Antibiotic use in pyometras

Re: Antibiotic use in pyometras

Francisco Gomez — Tue, 30 Sep 2014 17:03:34 GMT

[quote user="Birte Toft"]

Therapy : The treatment is surgery ( ovariehysterektomi ) . Perioperative antimicrobial therapy is generally not recommended (see
Otherwise separate chapter on the use of antibiotics in surgery ) .

[/quote]

Nice link, and very recent too.

Perhaps not so recent and, unfortunately, I can't give you full access for obvious legal reasons. This is the link to the abstract:

http://www.ncbi.nlm.nih.gov/pubmed/16828152

Frances O. Smith (2006) believes that

'Leukocyte inhibition in the progesterone primed uterus often supports bacterial growth.'

'The E. coli present in naturally occurring cases are also found in the
urine and feces of affected bitches [8]. It appears that
sub-clinical urinary tract infection is associated with
pyometra'

and

'Bitches that are
seriously ill should be medically stabilized with
appropriate intravenous fluid therapy and broadspectrum
antibiotics prior to surgery.'

I guess it could be argued that not all cases of pyometra need an antibiotic, but to bear in mind that the infection might not be only in the uterus.

Re: Antibiotic use in pyometras

Birte Toft — Tue, 30 Sep 2014 16:25:25 GMT

Here you go. If you can't read Norwegian, it may not be very interesting reading.

http://www.legemiddelverket.no/Veterinaermedisin/terapianbefalinger/Documents/Terapianbefaling_Antibakterielle%20midler%20hund%20og%20katt_2014_N.pdf

Norwegian vets pride themselves on their restrictions on antibiotic use, and on our low levels of antimicrobial resistance compared to much of Europe.

Google translate actually does reasonably well, here's the relevant section (on page 48):

Etiology : Caused probably a hormonal dysfunction that causes uterine secretion that accumulate in the uterus and
predisposes to ascending secondary infection of the urinary tract. The bacteria detected in 80-90 % of cases.
E. coli is the dominant agent. In middle-aged / elderly females , it usually signifies an underlying cystic endometrial hyperplasia
which means that they will have relapses at later maturity and fertility is poor.
Diagnosis : Enlarged pus -filled uterus , usually 2-4 weeks after maturity , increasing incidence with increasing age .
Patients often have polyuria and polydipsia with an elevated sedimentation rate , but the symptoms can vary. development
of the disease can be very acute.
Therapy : The treatment is surgery ( ovariehysterektomi ) . Perioperative antimicrobial therapy is generally not recommended (see
Otherwise separate chapter on the use of antibiotics in surgery ) .

Re: Antibiotic use in pyometras

Nicola Cole — Tue, 30 Sep 2014 14:36:18 GMT

Re: the earlier quote that says about a pyometra being no different to a routine bitch spay unless it ruptures- But if your bag of pus is not sterile you will have some contamination (even though you can't see it grossly) at your cervical end as you cut through -I flush the stump but always give antibiotics. Also, older, waggy-tailed Labradors may be a lot 'sicker' then they look!

Re: Antibiotic use in pyometras

Rob Loxley — Tue, 30 Sep 2014 13:39:38 GMT

[quote user="Birte Toft"]The same guidelines[/quote]

can you link to these

Re: Antibiotic use in pyometras

Hannah Wynne Richards — Tue, 30 Sep 2014 13:38:25 GMT

Francisco and Alastair. I'm 100% with you.

Wynne

Re: Antibiotic use in pyometras

Alastair Franklin — Tue, 30 Sep 2014 09:58:05 GMT

posted twice for some reason - deleted

Re: Antibiotic use in pyometras

Alastair Franklin — Tue, 30 Sep 2014 09:58:03 GMT

[quote user="Stephen Courtney"]I know pyometras are supposed to be sterile but the last few I cultured were hooching with E coli.[/quote]

I think that very few (if any) are genuinely sterile - the vast majority (all?) of true pyo's are infected (mostly with E coli, sometimes with Pasteurella, Klebsiella, Strep, etc etc). Whilst the name implies pus (which of course can be sterile), the traditional understanding of pyometra invariably implies the presence of infection. The possible exceptions to this may actually be other conditions such as mucometra or hydrometra, or potentially the sterile ones are in fact only cystic endometrial hyperplasia (whether this is a separate condition to pyometra or 2 spots along the same spectrum is up for debate).

My personal view is that all pyometras should have antibiotics (broad spectrum) at least pre/perioperatively and usually for a post-op course as well - particularly if they are systemically unwell or have a UTI (which most of them do). You are dealing with a contaminated/infected viscus, so antibiosis is indicated according to virtually all recommendations and studies. Many of these dogs may already be bacteraemic; any manipulation (inevitable) of the uterus could feasibly increase the bacteraemia.

Those that have done well without antibiotics (with a genuine pyo) are probably systemically well at the time of surgery, with a decent immune system working full time and just removing the uterus with its bacterial load is enough to permit the body to sort itself out. Risky to rely on this alone. I think it would be very hard to defend this approach if things didn't go so well.

