Male External Genitalia - Pathology

Pathology of external genitalia

Congenital abnormalities of the penis

• Absence of penis:usually seen only as part of a major whole-body malformation.
• Micropenis:seen in bulls (malformation of sigmoid flexure). Also some dogs.
• Persistent penile frenulum:bulls and dogs. Associated with cork screw or deviation of penis.

Congenital abnormalities of the prepuce

• Absence or agenesis:may be associated with pseudo-hermaphroditism.
• Absence of preputial orifice:seen in pups.
• Phimosis:small preputial orifice, penis cannot be extruded from prepuce.
• Paraphimosis: prepuce can be drawn behind the glans but cannot return after erection).
• Hypospadias/epispadius:failure of anatomical closure of prepuce and/or urethra.

Inflammation

• Posthitis:inflammation of prepuce
• Balanitis:Inflammation of glans penis
• Balanoposthitis:usual for both to be involved

Dogs:suppuration and/or ulceration due to E. coli, Proteus or Haemophilus spp.
Bulls:IBR virus causes ulceration which may become secondarily infected.
Rams and wethers:occlusion of the urethral appendage as a result of calculi causing a necrotising lesion of the glans ± urethral rupture and subcutaneous leakage of urine.

Neoplasia

• Transmissible fibropapilloma:seen in bulls, bovine papillomavirus type 2.

Multiple luxuriant growths, painful, easily traumatised. Transmissible to females. Spontaneous regression.

• Squamous cell carcinoma:seen in geldings.

Less common in bulls and dogs, low-grade malignancy may ulcerate and haemorrhage.

• Melanoma:occurs on prepuce and scrotum of grey horses. Often benign.
• Transmissible venereal tumour:seen in dogs and bitches.
• Sarcoids:equine prepuce

Male External Genitalia - Pathology Learning Resources
Flashcards Test your knowledge using flashcard type questions	Small Animal Soft Tissue Surgery Q&A 05

Information by kind permission of Professor R W Else