Estimating spatial and temporal trends of dog importation into Canada from 2013 to 2019

Abstract

Background and objective

For several years, there has been growing concern over the public and animal health impacts of dog importation, with many Canadian veterinarians reporting increasing diagnoses of exotic pests and pathogens. This study is the first to estimate the number of dogs imported into Canada and describe spatial and temporal trends.

Animal and procedure

Commercial and a subset of personal dog importation records, obtained from the Canada Border Services Agency, were used to estimate the total number of dogs imported into Canada from 2013 to 2019.

Results

The number of dogs imported annually increased by > 400% over the study period, with > 37 000 dogs imported in 2019. The majority of dogs (72%) were imported from the United States and Eastern Europe, and 23% originated in a country considered high-risk for canine rabies.

Conclusion

Dog importation into Canada has increased substantially over time. Moving forward, education and improved tracking will be essential.

Introduction

Dog ownership is on the rise in Canada. In 2020, the Canadian Animal Health Institute estimated the Canadian pet dog population to be 7.7 million, an increase of 100 000 over the previous 2 y (1). Furthermore, it is highly probable that these numbers increased further during the COVID-19 pandemic (2). The increasing demand for dogs is likely to accelerate the growing trend of importing dogs from other countries, including through rescue operations and international breeders (3,4).

Inherent to the international translocation of dogs are disease and welfare issues, which can pose risks to both human and animal health. Imported dogs can, and have, introduced pathogens from other countries that are either nonexistent or well-controlled in Canada (5–8). In 2021, 2 rabid dogs infected with canine-variant rabies virus were imported into Canada from Iran (9,10); and in 2018, a woman in British Columbia contracted Brucella canis from a pregnant dog she had rescued from Mexico (11). Also in 2017 to 2018, several clusters of canine influenza A(H3N2) in Ontario were traced back to dogs imported from Asia (12). Vector-borne diseases such as leishmaniasis, anaplasmosis, ehrlichiosis, and babesiosis have also been detected in dogs imported into Canada (13,14) and it follows that non-native tick species, such as brown dog ticks and other vectors, may be introduced through this route (15).

In addition to many being in poor health, imported dogs are often unsocialized, which can result in long-term challenges that may even lead to the animal being surrendered due to its incompatibility with a domestic lifestyle. Increasing demand for dogs has increased sale prices, promoting importation of dogs as a business venture, in some cases with little to no regard for the health and welfare of the animals (16,17). A recent example of this was a shipment of ~500 French bulldog puppies from Ukraine to Ontario in June 2020, of which almost 40 of the dogs died in transit (18). Dog breeding in many countries has been linked to illegal puppy trade and organized crime, where large numbers of puppies are produced at low cost, health records forged, and underage puppies sold at substantial profits to unaware buyers (19).

These issues are not unique to Canada; other countries, including the United States, Finland, and the United Kingdom (UK), have raised concerns over the rising numbers and associated risks of international dog movement. In 2019, the United States Centers for Disease Control and Prevention (CDC) estimated that ~1.06 million dogs are imported into the United States annually (20); and in 2021, after detecting a 52% increase in the number of falsified rabies vaccination certificates, amongst other concerns, they implemented a suspension on importation of dogs from countries at high risk for dog rabies (21,22). Similarly, Finland reported a 10-fold increase in the number of imported street dogs in less than a decade, with 53% of dogs tested in 1 study lacking internationally acceptable rabies antibody titers despite arriving with vaccination paperwork (23). In addition to rabies, a study conducted by the Finnish Food Authority raised concerns about dogs imported from eastern Europe testing positive for antimicrobial-resistant bacteria, Leishmania spp. and B. canis antibodies (24). The importation of B. canis positive dogs from eastern Europe has also been a problem in the UK (25). Overall, the UK estimates that, as of 2017, 331 000 dogs are imported annually, many of which are deliberately or unintentionally falsely declared as personal imports (26).

