The full truth about the viral gastroenteritis outbreak in Dublin dogs
There has been much talk in the media in recent days about a viral disease spreading around dogs visiting parks and public places in Dublin. The aim of this article is to provide a comprehensive explainer about what is going on, and what dog owners need to do.
What’s the background to the reported outbreak of the virus in dogs?
The media reports have stated that vets in certain areas (e.g. north Dublin) have been seeing clusters of dogs with signs of severe gastroenteritis. Some of the dogs have had a history of visiting local parks. The suggestion has been that this is being caused by a virus that is passing around the dog population. Dog owners are understandably worried.
What type of virus is causing the dog problem?
There are several different viruses that are commonly seen in the dog population of Ireland. This recent outbreak is most likely to be a virus with a name that makes people feel nervous: Canine Enteric Coronavirus Infection. However, it should be stressed that, to my knowledge, this specific virus has not been categorically identified. However, from circumstantial evidence, it’s very likely that this virus is involved, because it’s the most common cause of this type of problem in dogs.
Yes, we are talking about the high chance that this is a Coronavirus. But the first point to remember is that this carries absolutely no risk to humans: there is only one strain of Coronavirus that causes COVID-19, and that’s SARS-CoV-2. There are dozens of other Coronaviruses that can cause minor illnesses in humans, and hundreds of Coronaviruses that affect animals but cannot affect humans at all. So owners do not need to worry about any possible risk to themselves from this Canine Coronavirus.
How does the virus affect dogs?
As an “Enteric” Coronavirus, the virus only affects dogs’ digestive tracts: it does not cause coughing or affect their breathing like the human version. The virus moves into the cells that line the digestive tract, causing temporary damage and inflammation. The virus is usually then easily overcome by the dog’s own immune system. Some dogs show no signs of illness at all (like the human asymptomatic carriers of COVID), while others can show quite severe signs of gastroenteritis. In layman’s terms, this means some dogs suffer from dullness, vomiting, and diarrhoea. In severe cases, blood-stained diarrhoea may be seen.
How common is the virus?
This Canine Coronavirus is not new: we see this every year, all year round, in Ireland. Normally a vet clinic might see one or two cases at a month; however some clinics may be seeing a dozen cases a month just now. It’s normal to have peaks and troughs of a virus like this.
In fact, it’s probably far more common than we realise. One study found that between 5 – 20% of all cases of diarrhoea in dogs are caused by this Coronavirus.
In the real world, a specific diagnosis of this virus is rarely made, because to do that, you would need to carry out a special PCR test, similar to the tests for human Coronavirus that you hear so much about these days. But given that most dogs make a full recovery anyway, and given that it makes no difference at all to the treatment to know that the virus is the cause, it is rare for vets to request the PCR test. It’s expensive enough treating these cases without doing extra laboratory tests that don’t change the outcome for the animal.
How is the virus passed from dog to dog?
Dogs become infected with the virus by sniffing, licking, or eating traces of other dogs’ faeces: the virus is shed in the droppings of infected dogs for 3-14 days after infection. Dogs love investigating the world by sniffing and licking, so it is very difficult to stop dogs picking this virus up if they go to areas frequented by other dogs.
What are the signs of infection with Canine Enteric Coronavirus?
Some dogs show no signs at all, but affected animals typically have vomiting, dullness, loss of appetite, and diarrhoea. Fever is uncommon. Many patients have minimal clinical signs, and after a brief illness, they make a full recovery without any intervention.
However, some animals (especially puppies, elderly dogs, or those with weaker immune systems) may have more severe and prolonged signs.
The main sign that worries vets is when dogs pass blood-stained diarrhoea: this indicates severe damage to the lining of the intestines, with a greater risk of dangerous dehydration, and secondary bacterial infection causing more serious complications.
What treatment needs to be given to affected dogs?
