Common Diseases and Surgery in the Male Dog and Cat Flashcards
Larry is presented to you because he has missed the last 4 bitches he was mated to
Semen collection shows large number of abnormal sperm
What does the ultrasound image show?
Ultrasound of testicle showing hyperechoic regions usually should only see linear mediastinal testes as the only echogenic structures.
These testicles were small as well.
Hyperechoic regions could be areas of fibrosis or calcification or both.
Some substantial pathology throughout the testicle.
Two small testes with areas of fibrosis/calcification would assume there had been a previous insult and now has caused a chronic change
This dog has a condition called testicular degeneration
What Normal Expectations of Fertility are there?
When a fertile dog mates a fertile bitch at the correct stage of the oestrus cycle a conception rate of greater than 90% should be expected
What factors effect fertility?
Factors affecting fertility
–Age
–Breed (Irish wolfhound poor fertility due to small gene pool in that breed)
–Management
–Reproductive Tract Pathology
–(Infection)
Discuss mating problems caused by poor libido?
Poor Libido
- Frequently results from inexperience or poor breeding management
- No evidence that it is caused by low plasma testosterone
- Do not give androgens!
Discuss mating problems associated with mating difficulty?
Mating Difficulty
- Inexperienced stud dog
- Psychological problems
- Abnormal prepuce or penis
- (Inexperienced bitch)
- (Incorrect mating time)
- (Abnormal vulval, vagina)
- (Male-female size differences)
What can be seen here?
Bull mastiff with multiple lesions: prolapse of urethra, fibrous band between prepuce and tip of penis and deformed penis due to this.
What are Common Testicular / Scrotal Diseases?
In some sort of order relating to how common:
- Testicular tumours
- Abnormal testicular descent
- Torsion of the Spermatic Cord
- Orchitis
- Inguinal hernia
- Testicular degeneration
Discuss testicular tumours?
•Three common tumour types:
–Leydig Cell Tumour
–Sertoli Cell Tumour
–Seminoma
- May, or may not, be endocrinologically active
- May, or may not, cause testicular enlargement
- May, or may not, metastasise
- Diagnosis by palpation and ultrasound examination
Discuss diagnosis and treatment of testicular tumours?
Oestrogen production = feminisation:
–preputial swelling
–male attractiveness
–bilaterally symmetrical non-pruritic alopecia
–non-neoplastic testicle atrophies
–normal testicular tissue within abnormal testicle also atrophies
Diagnosis
–Clinical information, palpation, ultrasonography
Treatment
–Hemi-castration or castration
Why might there be one or no testes in scrotum?
Previously Castrated
- Previous history
- Diagnosis by lack of response of testosterone to intravenous injection of hCG
Anorchid
- Absence of both testes extremely rare
- Most cases are bilateral cryptorchid
- Diagnosis by lack of response of testosterone to intravenous injection of hCG
Monorchid
- A single testicle in the body is extremely rare
- Most cases are unilateral cryptorchid
- Diagnosis by lack of response of testosterone to intravenous injection of hCG
What is Cryptorchidism?
- Hidden testicle - unilateral or bilateral
- Testes normally descend by 10 days after birth
- Cryptorchidism is likely to be sex-limited autosomal recessive trait:
–Female and male parents are carriers homozygous males will be cryptorchid
•The retained abdominal testes is more likely to become neoplastic
What is the treatment for cryptorchidism?
Medical therapy is not ethical:
The retained abdominal testes is more likely to become neoplastic
–Treatment is by removal of both testes to prevent neoplasia and breeding
–Surgical approach is to look dorsal to bladder for vas deferens
Discuss Torsion of the Spermatic Cord?
- Rotation of the testes around the vertical axis
- Aetiology unknown
- Causes occlusion of the pampiniform plexus = massive swelling and necrosis of testis
- Subsequent swelling of the scrotum and significant self trauma
Differential diagnoses for torsion of the spermatic cord include:
–Orchitis
–Strangulated Inguinal Hernia
–Testicular Haematoma
What is the treatment for torsion of the spermatic cord?
- Prompt surgical removal is essential
- Subsequent risk of testicular degeneration in contralateral testis
What is orchitis?
- Commonly seen in cats
- Traumatic (most common) or non-traumatic (haematogenous) in origin
- Complicated by infection and haemorrhage
- May be significant swelling and self-trauma
- Treatment depends upon clinical appearance but may include local debridement, systemic antibiotics, castration etc
- Significance is that often results in secondary testicular degeneration
Discuss inguinal hernias?
- Non-traumatic (most common) or traumatic
- Incarcerated or non-incarcerated
–Fat/omentum or small intestinal
- Incarcerated with devitalised bowel present as rapid painful swelling, depressed, collapsed, peritonitis etc
- Differential diagnosis other causes of chronic or acute scrotal swelling. More common in stallion and covered in Week 5
- Treatment is surgical exploration, resection, repositioning and closure of the inguinal canal
(Also occurs in female sometimes with uterine entrapment (asymptomatic or may occur with pregnancy or pyometra)
What is Testicular
Degeneration?
