Antibioticumgebruik bij paarden : Uitkomsten van een survey onder dierenartspraktijken over de jaren 2012 t/m 2014

Vierentwintig dierenartspraktijken hebben hun inkoopcijfers (uitsluitend paardenpraktijken) dan wel prescriptieregels (gemengde praktijken) over 2012, 2013 en 2014 beschikbaar gesteld. Op basis van deze gegevens is voor de patiëntenpopulatie van deze praktijken berekend hoe hoog het antibioticumgebruik in de paardensector is. Het gebruik bij paarden is laag en nam over de jaren 2012 tot en met 2014 met 24% af van 0,735 naar 0,562 DDDA. Dit betekent dat een gemiddeld paard in Nederland op basis van de getallen van 2014 5,6 dagen per 10 jaar behandeld werd met antibiotica. Het grootste deel van de in 2014 bij paarden toegepaste middelen waren eerste keuze middelen (85,1%). Twaalf en een half procent waren tweede keuze middelen en het aandeel derde keuze middelen was slechts 2,5%. Het gebruik van derde keuze antibiotica is met 68% gedaald van 0,040 DDDA in 2012 naar 0,013 DDDA in 2014. Eenentwintig procent van de onderzochte praktijken gebruikte in 2014 zelfs helemaal geen derde keuze middelen. Hiermee is het aandeel derde keuze middelen welke toegepast wordt bij paarden laag. Alle praktijken hebben een laag antibioticumgebruik. De verschillen tussen de praktijken zijn wel relatief groot (spreiding van gemiddelde DDDA over de 3 jaar: 0,168 – 1,190). De in deze studie opgenomen praktijken hebben allen een eigen specifiek profiel hetgeen de onderlinge verschillen zeker voor een deel kan verklaren. De praktijken variëren van echte eerstelijns paardenpraktijken tot praktijken met uitgebreide opnamemogelijkheden voor paarden en intensieve zorg voor ernstig zieke patiënten waarbij een iets hoger antibioticumgebruik verwacht kan worden. Naar schatting omvat de totale paardenpopulatie in Nederland 450.000 dieren (gebaseerd op gegevens van de Sectorraad Paarden, 2014). Op basis hiervan is berekend dat het antibioticumgebruik in de paardensector maximaal 20,6% van het verschil tussen verkochte antibiotica en de reeds verantwoorde antibiotica (op basis van onderzoek in andere gemonitorde sectoren en op basis van diersoort specifieke registratiegegevens van bepaalde antibiotica) kan verklaren. Het antibioticumgebruik en het gebruik van derde keuze middelen bij paarden is laag. Het SDa-expertpanel concludeert dat het op basis van deze gegevens niet nodig is om voor de paardensector tot continue monitoring over te gaan. In lijn met deze conclusie is het ook niet voor de hand liggend om de dierenartsenpraktijken te benchmarken. Het is zinvoller om een soort gelijke survey, zoals in dit rapport beschreven, over 3 jaar te herhalen om eventuele veranderingen in gebruik te beschrijven

Dermatographism in a horse, responsive to cetirizine treatment

Dermatographism is a common condition in man that occurs when pressure is applied to the skin and mast cells are triggered to release histamine, causing local urticarial lesions. This case report concerns a 4‐year‐old Quarter Horse gelding that was presented with pressure induced urticaria. Moderate pressure on the skin induced nonpruritic urticaria‐like swelling after approximately 3–5 min, which lasted for approximately 2–3 h. Initial treatment with cyproheptadine gave an incomplete response and unacceptable sedation as a side effect. On the second generation antihistamine cetirizine (0.2 mg/kg bwt twice daily), dermatographism was no longer present and no side effects occurred. Treatment was continued for 4 months, with at least three attempts to discontinue therapy resulting in recurrence of lesions within 24 h. Lesions resolved each time within 24 h of recommencing therapy. Dermatographism did not recur after the horse was moved to another location despite discontinuation of therapy. This report describes a case of equine dermatographism responsive to cetirizine

Chronic iron overload causing haemochromatosis and hepatopathy in 21 horses and one donkey

Background: Iron toxicosis is rarely reported in horses and chronic excessive oral iron intake has not been reported to cause clinical symptoms in equids. Objectives: This case series describes 21 genetically unrelated horses and one donkey with chronic iron overload causing haemochromatosis and hepatopathy. Study design: Case series. Methods: All equids showing clinical signs compatible with chronic liver disease presented to Utrecht University and diagnosed with iron overload and haemochromatosis based on histopathological evaluation of liver tissue and/or blood transferrin saturation levels of >80% and proof of excess dietary iron intake due to excess iron content in drinking water were included. Results: This study included 22 equids. All tested animals (n = 19) had transferrin saturation >80% and 21 of 22 had increased gammaglutamyltransferase (cGT). Ultrasonography revealed rounded liver margins in five out of six horses and increased echogenicity in 4/6. Histological examination of liver tissue of 12 animals showed hepatitis, fibrosis and haemosiderin accumulation in macrophages and hepatocytes. Post-mortem examination also revealed haemosiderin accumulation in other organs in all seven examined animals. High iron content in drinking water was identified as the source of iron overload in all cases. All animals were housed under the same conditions for a minimum of 9 years prior to diagnosis of haemochromatosis. Of 22 animals, 13 survived until 1 January 2018, ranging from 17 to 79 months post diagnosis. Main limitations: Histology of liver tissue was not available for 10 of 22 cases. Conclusions: Chronic iron overload can lead to haemochromatosis and hepatopathy in equids. Development of disease is slow and clinical signs are nonspecific. Long-term excessive iron intake in equids should be avoided. If animals drink from natural water sources, it is important to test the water for iron content