The level of care needed depends on the severity of the signs of disease, and the age of the patient. Many dogs have minor signs (e.g. a couple of vomits, transient diarrhoea, and reluctance to eat their dinner). As long as they remain bright and active, and as long as there are no other signs, a simple home-remedy approach of offering water only for twelve hours, then a bland, easily digestible diet for 24 – 48 hours (e.g. cooked chicken and boiled white rice) may be sufficient, without need for hospitalisation.
However dogs that have more severe vomiting and diarrhoea, or those where the diarrhoea contains blood, or cases where the dogs become extremely dull and dejected, usually need to be hospitalised by their vet. Intravenous fluid therapy is needed, along with medication to control the vomiting, and special gastrointestinal recovery diets to assist the return of the digestive tract to normal. Antibiotics may also be needed for these severe cases.
What is the prognosis for dogs that pick up the virus?
In most cases the prognosis is very good: most dogs with mild signs recover spontaneously, thanks to their own immune systems, and most dogs with more serious signs recover with veterinary care within 48 to 72 hours.
The biggest risk is dehydration: if severely affected dogs (i.e. those with repetitive vomiting or diarrhoea, especially where blood is seen) are not taken to the vet for intravenous fluids, their entire system may be badly affected by the fluid loss from the body. Intravenous fluids can be critically important to keep such patients stable while their immune system fends off the virus.
How can dog owners protect their pets against the virus?
A vaccine against Canine Enteric Coronavirus is available (and is sometimes included in annual booster vaccinations), but it provides incomplete protection against the virus, and is not regarded as a “core” vaccine. For this reason, many vets do not recommend its routine use.
Arguably, if owners are worried, they should avoid public areas where there are many other dogs. However this is a virus that is continually doing the rounds, and it’s very difficult to find areas that other dogs don’t visit in Ireland’s cities and towns. Given that many infections cause minor, temporary signs, and even in severe cases, nearly all affected dogs make a full recovery with treatment, there is a reasonable argument that there is no need for owners to change their behaviour at all in response to this virus.
It is common sense to prevent your dog from sniffing or licking obvious hazards such as other dogs’ faecal deposits, but apart from a simple measure like this, there is no imperative to take other action.
Should dogs start to wear masks?
Nobody has yet managed to design a mask that is tolerated by dogs that’s effective at protecting them against this type of virus. If you are worried about your dog, then a standard basket type muzzle will prevent them from ingesting potentially infected deposits. However, it won’t stop them from sniffing such areas, possibly picking up infection.
Are there other causes of the same signs of illness?
There are a number of other possible causes of similar signs of vomiting and diarrhoea, from simple scavenging, to bacterial infections, to allergic reactions. There is a syndrome called Haemorrhagic Gastro Enteritis (HGE) which closely resembles Canine Enteric Viral infection (and indeed, HGE may sometimes be caused by this virus). It’s also possible that some other illnesses (such as kidney, liver or pancreatic disease) can cause vomiting and diarrhoea.
The rule of thumb is the same for all of these causes: if your dog has mild signs of vomiting and/or diarrhoea, then a simple approach is safe: a brief fast, offering only fluids, followed by bland food for 24 – 48 hours. If the signs are more severe, or if the mild signs do not resolve within 1 – 2 days, then it’s important that you take your pet to the vet.
There is one very serious situation that all owners should be aware of: Canine Parvovirus which is a highly lethal virus that causes severe gastrointestinal signs. This virus also causes vomiting, dullness, inappetence and diarrhoea. However the diarrhoea is always blood stained, and affected animals are far more ill, with a high temperature. Parvovirus is far more difficult to treat, with a high mortality rate even when intensive treatment is given.
The good news is that dogs can be fully protected from Parvovirus by vaccination, and this is a core vaccine, meaning that all puppies are vaccinated against it, and regular boosters ensure that most pets have lifelong protection. However vets are acutely aware that any dog with a severe digestive disorder could have Parvovirus, and this is a constant background threat. The answer is simple: make sure your pet has up to date vaccinations and ask your vet if you are not sure.
What can people do to find out more about the virus involved in the recent outbreak?
Petfix Club has been set up as a comprehensive online information source for pet owners: