One of the pleasures of having completed my dermatology certificate is that I get to peer down a microscope at cytology preps a fair amount.
Now, if you’re anything like me, you’ll have become frustrated with Diff-Quik preps (particularly if you are using tape strips and all three solutions) as the strip becomes soggy and opaque, making it hard to examine.
A handy tip I learned from a specialist dermatologist working in the States was to just use the blue/purple stain, pop a drop onto a slide and then stick your strip over the liquid and slide. Leave this a few minutes and examine as usual.
This is quick and allows easy identification of cocci and yeast microorganisms under the microscope.
However if it’s cells you’re interested in – in, say, suspected cases of pustular disease – I’d suggest you still go through the full staining process.
I do a fair amount of dermatology in our practice, so I use the microscope on a regular basis. I recently came across these top tips to keep your microscope in good working order, so thought I’d share them.
Keep the scope clean. Twice-daily cleaning is ideal – along with cleaning whenever the scope is used. In addition, it’s helpful to have the scope professionally cleaned and lubricated once or twice a year. It will make a huge difference in the functionality of your instrument.
Keep the scope covered when not in use. All hospitals tend to be dusty and have hair floating about, which can damage the scope.
Use a different microscope for faecal examinations. Faecal solutions (sugars, salt solutions, etc) are quite caustic if they come in contact with the microscope lens or get “spilled” onto the slide platform.
Adjust the scope (at least once daily) for Köhler illumination. This will help to “focus” your scope for use.
However, after reading through these, I realise it’s a case of “doing what I say and not what I do” – so I’m off to give the microscope a good clean!
References
Noxon J O (2015). Cytology and Cultures Successful Tips and Techniques to try tomorrow, Small Animal and Exotics Proceedings of the North American Veterinary Conference, Gainesville, Florida.
This one’s a little controversial, but some evidence exists that taking swabs for culture from cases of otitis externa can lead to poor reproducibility.
Swabs taken from the same ear may produce different isolates, and even when the isolates agree, they may have different (antibiotic) susceptibility patterns (Bloom, 2015; Graham-Mize et al, 2004; and Schick, 2007).
Bloom (2015), therefore, suggested using rational topical therapy based on cytological findings was more valuable than using bacterial culture and sensitivity. He also only advised repeat cytology if the ear was not clinically resolving or neutrophils and bacteria were present on initial cytology.
He only takes culture and sensitivity where rods are found on cytology, there are proliferative changes and the ear is responding poorly to therapy – a rare set of circumstances in Paul Bloom’s experience.
This approach was supported by a study in which the authors evaluated whether any correlation was noted between topical antibiotic selection, in vitro bacterial antibiotic sensitivity, and clinical response in 17 cases of canine otitis externa complicated by Pseudomonas aeruginosa (Robson et al, 2010).
VIDEO: How to properly swab an ear for aural cytology (source: YouTube).
References
Bloom P B (2015). Diagnosis of Otitis Externa in the Real World, Proceedings of the North American Veterinary Conference, Orlando, Florida: 944-953.
Graham-Mize C A and Rosser E J Jr (2004). Comparison of microbial isolates and susceptibility patterns from the external ear canal of dogs with otitis externa, J Am Anim Hosp Assoc40(2): 102-108.
Robson D C, Burton G G and Basset R J (2010). Correlation between topical antibiotic selection, in vitro bacterial antibiotic sensitivity and clinical response in 17 cases of canine otitis externa complicated by Pseudomonas aeruginosa, (Abst). In 25th Proceedings of the North American Veterinary Dermatology Forum, 2010: 245.
Schick A E, Angus J C and Coyner K S (2007). Variability of laboratory identification and antibiotic susceptibility reporting of Pseudomonas spp isolates from dogs with chronic otitis externa, Vet Dermatol18(2): 120-126.
Demodex gatoi is an unusual cause of pruritus in cats, but given the challenging nature of establishing a diagnosis in cats (Hobi et al, 2011) it is well worth ruling out this parasite as a possible cause (Moriello, 2015).
Karen Moriello reports finding this more oval, rather than cigar-shaped, form of Demodex more frequently in faeces (by faecal flotation) than on skin scrapes due to the cat grooming and ingesting the mite.
The good news is that, if we do find the mite, it is possible to treat (off licence) with Advocate Cat once weekly for six weeks.
References
Hobi S, Linek M, Marignac G et al (2011). Clinical characteristics and causes of pruritus in cats: a multicenter study on feline hypersensitivity associated dermatoses,Vet Dermatol, 2011.
