Brucella Canis Update

Since the Royal (Dick) School for Veterinary Studies put a Brucella canis protocol in place in June 2022, our hospital staff have become more skilled and accustomed to managing the risk posed by Brucella canis.

The Animal and Plant Health Agency (APHA), alongside other agencies, have engaged in a full review (HAIRS report) and recently concluded that the risk posed by Brucella canis is low, as long as appropriate precautions are taken and staff are educated in managing high-risk patients.

Given the serious consequence of a true positive diagnosis, our team wishes to ensure that only dogs highly suspicious for the disease are tested and that the chosen tests are as accurate as possible.

It is with this in mind that our hospital team continues to make changes to our testing recommendations which we hope will strike an improved balance between the need for ongoing disease surveillance, staff safety and patient welfare.

What is the advised change to current referral protocol in May 2024?

Not all travelled dogs will be blanket tested. Instead, the decision to test will be based on the presence of risk factors and the clinical signs presented by the dog.

Patient side testing will no longer be used at our hospital. All dogs who are therefore deemed high-risk who present to our hospital having not previously undergone B.canis testing will be required to undergo reference laboratory testing at (APHA).

Why has this change been made? 

Whilst patient side tests provide rapid results, their accuracy remains in question with false results regularly complicating patient care and client communication. Now that the team is more experienced in rationalising the use of PPE in high risk B.canis cases we feel more comfortable managing patients whilst awaiting reliable, reference laboratory results.

How do these specific changes affect my referral? 

We continue to recommend pre-referral testing for any non-urgent dog that originates from high-risk countries including Americas, Asia, Africa, Eastern and Central Europe with compatible clinical signs of B.canis. Dogs from Eastern Europe should ideally be tested before referral, regardless of the presenting reason.

Travel and reproductive history remain a vital piece of any clinical history and any breeding dog, travelled or otherwise, or dog with known reproductive issues history (e.g abortion or infertility) should have testing considered. Our internal medicine team are more than happy to discuss specific cases and whether testing is warranted. 

A negative APHA test result will permit the referral appointment and procedures to proceed as normal. If a dog’s condition deteriorates, and test results are pending, advice can be sought from our internal medicine team as with guidance, additional diagnostic tests may be able to be performed at your practice. Emergent referrals of high-risk dogs, or those tested within 3 months of possible exposure will be accepted but we ask for your patience as isolation space is limited and each high-risk patient requires a significant amount of planning. 

Whilst culture and PCR are the only way to confirm a B.canis infection, serological tests (antibodies), despite their limitations, continue to be the easiest way to test Brucella infection in dogs. It is important to understand that false negatives can arise if testing of the patient was early in the course of infection (within three months of travel), whilst false positives are reported if other infections are present. As such we may request that a repeat APHA tests are performed, ideally after three months later to ensure seroconversion. 

The serological test must be performed by APHA and takes between 7-21 days to return. It requires a single blood sample (2ml serum), which should be submitted to your local APHA laboratory. Please continue to factor this in for routine, non-emergent cases. 

The test codes are as follows: 

• Brucella canis SAT (TC1032) which tests for IgM. 
• Brucella canis iELISA (TC0116) which tests for IgG. 

These can be sent directly to the APHA as per sample submission form LSW008, and costs are as per the APHA Scientific Tests price list (vla.gov.uk). All diagnostic samples should be packaged and dispatched in according with UN3372 packing regulations. 

Results should be forwarded to the RDSVS Hospital for Small Animals reception (HFSAreception @ed.ac.uk) with the referral request. Results will be made available to the relevant hospital department and referral of a positive dog can still proceed, albeit with strict barrier nursing in place, in the event of a true positive. Clients should as always be reminded of the increased cost associated with B.canis testing and barrier nursing.

Any referring practices that require additional information can contact one of our internal medicine specialists who will be happy to advise about patient management and testing.