Monkey (not even a monkey) at the clinic Flashcards
Owner: Mr Norton
Name: Monkey
Species: Canine
Breed: Staffordshire Bull Terrier Cross
Age: 4 years
Gender: Female Entire
Colour: Brindle
Weight (kg): 19
Review of current medical history:
In this scenario, you are a Vet at the PDSA
Monkey was seen three days ago by your colleague in the practice. At that time she had a small volume of purulent vulval discharge that had been present for 4 days.
Monkey’s temperature was 39C and she was slightly polydipsic. There was enlargement of all mammary glands and upon manipulation a small volume of milk could be expressed from the caudal teats. Otherwise Monkey was bright and well.
Your colleague had made a presumptive diagnosis of ‘vaginitis’ and had supplied a 7 day course of Amoxyclav 250mg (at four tablets twice daily). He also took a vaginal smear for cytological and bacteriological examination.
Under the microscope he identified bacteria which looked like E. coli, Staphylococcus sp. and Steptococcus sp.
Mr Norton telephoned this morning to say that he has lost the antibiotic tablets, and that he’s not going to redonate for new ones. He has requested that you write him a prescription so that he can get them online.
Write a list of differential diagnoses for vaginal discharge(6)
· Vaginitis
· Open pyometra
· Closed pyometra
· Pregnancy
· Pseudopregnancy
· Brucella canis (post abortion vaginal discharge)
What are the stages of the oestrus cycle and what types of discharge are seen at these?
· Oestrus - Clear/straw coloured discharge or haemorrhagic discharge
· Metoestrus - Mucoid discharge
· Dioestrus - No discharge commonly seen
· Proestrus - Haemorrhagic discharge
What are the differentials for a purulent vaginal discharge in the bitch? (3)
Vaginitis (Vaginitis and juvenile vaginitis both present with a purulent discharge.)
Cystitis (Cystitis typically presents with a haemorrhagic discharge)
Pyometra (Although if it was a closed pyometra you may not see a noticeable discharge) Metritis (Metritis can present with a purulent or haemorrhagic discharge)
Vaginal ulceration (Vaginal ulceration can present with a haemorrhagic discharge)
Urinary tract neoplasia (Urinary tract neoplasia can present with a haemorrhagic discharge)
What are differentials for haemorrhagic discharge in the bitch during pregnancy?
Normal pregnancy (would have a typically mucoid discharge.)
Placental separation
Abortion (may have a haemorrhagic or brown coloured discharge)
Parturition (characterised by a green/brown discharge)
What should we do next?
Ultrasound
In this case, we would want to see the image ASAP. You could provide some sedation to Monkey as she may be in discomfort and could do with some analgesia but she should stand for an abdominal ultrasound easily.
Monkey is rapidly deteriorating, she has not eaten since yesterday, she has been vomiting throughout the night and this morning is very depressed and unwilling to stand.
Your clinical examination shows:
- Temperature: 40C
- Heart rate: 120 beats per minute
- Resp rate: 32 breaths per minute
- Mucous membranes: injected
- Skin tenting: 5 seconds
Using ultrasound you have diagnosed a pyometra.
What would you expect to see on an ultrasound image that may cause you to suspect a pyometra?
Fluid present in the Uterus - Black long sections on the image
The treatment of choice for pyometra is surgical removal of the ovaries and uterus
My Norton tells you (that according to Dr Google) there is a “no poking and prodding tablet option” for monkey instead of surgery, that would be much safer and she could still “keep her bits”. What do you respond?
In Monkey’s case medical treatment is unfortunately not an option. Treatment of pyometra is prompt removal of the uterus and ovaries (ovariohysterectomy); in more stable patients medical treatment is possible using a variety of products where the aim is to end the luteal phase (since the condition is essentially ‘driven’ by progesterone) and to cause dilation of the cervix and to promote uterine contractions in an attempt to encourage drainage of pus from the uterus. The current state of Monkey warrants a surgical approach as she is deteriorating rapidly, likely due to toxaemia. Ideally you want to encourage Mr Norton that removing the uterus is the best idea for Monkey and educate him that this condition will likely happen again if you do not remove it.
Medical treatment is possible in an open pyometra because the pus is draining but is not a plausible option if it is a closed pyometra (cervix is closed).
Mr Norton appears satisfied with your answer and understands surgery is crucial in this case. What would you like to tell Mr Norton prior to Monkey’s surgery?
Inform owner that with every anaesthetic there is a small risk that the patient will die, and although small it is still very important to inform the owner. You also need to get a signed consent form. The patient will need routine monitoring and there is a chance she may have to stay in overnight or moved to an overnight facility which the owner will have to move the animal to. There could also be a risk of post op complications. Finally the animal may have to keep up pain relief +/- antibiotics whilst at home so the owner needs to be informed and able to give this treatment.
Which bacteria are commonly cultured in pyometra (Note – there may be more than one correct answer)?
E. coli - correct
Staphylococcus spp - correct
Streptococcus spp - correct
You opt for a broad spectrum antibiotic - clavulanic acid-potentiated amoxycillin.
