Safety and accuracy of blind vs. ultrasound-guided dorsal retrobulbar nerve blocks in horses-A cadaveric study.

OBJECTIVE: There is limited knowledge regarding the safety and accuracy of ultrasound-guided retrobulbar nerve blocks in horses. The aim of this study was to compare these parameters between blind and ultrasound-guided injection techniques for the dorsal retrobulbar nerve block in horses. METHODS: Equine cadaver heads were used to inject the retrobulbar space with contrast medium (CM). Injections were performed either blindly based on anatomic landmarks (blind group, n = 44) or under ultrasonographic guidance (US-group, n = 44), equally divided between an experienced and unexperienced operator. Needle position and distribution of CM were assessed with computed tomography imaging and evaluated by a board-certified veterinary diagnostic imager blinded to the technique. Safety and accuracy of both techniques were compared. RESULTS: Ocular penetration was observed in two cases (n = 2/44) in the blind group but not in the US group (n = 0/44). No intrathecal, intraneural, or intravascular injections were seen in either group. Safety was significantly improved in the US group (p = .026). There was no statistically significant difference between the groups regarding the accuracy of the injection. Excellent accuracy was achieved more often with the ultrasound-guided technique (n = 11/22) than with the blind technique (n = 7/22) when performed by the unexperienced operator, but this difference was not statistically significant. CONCLUSION: To prevent globe-threatening complications and improve the safety of the injection, we recommend using the ultrasound-guided injection technique for the dorsal retrobulbar nerve block.

[Availability of drugs for the treatment of cats with ocular diseases in Germany - Discrepancy between theory and reality]. / Verfügbarkeit von Medikamenten für die Behandlung von Katzen mit Augenerkrankungen in Deutschland ­ Diskrepanz zwischen Theorie und Wirklichkeit.

OBJECTIVE: Only a few ophthalmologics specifically approved for cats are available on the market leading to frequent use of drugs approved for humans. In Germany, the administration, dispense or prescription of pharmaceuticals is regulated by the pharmaceuticals law ('Arzneimittelgesetz' (AMG)) as well as the regulation concerning pharmacies in veterinary practice ('Verordnung über tierärztliche Hausapotheken' (TÄHAV)). The aim of this study was to collect data concerning the occurrence and frequency of feline eye diseases and to evaluate the frequency of the necessity for extra-label drug use. Evidence-based, optimal treatment schemes were generated and reviewed with regard to their feasibility in Germany. MATERIAL AND METHODS: Data from 876 cats with ocular problems of the "Small Animal Clinic", Freie Universität Berlin as well as a small animal practice in Southern Germany were evaluated (01.01.2015-31.12.2018). Subsequently, the theoretical accessibility for approved agents and/or extra-label drug use in Germany was analyzed. RESULTS: 1198 diagnoses were based on 925 ophthalmic examinations. The most common diseases include conjunctivitis, keratitis, uveitis, hypertensive retinopathy and glaucoma. 885/1198 (73.9 %) of these diseases required treatment, which equates to 722/925 (78.1 %) cases. For all patients, treatment would have been possible according to evidence-based data. In 225/722 (31.2 %) cases, treatment with the pertaining, specifically approved agents would have been possible. Extra-label drug use would have been necessary in 497/722 cases (68.8 %). Of the 497 cases necessitating extra-label use, pharmaceuticals approved for humans would have been available for 481 cases (96.8 %), extra-label use of other veterinary pharmaceuticals would have been possible in 28 cases (5.6 %) and in 60 cases (12.2 %) especially manufactured drugs could have been employed. In a total of 36/722 cases (5 %), optimal care would not have been possible in the context of the current regulatory framework. CONCLUSION: Based on regulations concerning therapeutic necessity, the ophthalmologic therapy of cats in Germany is possible within the regulatory framework. In the present study, 5 % of the patients could not receive optimal medical care. The closure of this gap demands additional approval of veterinary ophthalmic drugs as well as the research and development of novel active agents and veterinary pharmaceuticals.

Molecular and phenotypic characterization of methicillin-resistant Staphylococcus pseudintermedius from ocular surfaces of dogs and cats suffering from ophthalmological diseases.

