Michael Leschnik

Medical University of Vienna, Wien, Vienna, Austria

Are you Michael Leschnik?

Claim your profile

Publications (43)99.56 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: A 5-year-old, female client-owned cat presented with acute onset of focal epileptic seizures with orofacial twitching and behavioural changes. Magnetic resonance imaging showed bilateral temporal lobe hyperintensities and the EEG was consistent with ictal epileptic seizure activity. After antiepileptic and additional corticosteroid treatment, the cat recovered and by 10 months of follow-up was seizure-free without any problem. Retrospectively, antibodies to LGI1, a component of the voltage-gated potassium channel-complex, were identified. Feline focal seizures with orofacial involvement have been increasingly recognised in client-owned cats, and autoimmune limbic encephalitis was recently suggested as a possible aetiology. This is the first report of EEG, MRI and long-term follow-up of this condition in cats which is similar to human limbic encephalitis.
    Epileptic disorders: international epilepsy journal with videotape 03/2014; · 1.17 Impact Factor
  • Michael Leschnik
    The Veterinary Journal 11/2013; · 2.42 Impact Factor
  • James Oliver Rushton, Michael Leschnik, Barbara Nell
    [Show abstract] [Hide abstract]
    ABSTRACT: A 7-year-old, 46-kg spayed female rottweiler dog was presented with sudden onset of disorientation, bilateral convergent strabismus, and enophthalmos. Diagnostic workup revealed hypothyroid-associated cranial neuropathy. Symptoms abated considerably upon treatment with levothyroxine-sodium (T4) at an initial dose of 800 μg/kg body weight (BW), PO, q12h, which was reduced 3 days later to 600 μg/kg BW, q12h due to severe agitation and panting. Two weeks later the dosage of the levothyroxine-sodium (T4) was reduced to 400 μg/kg BW in the morning and 600 μg/kg BW in the evening. Eight weeks after the initial presentation, the dog had recovered with only mild convergent strabismus in the right eye. This is the first case report of suspected hypothyroid-associated neuropathy resulting in these symptoms.
    The Canadian veterinary journal. La revue veterinaire canadienne 04/2013; 54(4):368-372. · 0.77 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Effective control of tick infestation and pathogen transmission requires profound knowledge of tick biology in view of their vector function. The particular time of the year when the different tick species start to quest and the favoured sites on the canine host are of major interest. The efficacy of acaricides/repellents to control ticks in the field requires observation. METHODS: To address these issues, 90 dogs, grouped in "untreated", "acaricide/repellent" (permethrin) and "acaricide only" (fipronil) animals and subjected to tick infestation under natural conditions in Burgenland (Eastern Austria), were examined. The number and species of ticks occurring during and outside the protection time was evaluated during a period of 11 months and the biting location on the dogs' skin was recorded. RESULTS: Of the 700 ticks collected, the most common species in that particular walking area was Ixodes ricinus, followed by Dermacentor reticulatus and Haemaphysalis concinna. Regarding the on-host activity, D. reticulatus displayed more infestations in early spring and late autumn, whereas I. ricinus occurred almost one month later in spring and one month earlier in autumn. H. concinna followed a monophasic pattern of activity with a peak in summer. The preferred feeding sites of the ticks on the dogs were on the head, neck, shoulder and chest. This distribution over the dog's body was not influenced by the use of the drugs, although on the whole fewer ticks (22.5% of all ticks) were found during the protection time. Interestingly, differences occurred with the use of drugs compared to non-protected dogs with regard to the infestation over the year. Acaricide-treated dogs displayed a higher prevalence in April, May and September, whereas dogs of the acaricide/repellent group showed a higher infestation in March, July, October and November. CONCLUSION: The different tick species display different on-dog activity peaks over the year, during which particular canine diseases can be expected and predicted, considering the specific incubation times for each pathogen.The tick species occurring in this study do not seem to choose particular sites on the dogs. Their arrival place seems to represent the attachment and consequently the feeding sites. The use of acaricides leads to a significantly (p<0.01) lower number of infesting ticks but no change of the distribution pattern on the dogs was observed.
