Dr. Gus Aguirre - DUSN Survey Results

Dear ACVO diplomates.

Thanks so much for the many responses to the survey on DUSN. Below are the responses to the 3 questions listed below:

Survey

1) Are you familiar with the retinal disease in man called DUSN (Diffuse Unilateral Subacute Neuroretinitis)?

2) If yes, are you aware of the relationship of DUSN and Ocular Larva Migrans from nematodes such as Toxocara canis and others?

3) If yes, based on your clinical experience do you think a DUSN-like condition occurs in dogs?

Results:

Yes: 11

No: 63

Comments: Several responders thought that the disease could occur in dogs. A common misconception expressed by some responders is that as many dogs receive monthly parasiticide treatment, it is unlikely that the nematode eggs ingested will cause problems. However, the parasiticides in use today are designed to kill the adult nematodes in GI tract when used as directed. Thus no adults leads to no eggs being shed. They may/may not kill larva in tissue but that might depend on tissue drug concentration. Obviously, the less nematode eggs are in the environment, the lower likelihood of ingesting them. In rural areas, nematode eggs in the environment from raccoon, foxes etc, the parasiticides will not prevent nematodes being ingested, developing, migrating and causing disease.