Moriello, K.A. (2015). Itchy Cats: Evidence Based Diagnosis and Treatment, North American Veterinary Conference, Orlando 2015.
If I am being perfectly honest, dentistry has never filled me with excitement.
That said, attending a number of sessions on dentistry at the North American Veterinary Conference this year was fascinating and convinced me of the value of buying a dental x-ray machine.
Goldstein (2015), to name but one speaker, evaluated the use of radiography in assessing dental conditions in cats and convinced me of the need.
In another talk the value in assessing canine lesions was discussed (Lewis, 2015) – definitely something to bring up at our practice’s next clinical effectiveness meeting.
References
Goldstein, G.S. (2015). Dental pathology case presentations, clinical and radiology: interactice discussion of what’s new, North American Veterinary Conference, Orlando 2015.
Lewis, J.R. (2015). Interpreting canine dental radiographs: learning what you were never taught, North American Veterinary Conference, Orlando 2015.
Have you ever wondered how easy (or not) it is for our clients to administer prescription topical ear therapy to their companions?
I would suggest this may be further complicated by data sheets that provide instructions such as “apply 8 drops once daily”.
Paul Bloom at the North American Veterinary Conference advocated filling the ear with topical medication at the prescribed number of times daily to address the risk of treatment errors leading to the exacerbation of perpetuating factors (Bloom, 2015).
Reference
Bloom, P.B (2015) Diagnosis of Otitis Externa in the Real World, Proceedings of the North American Veterinary Conference, Orlando, 2015.
I had the privilege of attending the North American Veterinary Community Conference in January. The experience provided me with a number of top tips, which I thought I would pass on to you in the coming few weeks.
For those of you who are skeptical of the role professional experience plays in establishing evidence, many authors accept that not all evidence is derived from academic sources, for example, Schon (1984) and Bolton (2000) to name just two. I have still included reference to the appropriate sessions to keep those of you happy.
Have you ever pondered when treating cases of diarrhoea with an infectious origin as to whether there is any point in using a probiotic at the same time as a course of antibiotics? Well yes, you can.
I attended a joint session hosted by Mike Lappin and Stan Marks. Although it is not possible to say definitively for all probiotics and all antibiotics, Dr Lappin has conducted work to show the strains in Purina Fortiflora are unaffected by metronidazole at doses up to 20mg/kg. Good to have this confirmed, as this is a strategy I often use.
References
Lappin M and Marks S (2015). Quench the Stench: Strategies for Control of Diarrhea, North American Veterinary Conference, Orlando 2015.
Bolton G (2000). Reflective Practice: Writing and Professional Development, Paul Chapman Publishing, London.
Schon D (1984). The Reflective Practitioner: How Professionals Think in Practice, Basic Books.
It occurred to me the other day I hadn’t seen an aural haematoma for some time. Saying that, I now expect three to come along in Monday-morning surgery.
I also recall a time when we immediately resorted to surgery as the primary treatment. However, lately we have drained the ear and injected dexamethasone into the space. If you do this, though, it is vital to inform the owner the ear will swell up again post-draining, but will resolve over the following week or so.
As long as we are treating any concurrent otitis externa (if present), I have found this a very effective means of treatment and very valuable in elderly patients with co-morbidities.
Greg Martinez DVM drains, injects and wraps an aural haematoma (source: YouTube).
Note: Greg uses cortisone rather than dexamethasone.
We routinely audit postoperative complications for our canine neutering surgery.
Over time, it became clear we were seeing a few castration wounds come back in where the dog had licked both the wound and surrounding area, making it sore to the extent it was delaying healing. In some cases, additional treatment was required.
We then wondered to what extent non-absorbable skin sutures were playing a role. Making the change to using absorbable skin sutures reduced our complication rate significantly – nuff said!
How to bury knots at the start and finish of a subcutaneous suture. Video by John Inns via YouTube
A very itchy, erythematous young boxer with very sore ears came in to my consult room.
A normally very docile chap, it really resented having topical treatments applied to its ear canals.
It turned out he was passing stools three to four times a day (two is more normal) and showed signs of gastrointestinal disturbance on an intermittent basis.
Thinking we were heading in the direction of atopic disease, I instigated a food trial, with my personal favourite, Purina HA. Three weeks later, we had a different (much better) dog.
Amazing – particularly given only 25% of cases respond within the first three weeks of a trial. Now I have to persuade the owners we should do a re-challenge to confirm our diagnosis.