When a dog is imported into Canada, the person receiving the dog (importer) must report it as either a commercial or personal import. The Canadian Food Inspection Agency (CFIA) defines “commercial dogs” as those intended for purposes including “given/transferred to another person, resale, adoption, fostering, breeding, show or exhibition and research” (27), whereas a personal import is “a dog that is intended to live with the owner who is bringing the animal into Canada as a personal pet dog” (28). Commercial dogs < 8 mo of age have more stringent importation requirements, such as permits, health certificates, and kennel of origin certificates, whereas commercial dogs > 8 mo of age and all personal imports only require a rabies vaccination certificate (28). Currently, the Canada Border Services Agency (CBSA) and the CFIA collect limited data on animals imported via the commercial stream and no data on animals imported via the personal stream, leading to difficulties in estimating the total number of dogs imported into Canada.

Although potential health and welfare risks associated with dog importation are evident, characterizing both the frequency of pathogen importation and the associated impacts is hampered by limited data on both the number of imported dogs and on disease surveillance in companion animals. The goal of this study was to estimate the total number of dogs imported into Canada from 2013 to 2019, and to describe the spatial and temporal trends to help inform future risk assessments.

Materials and methods

Derivation, cleaning, and validation of the commercial dog import dataset

Records of commercial import events into Canada from 2013 to 2019, inclusive, were extracted from CBSA systems based on Harmonized Commodity Description and Coding System (HS) codes. The HS is an international system that forms the basis of Canada’s Customs Tariff; all traders are required to assign HS codes to classify and declare their internationally traded goods (29). There is no specific HS code for dogs; they are instead captured under the “Other Mammals” code (HS 010619), along with other species. Dogs are also sometimes incorrectly declared under the “Other Animals” code (HS 010690). As a result, both “Other Mammals” and “Other Animals” importation events were extracted.

Using importer and exporter information, the dataset was cleaned to remove all records that were presumably not dog-related. Events with HS code “Other Mammals” were assumed to be dogs and included in the final dataset, unless it was clear based on keywords in the record that the species imported was not a dog (e.g., hedgehog, ferret, cat). Events with HS code “Other Animals” were assumed to not be dogs and excluded from the dataset, unless keywords in the record indicated it was dog-related (e.g., puppies, dogs, canine). Records related to research (e.g., universities, companies that supply research animals) were excluded, regardless of species. The same activity was assumed across all records for any given importer or exporter. For example, if 1 importer received dogs from a number of exporters and some were identified as a certain type (e.g., universities), it was assumed that all import events for that importer were the same (e.g., research) and they were excluded.

Included records were classified as either “dog” or “probable dog,” based on keywords. All import events for which importer or exporter information included any of the following words or derivatives were categorized as “dog:” dog, pooch, rescue, canine, K9, kennel, pup, hound, chien, wag, mutt, bar(c)k, and any specific dog breed names. All remaining events within the dataset were considered “probable dog.”

The number of dogs imported per event was only available in records collected under the “Other Mammals” code. Using these available data, the median number per event was calculated (n = 2), and median imputation techniques (30) were applied to complete the missing data.

A subset of electronically submitted “Other Mammals” events (n = 1989) from 2019 contained additional animal species information and was used to validate the inclusion/exclusion criteria that had been applied to the dataset. The validation process revealed a sensitivity and specificity of 99%, with only 1 event incorrectly included and 1 incorrectly excluded.

Each import record within the final dataset contained a unique ID, HS code, importer and exporter, dog classification (dog or probable dog), country of origin, country of export, state of origin, state of export (if from the United States), date of import, port of entry, number of dogs imported, and whether the dog originated in a country considered high-risk for canine rabies (31). Country of origin was used throughout the analysis unless this was listed as Canada. For those events, country of export was used, and these were assumed to be dogs that were originally from Canada but had travelled outside of the country for show or breeding purposes. Countries were further categorized into subregions based on the United Nations Classification System (32). For the subregion “Northern America,” which includes Canada, United States, and Bermuda, only United States was included, given the dataset did not contain any import events from Bermuda over the study period.

