Ambien (zolpidem) can be toxic at doses as little as 0.05 mg/lb but it's unpredictable. Clifford would have ingested 10 mg/30 lbs or 0.33 mg/lb. This is also pertinent in respect to the thorough review I posted below. Here's a quick synopsis for you:
Symptoms are usually mild to moderate but can include the following:
Respiratory or cardiovascular depression
I recommend inducing emesis by dosing Clifford with 2 measuring tablespoons (30 mL) of 3%hydrogen peroxide by means of a small poultry baster placed between his cheek teeth and cheek. He should vomit within 15 minutes particularly if fed a slice of bread prior to dosing. If he doesn’t vomit, you should repeat the same dose.
Here’s a thorough review of this intoxication:
J Vet Intern Med. 2002 Mar-Apr;16(2):208-10.
Clinical syndrome associated with zolpidem ingestion in dogs: 33 cases (January 1998-July 2000).
Richardson JA, Gwaltney-Brant SM, Albretsen JC, Khan SA, Porter JA.
Source: ASPCA Animal Poison Control Center, Urbana, IL, USA.***@******.***
Zolpidem is a nonbenzodiazepine hypnotic of the imidazopyridine class that is used to treat insomnia in humans. Zolpidem binds selectively to the benzodiazepine omega-1 receptor and increases the frequency of chloride channel opening, which results in inhibition of neuronal excitation. A retrospective study was conducted of zolpidem ingestion in dogs that were reported to the ASPCA Animal Poison Control Center (APCC) between January 1998 and July 2000. Data analysis included amount ingested, clinical effects, and time of onset of signs. Thirty-three reports of zolpidem ingestion in dogs (ranging in age from 5 months to 16 years) were evaluated. Approximate ingested dosages ranged from 0.24 to 21 mg/kg. Clinical signs reported included ataxia (18 dogs; 54.5%), hyperactivity (10 dogs; 30.3%), vomiting (7 dogs; 21.2%), and lethargy (5 dogs; 15.2%), as well as panting, disorientation, nonspecific behavior disorder, and hypersalivation (4 dogs each sign; 12.1%). Other signs reported include tachycardia, tremors, apprehension, vocalization, hypersalivation, weakness, and hyperesthesia. In 85% percent of reports, clinical signs developed within 1 hour and usually resolved within 12 hours. Although central nervous system (CNS) depression is reported as a primary effect of zolpidem in humans and would also be expected in dogs, information obtained from this study indicates that some dogs may exhibit a paradoxical excitation reaction. This effect appears to vary among individual dogs.