Antibody reactions of horses against various domains of the EHV-1 receptor-binding protein gD1.

Equid alphaherpesviruses 1 (EHV-1) and 4 (EHV-4) are closely related and both endemic in horses worldwide. Both viruses replicate in the upper respiratory tract, but EHV-1 may additionally lead to abortion and equine herpesvirus myeloencephalopathy (EHM). We focused on antibody responses in horses against the receptor-binding glycoprotein D of EHV-1 (gD1), which shares a 77% amino acid identity with its counterpart in EHV-4 (gD4). Both antigens give rise to cross-reacting antibodies, including neutralizing antibodies. However, immunity against EHV-4 is not considered protective against EHM. While a diagnostic ELISA to discriminate between EHV-1 and EHV-4 infections is available based on type-specific fragments of glycoprotein G (gG1 and gG4, respectively), the type-specific antibody reaction against gD1 has not yet been sufficiently addressed. Starting from the N-terminus of gD1, we developed luciferase immunoprecipitation system (LIPS) assays, using gD1-fragments of increasing size as antigens, i.e. gD1_83 (comprising the first 83 amino acids), gD1_160, gD1_180, and gD1_402 (the full-length molecule). These assays were then used to analyse panels of horse sera from Switzerland (n = 60) and Iceland (n = 50), the latter of which is considered EHV-1 free. We detected only one true negative horse serum from Iceland, whereas all other sera in both panels were seropositive for both gG4 (ELISA) and gD1 (LIPS against gD1_402). In contrast, seropositivity against gG1 was rather rare (35% Swiss sera; 14% Icelandic sera). Therefore, a high percentage of antibodies against gD1 could be attributed to cross-reaction and due to EHV-4 infections. In contrast, the gD1_83 fragment was able to identify sera with type-specific antibodies against gD1. Interestingly, those sera stemmed almost exclusively from vaccinated horses. Although it is uncertain that the N-terminal epitopes of gD1 addressed in this communication are linked to better protection, we suggest that in future vaccine developments, type-common antigens should be avoided, while a broad range of type-specific antigens should be favored.

Evaluation of dietary histories in cats presenting with chronic gastrointestinal clinical signs to a veterinary teaching hospital.

OBJECTIVES: Although less frequently described than in dogs, it is also well recognised in cats that chronic gastrointestinal (GI) disease can fully respond to dietary changes only. So far, no study has assessed how much dietary information can be obtained during veterinary consultations. METHODS: We retrospectively evaluated how much dietary information was available when owners presenting their cats to our gastroenterology (GE) and internal medicine (IM) service between October 2017 and January 2020 were questioned during consultations. Because of the larger IM caseload, for each week the first two cats presenting with chronic GI signs were selected for the IM group. Data from 80 cats presenting for first GE consultations were compared with data from 84 cats presenting with chronic GI signs for first IM consultations. RESULTS: Referrals comprised 42/80 (53%) GE cats and 53/84 (63%) IM cats. Referral documents mentioned the previously fed diet in 12/42 (29%) GE and 4/53 (8%) IM cats, and response to that previous diet trial was recorded in the referral documents of 4/12 (33%) GE and 3/4 (75%) IM cats. No cat had received more than one previous diet trial. During consultations, owners of 61/80 (76%) GE and 53/84 (63%) IM cats were asked about diet. Irrespective of referral status, previous dietary trials had been performed in 27/61 (44%) GE and 19/53 (36%) IM cats. The specific diet fed at the time of consultation could be named by 37/61 (61%) GE and 11/53 (21%) IM cat owners. CONCLUSIONS AND RELEVANCE: Overall dietary information gained from referring veterinarians and owners was often incomplete. Although more information could be gained from owners during GE consultations vs IM consultations, awareness of the importance of diet in cats with GI disease still appears to be low among veterinarians and cat owners. Future studies need to assess if more complete dietary information can be obtained at the time of consultations with a prospective study design.

A Descriptive Study on the Extent of Dietary Information Obtained during Consultations at a Veterinary Teaching Hospital.

The majority of dogs with chronic idiopathic gastrointestinal (GI) disease respond to diet. So far, no study has assessed how much dietary information is obtained during consultations. We retrospectively evaluated what dietary information was available from dogs presenting to our Gastroenterology (GE), and Internal Medicine (IM) Service between 10/2017 and 01/2020. Data from 243 dogs presenting for first GE consultations were compared to 239 dogs presenting with chronic GI signs for first IM consultations. Referrals comprised 131 (54%) GE dogs and 112 (47%) IM dogs. Referral documents specified the previously fed diet in 53/131 (40%) GE and 14/112 (13%) IM dogs. No dog had received more than one previous diet trial for chronic GI signs. Irrespective of referral status, diet trials had been performed in 127/199 (64%) GE, and 56/156 (36%) IM dogs. The specific diet fed at the time of consultation could only be named by 106/199 (53%) GE and 40/156 (26%) IM dog owners. Data on response to subsequent newly prescribed diets were available from 86 GE dogs and 88 IM dogs. A positive response to diet was noted in 50/86 (58%) GE and 26/88 (30%) IM dogs. A further 23/35 (66%) GE dogs and 12/21 (57%) IM dogs responded positively to a second diet trial, and 4/9 GE dogs (44%) and 6/7 (86%) IM dogs responded positively to a third diet trial. In conclusion, overall dietary information gained from referring veterinarians and owners was often incomplete. More dietary information could be gained during GE consultations compared to IM consultations for chronic GI signs. A positive response to diet can still be seen after two diet failures. Further studies will help to ascertain if the percentage of diet-responsive GI disease increases when more complete dietary information is obtained at the time of consultations.