Analysis

Data were maintained, cleaned, and analyzed using Microsoft Excel 2016 and R Version 4.0.2 software, and maps were generated using ArcGIS Version 10.6. A descriptive analysis was completed to estimate the number of dogs imported commercially into Canada as a range, with the most conservative estimate (minimum) derived by adding the numbers in the variable “dog,” and the higher end of the estimate (maximum) derived by adding the numbers for “dog” and “probable dog.” Throughout the remainder of the descriptive analysis, only the maximum estimate was used to calculate the number of dogs and proportions imported from each subregion and country of origin. To estimate the change in the number of imports over the study period and by country of origin, relative change was calculated by subtracting the total number of dogs imported in 2013 from the total number of dogs imported in 2019, divided by the total number of dogs imported in 2013, and multiplied by 100.

Commercial-to-personal dog importation ratio

The CBSA does not routinely capture data on personal dog imports; however, detailed records of dogs imported personally into Toronto Pearson International Airport, Ontario, were recorded in April 2015 as part of a short-term monitoring effort. The number of dogs imported personally was compared to the number imported commercially during the same interval and at the same location in order to calculate the ratio of commercial-to-personal dog importations. The ratio was used as a multiplier to estimate the overall number of dogs imported into Canada during the study period.

Results

Commercial dog imports

Overall, an estimated 21 829 to 42 540 dogs were imported commercially over the 7-year study period. Annual numbers increased over the study period, and by 2019, almost 13 000 commercial dogs were being imported, representing a 418% increase compared to 2013 (Figure 1).

Figure 1.

Estimated numbers of dogs imported commercially into Canada from 2013 to 2019.

Dogs were imported from 117 countries across 20 subregions. The top 4 subregions (Northern America, Eastern Europe, Central America, and Eastern Asia) accounted for 87% of all commercially imported dogs (Table 1). Northern America and Eastern Europe were the top exporting subregions throughout the majority of the study period, and although both had increases over time (186 and 871%, respectively), the relative proportions shifted, with Northern America decreasing 29% and Eastern Europe increasing 12% by 2019 (Figure 2). The proportions of dogs imported from Central America (~10%) and Eastern Asia (~5%) remained stable over the study period; however, the total number of dogs being imported from these subregions increased by 506 and 1028%, respectively, over the study period (Figure 2).

Table 1.

Estimated number of commercial dogs imported into Canada, and relative change, by subregion of origin.

Subregion	Number of dogs (2013)	Number of dogs (2019)	Relative change from 2013 to 2019	Total estimated number of dogs (2013 to 2019)
Northern America	1627	4656	186%↑	18 917
Eastern Europe	330	3205	871%↑	11 587
Central America	236	1430	506%↑	4075
Eastern Asia	112	1263	1028%↑	2627
Western Asia	15	336	2140%↑	777
Australia/New Zealand	9	263	2822%↑	746
South America	10	227	2170%↑	702
Caribbean	4	496	12 300%↑	695
Northern Europe	22	138	527%↑	433
Southern Europe	35	238	580%↑	424
Western Europe	45	89	98%↑	406
Southeastern Asia	14	131	836%↑	362
Southern Africa	24	136	467%↑	345
Northern Africa	1	223	22 200%↑	270
Southern Asia	3	40	1233%↑	105
Polynesiaa	0	36	3600%↑	36
Eastern Africa	1	1	0%	17
Central Asia	2	4	100%↑	9
Melanesia	0	0	0%	4
Western Africa	0	0	0%	3
Grand total	2490	12 912	419%	42 540

^aNo (0) dogs were imported in 2013; therefore, 1 was used for that year, to calculate relative change.

Figure 2.

Estimated proportions of commercial dogs imported into Canada from 2013 to 2019 by top 4 subregions of origin.