    Parasites & Vectors 03/2013; 6(1):76. · 3.25 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Tick-borne infections resulting from regular tick infestation in dogs are a common veterinary health problem all over the world. The application of repellent and acaricidal agents to prevent transmission of pathogens is a major protection strategy and has been proven to be highly effective in several trials under laboratory and natural conditions in dogs. Despite such promising results, many dog owners still report tick infestation in their dogs although acaricidal agents are used. Information about the current infection status and changes of the infection status regarding tick-borne diseases (TBD) in dogs treated by the owner's controlled acaricide application is lacking. METHODS: In this study 30 dogs were each treated with permethrin, fipronil + S-methoprene, or served as untreated controls. Application of the acaricide was performed by the owner who decided when and how often to use the spot on preparation. Over a period of 11 months, dogs were clinically examined and sampled for antibody responses against Babesia canis, Anaplasma phagocytophilum, Borrelia burgdorferi s.l., and TBE virus before the study started, 6 months later and at the end of the investigation period. RESULTS: The permethrin acaricide was applied on average 3.40 times within the examination period, whereas the fipronil + S-methoprene medication was applied 3.03 times. Approximately 2/3 of all dogs, independent of the group, had a positive immune response to one or more pathogens. Three dogs developed clinical symptoms of canine babesiosis, all other dogs remained healthy. Individual number of ticks per dog or number of infections per dog did not correlate with the application rate, and the number of ticks per dog did not influence the number of infections per dog. As owners did not apply the acaricides regularly no influence on the number of infections could be documented although the number of ticks was clearly reduced by the application of the spot-on drugs. CONCLUSIONS: Clinical disease in dogs exposed to tick-borne pathogens is rare, although a humoral immune response reflecting infection is common. More educational training for dog owners is necessary to make the application of acaricides effective regarding the prevention of tick-borne diseases.
    Parasites & Vectors 03/2013; 6(1):62. · 3.25 Impact Factor
  • Source
    Journal of Small Animal Practice 01/2013; · 1.18 Impact Factor
  • Journal of Comparative Pathology. 01/2013; 148(1):58.
  • A. Klang, M. Leschnik, P. Schmidt, A. Pakozdy
    [Show abstract] [Hide abstract]
    ABSTRACT: A 5-year-old dog was referred with the history of anorexia and apathy for 3 weeks and acute status epilepticus. Ten weeks later the animal was humanely destroyed due to refractory epilepsy, despite anti-epileptic medical treatment. Microscopicalexamination of the brain revealed bilateral malformation of the dentate gyrus with abnormal gyration. Cornu ammonis (CA) segments comprised of sparse pyramidal cells accompanied by marked gliosis. Additionally, there was severe generalized disseminated granulomatous meningoencephalitis, mainly localized to the white matter of the cerebral hemispheres. This is the first description of bilateral hippocampal malformation in a dog.
    Journal of comparative pathology 01/2013; · 1.73 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Treatment-resistant complex partial seizures (CPS) with orofacial involvement recently were reported in cats in association with hippocampal pathology. The features had some similarity to those described in humans with limbic encephalitis and voltage-gated potassium channel (VGKC) complex antibody. HYPOTHESIS/OBJECTIVES: The purpose of this pilot study was to evaluate cats with CPS and orofacial involvement for the presence of VGKC-complex antibody. ANIMALS: Client-owned cats with acute orofacial CPS and control cats were investigated. METHODS: Prospective study. Serum was collected from 14 cats in the acute stage of the disease and compared with 19 controls. VGKC-complex antibodies were determined by routine immunoprecipitation and by binding to leucine-rich glioma inactivated 1 (LGI1) and contactin-associated protein-like 2 (CASPR2), the 2 main targets of VGKC-complex antibodies in humans. RESULTS: Five of the 14 affected cats, but none of the 19 controls, had VGKC-complex antibody concentrations above the cut-off concentration (>100 pmol/L) based on control samples and similar to those found in humans. Antibodies in 4 cats were directed against LGI1, and none were directed against CASPR2. Follow-up sera were available for 5 cats in remission and all antibody concentrations were within the reference range. CONCLUSION AND CLINICAL IMPORTANCE: Our study suggests that an autoimmune limbic encephalitis exists in cats and that VGKC-complex/LGI1 antibodies may play a role in this disorder, as they are thought to in humans.
