Changes

==Aetiology==

==Aetiology==

The condition develops in the presence of '''[[Ovaries Endocrine Function - Anatomy & Physiology|progesterone]]''' - which stimulates '''endometrial growth, the development of [[Endometrial Hyperplasia|cystic endometrial hyperplasia]]''' and '''uterine secretion''', '''suppresses myometrial activity''' and causes '''immunosuppression''', producing an the ideal environment for bacterial overgrowth. Therefore pyometra is most likely to occur in the '''[[Oestrous Cycle - Anatomy & Physiology|early luteal phase]]''' when [[Ovaries Endocrine Function - Anatomy & Physiology|progesterone]] levels are at their highest, or following administration of '''[[Oestrous Cycle Pharmacological Manipulation - Anatomy & Physiology|exogenous progesterone or oestrogen products]]''' (which increase the effects of progesterone) that delay oestrus or prevent conception.   

The condition develops in the presence of '''[[Ovaries Endocrine Function - Anatomy & Physiology|progesterone]]''' - which stimulates '''endometrial growth, the development of [[Endometrial Hyperplasia|cystic endometrial hyperplasia]]''' and '''uterine secretion''', '''suppresses myometrial activity''' and causes '''immunosuppression''', producing an ideal environment for bacterial overgrowth. Therefore pyometra is most likely to occur in the '''[[Oestrous Cycle - Anatomy & Physiology|early luteal phase]]''' when progesterone levels are at their highest, or following administration of '''[[Oestrous Cycle Pharmacological Manipulation - Anatomy & Physiology|exogenous progesterone or oestrogen products]]''' (which increase the effects of progesterone) that delay oestrus or prevent conception.   

The causative organisms are normally '''''[[Escherichia coli|E. coli]]''''' or '''''[[Staphylococcus species - Introduction|Staphylococcus sp.]]''''' but many bacteria may cause the infection. Bacteria normally enters the uterus by [[Uterus - Inflammatory Pathology|ascending infection]].

The causative organisms are normally '''''[[Escherichia coli|E. coli]]''''' or '''''[[Staphylococcus species - Introduction|Staphylococcus sp.]]''''' but many bacteria may cause the infection. Bacteria normally enters the uterus by [[Uterus - Inflammatory Pathology|ascending infection]].

Although '''history and clinical signs''' may be very suggestive of pyometra, definitive diagnosis is achieved by '''ultrasound'''. This should reveal a '''distended, fluid-filled uterus''' with variable echogenicity (signs will be less severe with open pyometra). Alternatively '''radiography''' can be performed - this should show a '''soft tissue opacity in the caudal abdomen''', but it is hard to differentiate from pregnancy, pseudopregancy and other conditions affecting the uterus on the basis of these radiographic signs (so findings should be combined with the history and clinical signs).   

Although '''history and clinical signs''' may be very suggestive of pyometra, definitive diagnosis is achieved by '''ultrasound'''. This should reveal a '''distended, fluid-filled uterus''' with variable echogenicity (signs will be less severe with open pyometra). Alternatively '''radiography''' can be performed - this should show a '''soft tissue opacity in the caudal abdomen''', but it is hard to differentiate from pregnancy, pseudopregancy and other conditions affecting the uterus on the basis of these radiographic signs (so findings should be combined with the history and clinical signs).   

'''Haematology and biochemistry''' normally show '''[[Neutrophilia|neutrophilia]]''' with a left shift, [[Dehydration|dehydration]], mild normocytic, normochromic non-regenerative''' [[Anaemia|anaemia]]''' and sometimes [[Azotaemia|azotaemia]] and hyperproteinaemia. '''Urinanalysis''' can show '''isosthenuria''' (caused by a reduced sensitivity to ADH or renal dysfunction), '''proteinurea''' (caused by membrano-proliferative glomerulonephritis) or evidence of a urinary tract '''infection'''. As well as providing information about the physiological status of the animal, these tests help rule out any other causes of the clinical signs.  

