Ontario Animal Health Network (OAHN)
Companion Animal Expert Network
Veterinary Need-2-Know (N2K) Update – Jan-Apr 2024

OAHN spring survey and lab data: Key results

There were 93 survey respondents from 36 counties, including primary care, referral, emergency and mobile practices. As in the spring of 2023, the primary infectious disease concern was increases in ticks and tick-borne diseases, including pulling ticks off animals as early as February, and a cluster of cats testing positive for Anaplasma in Lanark county.  There were also multiple heartworm cases reported in Lambton and Toronto. “Spring dietary indiscretion” was noted by a few respondents (the things dogs eat …). Another comment about chronic diarrhea in patients previously treated with antibiotics for (acute) diarrhea highlights the importance of limiting use of antimicrobials in these cases whenever possible, from both a patient health and antimicrobial stewardship standpoint.  The new ENOVAT treatment guidelines for acute diarrhea in dogs will be available soon, and there is also the OAHN “Treat me right” infographic on the same topic!

At AHL, there was a rash of cases presented for necropsy diagnosed with suspected or confirmed parvoviral myocarditis or enteritis.  A cat with suspected mammary carcinoma turned out to be an unusual case of cutaneous blastomycosis, as a result of being impaled by a garden stake.  Trichinella was found in an excisional biopsy of an eyelid mass from a dog from Northern Ontario. Trichinellosis was then also diagnosed incidentally in another unrelated Ontario dog.

H5N1 flu: Cows & cats

H5N1 highly pathogenic avian Influenza A (HPAI) continues to keep everyone on their toes. Since March, it has unexpectedly been found in dairy cattle in over 60 herds in at least 9 US states. While most dairy cattle appear to recover from infection with time and supportive care (much like routine flu infections in other mammals like pigs, horses, dogs and people), cows shed large amounts of virus in their milk. Pasteurization effectively kills bacteria and viruses, including HPAI, so pasteurized products are safe to consume, but raw milk from infected cows is a risk, and has likely contributed to fatal H5N1 infections in barn cats fed raw milk on some of these dairies. This H5N1 flu has caused outbreaks in at least 29 species of mammals worldwide; in many of these (including cats) disease has frequently been fatal, but we still don’t know how often milder or subclinical infections may occur, especially in wild mammals.

The risk of humans contracting the H5N1 influenza continues to be very low. Nonetheless, owners are encouraged to take appropriate precautions to protect their pets and themselves by avoiding direct and indirect contact with sick or dead wildlife, especially migratory birds.  There are also precautions to take around livestock.

Ontario has only had two infected poultry premises since last summer, but there have been numerous detections in wild birds and one skunk (in Thunder Bay) this spring.

The companion animal and wildlife OAHN teams, along with CWHC, continue to collaborate on a joint pilot project on H5N1 influenza in primarily outdoor / feral cats.  Visit the project webpage for details on case eligibility, sample collection and submission.

Survey: FIP drug use

In February, Health Canada approved access to GS-441524 and remdesivir for the treatment of feline infectious peritonitis (FIP) through the emergency drug release (EDR) process.  Based on our OAHN survey results:

• 27% of respondents were still not aware that these drugs could be accessed legally in Canada (they are now! spread the word!)
• Only 1 respondent had ordered drug for a patient, but others had referred cats to clinics that had the drug on hand. Patients were responding well to treatment.

While it still takes about a week to order and receive drug, and a full treatment course is still not cheap ($2-3K+), legal access to these drugs is a game-changer. Veterinarians in the US will also soon be able to access these compounded drugs as of June 1, 2024. Work is also being done to help determine the most effective and efficient treatment regimens and further refine current recommendations. More information on FIP treatment guidelines and the EDR process for Canadian veterinarians is available on the Worms & Germs Blog.  Also watch for a new OAHN podcast on FIP treatment this summer!

Changes to US dog import rules – August 1

The US CDC has announced new rules for dogs coming into the US that will take effect on August 1, 2024.  The rules vary based on the country of origin, but ALL dogs will need to:

• Be at least 6 months old
• Have a microchip
• Appear healthy on arrival
• Have a CDC Dog Import Form receipt

Dogs crossing the border from Canada will require at least one additional document and other records, such as:

• Certification of Foreign Rabies Vaccination and Mircochip AND [a valid rabies serology titre OR 6 months of veterinary records]
• Certification of Dog Arriving from DMRVV-free or Low-Risk Country AND 6 months of veterinary records

A lot more details are available on the CDC website, including their DogBot to help determine what rules apply to a particular dog. It’s going to be more complicated, but not insurmountable for most Canadian dogs.  It will be more problematic for those travelling on an emergency basis (e.g. for veterinary care) and puppies less than 6 months old (good for discouraging puppy mill operators, but a business issue for legitimate dog breeders).  Some clarification is still needed on a number of aspects, and the CFIA is currently reviewing the requirements and engaging with the US authorities to provide further guidance as soon as possible.

Comments or concerns can be submitted to the CFIA via their online contact form.

RHDV2: Back again

Another case of rabbit hemorrhagic disease (RHD) was confirmed in a 7-year-old indoor pet rabbit from southern Quebec in April 2024. The rabbit died 3 days after becoming ill. There were no other rabbits on the property, but this virus can be easily transmitted by fomites and survives in feed for months. The last case in Quebec was detected in July 2023, and the virus was detected on two separate premises in Ontario in mid-2022. The OAHN wildlife and companion animal networks continue to offer heavily subsidized RHDV2 testing for wild and domestic rabbits. To date, more than 100 wild rabbits in Ontario have been tested, but only a handful of pet rabbits. For more details and eligibility, please contact Dr. Alexandra Reid via email, or via the OMAFRA AICC at 877-424-1300 during business hours.

Rabies update

It has been almost a full year since the last detection of raccoon-variant rabies in Ontario (!), but we must remain vigilant for new incursions or translocation events, and for lingering cases, particularly in the St. Catharines area.  Contact with bats remains a risk throughout Ontario, and 7 rabid bats have already been detected in 2024.

Rabies information for Ontario veterinarians is available on the Ontario.ca website. For additional resources and flowcharts, log in and visit the OAHN rabies resource page for veterinarians. Rabies information for the general public, including the MNRF’s interactive rabies case map and planned 2024 rabies control operations, is available at Ontario.ca/rabies.

New & updated OAHN resources for vets!

Check out all the latest veterinary resources and references available for free from OAHN!

• UPDATED Anti-parasitics for dogs and cats (Canada 2024): simplified (open access) and veterinary (login required)
• Raw meat-based diets infosheet: developed in collaboration with Worms & Germs Blog, to help talk to clients about the risks
• Drug-resistant hookworms in dogs factsheet: how to differentiate resistance vs larval leak, how to manage (login req.)
• Antimicrobials for dogs and cats (Canada 2024): quick reference for categorization of on label and off label drugs to help improve antimicrobial stewardship

Promoting One Health @ your clinic

A free One Health promotional kit from the CVO, OVMA and OAVT is now available to help spark discussions with clients about how human, pet and environmental health are connected (not just by infectious diseases!).

A who’s who of Companion Animal surveillance in Ontario

Check out the new summary graphic about all the individuals and groups that contribute to disease surveillance in companion animals in Ontario!

Help us help you!

Have an idea for an infographic you’d like to see, or a podcast you’d like to hear? Email oahn@uoguelph.ca to let us know!