Alexander Tichy

Clinical symptoms and diagnosis of encephalitozoonosis in pet rabbits.

Infections with Encephalitozoon cuniculi in rabbits are observed at increasing frequency and are known as opportunistic infections in immunocompromised humans. 191 pet rabbits with suspected encephalitozoonosis, presented at the Animal Hospital of the Veterinary University of Vienna (Austria), were included in this study. Rabbits were serologically examined for antibodies against E. cuniculi (144 positive out of 184 rabbits with suspected encephalitozoonosis compared to 14 positive out of 40 clinically healthy rabbits tested as part of a standard health check) and Toxoplasma gondii (8 positive out of 157). Of the 144 seropositive rabbits with clinical signs, 75% showed neurological symptoms, 14.6% demonstrated phacoclastic uveitis and 3.5% suffered from renal failure. 6.9% of the animals had combined symptoms. Vestibular disease dominated within the rabbits that showed neurological symptoms. Polymerase chain reaction (PCR) could not detect parasite DNA in urine or cerebrospinal fluid (CSF), but did so in 4 out of 5 samples of liquefied lens material in cases with phacoclastic uveitis due to lens capsule rupture. Additionally further diagnostic procedures, such as inspection of the external ear canal (N=69), radiography of the tympanic bullae (N=65) were performed to rule out differential diagnosis. 54.2% of the patients exhibiting neurological symptoms recovered within a few days, while 87.5% of the rabbits suffering from renal failure died or had to be euthanized.

Reservoirs of Listeria Species in Three Environmental Ecosystems

ABSTRACT Soil and water are suggested to represent pivotal niches for the transmission of Listeria monocytogenes to plant material, animals, and the food chain. In the present study, 467 soil and 68 water samples were collected in 12 distinct geological and ecological sites in Austria from 2007 to 2009. Listeria was present in 30% and 26% of the investigated soil and water samples, respectively. Generally, the most dominant species in soil and water samples were Listeria seeligeri, L. innocua, and L. ivanovii. The human- and animal-pathogenic L. monocytogenes was isolated exclusively from 6% soil samples in regions A (mountainous region) and B (meadow). Distinct ecological preferences were observed for L. seeligeri and L. ivanovii, which were more often isolated from wildlife reserve region C (Lake Neusiedl) and from sites in proximity to wild and domestic ruminants (region A). The higher L. monocytogenes detection and antibiotic resistance rates in regions A and B could be explained by the proximity to agricultural land and urban environment. L. monocytogenes multilocus sequence typing corroborated this evidence since sequence type 37 (ST37), ST91, ST101, and ST517 were repeatedly isolated from regions A and B over several months. A higher L. monocytogenes detection and strain variability was observed during flooding of the river Schwarza (region A) and Danube (region B) in September 2007, indicating dispersion via watercourses.

Diagnostic markers for encephalitozoonosis in pet rabbits.

Encephalitozoonosis is a common disease in pet rabbits, routinely diagnosed in vivo by serological examination or post mortem by histopathology. Recently molecular techniques have become increasingly important as diagnostic tools. The application of different diagnostic markers for in vivo and post mortem determination of E. cuniculi in naturally infected pet rabbits were compared. The examined population was divided into 33 rabbits with symptoms of encephalitozoonosis (group I) and 38 animals without symptoms (group II) which were all tested by serological analysis (Indirect Immunofluorescence Test), histological examination including special spore staining (Ziehl-Neelsen, acid-fast trichrome) and conventional and nested PCR (organs, body fluids). Additionally, in group III lens material (n=10) of animals (n=9) with phacoclastic uveitis were examined by conventional PCR. Infections with E. cuniculi could be determined post mortem in 78.8% of the rabbits of group I and in 57.9% of group II by histological examination combined with spore staining. In group I 69.7% and in group II 50.0% showed seroconversion. Conventional PCR was only sufficiently sensitive in samples of eyes with phacoclastic uveitis (n=10; 100%). Therefore nested PCR was performed in tissue samples, urine and cerebrospinal fluid (CSF) with positive results in 63.6% of group I and 42.1% of group II. Positive results in serology, pathohistology (spore detection and histological changes in the brain and/or kidneys) and nested PCR were obtained in 52.1% of the rabbits (group I and II, n=71), whereas 31.0% showed negative results in all three diagnostic techniques. 5.6% of the rabbits were positive in two methods and 11.3% in one method. In 37 rabbits (group I and II) with positive results in nested PCR, E. cuniculi DNA could be detected more frequently in the brain (91.9%) than in the kidney (54.1%). Furthermore nested PCR of urine revealed positive results in 29.7% of the rabbits (n=37) with seroconversion and/or confirmed E. cuniculi infection by spore detection. All 25 samples of CSF tested negative in nested PCR. Conventional PCR of eyes with phacoclastic uveitis was an excellent diagnostic marker in living rabbits, while nested PCR of urine or CSF was not reliable. Histological examination combined with special staining was the most sensitive method in post mortem diagnostics. Nested PCR appears to be a good post mortem method to investigate organs, especially brains, of chronically infected animals.