To gauge more information on Monkey’s condition prior to surgery, you take a blood sample
You identify the following;
High lactate –often indicating poor peripheral perfusion and metabolic acidosis
Hypokalaemia (low potassium)
Azotemia (raised urea, creatinine)
Neutrophilia/band neutrophils and changes on blood smear.
- These are due to SIRS (systemic inflammatory response syndrome) secondary to E.coli sepsis.
Treatment options for the following identified on the blood results are?
Metabolic (lactic) acidosis: A frequent finding which should resolve following restoration of tissue perfusion using fluid therapy; the use of bicarbonate is rarely if ever required.
Hypokalaemia: Appropriate addition of potassium to the intravenous fluids is often required in these cases, refer to BSAVA Formulary. If not supplemented, hypokalaemia will get worse once fluid therapy has started due to enhanced renal excretion of potassium with increased urine output
Raised amylase and lipase: These are not significant. Both are renally excreted and therefore increase in dehydration when renal excretion is compromised. The more specific test for pancreatitis (cPLI) is reassuringly normal
Changes in liver enzymes: A number of complications may occur in patients with pyometra. Increased liver enzymes (secondary to sepsis/endotoxaemia or poor hepatic perfusion associated with hypovolaemia) are common but usually return to normal rapidly following removal of the uterus and restoration of fluid and electrolyte balance.
A non-regenerative normochromic anaemia: May also develop due to mild bone marrow suppression from pyometra, blood loss at surgery and high volumes of fluid replacement therapy. Blood transfusion is rarely indicated, unless the packed cell volume (PCV) decreases below 20% and parameters such as HR, pulse
Your boss pops his head around the door on his way to lunch. He yells at you - “Don’t forget to do a urinalysis and a blood pressure reading!”
Why is urinalysis important in this case?
In a patient that is urinating we use urine SG to differentiate between pre renal azotaemia (ie dehydration) and renal azotaemia
A low urine SG would be more difficult to interpret because there are two possibilities: Endotoxaemia associated with E coli (pyometra) is having a reversible effect on the urine concentrating mechanism. This is one of the main reasons for polydipsia and polyuria in pyometra cases. In this case the azotaemia is still pre renal (due to dehydration) but the kidneys are unable to conserve water due to secondary effects of the endotoxaemia. This is reversible and therefore has no impact on a decision to operate.
Or this dog could have chronic kidney disease. The clinical signs of pyometra and chronic renal failure are similar but usually more short term and sudden in onset. Many owners would not want to consider surgery if there was a strong suspicion of pre-existing chronic kidney disease.
A sick diabetic (eg a dog with diabetes and pyometra) is very likely to have diabetic ketoacidosis which would also complicate stabilisation for surgery and significantly increase anaesthetic and surgical risk. It is therefore important to check blood or urine glucose to rule out significant hyperglycaemia and/or glucosuria before surgery as this may affect the owners decision to proceed.
Why is blood pressure monitoring important in this case?
Blood pressure of these patients is worth monitoring at presentation and during stabilization and anaesthesia. A GA and stages of the surgery (e.g pulling on the ovaries) can cause the BP to fluctuate, so should be monitored throughout. A decrease in BP can affect the blood supply to the kidneys, resulting in damage. Monitoring can be performed using indirect external methods (Doppler, oscillometric techniques) or by percutaneous direct measurement (cannulation of an artery). Mean blood pressure should be maintained above 60–80 mmHg.
You decide on stabilising Monkey using fluid therapy. Why is fluid therapy indicated? What is contributing to the dehydration?
Vomiting contributes to fluid, electrolyte and acid–base distrubances. Intravenous fluid therapy is therefore mandatory.
Restoring fluid balance and supporting kidney function allows the kidneys to correct the acid-base and electrolyte abnormalities. Dehydration causes pre renal azotaemia. Contributing factors to dehydration include:
- polyuria due to endotoxaemia
- fluid accumulation in the uterus
- vomiting due to endotoxaemia +/- abdominal pain
- poor appetite
- inadequate compensatory polydipsia due to debilitated state
What kind of fluids would you like to choose and at what rate?
- Hartmann’s (Choose a balanced electrolyte to restore intravascular volume and allow any acid–base and electrolyte imbalance to be corrected)
- Initial 90ml/kg hour bolus (The volume of boluses in SA fluid therapy is under discussion, to avoid the risk of overloading fluids; many regimes now advise 15-20mls/kg every 15 minutes up to the maximum of 90mls/kg in the first hour.)
- 2-3x maintenance (She may require a bolus initially to stabilise)
Supported by your thorough pre-operative planning and helpful team of nurses you start the surgery.
You remember the tips your collegue gave you:
- Make a large incision – at least from the umbilicus, half-way to the pubis (to allow exteriorisation of the uterus without excessive tension or trauma)
- Use abdominal retractors to improve exposure of the site
- Ask a nurse or student to scrub in. An extra pair of hands is invaluable!
