Rabies in Dogs

What is rabies?

Rabies is a fatal disease caused by a virus which belongs to the Lyssavirus genus of the Rhabdoviridae family and infects mammals - including dogs and humans. Rabies virus is shed in the saliva of an infected animal and is transmitted when that saliva comes into contact with wounds or mucosal surfaces (e.g. if the infected animal bites another animal, or licks an open wound on their body). It then makes its way along the nerves to the brain, where it causes a range of clinical signs before resulting in death. Rabies is a major public health concern: on average 60,000 people worldwide die from it every year. Over 99% of them are infected by dogs1, typically via bites or scratches. This is why it is so important to vaccinate dogs against it!

How does rabies affect humans?

Depending on the location and severity of the initial bite/scratch, signs can take days to months to develop. Initial symptoms may include fever, pain or a tingling sensation. The patient then develops either the ‘furious’ form or the ‘dumb’ form of rabies. The former involves hyperactivity, hypersalivation and periods of agitation and hydrophobia (fear of water); the latter involves flaccid muscle weakness and gradual paralysis. Once clinical signs appear, death occurs within days.

How does rabies affect dogs?

Similarly to humans, there is a variable period of time (3 weeks to 6 months) between infection and clinical signs. During this ‘incubation period’, the dog will seem normal. It may start shedding virus in its saliva before signs occur, meaning that an apparently healthy dog is capable of spreading rabies.

Early signs can include behavioural changes, a fever and chewing, licking or pain around the wound that infected them. Dogs can then pass into a ‘furious phase’ in which they are hypersensitive to light or noise, become aggressive, hypersalivate and have convulsions. They can also show a ‘dumb phase’ characterised by paralysis of the jaw and throat muscles. This causes their jaw to drop and they will be unable to eat. Their voice can change and the muscles needed for breathing can also become paralysed. Rabies is invariably fatal.

What should I do in Singapore?

In Singapore, there is no legislation that requires pet owners to vaccinate their pets against rabies in Singapore. However, pet relocation to Singapore has several law requirements. Dogs and cats must have a microchip implanted and at least had two inactivated rabies vaccinations. The dog/cat must have a blood sample taken and tested for acceptable rabies antibody levels at least one (1) month after the first vaccination and within six (6) months prior to export. Following the date of sampling for serology, the dog/cat must be vaccinated again. This additional vaccination must not be less than one (1) month prior to export.  If pets are coming from the US and Canada, they have a mandatory 10-day quarantine upon arrival, and reservations must be scheduled in advance. Check with your local vet for the specific legal requirement depending on the country of export.

How can I tell if my dog has rabies? It is extremely difficult to confirm a diagnosis of rabies in a living animal. After assessing a suspected rabies case, the authorities will decide whether to quarantine or euthanase the animal. If the animal dies in quarantine or is euthanased, its brain is submitted to a laboratory for immunofluorescence microscopy, which gives a definitive diagnosis.

What is the rabies situation in Hong Kong?

Hong Kong is officially a rabies-free territory; however, rabies is a serious problem in mainland China – including Shenzhen and elsewhere in Guangdong. Animals are often illegally smuggled from mainland China into Hong Kong, particularly as part of the pet trade; as a result, Hong Kong is constantly at risk of a rabies reintroduction.2 Even cute, apparently healthy puppies are capable of transmitting rabies - so before you get a dog, make sure you know where it has come from.

Hong Kong has strict laws to prevent and control any rabies outbreaks. Most importantly for owners, all dogs over the age of 5 months are required to be (1) microchipped, (2) vaccinated against rabies, and (3) licensed. Rabies vaccination can be done from 3 months of age, and must be repeated every 3 years in order to renew your dog licence. Keeping a dog without a licence can result in a fine of HKD10,000.3

If you suspect your dog might have been exposed to animals with rabies and/or you suspect your dog might have rabies, you must report this to the police or the Agriculture, Fisheries and Conservation Department (AFCD) in Hong Kong immediately, as it is a public health risk. Similarly, if your vet suspects that your dog might have rabies, he/she is legally and ethically bound to report it. Take care not to let any people or animals get bitten, scratched or licked by your dog.

 

What are the benefits and risks of vaccinating against rabies?

Vaccinating against rabies is not only a legal requirement but also potentially life-saving. It not only protects your dog from getting rabies (e.g. if he/she is bitten by another dog) but also prevents him/her from passing it on to other animals or to people. Studies around the world have shown that vaccinating dogs is by far the most effective way to prevent rabies in humans.4

Occasionally, the rabies vaccine may produce a local reaction such as a small, transient swelling of tissue at the injection site which should self-resolve. Rarely, vaccination may result in a hypersensitivity (anaphylactoid) reaction; signs can range from facial swelling, itchiness, weakness or diarrhoea to difficulty breathing or death.5 It is very unusual for this to happen, but should you notice any concerning signs following a vaccination, please contact your vet immediately. If your dog has had allergic reactions to vaccines in the past, please let your vet know before they vaccinate.