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Cardiotoxic Plants 143

• Chronic stomatitis: variably persistent clinical ○ Does not protect against all strains Client Education
signs ○ Follow American Association of Feline Educate clients on proper husbandry and vac-
VetBooks.ir up to 67% Association vaccination guidelines, includ- (e.g., home, shelter, cattery). Diseases and Disorders
cination practices for their specific environment
Practitioners/American Veterinary Medical
• VS-FCV: guarded prognosis, mortality rate
ing booster vaccinations
PEARLS & CONSIDERATIONS
• Proper cleaning and husbandry practices
○ FCV is resistant to most disinfectants. SUGGESTED READING
Radford A, et al: Feline calicivirus infection: ABCD
Comments Bleach (5% sodium hypochlorite) diluted guidelines on prevention and management. J Feline
Fomites (including hospital personnel) are to 1 part bleach to 32 parts tap water is Med Surg 11:556-564, 2009.
important factors in spread of disease. effective. AUTHOR & EDITOR: Megan Grobman, DVM, MS,
• Shelters: identify causative pathogen in an
Prevention URTD outbreak. Isolate affected cats, and DACVIM
• Vaccination: FCV is a core vaccine and vaccinate newcomers as soon as possible.
protects against acute oral/respiratory signs.
○ Modified live and killed (SQ and intra- Technician Tips
nasal) vaccines are available. Precautions should be taken for all cats showing
○ Vaccination does not prevent infection or signs of upper respiratory infection to prevent
shedding. an outbreak.

Cardiotoxic Plants Bonus Material Client Education
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BASIC INFORMATION • Grayanotoxin-containing plants: tachycardia, decreasing their ion selectivity (maintain
tachypnea, hyperthermia, vomiting, lethargy, state of depolarization). Results are similar
Definition hypotension, and bradycardia; diarrhea is to cardiac glycosides. Many cells are affected,
Toxicosis occurring as a result of ingestion of uncommon especially excitable cells (neurologic, cardiac,
plants that produce substances harmful to the muscle cells).
heart Etiology and Pathophysiology
Source: DIAGNOSIS
Epidemiology • Present in nature, landscaping, house plants,
SPECIES, AGE, SEX and floral arrangements Diagnostic Overview
Dogs are more likely to be affected than cats; • Common cardiac glycoside–containing Diagnosis is based on history of exposure
all ages and breeds plants: Asclepias spp (some): milkweed; and the presence of gastrointestinal (GI) and
Convallaria majalis: lily of the valley; cardiac signs. Plant material present in pet’s
RISK FACTORS Digitalis purpurea: foxglove; Hellebore spp; environment, vomitus, or lavage fluid may also
Plants or flower bouquets in pet’s environment. Kalanchoe spp; Nerium oleander: oleander; help in arriving at a diagnosis. Serum digoxin
Pre-existing cardiac disease may increase risk. Thevetia nerifolia: yellow oleander; Thevetia levels are confirmatory for cardiac glycoside
peruviana: yellow oleander plants (cross-reactivity with cardiac glycosides);
GEOGRAPHY AND SEASONALITY • Common grayanotoxin-containing plants: turnaround time limits utility in critical cases,
Toxicosis occurs throughout the year but is Rhododendron spp: rhododendron, azalea, but in cases that are less severe, the test is helpful
more likely to occur in spring and summer rosebay; Kalmia spp: laurels; Pieris spp: for identifying exposure and to prevent future
months (outdoor exposures). Japanese pieris, mountain pieris; Leucothoe re-exposure.
spp: black laurel
Clinical Presentation Mechanism of toxicosis: Differential Diagnosis
HISTORY, CHIEF COMPLAINT • Cardiac glycosides Toxicologic:
+
+
• History or evidence of exposure (witnessed ○ Inhibition of Na /K -ATPase pump in the • Bufo toad ingestion
ingestion, chewed plant, or plant material myocardial cell • Digoxin overdose
present in the vomitus) ○ Result: decreased intracellular potassium, • Antiarrhythmic medication ingestion
• Cardiac glycosides: onset of clinical signs increased intracellular sodium. Intracel- Spontaneous, non-toxicologic:
within 2-8 hours of ingestion: salivation, lular sodium is exchanged for calcium, • Primary cardiac disease
vomiting, lethargy, depression, hypoglycemia, raising intracellular calcium levels. Exces- • Systemic illness causing ventricular arrhythmias
and ataxia. With severe intoxications, convul- sive extracellular potassium may depress • Gastroenteritis
sions and death are possible. cardiac contractility.
• Grayanotoxins: signs occur within 6 hours of ○ Effects noted include atrioventricular Initial Database
ingestion: lethargy, salivation, vomiting, signs (AV) block due to progressive interference • CBC: no significant changes expected
of abdominal pain, ataxia, lateral recumbency, with cardiac electrical conduction and • Serum biochemistry panel: hyperkalemia
and seizures are possible. increased vagal tone; decrease in normal possible; hypokalemia markedly worsens
• Yew (Taxus spp) resting membrane potential; decreased the toxic effects (including making the
myocardial cell pacemaker activity, leading heart refractory to antiarrhythmics such as
PHYSICAL EXAM FINDINGS (in severe toxicoses) to malignant cardiac lidocaine and procainamide) and needs to
• Cardiac glycoside–containing plants: pale arrhythmias (ventricular) or asystole. be corrected if present (p. 516).
mucous membranes, weak pulses, tachypnea, • Grayanotoxins: bind to sodium channels, • Blood glucose: hypoglycemia has been
bradycardia, or paroxysmal tachycardias slowing their opening and closing and reported secondary to oleander intoxication.

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