    Journal of Veterinary Internal Medicine 12/2012; · 2.06 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We report an evaluation of the treatment and outcome of cats with suspected primary epilepsy. Phenobarbital therapy was used alone or in combination with other anti-epileptic drugs. Outcome after treatment was evaluated mainly on the basis of number of seizures per year and categorised into four groups: seizure-free, good control (1-5 seizures per year), moderate control (6-10 seizures per year) and poor control (more than 10 seizures per year). About 40-50% of cases became seizure-free, 20-30% were considered good-to-moderately controlled and about 30% were poorly controlled depending on the year of treatment considered. The duration of seizure events after treatment decreased in 26/36 cats and was unchanged in eight cats. The subjective severity of seizure also decreased in 25 cats and was unchanged in nine cats. Twenty-six cats had a good quality of life, nine cats an impaired quality of life and one cat a bad quality of life. Despite being free of seizures for years, cessation of treatment may lead to recurrence of seizures in most cats.
    Journal of feline medicine and surgery. 10/2012;
  • [Show abstract] [Hide abstract]
    ABSTRACT: The main aim of this study was to identify interictal epileptiform discharges in a group of dogs with seizures of known aetiology (symptomatic epilepsy, SE) and in dogs with idiopathic epilepsy (IE). Propofol was used for chemical restraint in all dogs. We found electroencephalographic (EEG) changes that could be considered epileptiform discharges (EDs) in 5 out of 40 dogs (12.5%). The EEG changes identified were spikes in four cases and periodic epileptiform discharges in one case. All EDs were seen in the SE group. We conclude that the interictal electroencephalographic examinations of propofolanaesthetised dogs suffering from IE and SE rarely show epileptic discharges and that the diagnostic value of such EEGs in the work-up for epilepsy seems to be low as epileptic discharges were unlikely to be detected. However, positive findings are more likely to be connected with SE. We found frequent, transient EEG phenomena (spindles, K-complexes, vertex waves, positive occipital sharp transients of sleep, cyclic alternating patterns), which are non-epileptic but their differentiation from epileptic phenomena is challenging.
    Acta Veterinaria Hungarica 09/2012; 60(3):309-24. · 1.17 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A 2-yr-old male captive timber wolf, kept in an outdoor enclosure in Austria, presented with anorexia, depression, and fever in June. Tick infestation was reported despite monthly acaricidal treatment. The microscopic examination of a blood smear revealed elementary bodies and morulae suspicious for Anaplasma phagocytophilum. Polymerase chain reaction confirmed the infection by the G-variant of the pathogen, also found in horses and humans but not in wild ruminants. The wolf seroconverted within 2 wk, and antibodies persisted thereafter. Therapy was started with doxycycline for 10 days, and the wolf recovered within 24 hr. Clinical symptoms and temporary changes in blood parameters (thrombocytopenia, lymphopenia, mild anemia) in this wolf show high similarity to granulocytic anaplasmosis seen in dogs. This is the first report on granulocytic anaplasmosis in a wolf, indicating that A. phagocytophilum might cause clinical disease in the wolf.
    Journal of Zoo and Wildlife Medicine 09/2012; 43(3):645-8. · 0.43 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Research into tick-borne diseases implies vector sampling and the detection and identification of microbial pathogens. Ticks were collected simultaneously from dogs that had been exposed to tick bites and by flagging the ground in the area in which the dogs had been exposed. In total, 200 ticks were sampled, of which 104 came from dogs and 96 were collected by flagging. These ticks were subsequently examined for DNA of Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Rickettsia spp. and Babesia canis. A mixed sample of adult ticks and nymphs of Ixodes ricinus (Ixodida: Ixodidae) and Haemaphysalis concinna (Ixodida: Ixodidae) was obtained by flagging. Female I. ricinus and adult Dermacentor reticulatus (Ixodida: Ixodidae) ticks dominated the engorged ticks removed from dogs. Rickettsia spp. were detected in 17.0% of the examined ticks, A. phagocytophilum in 3.5%, B. canis in 1.5%, and B. burgdorferi s.l. in 16.0%. Ticks with multiple infections were found only among the flagging sample. The ticks removed from the dogs included 22 infected ticks, whereas the flagging sample included 44 infected ticks. The results showed that the method for collecting ticks influences the species composition of the sample and enables the detection of a different pattern of pathogens. Sampling strategies should be taken into consideration when interpreting studies on tick-borne pathogens.