Methicillin-resistant Staphylococcus pseudintermedius (MRSP) have recently emerged as a major therapeutic challenge in small animal medicine because of their antimicrobial multidrug resistance and their role as nosocomial pathogens. This study focused on the prevalence, molecular characteristics and antimicrobial resistance pheno- and genotypes of MRSP isolated from conjunctival swabs of dogs and cats. Conjunctival swabs were collected from 72 dogs and 24 cats suffering from conjunctivitis/blepharitis, keratitis or uveitis and screened for the presence of MRSP. S. pseudintermedius was isolated from 38 (39.6 %) of all samples. Three (7.9 %) S. pseudintermedius isolates were confirmed as MRSP. They harboured the mecA gene and originated from dogs. One MRSP isolate was from a case of uveitis while the other two MRSP isolates originated from cases of conjunctivitis/blepharitis. All MRSP isolates were subjected to broth microdilution and whole genome sequencing (WGS). Resistance and virulence genes, multilocus sequence (MLS), spa, dru and SCCmec types were deduced from WGS data. Two of the three MRSP isolates, IMT360/16 and IMT515/16, shared the same MLS type (ST71), spa type (t02), dru type (dt9a), SCCmec type (II-III), and indistinguishable multidrug resistance pheno- and genotypes, including resistance to ß-lactams (blaZ, mecA), erythromycin and clindamycin (erm(B)), streptomycin (aphA3), gentamicin (aacA-aphD), enrofloxacin (mutations in grlA and gyrA), tetracycline (tet(K)), and trimethoprim (dfrG)/sulfamethoxazole. The third isolate, IMT1670/16, differed in all those characteristics (MLST (ST1403), dru type (dt10h), SCCmec type (IVg), except the spa type (t02). In addition, isolate IMT1670/16 carried a different tetracycline resistance gene (tet(M)) and was susceptible to erythromycin and clindamycin.

Study of congenital Morgagnian cataracts in Holstein calves.

Cataracts are focal to diffuse opacities of the eye lens causing impaired vision or complete blindness. For bilateral congenital cataracts in Red Holsteins a perfectly cosegregating mutation within the CPAMD8 gene (CPAMD8:g.5995966C>T) has been reported. We genotyped the CPAMD8:g.5995966C>T variant in Holstein calves affected by congenital bilateral congenital cataracts, their unaffected relatives and randomly selected herd mates. Ophthalmological examinations were performed in all affected individuals to confirm a congenital cataract. Whole genome sequencing was employed to screen variants in candidate genes for the Morgagnian cataract phenotype. In the present study, 3/35 cases were confirmed as homozygous mutated and 6/14 obligate carriers. Further 7/46 unaffected animals related with these cases were heterozygous mutated for the CPAMD8:g.5995966C>T variant. However 32 cases with a congenital cataract showed the wild type for the CPAMD8 variant. We did not identify variants in the candidate genes CPAMD8 and NID1 or in their close neighborhood as strongly associated with the congenital cataract phenotype in Holstein calves with the CPAMD8 wild type. In conclusion, the CPAMD8:g.5995966C>T variant is insufficient to explain the majority of Morgagnian congenital cataract phenotypes in Holsteins. It is very likely that congenital bilateral cataracts may be genetically heterogeneous and not yet known variants in genes other than CPAMD8 and NID1 are involved.

Microbiota of the conjunctival sac of 120 healthy cats.

OBJECTIVES: To describe the bacterial and fungal microbiota of the conjunctiva and factors influencing these microbiota of healthy cats. To evaluate the antimicrobial resistance profile and discuss the use of appropriate antimicrobial drugs. ANIMALS STUDIED: One hundred and twenty healthy cats PROCEDURES: Conjunctival samples with dry or premoistened swabs were obtained from both eyes and cultured for aerobic and anaerobic bacteria and fungi. In vitro bacterial, susceptibility testing was performed. The effects of age, sex, breed, season, living environment, and sample collection technique on the frequency and composition of microbial isolation were evaluated. RESULTS: In 49 of 120 cats (40.8%) and 73 of 240 swabs (30.4%), microorganisms were isolated. Of the isolates, 71% (61/86) were Gram-positive bacteria, 26% (22/86) were Gram-negative bacteria, and 3% (3/86) were fungi. Staphylococcus felis (17/86; 19.8%) was the most commonly isolated species. Moraxella osloensis (5/86; 5.8%) was the most frequent Gram-negative species. The season had a statistically significant influence (P = 0.04) on the frequency of isolation. The use of premoistened swabs increased the rate of Gram-positive bacterial detection significantly (P = 0.03). The in vitro susceptibility testing showed high efficacy of chloramphenicol, gentamicin, pradofloxacin, and enrofloxacin. CONCLUSIONS: The isolated microbiota aligns with previous studies performed in other countries, although the microbiota of cats in the present study showed wider bacterial diversity, and more Gram-negative species were isolated. Swab sampling should be performed with premoistened swabs. The topical antimicrobials gentamicin and chloramphenicol are suitable therapeutics for first-line treatment.

