Prognostic Factors and Life Expectancy in Canine Leishmaniosis

Abstract

Canine leishmaniosis (CanL) is a chronic and potentially fatal disease. The prognosis of CanL depends on the severity of the clinical signs and clinicopathological abnormalities presented by the dog at the time of diagnosis. This study aims to estimate the survival time of dogs with CanL, determining the prognostic value of different clinical and clinicopathological parameters. Medical records of 99 dogs diagnosed with CanL in five veterinary centers of the Alentejo region (Portugal) were examined retrospectively. The majority of dogs presented hyperproteinemia, moderate normocytic normochromic anemia, normal blood urea and creatinine levels and were classified as stage 1 according to the International Interest Society (IRIS) guidelines at the time of diagnosis. The severity of anemia, presence of concomitant infectious diseases at the time of diagnosis and the anti-Leishmania therapy were correlated with the survival time. The influence of renal dysfunction was evaluated by Receiver Operating Characteristic (ROC) curve and survival analysis. Survival analysis demonstrated that patients classified as IRIS 1 at the time of diagnosis survived more than four years, in contrast with dogs classified as IRIS 2 that survived around two and half years and dogs classified as IRIS 3–4 that survived around one month. IRIS stage deteriorated during the course of CanL in one third of the dogs and was the principal cause of death or euthanasia in a high proportion of animals. In some cases, dogs did not receive anti-Leishmania treatment or abandoned the veterinary follow-ups, which may have considerable repercussions for animal wellbeing and public health. This study reinforces the value of blood urea and creatinine levels as prognostic factors in CanL.

Diagnosis and clinical management of canine leishmaniosis by general veterinary practitioners: a questionnaire-based survey in Portugal

“…In the present study, this stage was the only one for which euthanasia was considered as an option. Given that the main differences between the stage III and IV CanL clinical scenarios were the renal values and serological titres, these results may emphasise the importance of renal disease in the establishment of a prognosis and the decision to euthanise [ 37 , 38 ].…”

Redox Status in Canine Leishmaniasis

“…In our study the average age of the animals enrolled, that were naturally infected by Leishmania infantum was higher than expected (four years). This may be due to the fact that CL presents a widespread range of clinical manifestations varying from visceral to cutaneous or viscerocutaneous presentation and polymorphic clinical aspects in times ranging from a few weeks to many months, thus determining a delay before the owner submits the pet to a clinical visit, as recently observed by Pereira et al [ 30 ]. Except for the animals of stages I and II, in the present study male dogs >2 years with medium to high positive antibody levels were the most predisposed, thus suggesting that gender can be involved in the development of the disease, as already shown by other research [ 31 ].…”

“…Moreover, enhanced lipid peroxidation may be linked to liver and kidney damage in CVL [ 14 , 16 ]. In particular, BUN (Blood Urea Nitrogen) and creatinine concentrations are the major biochemical findings of leishmaniasis, and the variability and degree of biochemical abnormalities depend mainly on progression of the disease [ 15 ], assuming also a prognostic value [ 30 ]. Conversely, the decrease of almost all the reducing capacities of the organism may be a result of the host’s defense mechanisms against the increase in oxidation caused by the parasite.…”

Investigation of canine visceral leishmaniasis in a non-endemic area in Brazil and the comparison of serological and molecular diagnostic tests

“…In addition, serology represents an indirect test that can be positive up to two years after symptomatic infection 31 , even in the absence of the parasite. However, animals with symptomatic VL commonly recover from the disease 32 , even under treatment 33 , 34 . In addition, the positive serology for leishmaniasis is directly associated with parasite presence 35 , and the level of antibodies is directly associated with the parasite load and intensity of symptoms 36 .…”