Approach to Examining the Male Reproductive Tract Flashcards
Trevor is a two year old intact cross bred dog that has a muco-purulent preputial discharge
How do you know whether this is normal?
- It is dripping onto the floor, stains carpets – quite a significant volume so the owners are worried
- Could do cytology – will be full of neutrophils because its purulent in nature, quite a lot of bacteria also – so will just confirm what we can see
- Could send off for microbiology and C&S
- There are no venereal pathogens in dogs that are bacterial
- The above will just show what we already know – so might not need to do these!
- Could be urinary, could be prostatic, could be preputial – makes you ask the question, how do I do a CE to identify the source of the problem
- Interesting – this is a normal discharge, large volume – not uncommon for male dogs to have small volume of purulent discharge within the sheath. It’s a larger volume but doesn’t mean we make this assumption as this dog may have other diseases
- Makes you ask the question – you want to culture or cytology, but the real question is where could it be coming from? In the dog, this is likely to be norma
Why are male reproductive tracts examinations undertaken?
–Document normality (BSE – breeding soundness exam)
–To determine prognosis for fertility:
- Fertile (ability to reproduce normally) – an animal has normal fertility, but animal might be fertile but not have normal fertility – might be able to produce offspring but not at the right level
- Infertile (often used inter-changeably with sterility but not the same – probably better described as impaired fertility) – sometimes people use this to describe an animal that is unable to reproduce, but the true word for this would be STERILE. Do we mean sterile or subfertile??
- Sterile (absolute inability to reproduce)
–Detect an abnormality (not necessary relating to fertility)
What do we want to find out with the clinical history for a male reproductive exam?
•Want to know why animal has presented to us, what information has the owner got that is useful to us?
–Has the animal recently been fertile, has it reached puberty, has there been a change in documentation of animals success rate? Information isn’t always necessarily clear – might be that there is a stud dog that breeds female that doesn’t get pregnancy and he is likely to have bred before so we have his information readily available – with clients animals, it wont be quite the same!
–Also establish if it’s a seasonal breeder – where are we in its breeding season? Such as management things – could there be other components of the alledged fertility problem?
- History taking should be relevant and specific to the species, age and presentation of the clinical problem
- What is the reason for presentation?
- Importantly if relating to fertility; previous breeding history
–Reached puberty?
–Previous breeding success?
- Yes
- No: but other circumstances may explain this
- No: and a fertile mating was expected
If we are looking for a genuine cause for concern over fertility, what are some things we want to find out about previous breeding records?
–Number of females mated
–Environmental conditions of mating
–Management conditions of mating (e.g. commonest cause of infertility is dogs is that the owner chooses the incorrect time for breeding)
–‘Mating workload’
•Consider female factors
–Mating in relation to season of the year
Before any examination, what should we check first?
–Transmission of venereal / other pathogens as a result of clinical examination
–Could there be any requirement to report this condition or is it notifiable? e.g.
- Contagious equine metritis (CEM) [Taylorella] in stallions
- Is any bacteriological screening required?
–CEMO, Klebsiella, Pseudomonas in stallions
•Is any virological screening required?
–BoHV-1 (either virus isolation or PCR on ejaculate or preputial wash)
•Are any genetic tests required?
–Dogs: many eye disease (PLL, Cataract, PRA), von Willibrands, hips, shoulders, elbows etc.
Before going to the male anatomy, we want to do a general clinical examiantion - what should we be looking for and why?
•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?)?
- And to rule out hereditary defects
–Hip dysplasia in dogs etc
How can we observe libido?
What is the process from interaction with an oestrous female in normal mating environment?
- Interest in the female
- 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, in the dog penis rigidity is produced by the os penis and full erection occurs after intromission)
- If you cannot observe it, might need to ask other specific questions to help narrow it down – what aspect of the process is not working? E.g. might have MSK pain and not want to mount
5.Intromission
- Ability to achieve correct position
- Size differences between male and female
6.Ejaculation
- External production of the ejaculate
- 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)
When examining the scrotum, what things should we look at and observe? What can we do to futher investigate them?
•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
–Should be free movable, not damage preventing it moving around
•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
–Should be able to feel the epididymis, vas deferens etc. but nothing abnormal!
•Ultrasound of scrotum
–May document cause of abnormal palpation findings
•e.g. hernia or fluid
When examining the testes, what things should we look at and observe? What can we do to futher investigate them?
