A University of Sydney study has found that canine parvovirus (CPV), a highly contagious and deadly disease that tragically kills puppies, is more prevalent than previously thought with 20,000 cases found in Australia each year, and nearly half of these cases result in death.
Despite the extent of this disease, this is the first survey study to examine the impact of CPV in Australia since 1982.
Published in Transboundary and Emerging Disease, the national survey of 534 veterinary clinics investigated the number of cases of CPV, their geographic distribution, and financial impacts on pet owners.
The survey revealed that CPV remains a major cause of disease in puppies and dogs across Australia, particularly in rural and remote areas of the country, despite improvements in vaccination technology over the last 40 years.
CPV in dogs causes the destruction of the intestinal lining and villous atrophy, resulting in severe gastroenteritis, haemorrhagic diarrhoea, vomiting and dehydration.
“CPV can kill puppies, so is an especially tragic disease, and most people are unaware that this is a big issue nationally,” said lead researcher Dr Mark Kelman, a veterinarian and PhD candidate at the Sydney School of Veterinary Science.
“The estimated number of cases of CPV across Australia was 20,661 in 2015 and 20,110 in 2016, and the overall reported euthanasia rate was 41 per cent.”
The survey identified large numbers of CPV in rural, remote, and lower socioeconomic areas of Australia. Where cases occurred in capital city areas, they were more commonly seen in outskirt areas, away from the inner city.
The Northern Territory had the highest rate of CPV, twice as high as NSW, highlighting the severity of the disease in this area. The only areas with relatively lower rates were the ACT and Victoria.
“A range of risk factors might contribute to these differences across the country and requires further research,” said Dr Kelman.
“We suggest that socioeconomic factors and other issues in these regions may result in poor vaccination rates. If these rates could improve, this might stop these outbreaks and disease cases from occurring.”
The study found that the average cost to treat CPV cases was $1,500 per patient, with a significant difference in the cost of treating cases between Australian states - Western Australia being the most expensive state (median cost $2,500).
“There was a strong link between the cost of treatment and the rate of euthanasia without treatment,” he said.
“The data shows that cost factors were linked to the pet owners’ decisions to seek treatment for their dog—higher costs were linked to pet owners opting for euthanasia instead of seeking treatment. An inability to afford treatment might be a factor in the high euthanasia rates reported by veterinarians.
“In my personal experience as a vet, the inability of a client to afford treatment for CPV is a common reason cited for euthanasia, surrender, or sometimes the abandonment of these animals.
“Now that the impact of CPV in Australia has been estimated, and the regions where the highest numbers of cases have been identified, we need targeted communication and vaccination strategies in these areas to improve herd immunity and reduce CPV case numbers.
“Strategies could be developed to quickly intervene in CPV‐related disease outbreaks, or to address areas where CPV cases are endemic.
“This is now something that we are looking at, and a charity that I have started called Paws for a Purpose has also now begun some pilot vaccination programs in high-risk rural areas to try and prevent cases from occurring.
“We are currently heading into the worst time of year for parvovirus, so we also urge people to vaccinate their dogs if they aren’t fully vaccinated - especially puppies.”
This survey is the most comprehensive epidemiological investigation of canine parvoviral‐related disease to date, globally and provides a process for national disease surveillance.