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Tag: pruritus

  • Immunotherapy in cats

    Immunotherapy in cats

    Although “off-licence”, immunotherapy is well worth considering in our pruritic feline friends.

    Feline head pruritus secondary to food allergy
    Feline head pruritus, a result of food allergy. Image by Caroldermoid. Licensed under CC BY-SA 3.0 via Wikimedia Commons.

    Of course we need to rule out all other causes of pruritus first:

    • Ectoparasites: As well as all the usual suspects, don’t forget Demodex can occasionally cause ventral alopecia and pruritus (that’s the funny flat form, not the cigar shaped one).
    • Food allergies: Let’s face it, food allergy is tricky to pursue in cats – and if they have a partly outdoor lifestyle, hypoallergenic diets are of not of any use.

    Case study

    I recently saw a case that had typical excoriation lesions around the head and neck.

    The owner was able to keep the cat indoors on Purina HA Hypoallergenic for six weeks, and was happy to dose monthly with Stronghold. This, together with a good response to steroids, was highly suggestive of atopy.

    Serum IgE testing produced a range of high levels to pollens, house dust mite and moulds.

    Our friend has recently started on immunotherapy injections and is now starting to show signs of a good response. With the feline response to immunotherapy reported to be higher than that in dogs, this may be something well worth considering in cats.

  • Don’t forget cytology and Malassezia dermatitis

    Don’t forget cytology and Malassezia dermatitis

    Tape cytology from dog with Malassezia dermatitis (Dif-Quik stain).
    Tape cytology from dog with Malassezia dermatitis (Dif-Quik stain) – note the “peanut-shaped guys”. Image: Wikimedia Commons

    Ever had one of those cases, which seem to typically occur around this time of year, that you think must be the start of an allergic dermatitis?

    These present with pruritus, erythema and sometimes a yellowish/grey, greasy feel to the skin and hair coat.

    The dog is already on a regular POM-V broad-spectrum antiparasiticide.

    Initial thoughts

    Pyoderma immediately springs to mind – it’s 6.55pm on a Friday, you skip the cytology and start on an appropriate antibiotic; maybe even a short course of prednisolone.

    A week later and the dog has not really improved, so it’s a great time for some cytology. There is a good chance we have got a Malassezia dermatitis, and hey presto – the peanut-shaped guys are visible on microscopy. A couple of Malaseb shampoos later and we are rocking.

    Then the fun really starts as we try to determine the underlying cause…

  • What’s causing the recurrent pyoderma and pruritus?

    Itchy Charlie
    Itchy Charlie by Dan Boldy [CC-BY-SA-3.0], via deviantART.
    Given my interest in dermatology a lot of itchy canine and feline individuals are passed in my direction.

    They often have a history of recurrent microbial skin infections either in the form of Staphylococcal pyoderma or Malassezia dermatitis, which is treated as and when it occurs.

    I’m often surprised to find these individuals are not receiving routine parasite control, even when many of them have been prescribed it (sadly it is not effective while still in the packet), particularly as we do have both lungworm (Angiostrongylus vasorum) and Sarcoptes about in our practice locality.

    My tip would be start to look for the underlying cause when these patients keep coming back – starting with Sarcoptes (and I personally prefer the blood test because I rarely find mites on scrapings).

  • Sarcoptes ELISA

    Sarcoptes scabei
    Sarcoptes scabei – a parasitic arthropod that burrows into skin and causes scabies. Image by Kalumet. Licensed under CC BY-SA 3.0 via Wikimedia Commons.

    Have you ever had an atopic dog that’s really well managed but suddenly flares, becomes very pruritic and seems to stop responding to therapy? I had one such case just a couple of months ago.

    Skin scrapes did not reveal the presence of any ectoparasites and cytology was pretty unexciting (a bit of bacterial colonisation but otherwise unremarkable).

    However, noticing the pruritus to be primarily around the head, ears and ventral abdomen tipped me off to think about Sarcoptes scabei – particularly as we have a very prolific and confident urban fox population in our practice area.

    A serum sample was duly sent off and – lo and behold – proved positive for Sarcoptes antibodies.

    The client then confessed to missing “a dose” of Advocate but, upon reapplication, management was readily restored.