- Testes develops normally and has normal functional but following an ‘insult’, fibrosis and degeneration occur
- This may take several months during which time semen quality deteriorates
- Often the ‘insult’ was not recognised by owner
–High temperature / Local inflammation (e.g scrotal dermatitis)
–Vascular lesions
–Drugs
–Endogenous hormones (tumours)
–Exogenous hormones
–Toxins
–Auto-immune disease
What is Lymphoid Hyperplasia?
- Found in a very large number of dogs
- Raised nodule-like lesions on at the base of the penis, or preputial lining
- Normally pale in colour and firm (not vesicular)
- May bleed when prepuce is retracted or semen collected or at normal mating
- Requires no treatment
- Must be differentiated from Canine Herpes Virus lesions which are normally vesicular and red in colour or may be ulcerated in the later stage
What is Balanoposthitis?
- Inflammation of the prepuce (and penis)
- Usually associated with moist prepuce tip
- Overgrowth of commensal bacteria
- Commonly seen in dogs that frequently lick the prepuce (therefore common in dogs with a ‘normal’ prepuce discharge)
- May require topical cleaning / local antiseptic / topical antibiotic creams / systemic antibiotics
What is Posthitis?
- Inflammation of the penis
- Noted as haemorrhagic spots on the penile skin
- May progress to thickening penile skin
- May be associated with masturbation or sometimes with balanitis
- Seen in some cases with phimosis and urine retention within prepuce
Discuss Canine Herpes Virus
Infection?
- May cause raised nodular / vesicular / ulcerative lesions on the penis and sheath and vagina of bitch
- Lesions should not be confused with lymphoid hyperplasia
- No treatment except conservative management but important to recognise the venereal pathogenicity and remove from breeding programme
Discuss penile Trauma?
- Trauma may follow a number of insults from bites, jumping fences, to injuries at the time of mating
- Each injury requires its own careful inspection
- May consider radiography
- May consider urethroscopy
- Most importantly need to ensure that the male can urinate and retract the penis (if not is should be replaced into the sheath and held in place with sutures)
- PIC: GSD trauma to penis, devitalised black penis this dog had an elastic band put around it’s penis
Discuss Phimosis?
- Abnormally small preputial orifice which may result in accumulation of urine in sheath
- Congenital or the result of trauma or inflammation
- Signs
–narrow stream of urine
–urine pooling within prepuce
–may cause balanoposthitis
–unable to copulate
•Preputical wedge resection is normally curative
What is Paraphimosis?
- Failure of the glans penis to be retracted fully into the prepuce
- Causes
–Small preputial orifice
–Inversion of the preputial skin / hair
–Hair ring (tom cat)
–Short prepuce
- Penis may become dry and necrotic
- Treatment
–Ensure that there is ability to urinate
–According to cause
- Prepucial wedge resection
- Removal of hair
- Preputial advancement
- Penile amputation
What is Priapism?
- Persistent enlargement of the penis in the absence of sexual excitement
- Causes
–May actually be sexual excitement (common)
–Neurogenic abnormalities [eg. lumbar spinal lesions or lumbosaccral disease] (not common)
- Myelography is often necessary for accurate diagnosis
- Treatment
–Management using progestogens often successful
–May require neurological referral
When is Scrotal Ablation performed?
- Occasionally performed with routine castration when there is concurrent scrotal disease
- May be performed when there is scrotal haemorrhage following castration (but in my view this is better to treat conservatively)
- May be performed when there is scrotal and testicular injury
- Technique
–Elliptical incision made around scrotal base
–Dissect subcut tissue, separate testes within tunic
–Undertake closed castration
–Transect fascia and close
–Close skin routinely
Discuss treatment of Persistent Penile Frenulum?
- Simple transection under GA
- Ligation is usually not required
What is a Preputial Wedge Resection and when is it used?
- Commonly performed for the management of phimosis and paraphimosis
- Insert blunt scissors into preputial orrifice whilst stretching prepuce forwards
- Cut caudally in ventral midline to an extent that allows protrusion of the penis
- Co-apt the mucosa to the skin on each side using simple interupted sutures
- Elizabethan collar
Discuss Penile Amputation?
- For the treatment of paraphimosis, occasionally for priapism and for short prepuce syndrome
- Catheterise urethra with large bore catheter
- Reflect prepuce and tie a tight ligature around penile base as tourniquet
- Make V-shape incision on ventral aspect of penis, blunt dissect urethra out of os penis and ensure 1cm length of urethra before transecting
- Cut os penis and then continue skin incision in V-shape dorsally
- Close V-incisions and suture the urethra in a splayed manner over the stump
- Honey is a 5 year old French Bulldog who was given Regumate from day 25-60 of pregnancy because she had a brown-coloured vulval discharge.
- 7 pups were born; 4 look like that on the left and have scrotal testes, 3 look like that on the right and have no testes.
- What’s going on here?
If you give regumate (progesterone) when they already have normal progesterone you get masculinisation of female fetuses.
