Canis ISSN: 2398-2942

Failure to show estrus

Synonym(s): Anestrus

Contributor(s): Carlos Pinto

Introduction

  • Prolonged anestrus following puberty, complete inactivity of ovaries.
  • Cause: ovariectomy, age, chronic administration of androgens or progestagens, hypothyroidism, delayed puberty Delayed puberty , idiopathic.
  • Signs: primary anestrus = failure to show signs of estrus >24 months of age; secondary anestrus: failure to display signs of estrus 10-18 months after a preceding estrus.

Pathogenesis

Etiology

  • Ovariohysterectomy Ovariohysterectomy.
  • Systemic abnormalities → debility, eg diabetes mellitus Diabetes mellitus , hyperadrenocorticism Hyperadrenocorticism and hypothyroidism Hypothyroidism.
  • Ovarian disorders: ovarian aplasia, progesterone-secreting cysts, auto-immune oophoritis.
  • Congenital abnormalities of sexual differentiation.
  • Drug-induced anestrus: exogenous administration of progestagens or androgens.
  • Ovulatory estrus without accompanying behavioral signs of sexual receptivity (silent heat).
  • Pregnancy.
  • Delayed puberty Delayed puberty.

Predisposing factors

General
  • See above (congenital, acquired disorders, iatrogenic).

Pathophysiology

  • Ovariectomy → lack of ovarian hormones.
  • Systemic disease may → hypothalamic-pituitary-gonadal axis abnormality Hypothalamic-pituitary-ovarian axis diagram - female.
  • Aging → ovarian senescence not clearly documented in the dog.
  • Exogenous androgens or progestogens → chronic suppression of ovarian activity.

Diagnosis

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Treatment

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Prevention

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Bouchard G F, Gross S, Ganjam V K, Younquist R S, Concannon P W, Krause G F & Reddy C S (1993) Oestrus induction in the bitch with the synthetic oestrogen diethylstilboestrol. J Repro Fertility 47, 515-516 PubMed.
  • Moses D L & Shille V M (1988) Induction of estrus in Greyhound bitches with prolonged idiopathic anestrous or with suppression of estrus after testosterone administration. JAVMA 192 (11), 1541-1544 PubMed.
  • Jeffcoate I A (1983) Endocrinology of anestrous bitches. J Repro Fertility 47, 69-76 ResearchGate.

Other sources of information

  • Johnston S D, Root-Kustritz M V, Olson P N S (2001)Canine and Feline Theriogenology.Philadelphia, W B Saunders Co.


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