title: Macrocyclic lactone toxicity due to abamectin in farm dogs without the ABCB1 gene mutation.
abstract: METHODS
  A 5-year-old entire female Huntaway from a sheep and beef farm was one of four dogs that developed clinical signs including hypersalivation, depression, blindness and ataxia after the death of another dog. A 4-year-old female Huntaway farm dog from a second farm was observed to be sitting down more often than usual on the day after being fed part of a calf carcass that had been treated with an abamectin pour-on.
  
  
  RESULTS
  The first dog was ataxic and depressed but did respond to sound. The second dog presented with an acute onset of blindness, mydriasis, absence of a menace response, hypersalivation, gait abnormalities (e.g. high stepping gait and ataxia), and depression. Other presenting signs included muscle tremors, dehydration and difficulty eating. No abnormalities were detected from routine haematology and biochemistry. Analysis of samples of plasma from both dogs revealed concentrations of abamectin of 0.149 mg/L and 0.260 mg/L for the first and second dogs, respectively. Buccal swabs taken from the first dog for DNA testing for the ABCB1 gene mutation, gave a negative result.
  
  
  METHODS
  In addition to the presenting signs which suggested a toxicosis, both dogs had measurable concentrations of abamectin in plasma confirming exposure.
  
  
  CONCLUSIONS
  Farm dogs exposed to concentrated pour-on products containing abamectin have been poisoned and recover or die. The product labels do not carry any warnings as to the risk of poisoning to dogs. This paper discusses two incidents affecting six farm dogs, but the authors are aware of more toxicoses in farm dogs exposed to abamectin.
authors.affiliation: Institute of Veterinary, Animal & Biomedical Sciences, Massey University, Palmerston North, New Zealand. k.parton@massey.ac.nz
authors.forename: K
authors.initials: K
authors.lastname: Parton
authors.forename: E M
authors.initials: EM
authors.lastname: Wiffen
authors.forename: N D
authors.initials: ND
authors.lastname: Haglund
authors.forename: N J
authors.initials: NJ
authors.lastname: Cave
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics*; D000818:Animals; D004283:Dog Diseases / Q000139:chemically induced* / Q000235:genetics; D004285:Dogs; D005260:Female; D007306:Insecticides / Q000506:poisoning*; D007559:Ivermectin / Q000031:analogs & derivatives* / Q000506:poisoning
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D007306:Insecticides; C048324:abamectin; D007559:Ivermectin