title: Detecting Methemoglobinemia in Animals with a Drop of Blood.
abstract: A major concern during pesticide development and use is the impact on non-target species, such as raptors or domestic cats and dogs. Sodium nitrite and para-aminopropiophenone (PAPP) are two toxicants currently being studied for the control of invasive species, such as starlings and feral swine. When given to an animal these compounds oxidize hemoglobin, which renders it unable to carry oxygen resulting in methemoglobinemia. This study developed a method to estimate methemoglobin levels in mammals and birds by examining the efficacy of sodium nitrite to induce the conversion of hemoglobin to methemoglobin. Varying concentrations of sodium nitrite were added to aliquots of coyote, vole, feral swine, starling, and duck blood, collected from captive animals. The blood samples were analyzed spectrophotometrically to determine percent methemoglobin and digitally to determine red color values (RCV) associated with different methemoglobin levels. The avian and mammalian blood reached 100% methemoglobin levels at 200 mM and 15 mM sodium nitrite, respectively. All animals had similar RCV for a given percent methemoglobin. In conclusion, this study developed a procedure to quickly determine methemoglobin levels in mammals and birds. Furthermore, percent methemoglobin can be estimated with one standard curve from any animal species and an image of a blood spot. The technique will be useful during field studies, in agricultural areas, or in a veterinarian's office for the rapid diagnosis of methemoglobinemia in non-target animals that have eaten toxicants/baits or baited animals.
authors.affiliation: Fertility Control Project1, National Wildlife Research Center, Animal and Plant Health Inspection Service, United States Department of Agriculture, Ft. Collins, Colorado, United States of America.
authors.forename: Toni G
authors.identifier: http://orcid.org/0000-0001-6400-9627
authors.initials: TG
authors.lastname: Patton
authors.affiliation: Chemistry Laboratory Unit2, National Wildlife Research Center, Animal and Plant Health Inspection Service, United States Department of Agriculture, Ft. Collins, Colorado, United States of America.
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Blamer
authors.affiliation: Fertility Control Project1, National Wildlife Research Center, Animal and Plant Health Inspection Service, United States Department of Agriculture, Ft. Collins, Colorado, United States of America.
authors.forename: Katherine E
authors.initials: KE
authors.lastname: Horak
mesh_terms: D000818:Animals; D000835:Animals, Wild / Q000097:blood*; D003411:Arvicolinae / Q000097:blood; D001715:Bird Diseases / Q000097:blood / Q000175:diagnosis; D003124:Colorimetry / Q000662:veterinary; D046029:Coyotes / Q000097:blood; D004372:Ducks / Q000097:blood; D008706:Methemoglobin / Q000032:analysis / Q000187:drug effects; D008708:Methemoglobinemia / Q000097:blood / Q000175:diagnosis / Q000662:veterinary*; D012977:Sodium Nitrite / Q000494:pharmacology; D013053:Spectrophotometry / Q000662:veterinary; D046749:Starlings / Q000097:blood; D013552:Swine / Q000097:blood; D013553:Swine Diseases / Q000097:blood / Q000175:diagnosis
chemical_list: D008706:Methemoglobin; D012977:Sodium Nitrite