Seroprevalence and risk factors for infection with equine coronavirus in healthy horses in the USA

Equine coronavirus (ECoV) is considered an enteric pathogen of foals and has only recently been associated with infections in adult horses. Seroprevalence data is needed to better understand the epidemiology of ECoV in adult horses, evaluate diagnostic modalities and develop preventive measures. The objective of this study was to investigate the seroprevalence and selective risk factors for ECoV in 5247 healthy adult horses in the USA, using a recently established and validated IgG enzyme-linked immunosorbent assay. Prevalence factors analysed in this study included geographic region, age, breed, sex and use. A total of 504/5247 horses (9.6%) horses tested seropositive. Geographic region (Mid-West; P = 0.008), breed (Draft horses; P = 0.003) and specific uses of horses (ranch/farm, P = 0.034; breeding use, P = 0.016) were all statistically significant risk factors for seropositivity

Dermatographism in a horse, responsive to cetirizine treatment

Dermatographism is a common condition in man that occurs when pressure is applied to the skin and mast cells are triggered to release histamine, causing local urticarial lesions. This case report concerns a 4‐year‐old Quarter Horse gelding that was presented with pressure induced urticaria. Moderate pressure on the skin induced nonpruritic urticaria‐like swelling after approximately 3–5 min, which lasted for approximately 2–3 h. Initial treatment with cyproheptadine gave an incomplete response and unacceptable sedation as a side effect. On the second generation antihistamine cetirizine (0.2 mg/kg bwt twice daily), dermatographism was no longer present and no side effects occurred. Treatment was continued for 4 months, with at least three attempts to discontinue therapy resulting in recurrence of lesions within 24 h. Lesions resolved each time within 24 h of recommencing therapy. Dermatographism did not recur after the horse was moved to another location despite discontinuation of therapy. This report describes a case of equine dermatographism responsive to cetirizine

Fecal carriage of Extended Spectrum ß-Lactamase (ESBL)/AmpC-producing Escherichia coli in horses

A nationwide study on the occurrence of ESBL/AmpC in non-hospitalized horses in the Netherlands was performed. Molecular characterization was done and questionnaires were analyzed to identify factors associated with carriage. In total, 796 horse owners were approached, of which 281 submitted a fecal sample of their horse(s), resulting in 362 samples. All samples were cultured qualitatively in LB broth and subsequently on MacConkey agar, both supplemented with 1 mg/L cefotaxime (LB+ and MC+). Positive samples were subsequently cultured quantitatively on MC+. Initial ESBL/AmpC screening was performed by PCR, followed by whole genome sequencing on selected strains. Association between ESBL/AmpC carriage and questionnaire items were analyzed using a univariate generalized estimating equation (GEE) regression analysis, followed by a multiple GEE model for relevant factors. In total, 39 out of 362 samples (11%) were positive for ESBL/AmpC. blaCTX-M-1-carrying isolates were obtained from 77% of positive samples (n=30). Other ESBL/AmpC genes observed were blaCTX-M-2, blaCTX-M-14, blaCTX-M-15, blaCTX-M-32, blaSHV-12, blaCMY-2, blaACT-10. A high association between the presence of blaCTX-M-1 andIncHI1 plasmids was observed (46% of samples; n=18). Based on core genome analysis (n=48 isolates), six E. coli clusters were identified, of which three represented 80% of the isolates. A negative association between ESBL/AmpC carriage and horses being in contact with other horses at a different site was observed. The presence of a dog on the premises and housing in a more densely human-populated region were positively associated. IMPORTANCE Extended spectrum ß-lactamases (ESBL) are widespread in the human and animal population and the environment. Many different ESBL-variants exist. The dissemination of ESBLs within and between populations and the environment is also largely influenced by genetic mobile elements (e.g. plasmids) that facilitate spread of these ESBLs. In order to identify potential attributable ESBL-sources for e.g. the human population, it is important to identify the different ESBL-variants, the bacteria carrying them and the potential risk factors for ESBL carriage from other potential sources. This nationwide study focuses on ESBL-carriage in the open horse population and investigated the molecular characteristics, geographical distribution throughout the Netherlands and potential risk factors for fecal ESBL-carriage in horses. This data can be used for future attribution studies in order to reduce potential transmission of ESBL-producing bacteria between sources