awful ears

Re: awful ears

Evelyn Barbour-Hill — Sat, 05 May 2012 23:27:44 GMT

[quote user="bob lehner"] I have been to some talks by 'experts' who have dismissed the LWR as virtually a waste of time. [/quote]

P'raps the expert wasn't very good at doing a LWR?

[quote user="bob lehner"]I would agree with Malcom that when done at the right time the LWR is a very worthwhile operation.[/quote]

Me too.

Re: awful ears

Anthony Todd — Sat, 05 May 2012 23:21:33 GMT

[quote user="John Rimmer"]within the first 48 hrs of flushing[/quote]

With what?? Not Hibitane, I hope?

And LWRs [all those cocker spaniels!] used to be the treatment of choice with chronic OE and the results, in true OE, were excellent, even when you removed the stitches after 2 days [me, the healing looked so good and I didn't check the date....] and have to restitch it all.....

Failures were mainly chronic horizontal canal infection, probably plus or because of, otitis media, and allergic otitis, you know the red, verrucose itchy ones which respond brilliantly to topical steroids either before or after the LWR.... Remember Synalar or triamcinalone topical; brilliant!

But then I'm a dinovet, I think, which, I think, is not some incomprehensible computer game, but an abbreviation for dinosaurial geriatric retired MRCVS? [I googled it]

Re: awful ears

bob lehner — Sat, 05 May 2012 15:58:59 GMT

[quote user="Malcolm Ness"]In our primary care practice, we generate remarkably few TECA cases and I believe that this reflects the way we integrate medical and surgical management of chronic otitis and a key feature of that is the relatively early use of LWR to facilitate management of chronic skin disease with ear involvement. [/quote]

I'm greatly heartened to read this. Before TECA was invented we used to do plenty of LWRs, mostly with pretty satisfactory results. In more recent years there seems to have been a marked trend away from doing them by many first opinion vets. I have been to some talks by 'experts' who have dismissed the LWR as virtually a waste of time.

The cynic might think that 'the expert' had a vested interest in gaining referral cases for TECA.

I would agree with Malcom that when done at the right time the LWR is a very worthwhile operation.

Re: awful ears

Sarah Keir — Sat, 05 May 2012 11:46:45 GMT

[quote user="Gillian Mostyn"]

[quote user="Julian Earl"]However re. food allergies, it is my understanding that dogs "have" to be on food for six months or more before allergy develops; new foods do not cause allergies.[/quote]

Didn't know that. I assume eating something to which they have already developed an allergy would result in an 'immediate' reaction though?

[/quote]

Remember most food manufacturers will change the constituents of the bag of food on a regular basis to what ever is cheapest. Remember if it says 'chicken flavour' there may only be a few percent chicken like ingredients!

Re: awful ears

Malcolm Ness — Fri, 04 May 2012 13:56:20 GMT

[quote user="Tim Browning"]I have done many LWR in pseudamonous cases with multi-resistant profiles. The opportunistic little bug (ger) hates fresh air and a good LWR will kill it and allow more effective topical applications.[/quote]

My experience too.

Re: awful ears

Tim Browning — Fri, 04 May 2012 13:53:54 GMT

I have done many LWR in pseudamonous cases with multi-resistant profiles. The opportunistic little bug (ger) hates fresh air and a good LWR will kill it and allow more effective topical applications. I have never had to progress to a TECA yet. They can be very painful as ulcerated and any medical topical treatment is problematical even if theoretically effective.

You have to a good technique with a well exposed horizontal canal that can drain and a lot of the lateral wall taken out.

It may well break down and healing delayed and require re-ops, but you get there in the end. The infection persists at the horizontal canal but is in full retreat ! I tried 10% vinegar for a while and seemed miraculous on residual infection but seemed too cheap to be true...

Re: awful ears

Malcolm Ness — Fri, 04 May 2012 10:47:16 GMT

[quote user="Mark Holmes"] I can offer LWR, a surgery I am familiar with, have good success [/quote]

Because of that and because, as you point out ,TECA is not without significant risk of complication, LWR is appropriate in such a case and TECA would be inappropriate. Regrettably, LWR is often performed too late in the progression of the disease (timely LWR improves ventilation, allows drainage and improves access for medical treatments so if it is done early on in the disease, it can halt the otherwise inevitable progression to "end-stage" ears). Once the end-stage" ear has been achieved then TECA is indicated and LWR is a waste of time. The inappropriate use of LWR the end-stage ear is reflected in the fact that some clinicians believe it generally to be a poor technique.

