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Tag: test

  • Don’t talk to clients about free T4 evaluations

    Don’t talk to clients about free T4 evaluations

    Free, not gratis!
    Free, not gratis – image ©iStock.com/Aquir

    We recently had an elderly cat that presented with typical signs of hyperthyroidism.

    However, as is sometimes the case, total T4 proved stubbornly normal on two estimations a couple of weeks apart.

    So we suggested it would be a good idea to send a blood to the lab for free T4 estimation – and you may be able to guess what’s coming next…

    But, you said…

    Yes, you’re right – the client then complained profusely that they had to pay for the test, because (and I quote): “You said it was free!”

    We now call this an “unbound” thyroid blood test – it just makes life simpler.

  • Blood testing for E cuniculi in rabbits

    Blood testing for E cuniculi in rabbits

    Figure 1. Neurological signs are considered the most common clinical presentation of encephalitozoonosis in pet rabbits. The most frequent neurological signs are often associated with vestibular disease and can include head tilt, ataxia, circling and rolling, nodding or swaying at rest, and nystagmus.
    Neurological signs, including head tilt, are considered the most common clinical presentation of encephalitozoonosis in rabbits.

    Image taken from article Treatment of Encephalitozoon cuniculi infection in rabbits by Elisabetta Mancinelli – the first in a two-part series that also includes Diagnosing Encephalitozoon cuniculi infection in rabbits.

    Antibodies to E cuniculi in rabbits can be detected on a blood test. Hence, a rabbit that has been infected by E cuniculi will produce antibodies that will produce a positive test.

    However, some rabbits appear to clear the infection completely and over time their blood test will become negative again.

    Have or have not

    Until recently, tests available in the UK could not distinguish between current and past infection. A negative result basically ruled out E cuniculi as the cause of illness but a positive result only told you the bunny had been infected at some point in time, and did not help to determine whether the infection was recent and ongoing.

    However, quantitative tests that can actually measure the levels of antibody in the blood sample (not just whether they are there or not) are now available in the UK, introduced by Medlab in Cheshire.

    By testing two separate samples (taken with an interval between them) it is now possible to determine if a rabbit is mounting an immune response to an active E cuniculi infection.

  • Take note of high Hgb and Hct levels on pre-anaesthetic bloods

    A young French Bulldog is sedated prior to surgery.
    A pre-anaesthetic blood test can reveal hidden or undetected health problems that are not obvious from a physical examination alone. Image ©iStock.com/DenGuy

    Have you ever noticed that, sometimes after starving, the haematocrit (Hct) and haemoglobin (Hgb) levels appear a little high on pre-anaesthetic bloods prior to a surgical procedure that morning?

    If so, make sure you look at the figures.

    If, like us, your laboratory machine produces a band with a red marker in the middle indicating some elevation, make sure you also look at the absolute figures.

    I recently saw a nine-year-old boxer that, after a surgical procedure, developed redder and redder skin and mucous membranes. She had high Hct and Hgb on pre-anaesthetic bloods and subsequently turned out to have polycythaemia vera with, eventually, a Hct of 84.9.

    Four episodes of venipuncture (taking 200ml to 300ml of initially very viscous blood on each occasion), plus treatment with hydroxycarbamide, and she was feeling much better.

  • Treatment of cat ringworm carriers

    Treatment of cat ringworm carriers

    Ringworm under UV
    Ringworm discovered using a Wood’s lamp (ultraviolet light). Image courtesy DermVet Skin and Ear Clinic.

    Cats, particularly long-haired varieties, can be carriers of ringworm but show no clinical signs at all.

    Diagnosis in the absence of skin lesions is made by either Wood’s lamp over the entire body (only 50-60% of positives will fluoresce), or by taking coat brushings and incubating the hairs, follicles and debris in a dermatophyte test medium (DTM).

    Once a cat is diagnosed as a carrier, treatment is the same as for those with lesions: oral itraconazole.

    Even after consecutive negative results, the cat should always be considered a carrier, as it’s so difficult to eradicate ringworm from the environment. Treatment is still considered worthwhile, however, and effective cleaning will reduce/prevent further outbreaks.

  • Check tear production in cases of facial paralysis

    Schirmer tear test
    Schirmer tear test

    We recently saw a 10-year-old, West Highland white that had developed a middle ear infection and facial paralysis.

    Following treatment and further investigation, it turned out the poor little chap had concurrent hypothyroidism. Several weeks later, I noticed the eye the same side as the ear infection had developed a mucopurulent discharge and mild keratitis.

    On checking its Schirmer tear tests, this was markedly reduced for that eye, and borderline for the other. A bit of research indicated facial paralysis can affect both tear and saliva production.

    The good news is the little chap is doing well with false tear preparations.

  • 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).