Page 584 - Cote clinical veterinary advisor dogs and cats 4th

266 Discospondylitis

○ Doberman pinschers, Irish wolfhounds, • Radiographic heart size is an insensitive patients are on continuous-rate infusions
and Great Danes marker for DCM, but radiography is gold (CRIs) to ensure adequate dosing and
VetBooks.ir ○ Portuguese water dogs and other • Do not delay CHF treatment in lieu of an • Furosemide is light sensitive, and if being
Poor median survival time after onset
patency.
standard for CHF diagnosis.
■
of CHF
administered by CRI, administration lines
echocardiogram.
juvenile-onset DCM dogs have a grave
prognosis. • In mild azotemia, reduce ACE inhibitor and syringes should be covered.
frequency or dose before adjusting diuretics.
○ Cats with DCM not caused by taurine • Supplement potassium when in low-normal Client Education
deficiency have a grave prognosis. range if patients are hyporexic or increasing • Monitor breathing rates at home daily for
diuretic dose. patients with a history of CHF and weekly
PEARLS & CONSIDERATIONS • Low fractional shortening (%) common in for patients with occult DCM.
normal large-breed dogs; high false-positive ○ Performed at rest (sleeping): normal < 30
Comments DCM diagnosis with inexperienced scanners breaths/min
• Screening is key to best long-term prognosis. • Reinforce importance of annual screening.
○ Doberman pinschers: begin screening at Prevention • Reinforce prevalence of sudden death in
2-3 years of age Patients predisposed should be screened at an asymptomatic and symptomatic DCM.
• Murmurs, gallops, or arrhythmias in a early age with an echocardiogram and Holter • Establish early discussions about quality-of-
predisposed, asymptomatic dog warrant monitor. Consider NT-pro-BNP in cases with life and end-of-life decisions after CHF.
full cardiac screening. financial constraints; if elevated, full screening
○ Soft murmurs do not rule out significant is recommended. Any VPCs noted on 5-minute SUGGESTED READING
disease (e.g., functional mitral regurgita- ECG strongly predicts DCM, and full screening Stern JA, et al: Myocardial disease: canine. In Ettinger
tion from severe dilation) is recommended. SJ, et al, editors: Textbook of veterinary internal
• Ventricular arrhythmias in the absence of medicine, ed 8, St. Louis, 2017, Elsevier.
echocardiographic changes are common. Technician Tips
• Do not discontinue antiarrhythmic therapy • IV catheters, volume received, and admin- AUTHORS: Ryan C. Fries, DVM, DACVIM; Jordan P.
Vitt, DVM, DACVIM
before consultation with a specialist. istration lines should be checked hourly if EDITOR: Meg M. Sleeper, VMD, DACVIM

Discospondylitis Client Education Bonus Material
Sheet
Online

BASIC INFORMATION CONTAGION AND ZOONOSIS Etiology and Pathophysiology
B. canis poses a zoonotic risk and is a reportable • Hematogenous spread to the vertebral
Definition disease endplates (with extension into the disc
Inflammation of the intervertebral disc and space); less commonly, direct inoculation
adjacent vertebral endplates due to a bacterial GEOGRAPHY AND SEASONALITY of the intervertebral disc
or, less often, fungal infection Prevalence of causative agents varies geographically. • Most common bacterial isolate is coagulase-
positive Staphylococcus spp. Others include
Epidemiology Clinical Presentation coagulase-negative Staphylococcus spp,
SPECIES, AGE, SEX HISTORY, CHIEF COMPLAINT Streptococcus spp, gram-negative aerobes
• Most commonly reported in large-breed, • Varied course of disease; usually chronic and (Escherichia coli, B. canis), and fungal agents
middle-aged to older dogs. Males outnumber progressive over weeks to months (Aspergillus, Paecilomyces, Candida).
females 2 : 1. • Spinal hyperesthesia is the most common • Source of infection is often elusive; proposed
○ Brucella canis more common in sexually chief complaint, present in > 80% of cases sites include the urogenital tract, oral
intact dogs • Systemic signs can include pyrexia, lethargy, cavity, respiratory tract, endocardium, and
• Although risk appears to increase with weakness, stiffness/lameness, anorexia, weight skin.
age, it has been reported in juvenile dogs loss, and dull mentation. • Local extension from migrating foreign
(<6 months of age). material, penetrating wounds, or surgical
• Rare in cats; typically associated with local PHYSICAL EXAM FINDINGS site infection is possible.
trauma such as a bite wound • Most cases have hyperesthesia on paraver-
tebral palpation. DIAGNOSIS
GENETICS, BREED PREDISPOSITION • Neurologic signs can develop from secondary
• Predisposed breeds include German shepherd compressive lesions; the dura is usually an Diagnostic Overview
dogs, Great Danes, boxers, rottweilers, Dober- effective barrier to prevent extension of infec- Diagnosis is primarily based on radiographic
man pinschers, bullmastiffs, and English tion into the spinal cord itself. Neurologic findings. Occult cases are possible; if radio-
bulldogs. signs occur in nearly half of cases and reflect graphs are inconclusive, advanced imaging
• German shepherd dogs and Rhodesian localization of the lesion, ranging from is indicated. If neurologic signs are present,
ridgebacks are overrepresented for fungal proprioceptive deficits to paralysis. advanced imaging is useful to detect spinal
infections. • Worsening neurologic grade correlates with cord compression.
an increase in the number of sites of infection
RISK FACTORS and the degree of spinal cord compression. Differential Diagnosis
• Immunosuppression • ± Fever • Intervertebral disc herniation
• Among juveniles, recent history of blunt force • Other findings relate to additional sites of • Spinal trauma
trauma, bite wounds, or previous parvovirus infection, if present (e.g., murmur due to • Meningitis/myelitis
infection endocarditis) • Spinal neoplasia
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