Canine prostate: non-neoplastic lesions

- benign prostatic hyperplasia: proliferation of prostatic epithelium associated with testosterone
- squamous metaplasia: associated with excess estrogen (e.g. Sertoli cell tumor)
- cystic hyperplasia

• usually secondary to benign prostatic hyperplasia or squamous metaplasia
• caused by obstruction of ducts that carry prostatic secretions to urethra
• results in multiple fluid-filled cavities

- paraprostatic cysts

• fluid-filled cysts adjacent to prostate
• develop from abnormal tissue that remains from embryonic development

- bacterial infection (bacterial prostatitis)

• may ascend or descend the urethra (if descending, comes from urinary bladder)
• usually associated with pre-existing prostatic abnormality

- prostatic abscess

• progression of bacterial prostatitis with accumulation of pus and abscess formation.

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Tell me about equine herpes virus 1

- an infectious agent that can induce abortion and stillbirth
- involves multifocal necrosis of lung, liver, lymphoid organs
- intranuclear viral inclusion bodies with chromatin margination are pathognomonic
- may also cause respiratory disease, fatal vasculitis, myelopathy secondary to vasculitis
- can also affect South American cammelids
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Female gonadal stromal tumors

GRANULOSA CELL TUMOR
- common in mares, but rarely malignant.
- may be solid or may involve one or more cysts.
- animal exhibits failure to cycle, visible as anestrus.
- contralateral ovary undergoes atrophy.
- 40-50% produce androgens, (result: male behavior)
- 90% produce inhibin, causing

• regression of the contralateral ovary
• lack of progesterone that results in nymphomania.

- may occur in pregnant mares.
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Abnormal gonads: hermaphrodites

- types: bilateral, unilateral, lateral.
- hypospadia: incomplete masculinization of the penis.
- confirm your diagnosis via karyotype, histopathology
- chimera: mosaic, XX (may have SRY), or unknown
- possible causes:

• congenital adrenal gland hyperplasia
• fetal exposure to sex hormones
• testicular feminization syndrome
• XY gonadal dysgenesis
• XY gonadal agenesis
• chromosomal abnormalities

- interruption of DAX-1 expression may lead to hypogonadotropic hypogonadism

- SOX 9 regulates SRY expression

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Abnormal phenotypic gender: pseudohermaphrodites

Pseudohermapthrodites may result from problems with receptors, hormones or enzymes:

• persistent paramesonepthric (Mullerian) duct syndrome involves a receptor abnormality (dogs have Mullerian Inhibiting Substance). Undescended testes are attached to uterine horns, vasa deferentia are located in uterine wall. Bilateral oviducts, complete uterus with cervix, and cranial vagina are present.

• androgen insensitivity (testicular feminization) involves deficiency or abnormality of cytosol receptors for androgen. Complete or partial failure of androgen-dependent masculinization. Wolffian system does not develop or does not develop fully. Uterus, cervix and anterior vagina regress as they do normally.

• steroid 5-alpha-reductase deficiency means that dihydrotestosterone cannot be produced; therefore closure of urethra and scrotum do not occur; also, prostate and penis fail to develop.

• adrenogenital syndrome means that a female can't make adrenal cortical steroids due to enzyme deficiencies. This results in overproduction of adrenal androgens. The female duct system is modified toward the male.

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