Feline leishmaniosis with focus on ocular manifestation: a case report

I. Schäfer, A. Schmidt, F. Gräßer, A. Schieszler, H. Aupperle-Lellbach, G. Loesenbeck, M. Gentil, E. Müller, T.J. Naucke

Parasites & Vectors volume 16 (161) 2023

Abstract

Background: In Europe, feline leishmaniosis is commonly caused by Leishmania infantum. There is little knowledge regarding pathogenesis, ocular manifestations and long-term follow-ups in cats with leishmaniosis.

Findings: A 6-year-old female, spayed European Shorthair cat was imported from Spain to Germany 2 years prior to its first clinical presentation. The cat showed lethargy, weight loss, ulcerative lesions on the front limbs and high-grade chronic uveitis. The diagnosis of L. infantum infection was based on the cytological finding of amastigotes in skin lesions, positive qPCR of EDTA-blood and positive PCR of a cyto-brush sample from the conjunctiva. Supportive findings included positive serology by IFAT, serum protein capillary electrophoresis with peaks in alpha2- and gamma-globulin sections and marked elevation of SAA. Enucleation had to be performed on day 288 on both eyes because of blindness, glaucoma and high-grade uveitis. Histologically, high numbers of Leishmania spp. amastigotes were found in histiocytes. IFAT and PCR were positive in the aqueous humor in both eyes, respectively. Feline leukemia virus antigen and feline immunodeficiency virus antibody testings were positive. Hematological and biochemical results revealed mild leukocytosis with lymphocytosis, monocytosis and eosinopenia as well as marked elevation of SAA and hyperglobulinemia. The cat was treated with allopurinol, responded well and was still alive at follow-up on day 288 after first presentation. However, enucleation was necessary because of refractory glaucoma and uveitis.

Conclusion: For the first time, ocular evidence of Leishmania IgG antibodies was demonstrated in the aqueous humor of both eyes in cats. There is limited knowledge about the pathogenesis, treatment options and outcomes in cats infected with L. infantum. This case report supports the hypothesis that immunosuppression increases the risk of clinical signs of leishmaniasis in cats. Alpha2- and gamma-globulin peaks in serum protein capillary electrophoresis are supportive criteria for the diagnosis of L. infantum infection. SAA is valuable for monitoring. Regarding ophthalmology, uveitis and glaucoma may have a poor prognosis.

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Ein Update zur Leishmaniose des Hundes: Diagnostik, Therapie und Monitoring

I. Schäfer, E. Müller, T.J. Naucke
Tierarztl. Prax. Ausg. K Kleintiere Heimtiere 2022; 50(06): 431-445

Zusammenfassung: Aufgrund von steigenden Importzahlen von Hunden aus dem Ausland, zunehmendem Reiseverkehr sowie den Veränderungen klimatischer Bedingungen in Europa gewinnen Infektionen mit Leishmania (L.) infantum bei Hunden in Deutschland zunehmend an Bedeutung. Daher sollten auch Hunde aus dem Ausland, die keine klinischen Symptome zeigen, direkt nach Import sowie erneut 6 Monate später auf vektorübertragene Infektionserreger getestet werden. Bei Hunden mit klinischer Symptomatik, die hinweisend auf eine Leishmaniose sind, werden direkte und indirekte Nachweisverfahren sowie eine hämatologische und biochemische Untersuchung unter Einbezug von Serumeiweißelektrophorese sowie Bestimmung des C-reaktiven Proteins empfohlen. Als Leitfaden für die Therapie sowie das Monitoring stehen die LeishVet-Guidelines zur Verfügung. Es stehen leishmanizide und leishmaniostatische Wirkstoffe zur Verfügung, die in first-line, second-line und third-line unterschieden werden. Zur Anpassung der Allopurinol-Dosierung wird der Stufenplan empfohlen. Aufgrund der Veränderung der klimatischen Bedingungen kommt es zu einer Ausbreitung der Habitate von Sandmücken, die als Vektoren der Leishmaniose bekannt sind. Als weitere Infektionsquellen sind Deckakte, transplazentare Infektionen, Bisswunden und Bluttransfusionen beschrieben. Leishmania infantum hat zoonotisches Potential und ist daher auch in Hinblick auf den „One-Health“-Gedanken bedeutend.  