Encephalitozoonosis in pet rabbits (Oryctolagus cuniculus): pathohistological findings in animals with latent infection versus clinical manifestation

Encephalitozoon cuniculi is a common infectious agent of rabbits. The aim of this study was to determine the distribution and extent of histological lesions in the brain and in the kidney of naturally infected pet rabbits with or without clinical encephalitozoonosis. In 71 animals (33 with symptoms) which died or were euthanised, histopathological examination including staining of spores (Ziehl–Neelsen, acid-fast trichrome) was performed and changes were described quantitatively. The cerebrum was the most frequently affected brain region (97.5%), whilst the cerebellum (55%) and the vestibular cores (37.5%) were less commonly concerned. Granulomas were found in 77.5% of animals with encephalitis and in 12.5% of rabbits with interstitial nephritis. Although cerebral granulomas were found irrespective of the grade of histological changes, they were significantly correlated with changes at higher grades. There was no correlation between the severity of encephalitis and neurological symptoms. Since severe lesions were also found in clinically inconspicuous animals, histological findings of inflammatory lesions are not indicative of overt encephalitozoonosis as the causative agent for neurological signs. Other diseases causing neurological symptoms, such as suppurative encephalitis, otitis media as well as malignant lymphoma were also detected in the rabbit population that was examined in the present study.

Fasciola hepatica – Monitoring the milky way? The use of tank milk for liver fluke monitoring in dairy herds as base for treatment strategies

In this study 595 lactating cows originating from 31 carinthian farms were investigated in accordance of liver fluke infection using individual and tank milk as well as individual blood and faecal samples. Two commercial ELISAs were used to test the milk and blood serum, and the results were compared with coproscopy and a commercial copro-antigen ELISA. Receiver operating characteristics (ROC) and two-graph operating characteristics (TG ROC) of tank milk results were conducted based on the individual milk to determine the minimum reliable in-herd antibody prevalence for the predominant condition in the investigation area. In 17.8% of the examined individuals located in 64.5% of the farms eggs were detected by coproscopy. The copro-antigen ELISA delivered 13.4% positive individuals from 54.8% of the farms. The milk ELISAs showed 42.7% (Euroclone) and 44.2% (Pourquier) positive cows on 90.3% of the farms. The blood samples were positive in 43% (Euroclone) and 45.2% (Pourquier) of the individuals from 90.3% to 96.8% of the herds, respectively. Based on the milk and the blood an average in-herd prevalence of 30-45% can be assumed. The serum and milk samples delivered correlating results with kappa values between 0.94 and 0.97, whereas the coproscopy and copro-antigen ELISA did not correlate well with the ELISA results. The two different ELISA tests highly correlated on individual and on herd level. Both showed a reliable minimum in-herd prevalence of ∼20%, meaning that one fifth of the individuals in a herd have to be positive to obtain a positive bulk tank milk result. In the investigated area a higher in-herd prevalence is expected, therefore the tank milk is useful as a monitoring tool and can be used as a basis for intervention strategies.

Clinical comparison of primary versus secondary epilepsy in 125 cats

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.

Retrospective clinical comparison of idiopathic versus symptomatic epilepsy in 240 dogs with seizures

In the present study, 240 cases of dogs with seizures were analysed retrospectively. The aim was to examine the underlying aetiology and to compare primary or idiopathic epilepsy (IE) with symptomatic epilepsy (SE) concerning signalment, history, ictal pattern, clinical and neurological findings. The diagnosis of symptomatic epilepsy was based on confirmed pathological changes in haematology, serum biochemistry, cerebrospinal fluid (CSF) analysis and morphological changes of the brain by CT/MRI or histopathological examination. Seizure aetiologies were classified as idiopathic epilepsy (IE, n = 115) and symptomatic epilepsy (SE, n = 125). Symptomatic epilepsy was mainly caused by intracranial neoplasia (39) and encephalitis (23). The following variables showed significant difference between the IE and SE group: age, body weight, presence of partial seizures, cluster seizures, status epilepticus, ictal vocalisation and neurological deficits. In 48% of the cases, seizures were found to be due to IE, while 16% were due to intracranial neoplasia and 10% to encephalitis. Status epilepticus, cluster seizures, partial seizures, vocalisation during seizure and impaired neurological status were more readily seen with symptomatic epilepsy. If the first seizure occurred between one and five years of age or the seizures occurred during resting condition, the diagnosis was more likely IE than SE.

Canine isosporosis - epidemiology of field and experimental infections.