In our primary care practice, we generate remarkably few TECA cases and I believe that this reflects the way we integrate medical and surgical management of chronic otitis and a key feature of that is the relatively early use of LWR to facilitate management of chronic skin disease with ear involvement.

I appreciate your caution about performing TECA's yourself - while this is an operation that is well within the capabilities of a surgeon in primary care practice, it does require attention to detail, good technique and ideally some supervised instruction.

Re: awful ears

Mark Holmes — Fri, 04 May 2012 10:25:51 GMT

[quote user="Malcolm Ness"]

[quote user="Mark Holmes"]LWR or preferably TECA[/quote]

Different ops with different indications - it isn't an either/or.

[/quote]

Maybe not in your hands, I radiograph ears and where the history and radiographs suggest it is necessary offer referral for surgery where the most appropriate technique offered. However there are cases where for a variety of reasons referral isn't an option.

I don't do TECA myself so have on occasion done a LWR in an attempt to get some improvement where TECA may have been better. I don't see a problem with "I would prefer to refer your dog but as that option is not available I can offer LWR, a surgery I am familiar with, have good success and will probably result in things being better than they are currently."

I could suggest that I attempt a TECA it is probably withing my ability but I have little practical experience of that procedure. Do I perform LWR with good success, attempt TECA with its attendant complications, continue with the status quo - using mutiple chronic ab preps or advise euthanasia?

Re: awful ears

Malcolm Ness — Fri, 04 May 2012 08:49:38 GMT

[quote user="Mark Holmes"]LWR or preferably TECA[/quote]

Different ops with different indications - it isn't an either/or.

Re: awful ears

Mark Holmes — Fri, 04 May 2012 07:23:55 GMT

I have had good success with ear wicks. Derm apet has a protocol suggested by Sue Patterson which I follow and has always been successful for me. Long term LWR or preferably TECA buut would get the infection under control first.

Re: awful ears

Alet Engelbrecht — Fri, 04 May 2012 07:06:28 GMT

I appreciate the reference, I was not aware of the study and learnt something new. When necessary, I will use otomax with more confidence in future.

Re: awful ears

John Rimmer — Thu, 03 May 2012 20:48:54 GMT

[quote user="Alet Engelbrecht"]

[quote user="John Rimmer"]Gentamicin only causes ototoxicity when given systemically. Like you say, anything is contraindicated with ruptured TM - coincidence that you only saw with otomax. [/quote]

http://onlinelibrary.wiley.com/doi/10.1097/00005537-199907000-00015/abstract;jsessionid=0505D7F1F1CA8EADEC53F849C193AC92.d04t04?userIsAuthenticated=false&deniedAccessCustomisedMessage=

http://www.australianprescriber.com/upload/pdf/articles/948.pdf

http://www.cmaj.ca/content/167/1/56.full

These are human case reports and it seems the main risk factors were extending the course of treatment beyond 7 days with a tympanic membrane defect. However, the instances to which I am referring happened within the first week of treatment (1 case from a colleague within the first 48 hrs of flushing and 'filling' the ear with otomax - this was in the notes... ?dose dependant). Surely, with an ulcerated and bleeding ear there will be a significant amount of systemic absorption as well.

Coincidence? Quite possibly. I don't think my clients will like what Dr Google has to say, though.

[/quote]

...yes. But why look at human literature when a study has been done in dogs? In the below, gentamicin was instilled into the middle ear of dogs, and no ototoxicity was seen.

Am J Vet Res. 1995 Apr;56(4):532-8.

Ototoxicity assessment of a gentamicin sulfate otic preparation in dogs.

Strain GM, Merchant SR, Neer TM, Tedford BL.

Source

Department of Veterinary Physiology, Pharmacology, and Toxicology, School of Veterinary Medicine, Lousiana State University, Baton Rouge 70803, USA.