'''Haematology and biochemistry''' normally show '''[[Neutrophilia|neutrophilia]]''' with a left shift, [[Dehydration|dehydration]], mild normocytic, normochromic non-regenerative''' [[Regenerative and Non-Regenerative Anaemias|anaemia]]''' and sometimes [[Azotaemia|azotaemia]] and hyperproteinaemia. '''Urinanalysis''' can show '''isosthenuria''' (caused by a reduced sensitivity to [[ADH]] or renal dysfunction), '''proteinurea''' (caused by membrano-proliferative [[glomerulonephritis]]) or evidence of a urinary tract '''infection'''. As well as providing information about the physiological status of the animal, these tests help rule out any other causes of the clinical signs.  

'''Vaginal cytology''' can be performed if vaginal discharge is present.  

'''Vaginal cytology''' can be performed if vaginal discharge is present.  

'''Curative treatment is ovariohysterectomy'''. The animal should be '''stabilised''' prior to surgery.  

'''Curative treatment is ovariohysterectomy'''. The animal should be '''stabilised''' prior to surgery.  

The uterus may be very '''distended, congested and friable''' if the pyometra is closed. Therefore care should be taken not to rupture the uterus and it should be '''packed off''' with moist swabs to minimise contamination should spillage occur. Perioperative '''[[Antibiotics|antibiotic]]''' treatment  with a product such as '''[[Penicillins|amoxicillin clavulanate]]''' (broad spectrum) is recommended. If the uterus does rupture it is necessary to '''lavage''' the abdomen copiously, take a '''swab for culture''' and treat prophylactically with '''antibiotics''' post-operatively. Any animals with evidence of '''sepsis''' should also be treated with broad spectrum antibiotics postoperatively. There is a greater risk of '''[[Haemorrhage|haemorrhage]]''' in cases of pyometra when compared to standard ovariohysterectomy as the uterus is more vascular, therefore accurate haemostasis is essential.  

The uterus may be very '''distended, congested and friable''' if the pyometra is closed. Therefore care should be taken not to rupture the uterus and it should be '''packed off''' with moist swabs to minimise contamination should spillage occur. Perioperative '''[[Antibiotics|antibiotic]]''' treatment  with a product such as '''[[Penicillins|amoxicillin clavulanate]]''' (broad spectrum) is recommended. If the uterus does rupture it is necessary to '''lavage''' the abdomen copiously, take a '''swab for culture''' and treat prophylactically with '''antibiotics''' post-operatively. Any animals with evidence of '''sepsis''' should also be treated with broad spectrum antibiotics postoperatively. There is a greater risk of '''[[Haemorrhage|haemorrhage]]''' in cases of pyometra when compared to standard ovariohysterectomy as the uterus is more vascular, therefore accurate haemostasis is essential.  

On the owners insistence, '''broad spectrum [[Antibiotics|antibiotics]] (such as [[Potentiated-Sulphonamides|potentiated sulphonamides]]) and [[Oestrous Cycle Pharmacological Manipulation - Anatomy & Physiology|prostaglandins (PGF2)]]''' may be used to treat the condition '''medically'''. In some cases (particularly closed pyometra) the clinical signs are too severe to consider this option. There is always a risk of recurrence with medical treatment therefore it should not be encouraged.  

On the owners insistence, '''broad spectrum [[Antibiotics|antibiotics]] (such as [[Potentiated-Sulphonamides|potentiated sulphonamides]]) and [[Oestrous Cycle Pharmacological Manipulation - Anatomy & Physiology|prostaglandins (PGF2)]]''' may be used to treat the condition '''medically'''. In some cases (particularly closed pyometra) the clinical signs are too severe to consider this option. There is always a risk of recurrence with medical treatment therefore it should not be encouraged.  

 

[[Category:To Do - Reproductive]]

[[Category:Reproductive Diseases - Dog]]

[[Category:Uterus - Pathology]]

[[Category:Uterus - Pathology]]

[[Category: To Do - Siobhan Brade]]

[[Category:Reproductive Diseases - Cat]]

[[Category:To Do - Manson review]]

[[Category:Expert Review - Small Animal]]