Summary Isospora spp. are the causative agents of canine isosporosis. Of the 3590 diagnostic samples from Austrian dogs (≤2 years old), 8.7% contained Isospora oocysts, 78% of which from dogs up to 4 months of age. Non‐haemorrhagic and haemorrhagic diarrhoea were significantly more prevalent in Isospora‐infected animals than in coccidia‐negative ones. Twelve of 15 litters from a large commercial dog breeding unit (examined from the third to the 10th week of life) also excreted Isospora (average prevalence: 36.4%) in intensities from 333 to 35 000 oocysts per gram of faeces (opg). In experimental trials 26 3‐week‐old Beagle puppies were infected with low (600–6000), medium (10 000) or high (20 000) dose of Isospora ohioensis‐group or Isospora canis field isolates. Additionally 21 puppies were infected as above and treated with a symmetrical triazintrione. Parasitological and clinical parameters were examined. The two Isospora species differed significantly concerning intensity and duration of excretion. The pre‐patent period was 6–7 days for I. ohioensis and 10–12 days for I. canis. The latter species showed significantly longer excretion and higher opg. This was not influenced by simultaneous infections with both species. Individual patterns of faecal consistency were very variable, irrespective of the infection dose. Treatment significantly reduced both the intensity and the duration of oocysts excretion as well as diarrhoea in comparison with the infected, untreated group and thus proved to be effective against coccidiosis in experimental infections.

Correlation between corneal sensitivity and quantity of reflex tearing in cows, horses, goats, sheep, dogs, cats, rabbits, and guinea pigs.

OBJECTIVE Guinea pigs have a very low threshold of corneal sensitivity and at the same time nearly no reflex tearing compared to dogs, cats, and horses. The question arose whether there is a general correlation between corneal sensitivity and the quantity of reflex tearing. ANIMALS STUDIED Totally 160 animals of 8 different species (20 animals per species) were investigated. PROCEDURES The corneal touch threshold (CTT) was measured with a Cochet-Bonnet esthesiometer. The palpebral fissure length (PFL) was measured with a calliper ruler. The Schirmer tear test (STT) was modified by adapting the width of the STT strip to the PFL of every species. For the STT II, 0.4% oxybuprocaine was applied. RESULTS Corneal touch threshold: Cows (1.67 g/mm(2)), horses (1.23 g/mm(2)), sheep (1.13 g/mm(2)), goats (1.44 g/mm(2)), dogs (2.16 g/mm(2)), and cats (1.33 g/mm(2)) show similar CTT values. In contrast, rabbits (6.21 g/mm(2)) and guinea pigs (7.75 g/mm(2)) show a significantly lower CTT. Tear Production Difference STT I - STT II: Rabbits have the greatest decline in tear production with 38.4%, followed by sheep (33.3%), dogs (31.1%), cats (24.7%), cows (23.7%), horses (18.0%), and goats (14.0%). Guinea pigs have no decline, but a slight increase of -16.0%. Correlation CTT and STT II - STT I Difference: Pearsons correlation coefficient shows a small, but significant correlation. The coefficient of determination can only forecast a value with 7.1% certainty. CONCLUSIONS The high variance and low reproducibility of results suggest that the measuring devices are inappropriate to assess the evaluated parameters. Therefore, no assured correlation between the corneal sensitivity and the quantity of reflex tearing could be found.

Detection of Encephalitozoon cuniculi in the feline cataractous lens

PURPOSE Identification of Encephalitozoon cuniculi (E. cuniculi) as a possible causative agent for cataracts and uveitis in cats. METHODS Within a 12-month study period, cats that were presented with focal anterior cortical or mature cataract and secondary uveitis underwent a complete ophthalmic examination, complete blood count, serum biochemistry, serologic tests for E. cuniculi and tests for feline immunodeficiency virus (FIV), feline infectious peritonitis (FIP), feline leukemia virus (FeLV) and Toxoplasma gondii (T. gondii). PCR for DNA detection of E. cuniculi and T. gondii as well as cytologic examination of aqueous humor after paracentesis and phacoemulsified lens material were also performed. In addition histopathologic examination of the resected anterior lens capsule and attached lens epithelial cells was performed. Serologic testing for antibodies against E. cuniculi was also performed in 100 ophthalmologically healthy cats. RESULTS Eleven (19 eyes) European shorthair cats with a median age of 3.5 years were included. Nine of 11 cats had bilateral cataracts, with 12/19 eyes having focal anterior cortical cataracts and 7/19 eyes having mature cataracts. In 14/19 eyes anterior uveitis was present. All cats had a positive antibody titer (1:80-1:10,000) for E. cuniculi. Encephalitozoon cuniculi DNA was detected by PCR and sequencing in 18/19 lenses and in 10/19 aqueous samples. Five tentative positive results were detected by cytologic examination. Spores were detected in 15/19 samples of lens material with histopathologic staining. Only 2/100 ophthalmologically healthy cats showed a positive antibody titer for E. cuniculi. CONCLUSION Encephalitozoon cuniculi is a cause of focal anterior cortical cataract and anterior uveitis in cats.