Page 1296 - Cote clinical veterinary advisor dogs and cats 4th

Methicillin-Resistant Staphylococcal Infections 653

• Nontoxic continuous-rate infusion (CRI) 10 mg/kg/h PROGNOSIS & OUTCOME
○ Head trauma to start or repeat boluses 25-50 mg/kg Due to rapid onset of severe neurologic signs
VetBooks.ir ○ Meningitis mg/kg/day may be exceeded, but monitor- and low margin of safety, prognosis is guarded. Diseases and Disorders
○ Intracranial neoplasia
IV as needed; maximum daily dose of 330
ing for CNS depression is warranted.
○ Encephalitis
Difficulty controlling tremors or seizures, severe
○ Other causes of tremor or seizure
(pp. 1279 and 1288) ○ Diazepam 0.5-1 mg/kg IV, 0.1-2 mg/kg/h hyperthermia, large ingestion, liver injury,
as CRI, or
aspiration, or significant pre-existing disease
○ Midazolam 0.1-0.3 mg/kg IV or IM, worsen prognosis.
Initial Database 0.05-2 mg/kg/h CRI
• CBC: typically unremarkable; disseminated ○ If insufficient response to above therapies, PEARLS & CONSIDERATIONS
intravascular coagulopathy rarely reported general anesthesia may be warranted with
• Chemistry profile: may be normal on gas anesthesia, propofol, or barbiturates. Comments
presentation, but liver injury is possible • Nonspecific • Iron-based snail baits are becoming more
and is seen within 2-3 days of ingestion; ○ Fluid therapy: treat or prevent dehydra- popular; make sure to check active ingredi-
prolonged tremors and seizures can increase tion, maintain electrolyte and acid base ents of product to which patient was exposed.
creatine kinase level and cause azotemia due balance • Minimum lethal dose of metaldehyde in dogs
to rhabdomyolysis ○ Thermoregulation (e.g., cool IV crystalloid is 100 mg/kg.
• Blood gas analysis: ± acidosis fluids, fans, alcohol spray) • Onset of signs can occur within 30 minutes
• Urinalysis: normal; if rhabdomyolysis present, ○ If present, control acidosis. to 4 hours of ingestion.
may detect myoglobinuria
Chronic Treatment Prevention
Advanced or Confirmatory Testing Manage liver injury, if present (p. 442). Prevent access to areas where metaldehyde is
Confirmatory testing can be performed on used; use pet-friendly bait alternative.
gastric content, urine, plasma, or liver tissues. Nutrition/Diet
Withhold food from patients that are vomiting, Technician Tips
TREATMENT tremoring, or seizing. Monitor body temperature closely. Although
hyperthermia is the usual concern, enemas or
Treatment Overview Behavior/Exercise lavage can cause hypothermia.
Because onset of signs (often severe) is rapid, Restrict activity, and minimize stimuli when
prompt and aggressive control of tremors signs are present. Client Education
or seizures is paramount. If exposure is recent Educate owners to the dangers of common
(<30 minutes) and patient is not showing Possible Complications pesticide products, and explain that common
clinical signs, decontamination recommended. Aspiration is a concern due to rapid onset bittering agents used as deterrents are frequently
of severe neurologic signs. Use great care ineffective for canines.
Acute General Treatment if inducing emesis or giving activated
• Decontamination (p. 1087) charcoal, and use these techniques only SUGGESTED READING
○ Emesis (p. 1188): apomorphine 0.03 mg/ before signs are apparent. Control vomiting Brutlag AG, et al: Metaldehyde. In Peterson ME,
kg IV, 0.04 mg/kg IM (canine) aggressively. et al, editors: Small animal toxicology, ed 3, St.
○ Gastric lavage (p. 1117) for large expo- Louis, 2013, Saunders, pp 635-642.
sures, particularly when emesis is not safe Recommended Monitoring
○ Activated charcoal 1-2 g/kg with sorbitol Monitor neurologic signs, hyperthermia, and AUTHOR: Kirsten Waratuke, DVM, DABT
EDITOR: Tina Wismer, DVM, MS, DABVT, DABT
○ Enema 10 mL/kg water acidosis. Rarely, rhabdomyolysis or disseminated
• Tremors/seizures intravascular coagulopathy may be a complica-
○ Methocarbamol: start with initial tion. Monitor for aspiration as complicating
bolus (50-150 mg/kg IV), followed by factor.

Methicillin-Resistant Staphylococcal Infections Client Education
Sheet

Epidemiology
BASIC INFORMATION health care contact (e.g., hospital visitation,
SPECIES, AGE, SEX owned by recent hospital patient) increases
Definition • Any animal, either sex, any age the risk of methicillin-resistant Staphylococcus
Infections with methicillin-resistant staphylococci • In dogs, methicillin-resistant Staphylococcus aureus (MRSA) infection.
(MRS), which are staphylococci that have pseudintermedius (MRSP) predominates.
acquired the mecA gene. MRS are resistant CONTAGION AND ZOONOSIS
to virtually all beta-lactam antimicrobials RISK FACTORS • MRSA can be transmitted between people
(penicillins, cephalosporins, carbapenems) and • Influenced mainly by risk factors for whatever and pets; transmission is most often from
often acquire resistance to various other is predisposing to opportunistic infection human to pet. MRSA can also be transmitted
antimicrobials. (e.g., atopic dermatitis, wound) between pets.
• Prior antimicrobial exposure • MRSA colonization rates are higher among
Synonyms • Veterinary hospital exposure increases the risk veterinary personnel than in the general
Methicillin and meticillin are synonymous. of MRSP infection. Direct or indirect human public. Colonized veterinary personnel can

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