Abstract

Vestibulotoxic and ototoxic effects often are seen after long-term, high-dose systemic treatment with gentamicin, but toxic effects after topical use have not been reported in animals, to the authors' knowledge. Vestibular and auditory effects of twice daily otic gentamicin treatment for 21 days were evaluated in 10 dogs with intact tympanic membranes and in the same 10 dogs after experimental bilateral myringotomy. Each dog served as its own control; 7 drops of gentamicin sulfate (3 mg/ml in a buffered aqueous vehicle) were placed in 1 ear, and 7 drops of vehicle were placed in the opposite ear. Treatment and control ears were reversed after myringotomy. Vestibular function was evaluated daily by neurologic examination and behavioral assessment. Auditory function was evaluated twice weekly by determination of brain stem auditory evoked potentials. Gentamicin sulfate placed in the ear of clinically normal dogs with intact or ruptured tympanic membranes, in the quantities used in this study, did not induce detectable alteration of cochlear or vestibular function. Serum gentamicin concentration after 21 days of treatment was detectable in only 2 dogs and was an order of magnitude below documented toxic concentrations.

Re: awful ears

Gillian Mostyn — Thu, 03 May 2012 14:47:09 GMT

[quote user="Julian Earl"]However re. food allergies, it is my understanding that dogs "have" to be on food for six months or more before allergy develops; new foods do not cause allergies.[/quote]

Didn't know that. I assume eating something to which they have already developed an allergy would result in an 'immediate' reaction though?

Re: awful ears

Julian Earl — Thu, 03 May 2012 12:53:13 GMT

[quote user="Gillian Mostyn"]

They are outdoor, kennelled dogs so house dust mites not really an issue. Food allergies would be odd at this age with no dietary changes.

I do appreciate the input - just going through it all in my head already and not finding any straight forward solutions.

[/quote]

Not likely to be house mites then, but still could be food storage mites if they're on dry food. IME though they usually have facial dermatitis rather than aural. However re. food allergies, it is my understanding that dogs "have" to be on food for six months or more before allergy develops; new foods do not cause allergies.

Re: awful ears

Alet Engelbrecht — Thu, 03 May 2012 00:20:25 GMT

[quote user="John Rimmer"]Gentamicin only causes ototoxicity when given systemically. Like you say, anything is contraindicated with ruptured TM - coincidence that you only saw with otomax. [/quote]

http://onlinelibrary.wiley.com/doi/10.1097/00005537-199907000-00015/abstract;jsessionid=0505D7F1F1CA8EADEC53F849C193AC92.d04t04?userIsAuthenticated=false&deniedAccessCustomisedMessage=

http://www.australianprescriber.com/upload/pdf/articles/948.pdf

http://www.cmaj.ca/content/167/1/56.full

Coincidence? Quite possibly. I don't think my clients will like what Dr Google has to say, though.

Re: awful ears

Alet Engelbrecht — Wed, 02 May 2012 23:42:08 GMT

[quote user="Hannah Wynne Richards"]home-made mixture for pseudomonas ears 50/50 baytril injection and dexadreson[/quote]

A friend of mine's has 2 recipes for pseudomonas - I wrote it down when I saw her at a CPD recently:

(1) 5 ml Baytril injectable, 5 ml DMSO, 1 ml Colvasone - all mixed in 40 ml saline

(2) 10 ml Flamazine mixed in 100ml water (?not sure if sterile or tap)

I haven't yet used it myself and don't know what criteria to use to choose which recipe for which ears, but if I see her at our Dermatology Grand rounds tomorrow, I will ask again. Both her recipes are based on existing knowledge wrt pseudomonas infections (and from the other reports in this forum), but just wondering what the implications for the cascade is with home-made mixtures? (We are not currently in the UK, so the cascade does not apply in this instance. Serious lack of effective ear drops here, though.)

Re: awful ears

Rob Loxley — Wed, 02 May 2012 23:35:13 GMT

[quote user="James Laidlaw"]Gentamicin only causes ototoxicity when given systemically. How does that work exactly? Genuinely would like to know.[/quote]

If you mean how does systemic administration cause ototoxicity a quick google throws up http://www.hindawi.com/journals/ijol/2011/937861/

Or do you mean: why not if given topically?