Re: Antibiotic use in pyometras

Francisco Gomez — Tue, 30 Sep 2014 09:51:10 GMT

I would expect an open pyometra not to be sterile. And once your uterus is inflamed and infected I would guess bacterial translocation leading to peritonitis is also possible, even without uterine rupture. I'm using strong ab cover unless some1 proves me wrong

Re: Antibiotic use in pyometras

Martin Atkinson — Tue, 30 Sep 2014 09:28:35 GMT

[quote user="mariette asselbergs"]

I would think that certainly open pyos cannot possibly be sterile?

[/quote] The issue is not whether they are sterile or not but your surgery should be sterile so unless the uterus ruptures and spills its contents into the abdomen there is no reason why this should not be a sterile procedure and in any more need of antibiotics than a routine spay.

I'll admit I am playing Devils Advocate here and would probably give some antibiotic cover if the dog was sick and there was pus all over the surgical site but if you're removing the source of potential infection why do you need antibiotics?

Re: Antibiotic use in pyometras

Julian Earl — Mon, 29 Sep 2014 23:55:37 GMT

I I think routine peri-operative antibiotics are indicated for a pyometra just as one uses them for any laparotomy. I assume the original question is only related to post-operative sepsis and not about therapy of a pyometra itself? Forty-eight hours cover is plenty but flush the stump,, and all should be well.

Re: Antibiotic use in pyometras

Birte Toft — Mon, 29 Sep 2014 23:09:20 GMT

The same guidelines which claim antibiotics aren't indicated also state that 80-90% of pyometras are bacterial infections.

Re: Antibiotic use in pyometras

ChrisBVSc — Mon, 29 Sep 2014 22:12:36 GMT

I wonder what the VDS opinion would be if you didn't give antibiotics?

Re: Antibiotic use in pyometras

Sammy82 — Mon, 29 Sep 2014 22:07:26 GMT

I think as they can, but don't have to be sterile- and you won't know until the culture result is back- antibiotics are indicated.

Re: Antibiotic use in pyometras

mariette asselbergs — Mon, 29 Sep 2014 21:40:31 GMT

I would think that certainly open pyos cannot possibly be sterile?

Mariette

Re: Antibiotic use in pyometras

Stephen Courtney — Mon, 29 Sep 2014 21:38:25 GMT

I know pyometras are supposed to be sterile but the last few I cultured were hooching with E coli.

I give antibiotics, usually pre op and 4 days post.

Re: Antibiotic use in pyometras

Martin Atkinson — Mon, 29 Sep 2014 19:24:31 GMT

I had always understood that pyometras were sterile, that it is an inflammatory/toxaemic process and the pus is just a load of dead neutrophils - no bacteria have to be present. If your sterile technique is a good as for a bitch spay (which it should be) then surely there is no need for antibiotics as you've removed the big bag of pus even if my understanding was incorrect. Same logic as lancing an abscess no?

So if the bitch is clinically well I may not give antibiotics, if it was toxaemic and sick then Virginia's logic is not a bad one.

Re: Antibiotic use in pyometras

Virginia Campbell — Mon, 29 Sep 2014 14:16:34 GMT

[quote user="Matt Hilary"]

Given possibility of septicaemia I'd say antibiotics are indicated.

However long post-op courses are a bit more debatable.

[/quote]

I agree with this. Even if it is toxemic rather than septicemic, generally speaking dog has used up almost all available mature neutrophils and sitting duck for other infections.

Re: Antibiotic use in pyometras

Rob Loxley — Mon, 29 Sep 2014 13:55:51 GMT

BSAVA Protect poster says "Endometritis/Pyometra: amoxicillin/clavulanate OR trimethoprim/sulfadiazine"

[quote user="Birte Toft"]At the same time, there is a vet in another part of the country currently being rather viciously attacked on facebook over the death of a dog which wasn't given antibiotics following pyo surgery.[/quote]

I'm not sure that's the best rationale to decide upon

Re: Antibiotic use in pyometras

Hannah Wynne Richards — Mon, 29 Sep 2014 13:09:51 GMT

EXACTLY!

Wynne

Re: Antibiotic use in pyometras

Birte Toft — Mon, 29 Sep 2014 12:09:17 GMT

Am currently working my way through the Norwegian Medicines Agency's 57 pages worth of recommendations to find out when we ARE supposed to use antibiotics (in summary: hardly ever). At the same time, there is a vet in another part of the country currently being rather viciously attacked on facebook over the death of a dog which wasn't given antibiotics following pyo surgery.

Re: Antibiotic use in pyometras

Matt Hilary — Mon, 29 Sep 2014 11:24:36 GMT

Given possibility of septicaemia I'd say antibiotics are indicated.

However long post-op courses are a bit more debatable.

Re: Antibiotic use in pyometras

Hannah Wynne Richards — Mon, 29 Sep 2014 11:15:15 GMT

ps I bet these guidelines came from some university bod - and how many of you refer pyos? Evidence based medicine - I DON'T think so!

Wynne

Re: Antibiotic use in pyometras

Hannah Wynne Richards — Mon, 29 Sep 2014 11:13:23 GMT

NOT giving antibiotics in pyos is frankly bonkers. You can't properly sterilise the vaginal lining pre-op, so you're cutting into a dirty environment.

Wynne

Re: Antibiotic use in pyometras

Dagmar Steele — Mon, 29 Sep 2014 11:07:32 GMT

Being a dinosaur myself I do give antibiotics. US guidelines for abdominal operations on humans (and afaik animals) state the use of single shot antibiotics before surgery starts.