This retrospective study determined the prevalence of dermatological lesions associated with canine leishmaniasis (CanL) in a nonendemic area in Italy. The medical records of 131 dogs with CanL were reviewed and, of these, 115/131 dogs (88%) had dermatological manifestations of which 100/131 dogs (76%) met the inclusion criteria. Sixty-two percent of dogs were male and 38% were female and the mean age was 6.4 years. Thirty-two percent of dogs were mixed breeds; the remainder represented a variety of pure breeds. In 79% of dogs dermatological signs occurred in association with systemic signs of CanL, whilst 21% of dogs had only dermatological manifestations. The most common dermatological manifestation was exfoliative dermatitis (74%), followed by ulcerative (18%) and nodular (11%) lesions. In 51% of dogs the lesions were localized mainly on the pinnae, head, and pressure points; in the remaining 49% lesions were generalized. The only statistically significant association was between Retriever breed and animals with only dermatological signs (
Canine leishmaniasis (CanL) is a zoonotic chronic wasting disease that is endemic along the Mediterranean basin, subtropical and tropical regions of Asia, South and Central America [
Other manifestations often reported in cases of CanL are onychogryphosis, paronychia, nasal and digital depigmentation, and hyperkeratosis [
Additionally, there are a number of atypical cutaneous forms of CanL such as papular dermatitis [
In human leishmaniasis it is proposed that the efficiency of the immune response may account for the variety of dermatological lesions [
Despite the extensive literature concerning CanL, few (and no recent) studies have focused exclusively on the prevalence and description of the cutaneous lesions [
The aim of this retrospective study was to determine the prevalence and type of dermatological lesions in a large group of dogs with CanL referred to the Veterinary Teaching Hospital in Milan, Italy, which is in a currently nonendemic area for CanL [
A retrospective study was performed. The medical records of all cases of confirmed leishmaniasis in dogs presented at the Teaching Hospital of the University of Veterinary Medicine in Milan between 2000 and 2013 were reviewed. Dogs were eligible for inclusion in the study if they fulfilled the following criteria. A complete physical examination at the first consultation with a detailed description of signs referable to CanL as previously reported in the literature [ Living in nonendemic area of Milan. Presence of at least one common or atypical dermatological manifestation referable to CanL according to the literature [ A diagnosis of leishmaniasis established by clinicopathologic abnormalities, positive serology for
All dogs with other neoplastic, inflammatory, endocrine, immunologic, and genetic diseases potentially associated with dermatological signs were excluded. Furthermore dogs were also excluded if they had concomitant infectious diseases (e.g., babesiosis, ehrlichiosis, dirofilariasis), diagnosed by parasitological or serological examinations, or both.
Information extracted from the medical records of each dog with leishmaniasis included in the study comprised signalment (age, sex, breed, provenance/travel history), dermatological signs classified as localized or generalized and as common form (exfoliative dermatitis with or without alopecia, ulcerative dermatitis, nodular dermatitis, pustular dermatitis), common adnexal manifestations (onychogryphosis, paronychia, and nasal/digital hyperkeratosis), or atypical form (papular dermatitis and inoculation chancre) as described in the literature [
All statistical analyses were performed using commercial statistical software (MedCalc, v. 12.3.0). For each analyzed parameter the distribution of data recorded was assessed using descriptive statistics. A chi-square test or a Fisher exact test, depending of the number of observations, was used to test for associations between breed, age, sex, and common or atypical dermatological forms. Odds ratio (OR) was used to measure the degree of associations and 95% confidence intervals (CIs) were reported. Significance was based on
The medical records of 131 dogs with leishmaniasis were reviewed, and, of these, 16 dogs were excluded because of the absence of dermatological signs at the first consultation. Of the remaining 115/131 dogs (88%) who had CanL with dermatological manifestations, 5 dogs were excluded because of incomplete medical records, 6 dogs because of concomitant infectious diseases, and 4 dogs for other diseases potentially associated with dermatological signs. A total of 100/131 dogs (76%) met the criteria for inclusion in the study.
Of the 100 cases enrolled, 62 dogs (62%) were male (5 castrated) and 38 (38%) were female (12 spayed) and the mean age was 6.4 years (range from 1 to 14 years). Thirty-two dogs (32%) were mixed breeds, 10 (10%) Boxers, 8 (8%) Setters, 7 (7%) Retrievers, 5 (5%) German Shepherds, 5 (5%) Hounds, 4 (4%) Spaniels, 4 (4%) Nordics, 4 (4%) Great Danes, and 3 (3%) Bulldogs, and the remaining 17 dogs (17%) were pure breeds representing 13 different breeds. Thirty-five dogs (35%) came from kennels, 31 dogs (31%) came from private litters, 23 dogs (23%) came from national breeders, and 11 dogs (11%) came from pet stores. All dogs lived in Milan but had previously travelled to areas endemic for CanL.