Intraocular pressure measurements in cattle, sheep, and goats with 2 different types of tonometers.

The aim of this study was to investigate normal intraocular pressure (IOP) values of cattle, sheep, and goats with a rebound tonometer [TonoVet (TV)] and an applanation tonometer [Tono-Pen AVIA (TPA)] and to determine correction functions for the 2 devices. A total of 60 healthy cattle, sheep, and goats (20 of each) underwent slit-lamp biomicroscopy. Intraocular pressure (IOP) readings were taken from both eyes with the 2 different tonometers and statistically analyzed. For calibration purposes, the IOP was preset on each instrument at 5 to 60 mmHg using 5 mmHg increments in 10 bovine, 8 ovine, and 6 caprine freshly enucleated eyes. Readings were taken with both tonometers at each interval and compared to the manometrically controlled IOP (Mann-Whitney U-test, P ≤ 0.05; Bland-Altman plot, and regression analysis). The median IOP measurements (min to max) obtained with the TV were 23 mmHg (12 to 40 mmHg), 11 mmHg (7 to 20 mmHg), and 23 mmHg (9 to 37 mmHg) for cattle, sheep, and goats, respectively. Using the TPA, the median IOP measurements were 16 mmHg (8 to 27 mmHg), 10 mmHg (5 to 18 mmHg), and 13 mmHg (4 to 25 mmHg) for cattle, sheep, and goats, respectively. There were statistically significant differences between the readings taken with the TV and the TPA in all species (Wilcoxon-test, P ≤ 0.05). All measurements obtained with the TV and the TPA during the calibration procedure differed statistically significantly from the manometrically controlled IOP measurements (Mann-Whitney U-test, P ≤ 0.05). For both instruments, regression formulas were calculated to correct the measurements. Both tonometers can be used effectively to assess intraocular pressure in ruminants, using the specific regression formulas.

L'objectif de cette étude était de mesurer la pression intraoculaire (PIO) normale chez la vache, le mouton et la chèvre à l'aide de deux tonomètres différents; le (TonoVet (TV) et le Tono-Pen AVIA (TPA) et de déterminer les fonctions de correction pour ces deux appareils. Les vingt animaux de chaque espèce ont été examinés à la lampe à fente pour être qu'ils ne présentaient aucune anomalie oculaire puis la PIO des deux yeux fut mesurée avec les deux tonomètres différents et les valeurs furent analysées statistiquement. Pour des raisons d'étalonnage la PIO fut préréglée de 5 à 60 mmHg, divisée en incréments de 5 mmHg sur 10 yeux de vaches, 8 yeux de moutons et 6 yeux de chèvres fraîchement énuclées. Pour chaque incréments de pression, les lectures furent prises avec les deux tonomètres et furent comparées à la PIO mesurée manométriquement. Chez les bovins, les ovins et les caprins la PIO médiane (min-max) obtenue avec le TV fut de 23 mmHg (12­40 mmHg), 11 mmHg (7­20 mmHg) et 23 mmHg (9­37 mmHg) et avec le TPA de 16 mmHg (8­27 mmHg), 10 mmHg (5­18 mmHg) et 13 mmHg (4­25 mmHg). Dans toutes les espèces, des différences statistiquement significatives entre les lectures prises avec la TV et la TPA furent constatées. Lors de la procédure d'étalonnage toutes les valeurs de la PIO mesurés avec le TV et le TPA furent statistiquement significativement différentes des valeurs obtenues manométriquement. Afin de corriger les mesures les formules de régression furent calculées pour les deux instruments. En tenant compte des formules de régression spécifiques les deux tonomètres peuvent être utilisés efficacement pour évaluer la pression intraoculaire chez les ruminants.(Traduit par les auteurs).

Evaluation of one- vs. two-layered closure after wedge excision of 43 eyelid tumors in dogs.

