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Degenerative Myelopathy 241

beats/min in dogs, >260 beats/min in • Permanent brain damage from prolonged Prevention
cats), consider propranolol 0.02-0.06 mg/ • Acute kidney injury from systemic hypoten- • Keep medications out of animal’s reach.
stimulation/seizures
VetBooks.ir as needed. If also hypertensive, avoid Recommended Monitoring antihistamines for pets, they need to read Diseases and Disorders
kg IV only if normotensive, repeat
• Instruct owners that when purchasing OTC
sion or hypertension and/or rhabdomyolysis
labels carefully and avoid products that
propranolol (use esmolol 0.2-0.5 mg/kg
IV or 10-200 mcg/kg/min IV)
○ If ventricular tachycardia (p. 1033) Heart rate/rhythm, blood pressure, temperature, contain pseudoephedrine.
• Imidazoline decongestants mentation, serum biochemistry profile with Technician Tips
○ Atipamezole 50 mcg/kg ( 4 of the dose electrolytes, acid-base status The OTC availability of these medications may
1
IV and the rest IM); may be repeated as give owners the wrong impression that they
needed for life-threatening hypotension PROGNOSIS & OUTCOME are harmless. Any casual mention by an owner
and bradycardia, or of this type of medication is worth discussing
○ Yohimbine 0.1 mg/kg IV; repeat in 2-3 Generally favorable with prompt presentation with the veterinarian, especially if physical signs
hours if needed. Use if atipamezole is not and appropriate care. Presence of prolonged compatible with toxicosis are present.
available. hyperthermia or DIC carries a guarded/
Supportive care for all decongestant exposures poor prognosis. Pseudoephedrine exposures Client Education
causing overt clinical signs: > 10 mg/kg are potentially lethal without • Never administer OTC medications to
• Intravenous fluids treatment. pets without consulting a veterinarian, and
• Thermoregulation: cool fluids, external purchase medications with only the specific
cooling measures as needed PEARLS & CONSIDERATIONS active ingredient that has been recommended
• Keep the patient calm, and reduce external by a veterinarian.
stimuli (quiet surroundings). Comments • Prevent all pets from access to human
• The use and availability of pseudoephedrine medications.
Drug Interactions in several U.S. states has been restricted
• Diazepam may be contraindicated; paradoxi- because of use in illegal amphetamine SUGGESTED READING
cal response (when given at high doses or synthesis. Pseudoephedrine is being replaced Wegenast C: Toxicology brief: phenylephrine
when given too fast) may add to stimulatory by phenylephrine. ingestion in dogs: What’s the harm? Vet Med
signs from pseudoephedrine/ephedrine/ • Other agents (nonsteroidal antiinflammatory 107(11):476, 2012.
phenylephrine. drugs [p. 695], antihistamines [p. 73], cough
• Propranolol: contraindicated if systemic suppressants [p. 73], acetaminophen [p. 10]) AUTHOR: Brandy R. Sobczak, DVM
EDITOR: Tina Wismer, DVM, MS, DABVT, DABT
hypertension is present (blockade of beta-2 may also cause toxicosis if a combination
receptors in vessels may cause vasoconstric- product was ingested; be sure to monitor
tion, worsening hypertension) and treat accordingly.
• Atropine: contraindicated for reflex brady- • The signs of pseudoephedrine toxicosis are
cardia due to hypertension very similar to amphetamine toxicosis in dogs
and cats.
Possible Complications • Several weight-loss OTC products contain
• Disseminated intravascular coagulation various levels of ma huang, a natural source
(DIC) due to hyperthermia of ephedrine.

Degenerative Myelopathy Bonus Material Client Education
Online
Sheet

BASIC INFORMATION retriever, Nova Scotia duck tolling retriever,
GENETICS, BREED PREDISPOSITION Pembroke Welsh corgi, poodle (miniature),
Definition • Presumed autosomal recessive mutation in poodle (standard), pug, Rhodesian ridge-
Canine degenerative myelopathy (DM) is an the canine superoxide dismutase-1 gene back, Shetland sheepdog, Siberian Husky,
inherited, adult-onset central nervous system (SOD1) soft-coated wheaten terrier, wire-haired fox
(CNS) degenerative disease, most severely • The genetic mutation is similar to some forms terrier
affecting the thoracolumbar spinal cord. of human amyotrophic lateral sclerosis (Lou Clinical Presentation
Gehrig disease)
Synonyms • Breed predisposition: purebred and mixed- HISTORY, CHIEF COMPLAINT
Canine degenerative radiculomyelopathy, breed dogs—American Eskimo dog, Australian • Progressive weakness of pelvic limbs
German shepherd dog myelopathy shepherd, Bernese mountain dog, blood- • Initially, affected dogs drag the claws and
hound, borzoi, boxer, Cardigan Welsh corgi, show general proprioceptive ataxia in pelvic
Epidemiology Cavalier King Charles spaniel, Czechoslo- limbs.
SPECIES, AGE, SEX vakian wolfdog, Chesapeake Bay retriever, • Difficulty jumping
Canine; age at onset approximately 8-14 years; collie (rough coat), English Springer spaniel, • The disease results in a progressive paraparesis
mean age: 9 years in large dogs, 11 years in German shepherd dog, golden retriever, to paraplegia within 12 months of onset of
Pembroke Welsh corgis Hovawart, Kerry Blue terrier, Labrador clinical signs.

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