Discospondylitis Meta-Analysis in Dogs

A recently published (January 2026) meta-analysis of discospondylitis (DS) in dogs was a good review of what we do, or should do, when faced with these cases.

This was a meta-analysis, which means that the authors undertook the difficult job of evaluating the available literature about DS and deciding if it was bias, and what the collective “take away” message could be.

• All 48 included studies were retrospective case series or cohort studies, all with moderate–high to high risk of bias. There were no standardized outcomes, further complicating the knowledge gained.

• Surgical and medical management were comparatively effective, remembering that surgical correction is reserved for very selective cases. (69 and 75% respectively).

•  Practical implication: This paper does not justify earlier or more aggressive surgery in otherwise stable cases.

How should you manage a case with suspected discospondylitis based on this meta-analysis?

Imaging

• Radiographs are the first line diagnostic tool, but evidence is often delayed (2–8 weeks after clinical onset).

• CT and MRI are equivalent for detecting DS lesions, with MRI offering better soft-tissue and epidural assessment.

Culture

• Disc sampling (CT- or fluoro-guided) has the highest diagnostic yield.

• Blood and urine cultures are important but less sensitive.

• Empirical antibiotics before sampling were common and contribute to bias—but also reflect real-world constraints.

Take away: If the patient is stable enough, delay antibiotics until cultures are obtained

Antibiotics

• Culture-guided antibiotics are strongly recommended (although about 1/3 of bacterial DS is culture negative at the time of diagnosis)

• Most commonly reported empiric choices: Amoxicillin–clavulanate and Cephalexin because they readily cross into bone and are broad spectrum.

• Mean duration of treatment: ~105 days (~3.5 months). Remember, this is a study evaluating studies so some of these patients stopped treatment and relapsed, some stopped treatment due to euthanasia and some stopped treatment with stringent criteria. I stop treatment after radiographic evidence of disease resolution which typically means 6+ months of antibiotics. I (knock on wood) haven’t had any relapsed cases in 20+ years but perhaps I’m OVER treating?

Antifungals

• Ketoconazole, itraconazole, and fluconazole were effective in reported cases.

• Fungal DS remains uncommon but should be suspected in German Shepherds, systemic illness, or poor antibiotic response.

Monitoring response

Across studies, follow-up quality was inconsistent, but practical trends emerge:

• Neurological exam + pain assessment were the most reliable indicators of response.

• Imaging was variably used; MRI/CT follow-up was uncommon.

• Radiographic “healing” lagged behind clinical improvement.

Surgical Treatment

Surgical intervention is complicated. Anytime we go to surgery on an infected site we risk spreading the infection, so it is often reserved for dogs with vertebral instability, pathological fracture or subluxation or progressive neurological deficits AND we think instability is the cause. This study also listed failure of adequate medical management as a reason to pursue surgery, but I struggle with this reason. What constitutes failure? That doesn’t automatically mean a surgical treatment is needed, does it? This study reiterated that surgical correction is adjunctive to medical management but does not replace antibiotics or antifungal treatment.

What is the big-picture takeaway (clinical bottom line)

This systematic review reinforces what most of us already do in practice:

• Medical management with prolonged, targeted antimicrobials remains first-line for the majority of canine DS cases.

• Surgery is clearly indicated in specific scenarios (instability, neurological deterioration, failure of medical therapy).

• Evidence quality for these studies was uniformly low, so decisions should be driven by clinical status, imaging findings, and response to therapy, not perceived “success rates” alone

• Counseling owners on the long term need for treatment is important up front.

Thanks for reading! I enjoy reading studies that remind me that sometimes the basics are really the best route for our patients. We all love shiny new surgical treatments or fancy sounds medications (me included), but we shouldn’t lose sight of the tried and true treatments either. Thanks for reading! I hope you have a good week and stay healthy out there!

Reference: Vallios VI, Sourla E, Low D, et al. VetRecord 2026. DOI: 10.1002/vetr.70334

Long-term infection and monitoring of Brucella suis in dogs

B.suis, you say? Why do I need t know about a swine variant of Brucella?? Did you know that B. suis can be pathologic in dogs, as well as swine, and is also zoonotic? You're welcome :)

A recently published article detailed the clinical signs, blood work, imaging (when available), serologic progression over time, and body fluid levels of organism over an 18 month period in 27 dogs from 17 households. The study population was located in Australia where naturally occurring B. canis is not found. Exposure to feral pigs was considered an important source of disease acquisition and may be a stand alone reason to test. (1 in 10 pigs are positive in Australia.) Although B. suis is not as commonly noted in our US canine population, we are a global veterinary profession now with lots of dogs traveling or being adopted from international locations. I felt this article was a nice reminder that B. suis exists, and is pathologic in dogs as well as having zoonotic potential, like B. canis. 

