Leishmaniasis in a dog native to Colorado

Abstract

A 1-year-old 32.5-kg (71.5-lb) sexually intact male foxhound-Treeing Walker Coonhound cross was evaluated because of a 2.5-month history of dermatologic lesions, weight loss, and diarrhea. Physical examination revealed muscle wasting, lymphadenopathy, and multifocal pruritic dermatologic lesions of alopecia, thickening, erythema, and follicular casting. Hematologic and serum biochemical analyses revealed nonregenerative anemia, mono-cytosis, hypercalcemia, hyperproteinemia, and hyperglobulinemia. Proteinuria was identified on urinalysis. Hepatomegaly, splenomegaly, and diffuse abdominal lymphadenomegaly were detected on abdominal ultrasonography. A diagnosis of leishmaniasis was confirmed by ELISA detection of serum antibodies against Leishmania spp, a high serum indirect fluorescent antibody titer (1:1,024) against Leishmania infantum, amplification of Leishmania DNA on PCR assay of a whole blood sample and a lymph node aspirate, and histologic identification of suspected Leishmania amastigotes in skin specimens. In addition, the dog had a low CD4+:CD8+ lymphocyte ratio of 1:1. The dog was euthanized because of the severity of leishmaniasis and poor prognosis. This dog was from a litter of 10 puppies that included 4 stillborn puppies, 2 puppies that died as neonates, and 1 littermate that was euthanized at 1 year of age because of a high serum antibody titer against Leishmania spp. Eventually the foxhound dam was euthanized because of a high serum antibody titer against Leishmania spp. The dog had been raised with an unaffected littermate, its sire, and an unrelated Treeing Walker Coonhound female that were seronegative for Leishmania infection. Although vertical disease transmission was suspected, it is possible that L infantum is now endemic in Colorado. Leishmaniasis should be considered in dogs with scaly dermatoses.