Re: awful ears

James Laidlaw — Wed, 02 May 2012 23:21:26 GMT

John - you said: Gentamicin only causes ototoxicity when given systemically. How does that work exactly? Genuinely would like to know.

Re: awful ears

Gillian Mostyn — Wed, 02 May 2012 23:18:44 GMT

They are outdoor, kennelled dogs so house dust mites not really an issue. Food allergies would be odd at this age with no dietary changes.

I do appreciate the input - just going through it all in my head already and not finding any straight forward solutions.

Re: awful ears

Julian Earl — Wed, 02 May 2012 23:06:10 GMT

Bloods for allergens esp. storage and house mites; food trial. (I know bloods are not diagnostic of atopy per se, but on the assumption that it is an atopic dog I would do the testing.)

Re: awful ears

Gillian Mostyn — Wed, 02 May 2012 22:43:15 GMT

[quote user="Julian Earl"]Still could be atopy (or food allergy etc.).[/quote]

Absolutely. What further diagnostics would you do?

Re: awful ears

Julian Earl — Wed, 02 May 2012 22:41:56 GMT

[quote user="Gillian Mostyn"]

[quote user="Julian Earl"]The question has been addressed but not answered I think: what is the underlying disease? [/quote]

wish I knew It is 2 1/2yrs and hasn't had any problems until recently. Outdoor dog. Rest of skin on dog AOK and always has been.

[/quote]

Still could be atopy (or food allergy etc.).

Re: awful ears

Gillian Mostyn — Wed, 02 May 2012 21:49:32 GMT

The dog has already been on preds for a month, starting at 1mg/kg and then reducing - currently on 0.4mg/kg sid. I assume this is why the dog is a lot more comfortable and the whole canal is open - the vertical canal is now completely normal. Application of topicals no easier.

[quote user="Julian Earl"]The question has been addressed but not answered I think: what is the underlying disease? [/quote]

wish I knew It is 2 1/2yrs and hasn't had any problems until recently. Outdoor dog. Rest of skin on dog AOK and always has been.

[quote user="Julian Earl"] I'd eat my shirt if the pseudomonas took advantage of the lack of abs when the canal was maintained clean and dry by the preds.[/quote]

I was hoping the same. Seeing the pus and debris in there today suggests otherwise.

Re: awful ears

Julian Earl — Wed, 02 May 2012 21:16:59 GMT

[quote user="Gillian Mostyn"]

However, horizontal canal ulcerated, lots of pus and bled easily when touched by otoscope speculum. TMs intact though. I flushed them out today but I think we'll have to go for a lateral wall resection. I figure that if the vertical canal is now AOK maybe if we can get some fresh air and drainage in there, maybe it will help?

Unless there are any better ideas??

[/quote]

The question has been addressed but not answered I think: what is the underlying disease? Atopy would be at the top of the list surely and consequently, for me after years of denying their use in my cases, I stuff these dogs full of preds 1-2mg/kg in combination with sedation/cleaning and drying the ears. Topical abs are given, and I am another in the Easotic fan club. I would imagine that after a few days on preds the application might be a bit easier; if not, then wait until the dog is more comfortable, sedating again if needs be.

Now, I may be called reckless or a heathen for this, but if you've cleaned and dried the ears, got the dog on preds and still can't get drops in, I wouldn't worry too much about abs in the immediate aftermath. Why? Because if you've got the environment in the canals dry, then pseudomonas won't re-colonise after cleaning and dealing with the (presumed) atopy should control the susceptibility to secondary infection. I'd eat my shirt if the pseudomonas took advantage of the lack of abs when the canal was maintained clean and dry by the preds.

Re: awful ears

Rob Loxley — Wed, 02 May 2012 21:00:40 GMT

[quote user="John Rimmer"]Otomax has been on the market a bloody long time and resistance hasn't developed yet. [/quote]

But we see plenty of pseudomonas cases that are gentamicin resistant...? I wonder how many fewer might we see if we reserved gentamicin for 2nd line use, given that it is antibiotic use that drives resistance (correct me if I'm wrong).
Anyways, just a thought, as an extension of the same thought as to reserving FQs away from 1st line use.