A comparison of reverse line blot hybridization and IDEXX SNAP 4Dx® test in detecting canine anaplasmosis/ehrlichiosis in Trinidad

Ehrlichia canis and Anaplasma platys are known to be among the most common tick-borne hemopathogens of dogs in Trinidad that are transmitted by ixodid ticks of the Rhipicephalus sanguineus sensu lato species complex. These pathogens are commonly diagnosed in Trinidad based on clinical signs, laboratory tests and response to treatment. However, as these hemopathogens are often not observed on microscopic examination of blood smears, alternative methods to provide a definitive diagnosis are warranted. The IDEXX SNAP 4Dx® test is used frequently by veterinarians in Trinidad to determine exposure status and inform decisions on whether a canine patient should be treated. This study investigated the use of the IDEXX SNAP 4Dx® test and polymerase chain reaction (PCR) followed by a reverse line blot hybridization (RLB) assay on samples obtained from 231 dogs in order to determine if there was an acceptable level of agreement between the two tests. The study showed poor agreement between the IDEXX SNAP 4Dx® test and RLB.