OBJECTIVE: The aim was to evaluate how two closure techniques after full-thickness V-shaped excision relate to wound recovery and how these techniques affect eyelid function and stability of the preocular tear film. ANIMALS STUDIED: Thirty-eight dogs with 43 eyelid tumors involving <25% of eyelid margin length were included in a prospective randomized trial. PROCEDURES: The method for wound closure was chosen randomly before the operation. In group A (n = 20), the wound was closed in one layer and in group B (n = 23) in two layers. The wound and eyelid structure were directly evaluated by slit-lamp biomicroscopy several times postoperatively. Eyelid function was indirectly evaluated by interferometry, noninvasive tear film breakup time (nTFBUT), and Schirmer's tear test at the last examination, 5 weeks to 19 months postoperatively. RESULTS: No significant differences were found in group A vs. B although slightly more cases with perfect alignment of the eyelid were seen in group B. In both groups, neither slit-lamp biomicroscopy, interferometry, nTFBUT, nor Schirmer's tear test revealed negative influence on the eyelid function by the previous surgery. Histologically, 29 of 32 tumors were diagnosed as meibomian gland adenomas. CONCLUSIONS: These results do not demonstrate a significant difference in wound recovery, eyelid structure, and function after wound closure in 1 vs. 2 layers.

Feline calicivirus: a neglected cause of feline ocular surface infections?

OBJECTIVE: To investigate the prevalence of feline calicivirus (FCV) infection in relation to ocular surface lesions in cats with upper respiratory tract diseases (URTD). ANIMALS STUDIED: Ninety-nine cats with ocular surface infection and symptoms or recent history of URTD were examined at various rescue shelters and hospitals. PROCEDURE: A complete general and ophthalmic examination was performed including Schirmer tear test, slit-lamp biomicroscopy, fluorescein and lissamine green staining. Clinical and ocular symptoms were scored and recorded. Conjunctival samples were collected using a cytobrush, and nucleic acid extraction using RT-PCR was carried out to analyze for the presence of various infectious agents. RESULTS: RT-PCR detected either FCV, feline herpes virus type 1 (FHV-1), Chlamydophila felis or Mycoplasma spp. in 63/99 samples. 30/63 samples were positive for FCV, 23/63 for C. felis, 21/63 for Mycoplasma spp., and 16/63 for FHV-1. Out of the 30 FCV-positive samples, 11 were positive only for FCV and in 19 samples FCV was seen in combination with other agents. FCV infection was highest in animals examined at the rescue centers and in the age group of 0-2 months. Erosive conjunctivitis was an important ocular finding. Oral ulcers were detected in all FCV-infected cats. CONCLUSION: Results indicate that FCV is highly prevalent in cats with URTD either as a sole infectious agent or in combination with other pathogens and therefore is a potential cause for ocular surface lesions during the URTD.

A MITF mutation associated with a dominant white phenotype and bilateral deafness in German Fleckvieh cattle.

A dominantly inherited syndrome associated with hypopigmentation, heterochromia irides, colobomatous eyes and bilateral hearing loss has been ascertained in Fleckvieh cattle (German White Fleckvieh syndrome). This syndrome has been mapped to bovine chromosome (BTA) 22 using a genome-wide association study with the bovine high density single nucleotide polymorphism array. An R210I missense mutation has been identified within microphthalmia-associated transcription factor (MITF) as responsible for this syndrome. The mutation is located in the highly conserved basic region of the protein and causes a negative-dominant effect. SOX10 and PAX3 promoter binding site mutations in MITF could be ruled out as causative for the German White Fleckvieh syndrome. Molecular characterization of this newly detected bovine syndrome means a large animal model is now available for the Tietz syndrome in humans.

Reference intervals for intraocular pressure measured by rebound tonometry in ten raptor species and factors affecting the intraocular pressure.