Throughout the study period, the top 3 exporting countries were the United States, Ukraine, and Mexico. These countries accounted for ~86% of all dogs imported in 2013, but only 61% by 2019. The number of countries exporting dogs almost doubled over time, with 45 countries involved in 2013 and 89 by 2019. Over the study period, 72% of the 117 countries involved had an increase in the number of dogs exported to Canada (Table S1, available online from: www.canadianveterinarians.net), with Slovakia, Russia, and South Korea having the highest relative change from 2013 to 2019 (Table 2).

Table 2.

Estimated number of commercial dogs imported into Canada, and relative change, by top 10 countries and states of origin.

Country of origin	Number of dogs (2013)	Number of dogs (2019)	Relative change from 2013 to 2019	Total estimated number of dogs (2013 to 2019)
United States	1627	4656	186%↑	18 917
California	1040	742	−29%↓	7247
Texas	63	1346	2037%↑	2369
New York	151	45	−70%↓	996
Kentucky	2	382	19 000%↑	975
Ohioa	0	338	33 700%↑	914
Florida	59	43	−27%↓	761
Alabama	58	102	76%↑	553
Missouri	30	105	250%↑	513
Georgia	22	126	473%↑	471
Minnesota	8	5	−38%↓	433
Ukraine	273	2042	648%↑	5710
Mexico	235	1298	452%↑	3924
Slovakia	1	155	15 400%↑	2589
Hungary	23	595	2487%↑	1403
South Korea	10	822	8120%↑	1394
Poland	15	215	1333%↑	994
Russia	1	153	15 200%↑	726
Australia	9	207	2200%↑	640
Taiwan	79	143	81%↑	633
Top 10 totalb	2273	10 286	353%↑	36 930

^aNo (0) dogs were imported in 2013; therefore, 1 was used for that year, to calculate relative change.

^bTotal number of dogs imported from all countries = 42 540.

Two states (California and Texas) accounted for 51% of the commercial dogs imported into Canada from the United States (Table 2). Although imports from California accounted for 64% of American dogs in 2013, this decreased to 16% in 2019. Inversely, the proportion of dogs imported from Texas increased 25% over the study period.

An estimated 9725 dogs (23%) were imported into Canada from 55 countries considered high-risk for canine rabies over the study period (Figure 3). Ukraine and Russia accounted for 66% of these dogs; however, Dominican Republic and Egypt had the highest relative change over the study period (Table 3). In 2019, 3722 of the dogs imported into Canada originated in 1 of these high-risk countries, representing a 10-fold increase since 2013. The proportion of dogs imported from countries at high risk for canine rabies rose from 14% in 2013 to 29% in 2019 (Figure 4).

Figure 3.

Map showing the estimated numbers of dogs imported into Canada from countries at high risk for canine rabies (31) from 2013 to 2019.

Source: Public Health Agency of Canada.

Table 3.

Estimated number of dogs imported commercially into Canada from top 10 countries of origin at high risk for canine rabies (31).

Country of origin	Number of dogs (2013)	Number of dogs (2019)	Relative change from 2013 to 2019	Total estimated number of dogs (2013 to 2019)
Ukraine	273	2042	648%↑	5710
Russia	1	153	15 200%↑	726
Colombiaa	0	197	19 600%↑	586
China	20	264	1220%↑	509
Dominican Republica	0	299	29 800%↑	437
South Africa	22	136	518%↑	341
Egypt	1	218	21 700%↑	260
Turkeya	0	54	5300%↑	257
Thailand	3	103	3333%↑	242
United Arab Emirates	11	47	327%↑	180
Top 10 totalb	331	3513	961%↑	9248

^aNo (0) dogs were imported in 2013; therefore, 1 was used for that year, to calculate relative change.

^bTotal number of dogs imported from all high-risk countries = 9725.

Figure 4.

Estimated proportions of dogs imported into Canada from countries at high risk for canine rabies (31) from 2013 to 2019.