    Medical and Veterinary Entomology 08/2012; · 2.21 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Haematological changes in dogs and climatic conditions favourable for the vector may assist in the quick in-house diagnosis of canine babesiosis. Blood samples from 358 dogs suspected to have canine babesiosis were evaluated. The diagnosis was confirmed in 113 dogs by detection of Babesia canis by microscopic examination of a stained blood smear using the concentration line technique. Thrombocytopenia was present in all 113 dogs. Red blood cell count, packed cell volume and haemoglobin values were below the reference range in 62.8%, 61.1% and 46.0% of affected dogs, respectively. An increased reticulocyte count was apparent in five Babesia canis -positive dogs. Leukopenia, lymphopenia, neutropenia and monocytosis were present in 54.9%, 47.8%, 30.4% and 6.5% of the dogs, respectively. Evaluating haematological parameters by CART-analysis revealed a predictive model (accuracy= 93.5%) for canine babesiosis, when using the leucocyte, thrombocyte, and reticulocyte count. Climatic conditions present at the most probable time of Babesia canis- infection accounted for biseasonal occurrence. Changes of climatic factors during the year influence the vector activity and in conclusion should highlight babesiosis in the ranking of differentials for veterinarians. The results demonstrate that a tentative diagnosis of canine babesiosis can be made based on typical haematological changes. The results recorded match well with the seasonality of the tick vector and were confirmed here by the month of sample submission.
    Tierärztliche Praxis. Ausgabe K, Kleintiere/Heimtiere 04/2012; 40(2):87-94. · 0.47 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Seventeen cats were presented with acute onset of complex partial seizures with orofacial involvement (salivation, facial twitching, lip smacking, chewing, licking or swallowing), motor arrest (motionless starring) and behavioural changes. In 11 cats hippocampal necrosis (HN) was confirmed by histopathology. In a further six cats hippocampal changes were suggested by magnetic resonance imaging. The mean monitoring time of eight cats which were not euthanased in the acute phase of the disease, was 408 days (60-908): four cats are still alive. In all surviving cases, the owners reported a good quality of life. We conclude that an acute cluster of complex partial seizures with orofacial involvement are often associated with HN and that HN is not necessarily a fatal condition. Supportive and antiepileptic therapy can result in remission. The long-term outcome can be good to excellent; therefore, euthanasia should be avoided in the acute phase of the signs.
    Journal of feline medicine and surgery. 07/2011; 13(10):687-93.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Austrian field cases of canine distemper (14 dogs, one badger [Meles meles] and one stone marten [Martes foina]) from 2002 to 2007 were investigated and the case histories were summarised briefly. Phylogenetic analysis of fusion (F) and haemagglutinin (H) gene sequences revealed different canine distemper virus (CDV) lineages circulating in Austria. The majority of CDV strains detected from 2002 to 2004 were well embedded in the European lineage. One Austrian canine sample detected in 2003, with a high similarity to Hungarian sequences from 2005 to 2006, could be assigned to the Arctic group (phocine distemper virus type 2-like). The two canine sequences from 2007 formed a clearly distinct group flanked by sequences detected previously in China and the USA on an intermediate position between the European wildlife and the Asia-1 cluster. The Austrian wildlife strains (2006 and 2007) could be assigned to the European wildlife group and were most closely related to, yet clearly different from, the 2007 canine samples. To elucidate the epidemiological role of Austrian wildlife in the transmission of the disease to dogs and vice versa, H protein residues related to receptor and host specificity (residues 530 and 549) were analysed. All samples showed the amino acids expected for their host of origin, with the exception of a canine sequence from 2007, which had an intermediate position between wildlife and canine viral strains. In the period investigated, canine strains circulating in Austria could be assigned to four different lineages reflecting both a high diversity and probably different origins of virus introduction to Austria in different years.
    The Veterinary record. 04/2011; 168(14):377.