Intraocular pressure (IOP) was measured with the TonoVet rebound tonometer in 10 raptor species, and possible factors affecting IOP were investigated. A complete ophthalmic examination was performed, and IOP was assessed in 2 positions, upright and dorsal recumbency, in 237 birds belonging to the families Accipitridae, Falconidae, Strigidae, and Tytonidae. Mean IOP values of healthy eyes were calculated for each species, and differences between families, species, age, sex, left and right eye, as well as the 2 body positions were evaluated. Physiologic fluctuations of IOP were assessed by measuring IOP serially for 5 days at the same time of day in 15 birds of 3 species. Results showed IOP values varied by family and species, with the following mean IOP values (mm Hg +/- SD) determined: white-tailed sea eagle (Haliaeetus albicilla), 26.9 +/- 5.8; red kite (Milvus milvus), 13.0 +/- 5.5; northern goshawk (Accipiter gentilis), 18.3 +/- 3.8; Eurasian sparrowhawk (Accipiter nisus), 15.5 +/- 2.5; common buzzard (Buteo buteo), 26.9 +/- 7.0; common kestrel (Falco tinnunculus), 9.8 +/- 2.5; peregrine falcon, (Falco peregrinus), 12.7 +/- 5.8; tawny owl (Strix aluco), 9.4 +/- 4.1; long-eared owl (Asio otus), 7.8 +/- 3.2; and barn owl (Tyto alba), 10.8 +/- 3.8. No significant differences were found between sexes or between left and right eyes. In goshawks, common buzzards, and common kestrels, mean IOP was significantly lower in juvenile birds than it was in adult birds. Mean IOP differed significantly by body position in tawny owls (P = .01) and common buzzards (P = .04). By measuring IOP over several days, mean physiologic variations of +/- 2 mm Hg were detected. Differences in IOP between species and age groups should be considered when interpreting tonometric results. Physiologic fluctuations of IOP may occur and should not be misinterpreted. These results show that rebound tonometry is a useful diagnostic tool in measuring IOP in birds of prey because it provides rapid results and is well tolerated by birds.

Reference values for selected ophthalmic diagnostic tests and clinical characteristics of chinchilla eyes (Chinchilla lanigera).

OBJECTIVE: To establish reference values for the Schirmer tear test I (STT I), the phenol red thread tear test (PRTT), the intraocular pressure (IOP) with rebound tonometry, to determine the corneal sensitivity for healthy chinchillas, and to describe clinical aspects of normal chinchilla eyes. ANIMALS: One hundred and twenty-two eyes of 61 healthy pet chinchillas of different age and gender were investigated. PROCEDURES: A full ophthalmic exam including slit lamp biomicroscopy, ophthalmoscopy, measurement of STT I, PRTT, determination of the corneal touch threshold (CTT), and the measurement of the IOP (TonoVet) was performed. The normal appearance of the lid, the iris, the lens, the fundus, and the optic nerve disc was evaluated. Results The results of the STT I were very low and not reliable, and the measurement was discontinued. The median value of PRTT was 14.0 mm wetting/15 s (mean 14.6 ± 3.5 mm wetting/15 s). The median CTT was 32.5 mm (mean 31.2 ± 7.0 mm) respectively 1.2 g/mm(2) (mean 1.5 ± 0.9 g/mm(2)). The median IOP was 3.0 mmHg (mean 2.9 ± 1.8 mmHg). The predominating iris color was brown. The fundus pigmentation varied. Few lens alteration were seen in otherwise healthy chinchilla eyes. Most chinchillas had myelinated discs. Optic nerve cupping was present in 62% of the animals. CONCLUSION: Because of the small amount of tears, the PRT test is recommended for tear measurements in chinchillas. The IOP in chinchillas seems to be quiet is low in comparison to other rodents.

Accuracy and reproducibility of the TonoVet rebound tonometer in birds of prey.

OBJECTIVE: To examine the accuracy and reproducibility of intraocular pressure (IOP) measurements obtained by the TonoVet rebound tonometer. Animals studied Freshly enucleated healthy eyes of 44 free-ranging birds of prey out of the species Haliaeetus albicilla, Accipiter gentilis, Accipiter nisus, Buteo buteo, Falco tinnunculus, Strix aluco, Asio otus and Tyto alba euthanized because of unrelated health problems. PROCEDURES: IOP readings from the TonoVet were compared with a manometric device, with IOP being set from 5 to 100 mmHg in steps of 5 mmHg by adjusting the height of a NaCl solution reservoir connected to the eye. Reproducibility of the TonoVet readings was determined by repeated measurements. RESULTS: TonoVet and manometer values showed a strong linear correlation. In the Accipitridae, the TonoVet tended to increasingly overestimate IOP with increasing pressure, while in the other families, it increasingly underestimated it. In the Sparrowhawk, the values almost represent the ideal line. Reproducibility of TonoVet values decreases with increasing pressure in the clinically important range from 5 to 60 mmHg. CONCLUSION: IOP values measured with the TonoVet demonstrated species specific deviation from the manometric measurements. These differences should be considered when interpreting IOP values. Using the regression formulae presented, corrected IOP values could be calculated in a clinical setting.