epididymitis
scrotal dermatitis
Oligozoospermia (decreased number of spermatozoa in the semen)
infertility
Brucellosis can also be reported to cause:
Uveitis
Meningitis
Osteomyelitis
Diagnosis of Brucellosis in males. (3)
Same as for the female but remember:
Serological tests (RSAT, TAT, ELISA): high sensitivity → points out negative animals.
❖ Not for the first (45-60 days)
AGID: golden standard (high specificity → points out positive animals).
❖ Used if positive RSAT/TAT
❖ Can be used after 8-12 weeks
Culture of the organism from
❖ Semen, Blood, lymph node aspiration, bone marrow, infected tissue
❖ Can be done before day 30, most accurate in this period→ difficult to culture.
Treatment/prevention
❖ As for the female dog
If Azospermia in a patient, you should do the following: (4-5)
Be sure that you have collected the full semen fraction → check ALKP of the semen → ALKP is very high in the epididymis (normal >(5-)10000 ng/ml).
❖ If low → blockage of the semen from the epididymis OR inconsequent delivery.
Check a urine sample just after the collection for spermatozoa to make sure
there is no retro-ejaculation.
If the testicles are smaller than average for the breed and softer/harder in texture than expected → bad prognosis.
If nothing else is found → new collection in 8-10 weeks → new generation of
spermatozoa.
For prognosis of future fertility → testicle biopsies for histopathology.
Prostatitis→ can be secondary to…?
Signs of acute vs chronic prostatitis?
BPH.
Acute:
❖ Febrile, anorectic, lethargic
❖ Urethral discharge
❖ Pain if palpated rectally
Chronic:
❖ Recurrent urinary infection
❖ May be asymptomatic
❖ May have hematuria, poor semen quality, varying urinary discharge
❖ GI symptoms
❖ Usually no pain by rectal palpation
If abscessation → fever, abdominal pain.
Diagnosis of Prostatitis, diagnosis. (4)
Bloodwork:
❖ Neutrophilia with left shift in acute prostatitis and increased CRP.
Urinanalysis:
❖ Hematuria, pyuria and bacteriuria OR may be normal.
Ultrasound:
❖ Focal or diffuse hypoechoic changes – ”moth-eaten” appearance.
❖ Mineralization in chronic cases
Definitive diagnosis:
❖ Stick a needle in there → FNA → culture and bacteriogram.
Prostatitis, treatment
In acute prostatitis
❖ the blood-prostate barrier is disrupted → choose treatment from the culture and
sensitivity
❖ Treat for 4-6 weeks!
In chronic prostatitis (the barrier is intact → less penetration of AB)
❖ Empiric antibiotics while culture are pending → Trimethoprim/sulfa (TMS)
❖ High lipid solubility → allows for crossing the lipid membrane.
(TMS and fluoroquinolones)
Castration may shorten the mean duration of infection.
Cryptorchidism is…
a Developmental defect in which decent of one or both testes into the scrotum does not occur by 6 month of age.
The testicles in dogs will normally be at the inguinal ring at 10 days of age and in the scrotum at 42 days.
Inguinal canal closes at 6 month age and only few percent of the testicles descent after week 14.
Incidence:
small breeds > medium breeds > large breeds
Often unilateral and more often is the right testes involved. Can be inguinal or abdominal (72%/28%). Are inherited so don’t use these dogs for breeding.
Etiology of Cryptorchidism.
Inherited→ autosomal recessive trait carried by BOTH male and female.
Pathogenesis unknown → hypotheses:
❖ Inadequate secretion of GnRH, LH, testosterone.
❖ Early closure of the inguinal canal.
Retained testes are smaller than scrotal → no spermatogenesis. Predisposition to neoplasia = 9,2-13,6 times. Predisposition to torsion of the spermatic cord.
Diagnosis and differentiation between cryptorchidism and castrated dog:
❖ Ultrasonography (normally very easy to find)
❖ Evaluation of the prostate (smaller in castrated dogs)
Testosterone-stimulation test
▪ Blood sample → GnRH (receptal®) 1ml/10kg im/iv → blood sample after 60 min
▪ LH test (ELISA snap), will be elevated in castrated dogs.
Cryptorchidism Treatment:
❖ Bilateral castration
❖ Orchiectomy of the cryptorchid testis
❖ Orchidopexy → should always do vasectomy at the same time because dog should not be used for breeding.
