AFA Position on Distemper Vaccinations

Recently, Merial stopped producing Purevax, with no known date of when they will return to production -- and some rumors have been circulating that Merial has ceased production, permanently. Merial's Purevax is the only licensed vaccination against canine distemper (CDV) for the domestic ferret. Whenever available, the American Ferret Association (AFA) recommends the use of a licensed vaccine against canine distemper in ferrets. When such a vaccine is unavailable due to shortages orother problems, the AFA recommends considering the use of a limited antigen vaccine that has a track record of safe and efficacious use in protecting ferrets. At this time, that is limited to Merck's Nobivac DPv, also known as "The Puppy Shot," which has been used extensively in Europe for protecting ferrets against CDV. Although it does also vaccinate against canine parvovirus, which ferrets do not get, it is still the most proven vaccine available at times when the licensed product is not.  


The American Ferret Association's currently recommended vaccine schedule against CDV is as follows: 

• For healthy kits less than or equal to 14 weeks of age from mothers whose vaccination history is unknown, incomplete, or outdated; OR for kits that have unknown, incomplete, or no vaccination history: a series of three vaccinations, three weeks apart, with annual boosters thereafter. 
• For healthy ferrets over 14 weeks of age that have unknown, incomplete,  outdated, or no vaccination history: a series of two vaccinations, three weeks apart, with annual boosters thereafter.   

This protocol is evolving following some recent titer study data, which  suggests that ferrets that receive the appropriate series of initial vaccinations have protection titer levels both at a year and many for  over three years after vaccination. 


Dr. Ruth Heller suggests the kit series as noted above, with a serum neutralization titer test performed at a year, and annually thereafter; only vaccinating when titer  levels come back low ( <1:50, as noted in Wagner & Bhardwaj's study  "Serum-Neutralizing Antibody Responses to Canine Distemper Virus Vaccines in Domestic Ferrets (Mustela putorius furo) "Journal of Exotic  Animal Medicine, Volume 21, Issue 3, Pages 243-247. July 2012.)   Dr. Heller notes that Nobivac DPv "does, however, produce decent  titers, and I have seen no reactions in approaching two years of using it." 


Currently, there are several titer tests available to veterinarians through various laboratories. However, many are inconclusive in their results and can be quite expensive to the owner. Thus, the AFA suggests using a serum neutralization titer through Cornell University's College of Veterinary Medicine. Cornell only accepts tests from licensed veterinarians, so pet owners cannot submit samples themselves. Cornell offers an inexpensive and accurate titer that can help you as the  treating veterinarian determine if and when a patient needs another canine distemper vaccination. 


In light of the recent Merial production  halt of Purevax, this is an increasingly attractive option for ferret  owners and veterinarians alike.   Cornell currently charges $16.50 per sample, with a $2 Accession Fee. The General Submission form should be filled out with submissions,  noting that the Test Code is CDV SN. 


For more information on the titer through Cornell, including how to  prepare sera, please visit Cornell University's College of Veterinary Medicine's Animal Health Diagnostic Center webpage, where you must then search under Canine Virology tests for Canine Distemper (CDV) Virus SN.(https://ahdc.vet.cornell.edu/)  
General Submission Form: https://ahdc.vet.cornell.edu/docs/General_Submission_Form.pdf 
Shipping Guidelines for samples to Cornell: https://ahdc.vet.cornell.edu/docs/Shipping_Patient_Specimens_to_the_AHDC.pdf
Billing and Fee Policy: https://ahdc.vet.cornell.edu/billing/  


American Ferret Association, Inc.  
With special help from Dr. Ruth Heller, AFA Health Affairs Committee.  
Vickie McKimmey   Office Manager  American Ferret Association, Inc.  
www.ferret.org