Derm | Ophtho | Repro Flashcards
Superficial necrolytic dermatitis - 2 ddx in dogs? Skin lesion distribution?
What 2 endocrinopathies are commonly associated?
What nutritional deficiency is associated?
Hepatocutaneous syndrome, glucagonoma (classic sign in people, rare in dogs)
HAC, DM
Hypoaminoacidemia. (In glucagonoma –> increased gluconeogenesis so increased AA turnover)
What disease is cutaneous phlebectasia associated with in dogs? Does it resolve with treatment?
HyperA (iatrogenic or spontaneous), reported in up to 40% dogs with spontaneous HAC.
No.
Summarize the pathogenesis of BPH.
With age:
- Increased testosterone converted within prostatic epithelial cells by 5-alpha reductase enzyme to dihydrotestosterone (DHT). DHT = main mediator of prostatic stromal/glandular growth (less estradiol-17-beta, other local GFs)
- Decr testosterone but no change in E2 > altered androgen: oestrogen ratio contributes to increased no. & sensitivity of DHT-R > prostatic glandular (cystic) hyperplasia & hypertrophy
- Predisposes to prostatic cyst formation, chronic bacterial prostatitis (cystitis, orchitis, epididymitis)
What treatments (and associated AE) are recommended for benign prostatic hyperplasia?
Castration 1st
Anti-androgen tx (not all approved in USA)
- Megestrol acetate: single SQ inj. AE: E2-mediated (squamous metaplasia of prostatic epithelium, myelosuppression, mammary neoplasia) & P4-mediated (insulin & glucose dysregulation)
- Osaterone acetate (Ypozane): structurally related to P4, inhibits 5-alpha reductase (conversion of testosterone to DHT). AE - adrenal suppression (mostly PB-4 metabolite), some P4 activity.
- Finasteride: 5-alpha reductase inhibitor > causes atrophy of prostatic glandular and stromal tissues w/o changing testosterone [ ]
- Flutamide = anti-androgen, binds to DHT-R in prostate
Deslorelin acetate (Suprelorin implant): GnRH analogue, chronic use desensitizes AP gonadotropes, decr LH & FSH
Describe the origin & roles of
- LH
- FSH
GnRH (hypothalamus) stimulates LH & FSH release from AP
LH: pulsatile release
- Stimulates Leydig cells in interstitium of testicles > testosterone production & release
FSH: constant release
- Stimulates Sertoli cells in seminiferous tubules of testicles
- Assists in spermatogenesis
- Assists in formation of E2 from testosterone
- Produces inhibin > neg feedback on AP
Serum concentrations of what enzyme correlates with histologic evidence of BPH?
Canine prostate-specific arginine esterase - ELISA assay.
May be used if other diagnostics are inconclusive or unavailable. Also useful to screen for preclinical cases of BPH for proactive preventative treatment options.
