Presenter: Professor White DVM, Diplomate, ACVS University of California
The pruritic dog is one of the most common reasons for clients to seek our help, and can sometimes be a source of frustration to both vet and owner when their diagnosis and management is not always straight forward. A logical and systematic approach to working up these cases is crucial and we were privileged to have Professor White to lead last week’s veterinary webinar which provided the direction to approach cases in exactly this way.
Professor White emphasised throughout the webinar how important it is to get owners on board with any recommendations made by the vet in terms of diagnosing and managing their pet’s condition. Every client wants to know why their dog is itching and we can tell owners right from the start that it is likely to be at least one of three problems, allergies, infection and/or ecto-parasites.
We know that dogs suffering certain conditions such as allergies will have to be managed lifelong and owner compliance is key to successfully treating their pet, hence the importance of getting your client on board and keeping them there. Professor White suggested some ‘tricks of the trade’ which not only make for good practice but also demonstrate to your client the extra care you are taking with their dog’s examination. For example, he always recommends using a hand lens or otoscope when looking at skin as not only are you are more likely to find significant lesions which can be helpful in making a diagnosis, it will also be appreciated and remembered by the owner.
The importance of good history taking and physical examination was also discussed extensively by Professor White who gave many tips and hints on how to interpret certain findings. For example he interprets lesions found only on the back half of the animal as more likely to be flea related. Whereas lesions found on the front half of the animal are more likely to be associated with atopy and food allergy. As an aside, Professor White also showed pictures of popular eruptions found around the umbilicus which, previously unknown to me, are a strong indicator of fleas. Professor White also showed photos of epidermal collarettes which are always associated with bacterial infections with Staphylococcus pseudintermedius being the most common offender.
The use of the previously discussed hand lens can be particularly useful when studying papules as when one of these papules is populated by a hair shaft, folliculitis can be diagnosed and this finding is only associated with one of three condition, pyoderma, demodicosis and dermatophytosis.
Professor White also gave advice on collecting samples to confirm or rule out the presence of organisms such as ectoparasites, bacteria and yeasts. Skin scrapes were one of the diagnostic techniques discussed and it was recommended to use a medical grade spatula rather than a scalpel blade to obtain these scrapes. The spatula is preferable as it can still achieve the necessary capillary ooze of a skin scrape without terrifying both vet and client, as can be the case when a scalpel blade is being waved around the feet of a fractious dog.
The diagnosis of dermatophytosis was also discussed with Professor White reminding us that Microsporum canis is the only fungus that fluoresces apple green under a woods lamp. Alternatively Trichophyton mentagrophytes does not fluoresce and can be difficult to culture sometimes taking 2 or 3 attempts. This is an organism found in the soil and worth considering in dogs which dig a lot and present with non-pruritic hair loss over their muzzle which can spread across the face and the rest of the body. One clue to point you in the direction of dermatophytosis is, despite the entire muzzle being affected, the nasal planum is left untouched.
I have plucked just a small number of facts and tips supplied by this jam packed webinar which doesn’t even touch on the surface of information delivered by Professor White in the systematic and methodical way that we should be approaching our pruritic dogs. If at all confused or frustrated by some of the skin cases we face in practice today, of which I am one, ‘The Webinar Vet’ is where you need to be.
The Stethoscope (MRCVS