•Palpation of testicular size, texture, tone and evenness
–Measurement of testes – what is normal?
–Measurement of scrotal width or scrotal circumference
–Tone should be firm and resilient (softer in rabbit) – tone should be similar to that of when you close your eyelid and squish your eye
–Large, small, soft, flabby, uneven testes can be related to pathology and changes in semen quality
•Ultrasound examination of testes
–To look at internal aarchitecture
–Measurement of volume
–Estimation of parenchymal echogenicity
–Detection of focal or diffuse abnormalities
What is wrong with this US of a dog testicle?
Ultrasound appearance small Sertoli Cell tumour in a dog
Ellipsoidal focal lesion – Sertoli cell tumours
What is wrong with this US of a testicle?
Ultrasound appearance orchitis (hypoechoic testicular parenchyma)
Parenchyma is darker than normal
When examining the epididymides, what things should we look at and observe? What can we do to futher investigate them?
•Palpation of the head and tail of epididymides to assess size and turgidity
–Small and flaccid indicates disrupted sperm production
–Large and dilated may indicated a distal obstruction
–Might be more swollen in breeding seasons
•Palpation of ductus deferens (at neck of scrotum confirms normality and rules out previous vasectomy) whilst palpation of vasculature can rule out abnormality such as varicocoele
When examining the inguinal canal, what things should we look at and observe?
•Palpation for:
–Estimation of the size of the inguinal canal
–Detection of non-descended testes
•If stallion that you castrating, might palpate here and check there is no material here
When examining the sheath, what things should we look at and observe?
- Normal appearance includes normal direction
- Freely mobile penis (may not be the case if castrated pre-pubertally)
- Normality of preputial skin
- Might be a discharge, which can be normal in dogs
- 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)
When examining the penis, what things should we look at and observe?
- Remember normal appearance differs across the species. Body of penis might be different depending on the type of erection that may occur
- Examine the penis in the non-erect and erect state
–Normal appearance (e.g. spines in the tom-cat, should be present in intact male. Growth of spines stimulated and maintained by testosterone so would be smooth in castrated cats)
–Absence of penile-preputial adhesions
–Penile deviations
–Clinical exam can be useful
•Examine the penis in the non-erect and erect state
–Lesions of the penile skin (infection [balanitis], neoplasia)
•Examine the penis in the non-erect and erect state
–Normal even-size along penile length
–?radiographic examination
What is wrong with this bull penis?
Preputial frenulum in bull
Would cause some abnormality
What is wrong with this bull penis?
‘Cork-screw penis’ in bull (? Abnormal apical ligament?)
This animal has some banding type structure that is preventing normal elongation of the penis – causing it be in this deformed manner
What is wrong with this penis?
Corynebacteria + urine scalding and ulceration
= Pizzle Rot in ram
Significant ulceration, pyoderma in the penis associated with infections in the rams
What is wrong with this penis?
Multiple squamous cell carcinoma in gelding
What is a musculcavernous penis?
What is a fibroeleastic penis?
What is wrong with this contrast radiograph exam here?
Urethral fistula following traumatic catheterisation
Outline of bladder is smooth
Irregularity of filling of the urethra when its within the pelvis and leakage of this contrast material can be seen on dogs coat
What is wrong here?
Perineal hernia
Typical feature is that we don’t always know what is in it! Could be gut, omentum, prostate if enlarged etc.
Shows retroflexed bladder on radiograph
Dog been straining due to prostatic disease breakdown of pelvic wall musculature – significant defect and bladder pushed into this site
When we collect an ejacualte sample, what are some things we want to be looking for?
- Examination of number, motility, morphology, other cells
- Total sperm – what proportion have normal motility?
- Want to also stain the sperm to see if they have an abnormality, if they are alive or dead with the stain
What veneral pathogens are we concerned about in cattle?
What veneral pathogens are we concerned about in horses?
What veneral pathogens are we concerned about in sheep?
What veneral pathogens are we concerned about in pigs?
If we have a hypothalamus dysfunction, what happens to the rest of the axis and hormones?
If we have a pituitary dysfunction, what happens to the rest of the axis and hormones?
If we have a leydig cell dysfunction, what happens to the rest of the axis and hormones?
What are the principle causes of infertility in the male?