❖ Medical: GnRH (receptal®) 1ml/10kg day 1,3,5 week 1+3+5, or hCG (Chorulon® 100- 300IU/dog) twice/week, 3-4 times but these have not been validated.
Prevention:
❖ Don´t use cryptorchid animals for breeding!
Penile frenulum
Thin band of connective tissue between the ventral glans penis to the corpus of the penis or the prepuce.
- Not inheritable
- ALWAYS check penis and prepuce before a young dog can be used for breeding.
- Surgical resection → very easy
Describe Hypospadias
Abnormal termination of the penile urethra along the ventral surface of the penis
proximal to the normal urethral opening.
Is classsificated as:
- glandular (least severe)
- Penile
- Scrotal
- Perineal
No breed predisposition (Boston terrier overrepresented though).
Causes: intersex animal, progestins to the dam during pregnancy, Vit A deficiency.
Treatment: none if asymptomatic, amputation of penis, scrotal or perineal scrotal
urethrostomy → castration recommended.
Testicular neoplasias are the Second most common type of tumor in the dog after
skin tumors.
Mean age at diagnosis of affected dogs is 10 years, range of 2-19 years.
▪ Increased for boxers, 7 years
Breeds at decreased risk are Dachshund, beagle, Labrador retriever, and mixed-bred dogs.
More common in retained testicles than in descended testicles.
May be unilateral or bilateral
▪ Bilateral is reported in 45% of cases
Multiple types may be present
Three most common types:
sertoli cell tumors, seminona, leydig cell
tumor (interstitial)
Describe Interstitial Leydig cell tumors
25 % of all testicular tumors
More common in scrotal testes (99%)
Mean age of diagnosis 10 years
No breed disposition
Usually small lesions (<1cm)
Low malignancy
Paraneoplastic syndromes due to either hyperestrogenism or hypertestosteronism
❖ Elevated testosterone leads to prostate disease, perianal adenoma, perianal gland hyperplasia, perineal hernia.
Torsion of the spermatic cord, clinical signs?
Is more often seen in abdominal retained testes.
❖ Acute abdominal pain
❖ Vomiting
❖ Lethargy
❖ Anorexia
❖ Dysuria/hematuria
❖ Swelling of scrotum or inguinal area
❖ Testicles that are attached to a torsed spermatic cord are usually enlarged, congested.
Histology: ischemic necrosis, intravascular hemorrhage and edema.
Therapy: surgical excision and orchiectomy
Scrotal neoplasia, scrotal mast cell tumor, mastocytoma
Clinical symptoms of BPH.
Eccentric growth in dogs (concentric in humans)
❖ Tenesmus, flattened feces, constipation
❖ Stranguria/uncommon)
❖ Blood dripping from penis (not while urinating)
Semen:
❖ Hematospermia – no effect on semen quality in early stages→
❖ Later can occur asthenozoospermia (decreased motility) and
teratospermia (increased morphologic defects, often tail defects)
Diagnosis of BPH. (3)
Rectal palpation – only possible to palpate the most caudal part.
Ultrasonography:
❖ Good choice for most veterinarians in clinical practice. Good to visualize size and the context of the parenchyma but can´t diagnose early stages of BPH.
CPSE: Canine prostate specific esterase
Prostatic (retention) cysts can occur with
estrogen-secreting Sertoli cell tumors (SCT).
Paraprostatic cysts are often craniolateral to the prostate, displacing the
bladder or caudal to the gland within the pelvis.
❖ Hypothesized to be dilated embryonal remnants of wolffian ducts.
Urethral prolapse Etiology:
❖ Idiopathic
❖ Secondary to sexual excitement
❖ Urethral infection
❖ Genetic predisposition (often seen in English bulldogs)
Dyspnea → increase of abdominal pressure→ prolapse
Mean age at diagnosis → 20 months
Transmissible venereal tumor (TVT) Clinical signs:
❖ Cauliflower-like appearance
❖ Discharge from prepuce
❖ Urinary retention due to blockage of urethra
❖ Nasal discharge/nose bleeds
❖ Enlargement of regional lymph nodes
Diagnosis of Transmissible venereal tumor (TVT)
visual inspection, cytology, immunochemistry
Clinical appearance on penis/prepuce is very characteristic.
Histological aspect:
▪ A high rate of nucleus in the cytoplasm
▪ Oval nuclei with one or two prominent nucleoli
▪ Pale blue cytoplasm containing distinct clear vacuoles
▪ Biopsy for immunochemistry
