Immunosuppressive Therapy

!!! Before you think about immunosuppressive therapy you must be sure about your diagnosis. It can be very dangerous for your patient to start immunosuppressive drugs based only on history and clinical examination as a confirmation of the diagnosis of immune-mediated skin disease. If the animal has an infectious disease (fungal, bacterial, or parasitic), it can rapidly deteriorate and even die. There is no place for trial therapy in immune-mediated disease (except in the case of a patient facing euthanasia otherwise).

‡ Patients with immune-mediated skin disease commonly have secondary infections that need to be identified and treated. In patients with mild-to-moderate disease, I start antimicrobial therapy 3 weeks before immunosuppressive therapy to evaluate how many of the clinical signs are due to the infection and how many are due to the immune-mediated disease. In cases of severe clinical disease, however, treatment of infection and of the immune-mediated disease should be started concurrently.

♣ It is impossible to give you a good general purpose recipe for immunosuppression. Every dog or cat reacts differently to each of the drugs mentioned later in this section and you have to individualize treatment for each patient. Immunosuppression is a technique requiring instinct, sensitivity, and experience as well as theoretic knowledge that is beyond the scope of this text. There are, however, certain generalizations as well as certain starting dosages and ranges.

> Probably the best way is to start using one preferred drug, then, if your approach fails, refer the patient and learn from the way the specialist treats it. After you are familiar with that new drug, you add another one to your repertoire and use both of them and so on.

The doses mentioned in Table 3-10 are starting doses that are tapered as soon as possible to the smallest effective dose.

> Taper the drug once the patient is in clinical remission or if adverse effects are intolerable. In a patient with severe adverse effects and concurrent clinical signs of active disease, new drugs need to be added at the same time.

!!! Monitoring, as described in Table 3-10, is essential. I only compromise on monitoring standards because of financial considerations in patients facing euthanasia otherwise!

> Some dogs will have seasonal relapses. This mechanism is currently not understood. If a well-controlled patient suddenly seems to relapse, always check for demodicosis and fungal or bacterial infections first. Rather than a flare-up of the immune-mediated disease you may be encountering a problem secondary to your treatment. These patients are immunosuppressed and thus easily may be affected by infectious diseases! Increasing the dose of the immunosuppressive drug may not always be a good idea.