Ontario Animal Health Network (OAHN)
Companion Animal Network Team
Veterinary Need-2-Know (N2K) Update – Sep-Dec 2023

OAHN fall survey and lab data: Key results

There were 64 survey respondents from 27 counties, including primary care, referral, emergency and mobile practices. Once again, the primary infectious disease concern was increases in canine infectious respiratory disease complex (CIRDC), as well as a general increase in concern among clients regarding CIRDC due to the media attention in the fall.  A small cluster of leptospirosis cases was detected in York region; there are some helpful flowcharts available on the OAHN website to help practitioners navigate the complexities of diagnosing leptospirosis.  There were also at least two heartworm cases detected in the Ottawa area.

CIRDC – Same bugs doing more of the same

There has been a huge amount of media attention regarding the recent perceived increase in CIRDC cases in the US and Canada. While good surveillance data is lacking, a number of experienced research groups have failed to find any novel pathogens or strains in affected dogs, and analysis of insurance data suggests the “outbreak” is most likely the usual suspects doing their usual thing at a slightly higher rate (and possibly accentuated by the number of Frenchies now present in the population).  Clinics should focus on prompt triage of incoming cases, and encourage owners to think about their dogs’ “social networks” to help decrease the risk of community spread. Most affected dogs do not need antimicrobials, but anti-inflammatories and antitussives can be very helpful.

Treat me right: Acute dog diarrhea

A systematic review and meta-analysis of antimicrobial and nutraceutical treatment of acute diarrhea in dogs (Scahill et al. 2023) was recently published.  The main conclusions were that neither antimicrobials nor nutraceuticals (e.g. probiotics, fibre supplements) had a relevant clinical effect in these cases in terms of duration of diarrhea or hospitalization, or progression of disease (to name a few).  The certainty of the evidence with regard to antimicrobials was considered high in dogs with mild or moderate disease, but was low for dogs with severe disease.

The review was performed for the European Network for Optimization of Veterinary Antimicrobial Treatment (ENOVAT), which is expected to release new guidelines for acute diarrhea in dogs very soon, including an infosheet and a handy flowchart.  OAHN will share the materials when they’re available!  In the meantime, check out the OAHN “Treat me right” infographics on acute diarrhea and giardiasis in dogs and cats, and think twice before reaching for those antibiotics!

Survey: Anaplasma diagnosis & treatment

In an effort to learn more about the situation with anaplasmosis in dogs and cats across Ontario, the OAHN fall survey asked some specific questions about how often clinics are diagnosing exposure to this tick-borne pathogen and how they manage it:

  • 86% of respondents reported the same or slightly increased numbers of seropositive dogs in 2023 compared to 2022, and 84% reported approximately the same number of dogs with suspected clinical anaplasmosis.
  • 67% of respondents reported that for clinically normal seropositive dogs, they routinely run a complete blood count (CBC), which is the main recommendation in these cases. Of note, 10% of respondents reported that they routinely prescribe antimicrobials for these dogs; remember that antimicrobials are only recommended if the dog is clinically ill and/or has compatible changes on CBC.
  • Clinical anaplamsosis in cats appears to remain rare (or rarely diagnosed) overall.

Anaplasma phagocytophilum was added to the list of periodically notifiable hazards in Ontario in February 2023, which will hopefully improve our ability to monitor trends in this disease over time.

Ontario seroprevalence maps for this and other tick-borne diseases (based on monthly data provided by Antech and IDEXX laboratories) are available on the Companion Animal Parasite Council website.

Rabies update

In total, 6 skunks and 1 cat with rabies were detected in the St. Catharines area in 2023, along with 49 rabid bats across the province.

Rabies information for Ontario veterinarians is available on the Ontario.ca website, including risk assessment and post-exposure management guidelines.  You can view or download a pdf of the OMAFRA rabies risk assessment flowchart on the OAHN website. For additional resources and flowcharts, log in and visit the OAHN rabies resource page for veterinarians.

Rabies information for the general public is available at Ontario.ca/rabies, including the MNRF’s interactive rabies case map.

Update: Raw food XDR Salmonella Outbreak

In November, the Public Health Agency of Canada (PHAC) issued a follow up report on this outbreak, which was originally reported in Quebec.  A total of 40 cases in six provinces have now been detected since 2020, including 14 in Ontario. Children under 5 accounted for 43% of cases, and 13 people were hospitalized. While there were no human deaths, deaths in dogs and calves were reported. The main risk factors for infection were exposure to raw pet food or dogs fed raw food, and contact with cattle (calves).  This once again reinforces the risks of feeding raw pet diets, and the need for close attention to hygiene and other important precautions if owners chose to use them anyway.

AM susceptibility reporting changes

There has been a significant update to the CLSI performance standards for veterinary antimicrobial susceptibility testing.  It will take some time for diagnostic laboratories to implement these changes to their testing and reporting processes, but ultimately they should result in much more accurate reporting of the antimicrobial susceptibility of bacterial isolates from animals, which will help improve treatment success and avoid treatment failures.

Some of the key updates include:

  • Significantly lower breakpoints for enrofloxacin in staphylococci, Enterobacterales and Pseudomonas from dogs
  • Significantly lower breakpoints for chloramphenicol in staphylococci from dogs
  • The addition of “susceptible, dose dependant” (SDD) breakpoints for certain drugs (like fluoroquinolones) that can be safely used at a higher dose in some (canine) patients to help overcome low-level resistance
  • A change in terminology from “urinary tract infection breakpoints” to “urine breakpoints” to more accurately reflect that these are only applicable to lower (but not upper) UTIs, where bacteria may be exposed to higher concentrations of drug in the urine

These breakpoints are all based on mean inhibitory concentration (MIC) data.  For more details on these changes and interpreting MIC data, check out the posts on the Worms & Germs Blog.

FIP treatment options

In recent years, effective treatment options have been discovered and studied for the previously almost-invariably-fatal feline infectious peritonitis (FIP).  Treatment with the nucleoside analog GS-441524 and its parent nucleotide analog, remdesivir, have both proven to be effective options. Access to these drugs has been a huge challenge, with neither being approved for use in Canada, and none of the current manufacturers willing to provide the drugs based on an emergency drug release (EDR). This has led desperate cat owners to turn to disreputable sources to try to obtain the drug, often at great expense.

As of February 8, Health Canada’s Veterinary Drugs Directorate (VDD) has approved legally compounded remdesivir and GS-441524 products from the UK for importation through an Emergency Drug Release application, for veterinary use in individual patients.  More information is available on the Worms & Germs Blog.

RHDV2 subsidized testing still available

The OAHN wildlife and companion animal networks continue to offer subsidized RHDV2 testing for wild and domestic 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.

Anti-parasitics table: Update coming soon!

One of our most popular resources – the OAHN anti-parasitics table for dogs and cats – will be getting an update for spring 2024.  Stay tuned to OAHN for more information!

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!



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