Common Diseases and Surgery in the Male Dog and Cat Flashcards
(37 cards)
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
Discuss Penile / Preputial Diseases?
In some sort of order relating to how common:
- Preputial discharge
- Lymphoid hyperplasia
- Balanoposthitis
- Posthitis
- Canine herpes virus infection
- Penile trauma
- Phimosis
- Paraphimosis
- Priapism
Discuss Preputial Discharge?
- Muco-purulent preputial discharge is normal
- A volume of discharge in an entire male is fairly normal in the castrated male the volume of discharge would be much less or absent
- Many species of aerobic bacteria are isolated
- These are usually normal commensals
- Rarely there is a pre-disposing cause such as foreign body, preputual adhesion, penile abnormality, phimosis
- Careful inspection of the inner surface of the sheath and the penile skin is warranted
- Treatment
–May be normal (don’t call it ‘abnormal’ or use antibiotic unless you are sure it is not normal)
–Removal of predisposing causes
- Flushing with saline
- (or antimicrobial or weak antiseptic solutions)
- parenteral drug administration has little value
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
