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150 Chagas’ Disease

DIAGNOSIS neurologic recovery, but depending on the • Glucocorticoid-related complications if used
chronicity and severity of the lesions, it long term (e.g., iatrogenic hyperadrenocorti-
Diagnostic Overview
VetBooks.ir CSM should be suspected when a young • Surgical procedures for CSM can be PROGNOSIS & OUTCOME
cism, gastric ulcers)
may lead only to partial improvement or
stabilization.
giant-breed dog or a middle-aged large-breed
dog is presented for ataxia and weakness. The
sive (ventral slot, dorsal laminectomy),
neurologic examination (p. 1136) should grouped into three categories: decompres- • Surgical treatment leads to improvement in
confirm gait changes in all four limbs. Survey distraction/stabilization (pin or screws and ≈80% of patients.
radiographs ruling out other diseases with or polymethylmethacrylate), or disc arthroplasty. • Approximately 50% patients improve
without radiographic changes suggesting CSM The number and direction of compres- with medical treatment (restricted activity
support the presumptive diagnosis. Definitive sions should dictate the choice of surgical +/− glucocorticoids or NSAIDs), and 25%
diagnosis requires magnetic resonance imaging procedure. remain stable.
(MRI) or myelography with or without com- • It is important to consider comorbidities • Long-term prognosis is less favorable. Many
puted tomography (CT). when deciding on the type of treatment. dogs deteriorate ≈3 years after diagnosis,
independent of method of treatment.
Differential Diagnosis Acute General Treatment
• Intervertebral disc disease • Exercise restriction PEARLS & CONSIDERATIONS
• Neoplasia • Glucocorticoids: dose and route depends on
• Spinal cord cysts (arachnoid or synovial) the severity of neurologic status. Comments
• Discospondylitis or vertebral osteomyelitis ○ Severe (non-ambulatory) cases: dexametha- The large number (28) of reported surgical
• Trauma sone 0.25 mg/kg IV (once only) techniques for CSM indicates that the ideal
• Meningomyelitis ○ Mild presentations: low-dose oral pred- treatment is still unknown.
nisone therapy (e.g., 0.5-1 mg/kg PO q
Initial Database 12h), progressively tapering Technician Tips
• CBC, serum biochemistry profile, urinalysis: • Affected patients are often large, heavy dogs
generally unremarkable Chronic Treatment that require assistance. Self-protection to
• Cervical radiographs: mainly useful to rule • Chronic treatment with prednisone minimize the risk of human back injuries
out differentials such as neoplasia and disco- 0.5-1.0 mg/kg PO q 12h, progressively is essential.
spondylitis. Radiographs can reveal vertebral tapering every 5-7 days to the lowest effec- • The patient’s neck pain can be significant,
canal stenosis secondary to vertebral body tive dose every 48 hours, or nonsteroidal and the neck should be handled gently; use
malformation or articular facet proliferation. antiinflammatory drugs (NSAIDs) a harness if the patient is ambulatory.
• Myelography: useful to confirm the diagnosis • Glucocorticoids and NSAIDs should never
when CT and MRI are unavailable be coadministered. Client Education
• CT: must be combined with myelography to • Gastrointestinal protectants such as omepra- • Avoid breeding dogs with CSM.
determine sites and directions of compression zole should be administered to dogs on • Neck leashes are strongly contraindicated;
• MRI (p. 1132): best diagnostic modality chronic glucocorticoid therapy. use a body harness after the diagnosis.
because it is safe and allows assessment of
the spinal cord parenchyma. Kinematic MRI, Behavior/Exercise SUGGESTED READING
mainly extension views, can reveal lesions Dogs with CSM should have exercise restriction da Costa RC: Cervical spondylomyelopathy (wobbler
not seen with neutral positioning. and should always wear a body harness rather syndrome). Vet Clin North Am Small Anim Pract
than a neck collar. 40:881-913, 2010.
TREATMENT
Possible Complications AUTHOR: Ronaldo C. da Costa, DMV, MSc, PhD,
Treatment Overview • Non-ambulatory tetraparesis with lesion DACVIM
EDITOR: Karen R. Muñana, DVM, DACVIM
• Medical treatment can provide improvement progression
or stabilization of neurologic status. Surgical • Severe cervical pain
treatment offers the best chance for complete

Chagas’ Disease Client Education Bonus Material
Sheet
Online

BASIC INFORMATION Epidemiology CONTAGION AND ZOONOSIS
Vector-borne transmission by triatomines, also
Definition SPECIES, AGE, SEX known as kissing bugs: Triatoma gerstaeckeri,
Canine Chagas’ disease is a relatively rare Young dogs (<1 year of age) develop a more Triatoma protracta, Triatoma sanguisuga in the
zoonosis caused by the vector-borne hemo- severe form of the acute stage of the disease, United States, occurs in humans and dogs.
protozoan parasite, Trypanosoma cruzi. It has which is often rapidly progressive and fatal. Blood-borne transmission possible during
a tropism for cardiomyocytes, resulting in handling of blood samples from infected dogs;
myocarditis with arrhythmias and myocardial RISK FACTORS however, risk is low.
failure. Hunting dogs may be at increased risk because
of more frequent exposure to the vector GEOGRAPHY AND SEASONALITY
Synonyms and reservoir hosts, but house dogs can be In the United States, most canine cases occur
American trypanosomiasis, chagasic myocarditis infected. in Texas and other southern states. Chagas’

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