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− | ==Introduction==
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− | Hyperoestrogenism is caused by '''excessive levels of oestrogen''' in the body and has different aetiologies depending on the sex of the animal.
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− | In the bitch it is usually associated with '''cystic ovaries''' or more rarely a functional ovarian tumour. These are mostly granulosa-theca cell in origin and 10-20% are malignant. It can also occur iatrogenically through the administration of oestrogens used to treat mismating and urinary incontinence.
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− | In the male dog the syndrome is associated with a [[Sertoli Cell Tumour|'''Sertoli cell tumour''']] of the testicles or a [[Male Feminising Syndrome|male feminising syndrome]] for which the cause in unknown.
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− | Hyperoestrogenism is '''very rare in cats'''.
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− | ==Clinical Signs==
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| ===Females=== | | ===Females=== |
− | Bilaterally '''symmetrical alopecia''' and '''hyperpigmentation''' of the perianal, perigenial and axillary areas, enlargement of the nipples and vulva, comedones and pyoderma, '''oestrus cycle abnormalities''' such as nymphomania and pyometra.
| + | '''''Ovarian Imbalance Type 1''''' |
− | | + | Seen in adult bitches who present with alopecia and increased pigmentation round the perianal, perigenital and axillary areas. |
| + | Caused by: |
| + | *Cystic ovaries. |
| + | *Ovarian neoplasia. |
| ===Males=== | | ===Males=== |
− | Bilaterally '''symmetrical alopecia''' and '''hyperpigmentation''', gynaecomastia, pendulous prepuce, testicular mass, prostatomegaly, '''attractiveness to other male dogs''' and loss of libido.
| + | Dogs present with bilaterally symmetric alopecia, similar hyperpigmentation to that seen with female dogs with ovarian imbalance, loss of libido and gynaecomastia. The dogs become attractive to other male dogs. |
− | | + | Caused by: |
− | ==Diagnosis==
| + | *[[Sertoli Cell Tumour|Sertoli cell tumour]]. |
− | In all cases, history and clinical signs are suggestive.
| + | *[[Male Feminising Syndrome|Male feminising syndrome]]. |
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− | Haematology and biochemistry of is usually unremarkable except where '''oestrogen-induced bone marrow suppression''' occurs, in which case a [[Regenerative and Non-Regenerative Anaemias|'''non-regenerative anaemia''']], [[thrombocytopenia]] and leucopenia are seen.
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− | Other endocrine disorders which can cause the same skin changes should be ruled out, such as [[hypothyroidism]] and [[hyperadrenocorticism]].
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− | Blood oestrogens may be elevated in some dogs, however false positive and false negative results are common.
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− | Definitive diagnosis for bitches is by '''exploratory laparotomy''' to investigate the ovaries.
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− | In male dogs a '''mass may be palpated in the testicle'''.
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− | ==Treatment==
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− | Therapy for any concurrent infections together with '''supportive care''' if oestrogen-induced myelosuppression is present (fluids and whole blood transfusion) should be provided.
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− | '''Ovariohysterectomy''' is the treatment of choice if an ovarian cyst or tumour is present.
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− | Bilateral '''castration''' is the treatment of choice for testicular tumours. Any concurrent infections of the skin or prostate gland should be assessed.
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− | Radiographs of the thorax are useful prior to surgery to '''check for any metastases''' in the case of neoplasia.
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− | ==Prognosis==
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− | Most dogs show and improvement in clinical signs within 3-6 months.
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− | ==References==
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− | Paterson, S. (2008) '''Manual of skin diseases of the dog and cat''', ''John Wiley and Sons''
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| [[Category:Endocrine System - Pathology]] | | [[Category:Endocrine System - Pathology]] |
− | [[Category:Endocrine Diseases - Dog]]
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− | [[Category:Reproductive Diseases - Dog]]
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− | [[Category:To Do - Reproductive]]
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