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Vector-borne and other pathogens of potential relevance disseminated by relocated cats

R.G. Maggi, V. Halls, F. Krämer, M. Lappin, M.G. Pennisi, A.S. Peregrine, X. Roura, B. Schunack, V. Scorza, S. Tasker, G. Baneth, P. Bourdeau, D.D. Bowman, E.B. Breitschwerdt, G. Capelli, L. Cardoso, F. Dantas-Torres, G. Dobler, L. Ferrer, L. Gradoni, P. Irwin, F. Jongejan, V.A.J. Kempf, B. Kohn, S. Little, M. Madder, C. Maia, M. Marcondes, G. Miró, T. Naucke, G. Oliva, D. Otranto, B.L. Penzhorn, M. Pfeffer, Á. Sainz, S. Shin, L. Solano-Gallego, R.K. Straubinger, R. Traub, I. Wright

Parasites & Vectors 15(1) (2022)

Abstract: Large populations of unowned cats constitute an animal welfare, ecological, societal and public health issue world‑wide. Their relocation and homing are currently carried out in many parts of the world with the intention of relievingsuffering and social problems, while contributing to ethical and humane population control in these cat populations. An understanding of an individual cat’s lifestyle and disease status by veterinary team professionals and those work‑ing with cat charities can help to prevent severe cat stress and the spread of feline pathogens, especially vector‑borne pathogens, which can be overlooked in cats. In this article, we discuss the issue of relocation and homing of unownedcats from a global perspective. We also review zoonotic and non‑zoonotic infectious agents of cats and give a list ofpractical recommendations for veterinary team professionals dealing with homing cats. Finally, we present a consen‑sus statement consolidated at the 15th Symposium of the Companion Vector‑Borne Diseases (CVBD) World Forum in2020, ultimately to help veterinary team professionals understand the problem and the role they have in helping toprevent and manage vector‑borne and other pathogens in relocated cats.

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First evidence of vertical Hepatozoon canis transmission in dogs in Europe

I. Schäfer, E. Müller, A.M. Nijhof, H. Aupperle-Lellbach, G. Loesenbeck, S. Cramer, T.J. Naucke

Parasites & Vectors volume 15, Article number: 296 (2022)

Abstract

Background: Hepatozoon canis is a protozoal agent that is known to be transmitted by oral uptake of H. canis‑infected Rhipicephalus sanguineus sensu lato ticks in dogs. Vertical transmission of H. canis has only been describedonce in a study evaluating dogs from Japan. The aim of this study was to investigate the parasitological status of pup‑pies from a bitch that had tested positive for Hepatozoon spp. prior to giving birth.

Findings: A 4‑year‑old, female, pregnant dog imported from Italy (Sardinia) to Germany showed clinical signs of leth‑argy and tachypnoea and tested positive for H. canis by PCR. The dog gave birth to eight puppies, one of which wasstillborn and another that had to be reanimated. Haematology, buffy coat analysis and a biochemistry profile wereperformed for each dog. EDTA‑blood of the surviving seven puppies and bone marrow, liver, spleen, amniotic fluid,and umbilical cord of the stillborn puppy was tested for the presence of Hepatozoon spp. by PCR. The mother and the seven surviving puppies tested positive for H. canis by PCR at day 62 post‑partum. Gamonts weredetected in all dogs by buffy coat evaluation. Haematological and biochemistry results revealed mild abnormalities. Inthe stillborn puppy, spleen, umbilical cord, and amniotic fluid were positive for H. canis.

Conclusion: The results confirm that vertical transmission is a possible route of H. canis infection in dogs, dem‑onstrated by molecular detection of the pathogen in the stillborn puppy. In the seven surviving puppies, vertical transmission was the most likely transmission route. A potential impact of the level of parasitaemia on the health of puppies, as well as its pathogenesis, should be investigated further.

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Antibody ratios against NS1 antigens of tick-borne encephalitis and West Nile viruses support differential flavivirus serology in dogs

L. Könenkamp, U. Ziegler, T. Naucke, M.H. Groschup, I. Steffen

Transboundary and Emerging Diseases, June 2022 69(7)

Abstract: Flavivirus diagnostics are complicated by substantial cross-reactivity of antibodiesbetween different flavivirus species. This is of particular importance in regions withmultiple endemic flaviviruses in co-circulation. Tick-borne encephalitis virus (TBEV) isthe causative agent of tick-borne encephalitis, the most common infection of the cen-tral nervous system in endemic regions of Europe and Asia. Since 2018, the relatedWest Nile virus (WNV) has spread to Germany where its geographic distributionoverlaps with TBEV endemic regions. Besides humans, various animal species aresusceptible to TBEV and WNV infection. To compare antibody responses againstthese flaviviruses and test for cross-reactivity, we developed a multi-species luciferaseimmunoprecipitation system antibody detection assay for several different antigens.We performed a serosurvey of 682 dogs from five different European countries todetect antibodies against TBEV and WNV. Twelve specimens were positive for TBEVNS1 only and seven for WNV NS1 only. Two specimens were reactive to both NS1antigens and another two were equivocal for WNV NS1. Interestingly, 89.5% of pos-itive specimens had TBEV/WNV or WNV/TBEV signal ratios of 10 to >300 betweenindividual NS1 antigens, allowing for a clear distinction between the two viruses. Theremaining 10.5% of reactive specimens showed a five- to 10-fold difference betweenthe two viruses and included possible dual exposures to both viruses. In contrast,equivocal samples showed low signal ratios between the NS1 antigens, suggestingunspecific reactivity. Based on these data, we found the NS1 protein to be a suit-able antigen to distinguish between TBEV- and WNV-specific antibodies in dogs withsensitivity and specificity similar to virus neutralization tests.

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