Researchers from the Iowa State University College of Veterinary Medicine recently started an experimental medical treatment of SARDS patients using human intravenous immunoglobulins (IVIg). The client will be informed that the procedures contain risks and currently the treatment has not been widely adopted by the veterinary profession. A liability waiver and consent forms must be signed prior to treatment.

SARDS Treatment - Frequently Asked Questions

• What is IVIg?
  

  IVIg is a synonym for intravenous human immunoglobulins - it is a mixture of different class of globulins found in healthy human circulation. IVIg is made by mixing globulins of 5,000-10,000 samples from healthy human donors so it really represents a mosaic of normal circulating antibodies, which are controlling immune system not to get excessively aggressive in contact with antigens that we are regularly exposed to on daily basis. It is used extensively in human medicine for variety of immune-mediated disease which are poorly responsive (or non-responsive) to steroids and other immuno-supressive medications.

• What is the cost of IVIg?
  

  The cost of IVIg varies depending on market demand. The current cost of IVIg is $75-100/g. We use a total of 1 g of IVIg per kilogram of body weight. So IVIg cost for 10 kg dog is close to $750.

• Does IVIg work in all SARDS patients?
  

  Careful selection of patients for the IVIg treatment is of utmost importance for successful outcome of this therapy (please read section about diagnostic routines needed before pursuing IVIg treatment). Despite all preliminary diagnostic work, we can not predict whether IVIg treatment will recover vision in every SARDS patient. Human studies showed that some patients with similar diseases respond very well to IVIg therapy, while some patients do not respond at all. So far all dogs that we treated showed good response to IVIg treatment.

• Can IVIg therapy cause any systemic problems?
  

  Yes – IVIg solutions can cause significant increase in blood pressure, so dogs with pre-existing severe systemic hypertension, cardiac, liver and kidney diseases are not good candidates for the IVIg treatment. If cardiac disease is present, detailed examination by a cardiology specialist needs to be performed before deciding to pursue IVIg treatment.

• What is the time window for the IVIg treatment after SARDS is diagnosed?
  

  We do not know for sure. Some dogs have severe retinal degeneration even 2 weeks after they have been diagnosed with SARDS. Some dogs will have almost normal appearance of the retina even 2-3 months after onset of disease. Every dog with sudden onset of blindness needs to be evaluated immediately and sooner the referral to veterinary ophthalmologist is performed, better the chances are that IVIg therapy may actually work.

• What tests need to be performed to determine whether my dog is a good candidate for IVIg therapy?
  

  Your dog should be in good health and without major systemic diseases. Ophthalmic examination should show relatively normal appearance of the retina – dogs with advanced retinal degenerative changes are not good candidates for the IVIg treatment. Evaluation of the pupil light reflex (Melan-100 unit) should show absent pupil response when red light is used and good pupil constriction without pupillary escape when blue light is used. Presence of poor constriction or pupillary escape with blue light illumination is suggestive of advanced retinal degenerative changes which caused irreversible re-organization of retinal elements. Electroretinography amplitudes should be completely absent in both eyes of SARDS patients.

  Unfortunately even normal looking retinas can have severe loss of photoreceptors. Prior to initiating IVIg treatment, all our patients will have their retinas examined using optical coherence tomography to determine severity of retinal tissue loss.

• What are the costs of testing and treatment for SARDS at ISU?
  
  • Initial examination fee, general anesthesia, colorimetric pupil light reflex testing, optical coherence tomography (OCT) scan of the retina = $600 (up to $750 if blood and urine analysis was not performed within 14 days prior to the examination).
  • If the OCT scan is good, the patient is admitted to the medical center for additional 4 days. Patients are located in the ISU VMC Intensive Care Unit and are under continuous observation while receiving treatment. IVIg will be given on day 1 and day 3. Cost of hospitalization is $150-200/day (total $600-800)
  • Additional cost for IVIg is $75/kg of body weight. So IVIg for a 10kg dog will cost $750.
  • On the 4th day additional colorimetric pupil light reflex analysis, visual maze testing and electroretinography are performed again. These tests cost an additional $150-200.

  Total price for treatment of a 10kg dog = $2100-2500.

  *The price may vary in individual cases (especially if more detailed heart examination is needed, or if IVIg is not readily available).

• How long will the treatment last?
  

  We still do not have sufficient data from canine patients, however data from human patients showed that some patients may be fine with one dose of IVIg for years, while others need continuous treatment every 4-6 weeks.

• Can IVIg treatment be repeated in the future?
  

  No – this is a human product and there is a huge risk of severe reaction (anaphylactic shock) if human IVIg is given again at later time. Iowa State University is currently working with several companies with a goal of producing the canine IVIg which should be more affordable and safe option for canine patients.

• Referring patients to ISU from Iowa practitioners:
  

  The following tests should be performed and results sent to the ISU VMC as part of the referral documentation:

  1. Detailed history of any previous systemic diseases, vaccination history
  2. Detailed summary of physical examination
  3. Complete cell blood count, serum chemistry, urine analysis
  4. Blood pressure analysis data (if available)
  5. Results of the colorimetric (red and blue light) pupil light reflex testing
• Referring patients to ISU from other institutions
  

  All patients should be of good general health and should have the following tests performed and sent to the ISU VMC as part of the referral documentation:

  1. Detailed history of any previous systemic diseases, vaccination history
  2. Detailed summary of physical examination (including ophthalmology and neurology examination)
  3. complete cell blood count, serum chemistry, urine analysis
  4. Blood pressure analysis data (include thoracic radiographs if a heart murmur is present). We recommend that a cardiologist is consulted about suitability for IVIg treatment before the patient is referred to ISU for further testing
  5. Results of the colorimetric pupil light reflex testing
  6. Original electroretinography tracings (if veterinary ophthalmologists already performed examination)