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Over-the-counter availability of drugs in developing countries poses the risk of their abuse and overdosing in animals by the owners. This report describes ivermectin toxicosis and its treatment with neostigmine methylsulfate in 2 kittens and an adult cat that had been massively overdosed by their owners. Of two 4-w-old 300 g kittens, one was injected with 1.5 ml ivermectin (15 mg; corresponding to 250 times the recommended dose) by the owner and became comatose, started salivation and died after 2 1/2 h. The other kitten was treated with about 0.75 ml ivermectin (7.5 mg; corresponding to 125 times the recommended dose) by the same owner and developed ataxia and salivation after 2 h, went into coma the next morning and was presented for treatment with mydriasis, coma, slight fever (102.4 F), tachypnea (48/min) and severe tachycardia. This kitten was treated twice at a half hourly interval with neostigmine methylsulfate (25 microg) and 5% dextrose (20 ml) iv showed a transient improvement but died 12 h later. A 2-y-old, 4.5 kg male cat was treated s.c. with 1.5 ml ivermectin (15 mg; corresponding to 16.6 times the recommended dose) by its owner and developed slight salivation, lacrimation. mydriasis, protrusion of third eye-lid, tachypnea (42 breaths/min), tachycardia (128 beats/min) and ataxia. The patient was treated with neostigmine methylsulfate (150 microg) and 5% dextrose (100 ml) i.v., and 200 ml of Heartmann's solution i.v. Treatment was repeated after 6 h Follow up treatment over next 2 d was with daily i.v. administration of neostigmine and dextrose. The patient completely recovered 5 d after initiation of treatment.
... In developing countries such as Nigeria, the production and availability of these drugs are highly variable and often too expensive. Moreover, this approach has become a source of public concern in terms of both the use of proprietary medicines in farm production and the risk of chemical residues in food products (Muhammad et al., 2004;Mohammed et al., 2013). Hence, novel approaches to nematode parasite control are needed for small ruminants in the tropics and sub-tropics to counteract the problem of AR (Ombasa et al., 2012), creating a trend towards organic farming and sustainable animal husbandry. ...
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... Another MDR1(-/-) cat was euthanized after developing severe neurological signs due to unintended oral exposure of up to 523 µg ivermectin/kg (14). Interestingly, there are also some reports of cats recovering completely after administration of much higher doses of ivermectin (21,22). Moreover, in some cases severity and duration of neurological signs were reported to differ significantly between individual cats despite exposure to the same dosage of macrocyclic lactones (22)(23)(24). ...
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... It is absorbed up to 95% after oral administration in simple stomached animals (17). Acute toxicity investigated in dogs received 40 mg/kg BW orally and death due to respiratory depression (7). Likewise, dogs administered 2 mg/kg BW showed tremors, ataxia, anorexia, and developed dehydrated (17). ...
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