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Hi, thanks for your question today. Can you tell me what the weights of the 2 dogs are?
OK, thanks -- so was this the up-to-25 lbs size of Heartgard Plus? Do you know which of the dogs ate it all? Or was it likely to be both of them together?
OK, let me do a worst-case scenario by assuming Kodi ate all 24 doses, since that would be the highest risk situation. I'll be right back.
OK, so here's what we've got. Each chewable tablet contains 68 mcg of Ivermectin (the active ingredient that is most likely to be a toxic risk in dogs). 68 x 24 tablets = a total amount of 1632 mcg of ivermectin. If Kodi ate all of that, it would be a dose of approximately 360 mcg per kg of body weight, assuming 10 lbs is an accurate weight. This is not automatically a life threatening dose of this drug, unless either dog is genetically at-risk for having difficulty with metabolizing this particular medicine. There is a gene mutation that affects certain dogs, which causes them to be at higher risk of side effects from Ivermectin. Most often, Collies, Border Collies, Australian Shepherds, and other breeds can be affected, but the gene can appear in any breed. Typically, side effects include lethargy, confusion, weakness, paralysis, unconsciousness, or seizures, and these effects can be quite serious. Effects would be expected to occur within about 4 to 6 hours after ingestion of the medicine, though often it's faster than that.
If more than 6 hours has passed, with no symptoms, then I would not have much reason to worry.
Well, given that, it is likely that no issues will arise, unless it was within the last few hours that they got into the meds. There is the option of inducing vomiting, but this is not of much benefit beyond 2-3 hours after ingestion. I suspect that it's not likely to be necessary based on what you've described to me here.
Based on my calculations, most 10-lb dogs would not experience life threatening toxic effects from eating all 24 doses. If we assume it was a shared effort, and both dogs ate some, the risk is even less.
Certainly if 4 to 6 hours passes with no neurologic symptoms like I described earlier, I would not see much reason to worry further, other than the usual caution to watch for digestive upset that could occur after eating *anything* unusual.
Typically, side effects include lethargy, confusion, weakness, paralysis, unconsciousness, or seizures, and these effects can be quite serious. Effects would be expected to occur within about 4 to 6 hours after ingestion of the medicin
Watch closely, and get them to a veterinary emergency clinic if those signs appear. Merry Christmas!
Just following up to see if everything is going well!
Glad to hear it. Please let me know if you have any other concerns about this issue.