On the basis of the presence or absence of systemic signs referable to CanL detected on clinical examination the dogs were divided into two groups: seventy-nine dogs (79%) had dermatological and systemic signs of CanL, while 21 dogs (21%) had only dermatological manifestation of CanL and no identifiable systemic signs on clinical examination.
Table
Distribution of dermatological manifestation of CanL in all 100 dogs and in 21 dogs in the group with only dermatological manifestations of CanL and no identifiable systemic signs.
Number of subjects | Prevalence | |
---|---|---|
Dermatological form or manifestation in 100 dogs | ||
Exfoliative dermatitis with or |
74 | 74% |
Ulcerative dermatitis | 18 | 18% |
Nodular form | 11 | 11% |
Onychogryphosis | 10 | 10% |
Nasal and digital hyperkeratosis | 9 | 9% |
Nasal depigmentation | 1 | 1% |
Sterile pustular dermatitis | 1 | 1% |
Dermatological form or manifestation in 21 dogs with only dermatological manifestations | ||
Exfoliative dermatitis with or |
13 | 62% |
Ulcerative dermatitis | 5 | 24% |
Nodular form | 2 | 10% |
Onychogryphosis | 1 | 5% |
Nasal and digital hyperkeratosis | 2 | 10% |
There were no statistically significant associations between sex and age and dermatological manifestations (data not reported). The only statistically significant association was between Retriever breed and the group of patients with only dermatological signs (
To the authors’ knowledge this is the first retrospective study reporting on dermatological presentations of CanL in an area of northern Italy where CanL is not endemic. Results of this study suggest that dermatological manifestations commonly reported in dogs with CanL from endemic areas occur with the same frequency in dogs living in nonendemic areas. In this study 88% of confirmed cases of canine leishmaniasis at the Veterinary Teaching Hospital of the University of Milan over a 13-year period had dermatological manifestations. Our findings support those in the literature that report skin abnormalities in approximately 80%–90% of CanL cases in studies in endemic areas [
Also of note, in 21% of these cases only dermatological signs were reported at the first consultation, with no detectable systemic abnormalities. This percentage, similar to that of Cabassu et al. [
Some breeds such as Boxers, Setters, Retrievers, and German Shepherds appear to be overrepresented, and male dogs seem to be more numerous in our study. This is in partial agreement with the literature which suggests that Boxer, German Shepherd dogs [
The prevalence of the different dermatological forms identified in our study, both on the total sample of 100 dogs and on the subgroup of 21 dogs with only skin manifestations, was very similar to those seen in previous studies in endemic areas [
In our study many of the nodular lesions were localized to the head and pinnae, typical sites of inoculation. The dogs in this study, after visiting an endemic area where it is likely they contracted the infection, lived in a nonendemic area and were no longer subject to continuous stimulation of the skin immune system from repeated infectious bites and the simultaneous intradermal injection of sandfly saliva [
Exfoliative dermatitis was usually located on the pinnae, the periocular area, and head, while skin ulcerations were mostly located on pressure points and pinnae, as previously reported in the literature [
It is important to note that 22% of the dogs in this study had more than one dermatological form concurrently highlighting once again the extreme variability of the signs of this disease and the difficulty in accurately describing a dermatological form, as already reported by Koutinas et al. in endemic areas of Greece [
It should be emphasized that the Retriever breed appears statistically over represented (
In conclusion, the results of this study conducted in a nonendemic leishmania area confirm that dermatological manifestations, particularly exfoliative dermatitis, are very common in CanL and are often associated with variable systemic signs. Our results also underline the extreme variability of dermatological lesions in CanL that can easily be confused with other similar conditions.
Our study does not confirm our initial hypothesis that a lower antigenic stimulation associated with the absence of repeated infectious bites would lead to substantial differences in the prevalence and dermatological manifestations between endemic and nonendemic areas. In fact the prevalence and the clinical dermatological forms in our study are quite similar to previous epidemiological studies conducted in endemic areas, despite the lack of continuous antigenic stimulation. The author’s data also demonstrates no correlation between sex and age and common or atypical dermatological forms of CanL in a nonendemic area.
The authors declare that there is no conflict of interests regarding the publication of this paper.