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| + | ==Introduction== |
| + | 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== |
| ===Females=== | | ===Females=== |
− | '''''Ovarian Imbalance Type 1''''' | + | 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. |
− | Seen in adult bitches who present with alopecia and increased pigmentation round the perianal, perigenital and axillary areas.
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− | Caused by:
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− | *Cystic ovaries.
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− | *Ovarian neoplasia.
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| ===Males=== | | ===Males=== |
− | 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.
| + | Bilaterally '''symmetrical alopecia''' and '''hyperpigmentation''', gynaecomastia, pendulous prepuce, testicular mass, prostatomegaly, '''attractiveness to other male dogs''' and loss of libido. |
− | Caused by:
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− | *[[Sertoli Cell Tumour - Pathology|Sertoli cell tumour]].
| + | ==Diagnosis== |
− | *[[Male Feminising Syndrome|Male feminising syndrome]].
| + | In all cases, history and clinical signs are suggestive. |
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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== |
| + | Most dogs show and improvement in clinical signs within 3-6 months. |
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| + | ==References== |
| + | 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]] |
| + | [[Category:Reproductive Diseases - Dog]] |
| + | [[Category:To Do - Reproductive]] |