  • [Show abstract] [Hide abstract]
    ABSTRACT: In recent years opportunistic infections due to microsporidial organisms have become increasingly important in immunocompromised people. Infected animals could serve as reservoirs of such infections. A case of generalized encephalitozoonosis in a young kitten is reported. Diagnosis was established by histopathological, immunohistochemical and molecular biological investigations demonstrating characteristic lesions and DNA of Encephalitozoon cuniculi in formalin-fixed and paraffin wax-embedded tissue sections. Infections due to E. cuniculi are not common in cats, but a potential role of domestic cats in transmission of the infectious agent cannot be excluded.
    Journal of comparative pathology 02/2011; 145(2-3):126-31. · 1.73 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: There is a high incidence of hereditary degenerative diseases of the central nervous system in purebred dogs. Cerebellar ataxia in Malinois puppies, caused by degenerative changes that predominate in cerebellar nuclei and the granular cell layer, is a hereditary disorder that is distinct from cerebellar cortical abiotrophies. Thirteen Malinois puppies with cerebellar ataxia. Retrospective study. Records of Malinois puppies with spongy degeneration of the cerebellar nuclei were analyzed including clinical signs, histopathological changes, and pedigree data. Signs of cerebellar dysfunction were observed in puppies of both sexes from 5 different litters (1995-2009) of phenotypically normal parents. Clinical signs started before the age of 2 months and resulted in euthanasia of all puppies by the age of 13 weeks. Histopathology disclosed marked bilateral spongy degeneration of the cerebellar nuclei and vacuoles in the granular cell layer and foliate white matter of the cerebellum. In some puppies, discrete vacuoles in gray and white matter were present in other parts of the brain. Furthermore, spheroids and dilated myelin sheaths were observed. Pedigree data and segregation frequency support an autosomal recessive hereditary disorder. Malinois suffer from a hereditary spongiform degeneration that predominates in the cerebellum and causes an early onset of clinical signs with unfavorable prognosis. Future efforts should increase awareness among veterinarians and breeders and aim to identify underlying metabolic mechanisms and the affected genes.
    Journal of Veterinary Internal Medicine 01/2011; 25(3):490-6. · 2.06 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In the present study 125 cats with recurrent seizures were analysed. The main goal was to investigate the aetiology and compare primary epilepsy (PE) with secondary epilepsy (SE) regarding signalment, history, ictal pattern, clinical and neurological findings. Seizure aetiology was classified as PE in 47 (38%) and SE in 78 (62%) cats. SE was caused mainly by intracranial neoplasia (16), hippocampal necrosis (14), toxicosis (eight), and encephalitis (seven). A significant difference between PE and SE was found in: age, body weight, duration of seizure, occurrence of status epilepticus and neurological deficits. Status epilepticus, altered interictal neurological status and seizure onset over the age of 7 years indicated SE more frequently than PE. If the seizures occurred during resting conditions and rapid running occurred the aetiology was more likely to be PE than SE.
    Journal of feline medicine and surgery. 12/2010; 12(12):910-6.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Es wird über 4 Fälle von Morbus Alexander bei zwei Berner Sennenhunden, einem Berner Sennenhund-Mischling und einem Chihuahua mit progressiver neurologischer Symptomatik berichtet. Alle Tiere wurden im Alter zwischen 9 und 18 Wochen euthanasiert. Anschließend erfolgte eine Obduktion. Die histologische Untersuchung des Gehirnes ergab eine weitläufige Ansammlung von Proteinaggregaten, sogenannten Rosenthal Fasern, in Astrozyten. Die immunhistochemische Untersuchung für saures Gliafaserprotein, welche in zwei Fällen vorgenommen wurde, ergab eine deutlich positive Reaktion im Bereich der Rosenthal Fasern. In zwei Fällen wurde überdies eine elektronenmikroskopische Untersuchung durchgeführt. Dabei zeigten sich granuläre Aggregate im Bereich von Astrozyten. Die pathomorphologischen Ergebnisse korrelieren mit den bei Morbus Alexander beschriebenen Veränderungen. Diese seltene, bei der Rasse Chihuahua erstmals beschriebene, Erkrankung des zentralen Nervensystems hat aufgrund einer primären Fehlfunktion der Astrozyten sekundär eine Dysfunktion von Oligodendrozyten zur Folge. Eine Häufung dieses Krankheitsbildes beim Berner Sennenhund deutet auf eine genetische Disposition dieser Hunderasse hin.
    Wiener tierärztliche Monatsschrift 09/2010; · 0.39 Impact Factor