In August 1978, a novel disease affecting dogs emerged almost simultaneously in the United States, Europe, and Australia. This illness presented symptoms such as bloody diarrhoea, vomiting, lethargy, fever, and, in many cases, death. It was identified as canine parvovirus (CPV or Parvo), a viral enteritis that rapidly spread over two years, leading to the deaths of thousands of dogs worldwide. Once the virus entered a dog's body, it replicated in the lymph nodes of the throat and subsequently attacked the mucous membranes of the gastrointestinal tract.
Puppies and young dogs with compromised immune systems were particularly vulnerable to the disease. While nursing from their mothers, they are protected by antibodies in colostrum, which neutralise the virus. However, without vaccination, they become highly susceptible as they grow older.
The disease is highly contagious, transmitted through contact with contaminated faeces. Just three days post-infection, a dog's faeces can contain the virus, posing a risk to other dogs. This virus is remarkably resilient, remaining infectious for up to six months at room temperature. With a mortality rate of approximately 80% and its ease of transmission, the disease poses a significant threat to canine populations.
It is hypothesised that the emergence of canine parvovirus may have resulted from a mutation of feline parvovirus in the 1970s, given their structural similarities, differing only by a few amino acid residues.
Tackling the UK's Parvovirus Problem
The UK felt the impact of the pandemic during the early 1980s, with numerous dogs from various breeds succumbing to the disease, causing profound grief among their owners. Greyhound kennels were particularly affected, jeopardising the future of British greyhound racing as the virus decimated entire litters. The history of British parvovirus is chronicled in the long-established publication, Greyhoundstar.
Signs of the virus's emergence in England can be traced back to 1978, when an unusual connection was made to the branding of greyhound ears. That year, veterinarian Bruce Prole showcased ear branding techniques at the annual breeders' forum, where the National Greyhound Racing Club (NGRC) announced plans to brand all puppies in the UK starting from then. However, the marking methods proved ineffective as the brands quickly faded. The situation took a darker turn when greyhound puppies began to fall ill and die in large numbers from parvovirus, leading many breeders to mistakenly link the disease to the branding process. Eventually, the actual causes of the outbreak were identified, clearing the branding methods of blame.
Over the initial two years of the outbreak, tens of thousands of dogs perished due to parvovirus in the UK. The British Association of Small Animal Veterinarians played a crucial role in addressing this crisis by establishing a £15,000 grant dedicated to researching the deadly virus.
By 1980, British veterinary institutions conducted extensive clinical trials that led to the Ministry of Agriculture granting the first vaccine licence.
A report from the University of Glasgow in 1981 indicated that parvovirus had transitioned into an endemic disease over the three years since its emergence. It was recommended that once the vaccine became available in kennels, puppies should be vaccinated at eight, twelve, and sixteen weeks of age.
The sad experience of British coach Nick Savva
Despite the widespread presence of the disease in the British Isles as early as the 1980s, parvovirus did not infiltrate the Westmead kennel of renowned British greyhound trainer Nick Savva until 1983. Up until that point, Nick had successfully shielded his dogs from infection, but the situation rapidly deteriorated for dog owners and kennel staff during this challenging period. In retrospect, Nick regards it as the most devastating canine illness he has ever faced.
Nick and his wife, Natalie, took meticulous precautions to safeguard their dogs, managing to keep the virus at bay for an extended period. However, disaster struck in February 1983 when puppies born to two dogs, Glenroe Hiker and Westmead Seal, became infected. Initially, the puppies showed no symptoms while nursing, but as they weaned, the disease became apparent. The living room of their home transformed into a makeshift veterinary clinic as the puppies' conditions worsened dramatically, culminating in their tragic deaths overnight. Nick and Natalie desperately administered saline drips, only to witness blood flowing from the other end.
At that time, the vaccine was still under development and unavailable for purchase. The veterinarian suggested an alternative: vaccinating one of the dogs with a feline vaccine. Unfortunately, despite this effort, all the puppies in that litter died shortly after birth.
With only the vaccine to hope for, Nick Savva refrained from breeding dogs for two years following this heart-wrenching experience. Nevertheless, during this challenging period, he managed to protect the remaining runners from the virus and even successfully treated some of the afflicted dogs. One notable success was Westmead Account, who not only recovered but also competed in the Silver Collar and Scurry finals, even breaking the track record at Oxford. Another greyhound from the Westmead kennel, Westmead Chase, also triumphed over illness to win the Autumn Cup at Milton Keynes and later qualified for the Scottish Derby final.
Is parvovirus defeated?
After receiving the vaccine, the epidemic in the country gradually died down, but from that time on, vaccination of dogs became mandatory. Conscientious racing dog trainers follow vaccination protocols, eliminating potential infections of their runners. However, in 2021, the number of cases of parvovirus infection in dogs doubled in England. This was associated with the fact that some owners frivolously did not vaccinate their dogs, not taking into account that treatment for parvovirus is much more expensive than its prevention, the now two-stage vaccination of a puppy. In some cases, veterinary services were involved, issuing false vaccination documents to dogs for a fee, after which sick or infected puppies were sold to unsuspecting owners. Such cases are resolutely suppressed, including imprisonment of those involved in the fraud.
Many years have passed since the pandemic, and the danger from Parvo has dulled. Many people think that it will never affect them, because it was a long time ago, that fears are exaggerated, that their dog will never be at risk, even if it is not vaccinated.
But Parvo is a time bomb. You can’t be careless with this formidable virus and ignore vaccination. We must remember how it showed itself in the past, how the vaccine helped save thousands of dogs' lives, and prevent a repeat.