23 October 2000

Trying to get your pet dog to take a monthly heartworm tablet will become a battle of the past due to new drug delivery systems. The system has been developed by a US company with the assistance of Dr Rick Atwell at The University of Queensland School of Veterinary Science.

"The new technology will allow dogs to have a single annual injection that protects the dog from parasites. This is a world first for Veterinary Science and possibly for human drug delivery systems as well," said Dr Atwell.

Dr Atwell has spent the last four years assessing the effect of the technology in collaboration with American Home Products subsidiary Fort Dodge Australia Pty Ltd.

The system consists of an injection of organic polymer microspheres, like tiny 'golf ball' structures, that contain the drug. The microspheres sit just under the skin and slowly release the drug moxidectin through tiny holes in the spheres. The drug is released slowly over twelve months without causing any local skin or tissue reactions.

"Pet owners often forget to give dogs their heartworm preparations. About 40% of dogs don't complete a 12 month control program. Many people only remember to give 6 to 8 of the 12 doses," said Dr Atwell.

The product has had extensive field trials being tested in over 200 dogs in Queensland and New South Wales. Rather than the UQ Vet School needing to conduct all trials at their campus facility over the 18 months required for each dog, the research was done in partnership with the Manly Road Veterinary Hospital.

"Our association with private vet clinics is of enormous advantage to us. The Manly Road clinic was able to conduct many trials on our behalf using pet dogs that lived in normal home situations. The help they have given us is fantastic and their in-kind support is worth a considerable sum of money," said Dr Atwell.

"Through this program, we are also able to provide training and work experience for veterinary students from the University. This collaboration is invaluable and we hope to expand it in the future."

The effectiveness of the drug delivery system was confirmed using ultrasound of the pulmonary artery as it leaves the heart, enabling researchers to "see" if any adult heartworms were present.

The purchase of the ultrasound and other technology required for the study has to be self-funded within the Vet School. Dr Atwell said, "We are increasingly dependent on the on-going direct donations and bequests from the general public. However, the resulting contact with pet owners and clinics are the most effective way for us to promote better animal health care."

ftp site for pic of Dr Atwell: http://photos.cc.uq.edu.au/PNF:byName:/ScienceWriters/

For more information contact Dr Rick Atwell (telephone 07 3365 2551) or Jan King at UQ Communications (07 3365 1120) or email: communications@mailbox.uq.edu.au