Feline leishmaniosis: Is the cat a small dog?

Abstract

Leishmania infantum is a vector-borne zoonotic disease transmitted by phlebotomine sand flies and dogs are considered the main reservoir of the parasite. Feline leishmaniosis (FeL) caused by L. infantum is an emergent feline disease more and more frequently reported in endemic areas. This review summarizes current knowledge focusing similarities and differences with canine leishmaniosis (CanL). Cats are infected by the same Leishmania species than dogs but prevalence of the infection is lower and cases of disease are less frequently reported. Scarce information is available on adaptive immune response of cats naturally exposed to L. infantum infection and mechanisms responsible for susceptibility or resistance of feline hosts. However, about half of clinical cases of FeL are reported in cats with possible impaired immunocompetence. Coinfections or comorbidities are frequently detected in sick cats and they can contribute to a misrepresentation of clinical FeL albeit lesions associated with the presence of the parasite have been detected in skin, lymph nodes, spleen, bone marrow, liver, oral mucosa, stomach, large bowel, kidney, nasal exudate, lung, eye. As for dogs, skin or mucocutaneous lesions are the most common reason for veterinary consultation and finding on physical examination in cats with leishmaniosis. Molecular investigations of Leishmania DNA and anti- Leishmania antibody detection are largely used with the same methodologies for both CanL and FeL, however few information is available about their diagnostic performance in feline hosts. Treatment of cats with clinical FeL is still empirically based and off label by using the most common drugs prescribed to dogs. Life expectancy of cats with clinical FeL is usually good unless concurrent conditions or complications occur and prognosis does not seem significantly influenced by therapy or retroviral coinfection. According to current knowledge, cats can play a role as additional reservoir host of L. infantum and, in a « One Health » perspective, preventative measures should be taken. In conclusion, albeit feline infection and the associated cat disease caused by L. infantum is increasingly reported in endemic areas and have many similarities with CanL, consolidated evidence-based knowledge is not available and we cannot exclude that important differences between dogs and cats exist about transmission, immunopathogenesis and best practice for management and prevention.

Leishmania infection in cats and dogs housed together in an animal shelter reveals a higher parasite load in infected dogs despite a greater seroprevalence among cats

“…Most of the dogs (88%) and cats (55%) in the shelter had physical examination findings that were compatible with leishmaniosis and eventually after testing for the infection using specific tests, it was shown that indeed a significantly higher percentage of the dogs that were Leishmania-positive by serology or PCR had clinical signs of the disease when compared to their feline counterparts. This is reasonable when relating to the dog as the main host of the disease which often develops clinical disease after exposure to infection while the cat appears to be less frequently affected clinically by L. infantum with a much smaller number of clinical cases documented in the veterinary literature [2,3]. To our knowledge, this is the first report of feline leishmaniosis in Israel.…”

“…Leishmaniosis caused by Leishmania infantum is a major zoonosis which affects humans and dogs in many regions of the world [1]. Cats also develop clinical disease due to L. infantum infection and may have dermal as well as visceral manifestations of this infection [2,3]. Although the number of feline cases of clinical disease with L. infantum seems lower than the number of canine cases in endemic areas, there is no sufficient comparative knowledge relating to the prevalence of leishmaniosis in domestic dogs and cats exposed to the same conditions of disease transmission.…”

Serological and molecular investigation of Leishmania spp. infection in cats from an area endemic for canine and human leishmaniasis in Northeast Brazil

“…Baseado nestes dados, não foi observada nenhuma associação estatística significativa entre a soropositividade para Leishmania spp. e gênero, idade, presença de sinais clínicos, fatores Feline leishmaniasis (FeL), which is mainly caused by Leishmania infantum, is considered to be an emerging disease (PENNISI & PERSICHETTI, 2018). In the last two decades, there has been a considerable increase in epidemiological studies and reports of FeL, especially in areas endemic for canine and human leishmaniasis (PENNISI et al, 2015).…”

Clinical, haematological and biochemical findings in tigers infected by Leishmania infantum

“…After being long regarded as resistant, cats have gain the interest of the scienti c community as hosts of L. infantum, mainly in endemic areas (Iatta et al, 2019;Asfaram et al, 2019). Clinical signs compatible with feline leishmaniasis (FeL) include lymphadenomegaly, splenomegaly, weight loss, anorexia, as well as cutaneous, mucocutaneous and ocular lesions (Pennisi et al, 2018). However, the subclinical infection seems more common in endemic regions such as Mediterranean countries (Pennisi et al, 2018)…”

“…Clinical signs compatible with feline leishmaniasis (FeL) include lymphadenomegaly, splenomegaly, weight loss, anorexia, as well as cutaneous, mucocutaneous and ocular lesions (Pennisi et al, 2018). However, the subclinical infection seems more common in endemic regions such as Mediterranean countries (Pennisi et al, 2018)…”