Importation of Animals Can Introduce Disease to Local Animals and People
Aug 1, 2022
Dr Matthew Kornya, DVM, Resident ACVIM (SAIM)
As global trade resumes with the easing of pandemic restrictions and the world returns to a global economy, the importation and exportation of domestic animals is also increasing. Combined with global climate change and an increasingly “small world”, there are more and more reports of dogs (and less frequently cats) entering Canada with previously unknown diseases. These pose a threat to both humans and animals within the country.
Recent changes to Canadian import legislation have made it more difficult to import dogs from areas that are high risk for canine rabies, however the danger of disease importation remains. While adopting a rescue pet from another area or importing animals bred in other countries can have significant appeal, there are also significant risks of communicable disease.
Several diseases that are common in dogs in other countries do not exist or are rare in Canada. The importation of dogs with these conditions may lead to the occurrence of diseases that local veterinarians are not familiar with the diagnosis and treatment of, and as such they may go unrecognized. These diseases may also, in some cases, be transmitted between animals leading to outbreaks or the establishment of disease in the region.
Rabies is potentially the most significant disease of concern. While rabies exists in Canada, it is largely found in wildlife and widespread vaccination means that domestic animals are much more rarely affected. Minimally or non-vaccinated dogs coming from countries or regions where rabies is more prevalent result in the introduction of rabies to the domestic animal population, and the risk of human exposure may become very high. As rabies can be latent for many months prior to showing clinical signs, imported rabid animals may be exposed to a wide range of humans and pets before being diagnosed.
Other diseases are less transmissible to humans but still pose a significant risk of dogs. Some of these are uncommon but present in the domestic animal population, but are readily prevented by vaccination or parasite prevention. These include canine distemper and adenovirus, and many tickborne diseases such as anaplasmosis and ehrlichiosis.
Other diseases are not present in Canada endemically and may be introduced in imported animals. These include serious and often incurable diseases such as Leishmaniasis, hepatozoonosis, and transmissible venereal tumor.
Countries of origin for exotic animal disease do not need to be tropical, distant, or underdeveloped. Any change in geography can result in new diseases not seen in other areas. For example, the southern United States has a wide range of fungal, protozoal, viral and bacterial infections not seen in Canada. Even non-southern countries may have unexpected disease, for example, feline mycobacteria in the United Kingdom. Within Canada there can be marked variation based on geographic region as well. For example, cryptococcus is much more common on Vancouver Island, and plague is seen in the prairies. As a result, even movement within Canada can be of significant concern.
Screening of imported animals for these infectious diseases is of crucial importance. Ideally, animals should be tested for diseases of concern before leaving the country of export. Valid documentation proving vaccination and negative disease testing should be provided by a veterinarian from the exporting country. If these papers are not available, a pet should not be adopted or imported.
Any time a pet is adopted from a foreign country, it is important to have them examined by a veterinarian in Canada as soon as possible. This will ensure all needed parasite prevention and treatment, vaccination, and other preventative healthcare is provided. It will also allow any tests for imported diseases to be performed and disease detected before it becomes too severe.
Overall, ensuring the safety of humans, our domestic animals, and even imported animals relies on the careful screening, early disease detection, and proper disease prevention in our pets. When adopting an animal, ensure that all proper documentation has been performed and book an appointment with a veterinarian right away, making sure they know the geographic region the animal is coming from. Avoid imported animals with known infectious disease, and take leadership in the health of your pet.
While there are many good reasons to adopt a pet from another geographic region, make sure to take care to consider the risks associated with it as well. Animals can carry disease that can be a risk not only to themselves, but their humans and other pets as well.