BSE in males Flashcards
Why are breeding soundness examinations carried out?
- Document normality
- To determine prognosis for fertility:
- Detect an abnormality (not necessary relating to fertility)
Fertile definition
Ability to reproduce normally
Infertile definition
Often used inter-changeably with sterility but not the same – probably better described as impaired fertility
Sterile defintion
Absolute inability to reproduce
What should be considered before an examination?
- Does this male pose or potentially pose a infectious disease risk?
○ Transmission of venereal / other pathogens as a result of clinical examination
○ Could there be any requirement to report this condition or is it notifiable? - Is any bacteriological screening required?
○ Taylorella, Klebsiella, Pseudomonas in stallions - Is any virological screening required?
○ Porcine Reproductive Respiratory Syndrome in boars - Are any genetic tests required?
○ Dogs: many eye diseases
Reasons for general clinical exam
To ensure that there are no diseases or defects that preclude from achieving normal intromission
To rule out hereditary defects
* Hip/elbow dysplasia
To ensure that there are no diseases or defects that preclude from achieving normal intromission
○ Age and Body size
Has the animal likely reached puberty?
And is there appropriate masculinised appearance associated with peripheral actions of androgens?
○ Musculoskeletal disease
Is mating likely to occur (e.g. hock lesions in bulls)?
○ Concurrent illness
Could semen quality be affected (e.g. by pyrexia?)?
Observation of libido
Observation of interaction with an oestrus female in normal mating environment
1. Interest in the female
2. Detection of oestrus female response
Species-specific (e.g. playing in dog, aggression in cat)
3. Mounting behaviour
Species-specific (e.g. multiple attempts in stallion and dog but rapid in ruminant)
4. Erection
Species differences in mechanism
□ E.g. stallion musculo-cavernous penis achieves full erection before intromission
□ E.g. dog penis rigidity is produced by the os penis and full erection occurs after intromission
5. Intromission
Ability to achieve correct position
Size differences between male and female
6. Ejaculation
Duration compared to normal for species (short in ruminant / prolonged in dog and boar)
Ability to achieve normal position (e.g. in dog there is copulatory tie where male and female face opposite directions)
7. Interest after mounting?
Species differences in lag time to return of libido (e.g. very short in ram)
Examination of scrotum
- Normal or abnormal scrotal skin?
○ Previous trauma
E.g. cat bites with subsequent orchitis - Testis freely mobile within the scrotum?
○ No evidence of previous disease or trauma - Absence of abnormal scrotal contents?
○ Presence of hernia may result in increased testicular temperature and impact on fertility, may be important as an hereditary disease, may be important in the animal that is going to be castrated - Ultrasound of scrotum
○ May document cause of abnormal palpation findings
E.g. hernia or fluid
Examination of testes
- Palpation of testicular size, texture, tone and evenness
○ Measurement of testes
○ Measurement of scrotal width or scrotal circumference
○ Tone should be firm and resilient (softer in rabbit)
○ Large, small, soft, flabby, uneven testes can be related to pathology and changes in semen quality - Ultrasound examination of testes
○ Measurement of volume
○ Estimation of parenchymal echogenicity
Homogenous appearance
○ Detection of focal or diffuse abnormalities
Examination of sheath
- Normal appearance includes normal direction
- Freely mobile penis (may not be the case if castrated pre-pubertally)
- Normality of preputial skin
- Assess size of orifice and presence of discharge
- Absence of fibrosis/evidence of previous disease
- How much discharge is normal?
- Ability to protrude penile tip is a good guide to normality
- Remember differences in anatomy
○ E.g. preputial fold seen in the stallion
Examination of accessory glands
○ Semen collection
○ Rectal palpation
○ Radiographic (often including positive contrast)
○ Trans-rectal or trans-abdominal ultrasonography
○ Lavage techniques
Method of prostatic lavage
- Catheter inserted to level with the prostate
- Small volume of saline deposited
- Prostate massaged per rectum
- Lavage sample aspirated to collect prostatic cells
What qualities of sperm are assessed?
○ Number
○ Motility
○ Morphology
○ Live staining
○ Presence of other cells
Endocrinological testing in males
Not common
Injection of GnRH or hCG causes increased secretion of testosterone in normal dog
(hCG has LH like effects)