The majority (67%) of commercially imported dogs arrived in Canada by air. Of the 33% that arrived by land, 99% originated in the United States. Whether entering by air or land, no seasonality was detected in the number of dogs imported over the study period. Most dogs arrived in Canada through ports in Ontario (47%) and Alberta (24%) (Table 4). Pearson International Airport in Toronto, Ontario, received the most dogs over the study period (31%), and in 2019, it received 48% of all commercial dogs. There were some differences in dog import patterns observed across Canada. Dogs arriving in Toronto (Ontario), Vancouver (British Columbia), and Montreal (Quebec) airports were more often from Eastern Europe, whereas Calgary (Alberta) was more likely to receive dogs from Northern or Central America (Figure 5).

Table 4.

Total estimated number of dogs imported commercially into Canada from 2013 to 2019, in ascending order by province/territory^a and by air/land port of entry.

Province or territory	Total estimated number of dogs (% total)
Air or land port of entry
Ontario	20 117 (47%)
Toronto Pearson Intl. Airport	13 220
Niagara Falls	2219
Fort Erie	1315
Sarnia	1248
Windsor Detroit/Canada Tunnel	1235
Other	880
Alberta	10 270 (24%)
Calgary Intl. Airport	6491
Coutts	2549
Edmonton Intl. Airport	1178
Other	52
British Columbia	7148 (17%)
Vancouver Intl. Airport	4646
Pacific Highway	1768
Other	734
Québec	2963 (7%)
Montréal–Pierre Elliott Trudeau Intl. Airport	2565
Lacolle	339
Other	59
New Brunswick	1411 (3%)
St. Stephen	1409
Fredericton Intl. Airport	2
Manitoba	383 (1%)
Emerson	294
Winnipeg Intl. Airport	81
Other	8
Saskatchewan	165 (< 1%)
North Portal	134
Saskatoon Intl. Airport	6
Other	25
Nova Scotia	62 (< 1%)
Halifax Stanfield Intl. Airport	61
Yarmouth	1
Yukon	16 (< 1%)
Beaver Creek	16
Total number of dogs	42 535b

^aProvinces and territories not listed (Newfoundland and Labrador, Prince Edward Island, Nunavut, Northwest Territories) had no dogs imported during the study period.

^bData not available for 5 events.

Figure 5.

Estimated numbers of dogs imported commercially into Canada from 2013 to 2019 from the top 5 subregions of origin, by the top 4 ports of entry.

A total of 892 importers were involved in dog importation activities throughout the study period. The number of importers involved per year increased from 104 in 2013 to 445 in 2019. The median number of dogs imported by a single importer was 5 (range: 1 to 2012). Four importers (2 self-declared as rescue organizations and 2 assessed to be breeders, based on information provided) each received > 1000 dogs over the study period, accounting for 14% of all dogs imported. For the 2 of these importers assessed to be breeders, all dogs originated in Eastern Europe, whereas the 2 rescue organizations imported the majority (79%) of their dogs from the United States. Overall, 4105 exporters were identified throughout the study period. The top 3 exporters supplied 79% of the dogs received by the top 3 importers.

Estimated total number of dogs imported into Canada

In April 2015, 134 personal and 71 commercial dogs were imported through Toronto Pearson International Airport, resulting in a ratio of 1.9 personal dogs for every 1 commercial dog imported. Assuming that this ratio of personal-to-commercial importations was the same over the study period and across regions, an estimated total of up to 123 366 dogs were imported into Canada from 2013 to 2019, including an estimated 37 445 in 2019.

Discussion

This study is the first to estimate the number of dogs imported into Canada and to describe importation trends over space and time. Overall, there was a substantial increase in the number of dogs imported into Canada over the study period, with an estimate of over 37 000 annually by 2019.

In addition to the overall increase in the number of dogs, there were shifts in the dogs’ countries of origin. Although the United States was the primary source of dogs throughout the study period, numbers proportionally declined as more countries supplied dogs, including countries considered high-risk for canine rabies. Eastern Europe has become a top supplier of dogs imported to Canada, especially from Ukraine, Slovakia, Hungary, Poland, and Russia. Much of this activity is thought to be linked to the importation of supposedly purebred dogs, which indicates a possible growing issue with international puppy mills (33), considered the 3rd most lucrative form of illegal trade in Europe (34).