Clinical Signs of B. suis

Ten dogs had clinical signs attributed to brucellosis. Clinical signs included pyrexia with orchitis and epididymitits (4/10), lymphadenopathy (1/10), spinal pain (3/10), abortion or dystocia ( 1/10), and athritis (2/10). The remaining 17 dogs were assymptomatic throughout the entire 18 month period!

Serology and PCR

Titers did not correlate with severity of signs. Postive results were deemed positive if a Rose Bengal rapid plate test (RBRPT) yielded a positive result along with a complement fixation test (CFT) greater than or equal to 8. Only 2 dogs had seronegative results after 18 months and both had low baseline serology. Brucella DNA was not detected by PCR in blood, urine, saliva or preputial swabs in any dog at any time in the study. Notably, they weren't swabbed weekly or daily, so it is possible that some shedding occurred without detection on the sporadic testing. Only 3 positive PCR tests were found and this occurred in 1 bitch post whelping (vaginal fluid), as well as milk at 3 and 7 weeks post whelping as well as a lymph node at necropsy on a puppy that died. Although culture may be the gold standard diagnostic test for some countries, the RBRPT and CFT were considered safter to personnel performing the test and were preferred in this study. 

Diagnostic Imaging Results

Fifteen dogs had some sort of radiograph taken during the study period. Two of 15 had joint siease, 3/15 had vertebral lesions and 2 of 15 had lymphadenopathy. The dogs with radiographic changes had spondylosis, which we know can be a normal finding, therefore I question the inclusion of this as a clinical sign of brucellosis. 

Treatment Response

Six dogs were treated with doxycycline and rifampicin (one dog relapsed and was treated twice. It was generally well tolerated with one case of marked hepatitis. There is no standardized treatment for brucella and many dogs are considered to harbor the bacteria long-term, with or without clinical signs, with intermittent bacteremia. The zoonotic risk to humans, therefore remains present with dogs with a current or historic positive Brucella test. Euthanasia is the recommended treatment for positive livestock, however this causes emotional conflict for veterinarians and owners of companion animals. Check with your local veterinary health directors to determine the legal requirements in your state or country. This is a reportable disease in the USA. 

If you'd like to read more about this study you can find it here: https://onlinelibrary.wiley.com/doi/epdf/10.1111/jvim.16678

In honor of Memorial Day yesterday, I wish to thank all of you that have served or have friends or family members that have been lost during military service. We honor you!

Have a wonderful week! My schedule has changed for summer so please reach out if you cannot find a suitable time for a consult online - I may have additional flexibility that isn't listed. 

Zoonotic Discospondylitis!

This week I thought we could brush up on Brucella canis; an uncommon (in the northern US and Canada) cause of discospondylitis in dogs and a zoonotic disease of importance for humans. Why should we talk about this? Because I was contacted by a Wisconsin vet to help manage this case and I thought we could all benefit from this endeavor. 

What is Brucella canis?
Brucella is an intracellular bacteria that is known to be a cause of abortions and still birth in dogs. Dogs are the known reservoir for this bacterium however other Brucella spp. can be transmitted to dogs on rare occasion.

What signs does it cause?
Brucella canis is known to cause abortion and stillbirth in dogs but it's lesser known signs include discospondylitis, uveitis and fatigue/fever. Have I mentioned this is zoonotic? Wear gloves when handling the dogs, and any excrement. Avoid contact if pregnant.

When should I test a dog for Brucella canis?
Any dog with a history of chronic back pain that is diagnosed with discospondylitis should be tested for Brucella canis. The original case I was involved with had a several year history of "not wanting to be petted on the lumbar spine" that progressed to overt signs of pain over a few months. Another case was imported from Canada (not exactly a hotbed of B. canis activity!) with signs of back pain over several months duration and the most recent case I am working with the dog has a several month history of back pain, as well.

How do you treat Brucella canis in dogs?
Management is NOT recommended by experts and State Veterinarians due to the risk to human health and the poor likelihood of actual cure. No universally accepted treatment protocol is available however several choices in published literature include tetracycline-based antibiotic, aminoglycosides, enrofloxacin or rifampin. Some protocols recommend 2 or more drugs in combination, others have solo management. Repeated screening every 2-6 months, regardless of signs, is recommended. If treatment is going to be stopped, two sequential negative tests are recommended before stopping antibiotics. This is likely to be 8+ months after initiation of treatment...if ever. However, screening should continue life long to catch subclinical relapses. Again, euthanasia is recommended by the veterinary community.