Ports of entry across Canada received dogs from various countries of origin in varying proportions. From this, it follows that the risk of importation of certain pathogens may differ by province (35). Similarly, the large proportion of dogs arriving from the southern United States may have different risk implications than those coming from more northern states, especially considering the influence of climate change and increasing suitability for translocated pathogens and vectors (36). As the number of dogs imported increases, the strain placed on humans and animals at the ports of entry also increases, affecting both animal welfare and the efficiency and effectiveness of the overall importation process. If trends continue to increase, new facilities to accommodate dogs at ports of entry may need to be considered, as was done in New York with the creation of the ARK, a veterinary facility where imported dogs and their paperwork could be thoroughly assessed before release (37).

This study estimates that up to 37 000 personal and commercial dogs were imported in 2019, but this number is likely still an underestimate. With the UK estimating a 10:1 personal-to-commercial import ratio (26), and the United States estimating that < 1% of dogs are commercially imported (20), the 1.9:1 ratio used in this analysis is considerably more conservative, and it follows that the overall number of dogs imported into Canada could be considerably higher. More detailed tracking of both personal and commercial dog imports would help to further refine these estimates.

Although most prospective dog owners have good intentions when seeking an international dog for adoption or purchase, they are often unaware of the additional risks associated with imported dogs. In some cases, pet owners may not even know that their new dog was imported. There are documented cases in the United States and Canada of imported dogs being sold as domestically bred, often for a large profit (37). Educating owners before they purchase a dog about the importance of thoroughly researching any breeder or rescue group, as well as the potential health and welfare issues associated with international adoption, may help reduce these risks. Veterinarians and their staff are often a first point of contact for new dog owners, so these groups should also be educated on dog importation risks and provided with resources that can be shared with clients to help bridge gaps in public awareness. Individuals and organizations involved in dog importation also need to be educated, not only about the animal health and welfare concerns, but also about the current importation process, as this would help improve the accuracy of dog importation data. Research indicates that many dogs are incorrectly declared as personal pets; however, additional research is required to determine if these actions are deliberate or simply due to a lack of education (26). Given that a large number of groups and individuals are involved in importing dogs commercially into Canada, educational campaigns should be broad rather than targeted toward a small number of individuals or groups.

Limitations and recommendations

There are several limitations of this study to note. Given that there is no HS code specific to dogs, importation events may have been misclassified, potentially leading to dogs being excluded or other animals being included in the dataset. Although it was possible to validate a subset of the “Other Mammals” events, additional information was not available for “Other Animals,” so these entries could not be assessed further. In addition, having to estimate the number of dogs for each “Other Animals” event could have led to an over- or underestimation of the true number of dogs imported commercially. Developing a tracking system that can differentiate species would enable more accurate estimates.

Differences in the spellings of importer and exporter names may have resulted in an overestimation of the true number of importers and exporters involved. In future, an automated system that captures and digitizes standardized import data with rapid data retrieval capabilities could help to improve consistency of data entry and recording across import events.

Since personal dog importation is not tracked in Canada, the estimate in this study was extrapolated using a small dataset, collected from a single port of entry over 1 mo in 2015, when dog importations, based on this analysis, were relatively low. Based on other countries’ estimates of commercial-to-personal import events, the ratio used in this study is likely underestimated. A formal tracking system in which personal and commercial dog imports are documented would provide more accuracy and confidence in these estimates.

In conclusion, this research represents the first step in quantifying the risk associated with dog importation in Canada, by providing an estimated range of the number of dogs imported from 2013 to 2019. The results demonstrate that dog importation has increased substantially over time; however, it is unknown how global changes, including the COVID-19 pandemic and new importation measures in Canada (38) and the United States (22), will influence these trends. Assessing the risks associated with canine importation and mitigating them through education and improved tracking will be essential moving forward. CVJ