What do you do if you have a suspected or confirmed B. canis infection in a dog?
If you live in in the USA, call your State Vet. This is a reportable disease and must be reported! Furthermore, the state vet can provide additional guidance on treatment, testing and culling.

Wisconsin State Vet contact information:

• Phone: (608) 224-4872, Monday-Friday, 7:45 a.m.-4:30 p.m.

• Email: DATCPAnimalImports@wisconsin.gov

• Evenings & weekends: (800) 943-0003, after-hours. Tell the duty officer you are reporting a potential animal disease.

If you live outside of the USA - contact your local veterinarian for further guidance.

If you wish to read more about B. canis the most recent article from North America that I found is: Cosford KL. Brucella canis: An update on research and clinical management. Can Vet J 2018: 59:74-81.

Thanks for reading! Have a great week and keep those consults rolling!

Back Pain + Fever

The 2 year old MC Poodle with Back Pain

It is Friday afternoon, and you are about to evaluate a 2 year old Poodle with a recent onset history of reluctance to walk. Upon examination, you find back pain at TL junction and a fever or 104 F. The dog stands there, hunched, but has a normal neurologic exam (self high-five!) and normal remaining physical exam so.... now what?

When I hear this story, my first thought is of discospondylitis. (My second thought is steroid responsive meningitis-arteritis (SRMA), one of the many forms of inflammatory non-infectious meningitis. Let's talk about this another day.)

EtiologyBacterial or fungal infection of the vertebral end plates. Commonly Staphylococci, with other causes including Streptococcus, E. coli, and less commonly B. canis. B. canis is zoonotic and can cause abortion in humans so exercise caution when managing a dog with discospondylitis.

Hematogenous is the most common source, with less common direct transmission (bite wound, grass awn).

Fungal infection with aspergillus or coccidiomycosis (SW USA) most common fungal isolates. Rarely blastomycosis.

SignalmentYoung to middle aged dogs, rarely cats.
Large breed male dogs are more often affected (male: female ratio 2:1).

Clinical signsAcute pain, often with fever, anorexia and other signs of systemic illness. Signs of a myelopathy may develop if empyema occurs, or vertebral subluxation/fracture due to loss of bone integrity. <-- EEK!

Diagnostic testsSpinal radiographs may lag 3 weeks behind onset of clinical signs; however, they are an easy diagnostic test with high yield for many cases. If unrewarding and the index of suspicion is high, spinal CT and then MRI provides increasing better detection rates in early disease.
Or, you can treat the pet for suspected discospondylitis for 2-3 weeks and re-radiograph to confirm the diagnosis.

Treatment optionsAntibacterial or antifungal treatment based on blood, urine or disc cultures. If cultures are negative (approximately 30% of cases have no growth), broad spectrum bone penetrating antibiotics are recommended until radiographic resolution is obtained (maybe 9+ months). These include cephalexin, enrofloxacin and sulfa antibiotics. Pain management and exercise restriction in the early stage of disease is important.

PrognosisFavorable with appropriate treatment.

You're doing great!! I really enjoy helping you, help your patients, live their best lives with neurologic disease. Not sure what to do with a case? You can email or telephone with case questions or schedule a consult online at a time that works for you. (Vets and vet staff only, please!)

C Reactive Protein and Discospondylitis

C-Reactive Protein and Discospondylitis

What is C-Reactive Protein (CRP)?

It is an acute phase protein that has been used in other inflammatory conditions such as SRMA, IMPA or inflammatory bowel disease to support or monitor the clinical response to treatment. 

Is it elevated with Discospondylitis?

Short answer: yes.
Long answer: It was elevated in most dogs in a recent study that were diagnosed with bacterial discospondylitis, but not all. In 8 dogs they measured it again 4-6 weeks into antibiotic treatment and it was normal in all 8 dogs. 

What can we do with this information in practice?

When faced with a patient with discospondylitis you can use CRP to support the radiographic evidence of discospondylitis. I would NOT suggest using this as a disease monitoring tool for dogs with discospondylitis because, as the authors point out, the intervertebral disc is a very immune privileged area of the body therefore infection could persist that is not reflected in the CRP. One of the dogs, in the study quoted above,  with normal CRP, had a recurrence of signs after stopping antibiotics. This suggests that CRP may not be a good long-term monitoring tool. 

That's all for this week! Have a safe, happy week and keep those consults coming! 

Nye G, Liebel FX, Harcourt-Brown T. C-reactive protein in dogs with suspected bacterial diskospondylitis: 16 cases (2010-2019). Vet Rec Open. 2020;7(1):e000386. Published 2020 Jul 20. doi:10.1136/vetreco-2019-000386