Veterinary allergy diagnosis: past, present and future perspectives

Fleas, several aeroallergens as well as many food allergens are the most common allergenic sources for animals and frequent cause of allergic reactions with different target organs such as skin, eyes, and respiratory or digestive systems. Allergy diagnosis needs to follow well-established guidelines under clinical and laboratory approaches. Since 1980 with the Hanifin & Rajka’s criteria for the diagnosis of atopic dermatitis (AD) in humans, successive proposals have been developed to identify atopic dermatitis in dogs. A consensual plan was first proposed by Willemse in 1986 undergoing several modifications in 1994. Prélaud and colleagues made important changes to the plan in 1998 and it was further adjusted by Favrot in 2009. In 2010, this plan was approved by the International Task Force on Canine Atopic Dermatitis (CAD). It was subjected in 2015 to minor updates with regard to therapeutic options. To improve diagnostic accuracy by integrating the basic knowledge on sensitization development and allergen nature and diversity, allergen sources and implicated molecular allergens for animals should be clearly identified. As well as in human medicine, this molecular epidemiology concept is essential for the veterinary allergy diagnosis in the near future, standing as the basis of a component-resolved diagnosis (CRD). Besides current pharma- cotherapy, it will be highly relevant to increase the efficiency of the avoidance measures and specific immunotherapy. Clinical guidelines will lead to at least 80 % of positive diagnosis of atopy, but newer laboratory methods in veterinary medicine aiming to a more precise diagnosis and a better integration of the clinical/laboratory diagnostic course are needed. Allergoms identification for animals, from different allergen sources proteoms should become a priority in veterinary allergology, in order to allow the intended CRD, which is essential to understand the cross-reaction phenomena, allowing a more precise and possibly effective component-resolved immunotherapy (CRIT). Further research has been carried out for a better understanding of the interaction between allergic clinical condition and immune pathophysiology. As well as in human medicine, a deeper knowledge of the molecular immunological mechanisms in veterinary allergy — with their specific allergen triggers — will also provide the veterinary allergist with the necessary information to act more efficiently in the future.

Allergological evaluation of a dog population in a veterinary immuno-allergology consultation: What correlates in a canine model

Introduction: Allergic dermatitis (AD) is the most common canine pruritic condition in veterinary dermatology. Allergic dermatitis to flea bites presents the highest prevalence, followed by atopic dermatitis and food AD. This study aimed to identify possible correlation between data from clinical signs, intradermal tests (IDT) and specific IgE levels, which are used in dog AD assessment. Methods: Fifty five dogs from the Veterinary Hospital of the University of Évora (Portugal) and Rof Codina University Hospital (Lugo, Spain) outpatient consultations were studied by means of clinical inquiry, IDT and specific IgE determination. Thirty five of the patients belonged to predisposed breeds, 30 were females and 25 males. Forty one (74%) were indoor. Results: In 82% of cases first clinical signs appeared before the age of 3 years and 24% even before 1 year old. In 70% of the individuals clinical signs included itching, which was generalized in 66%, with 78% of paw licking and chewing. Clinical profile showed seasonal worsening in 64% of cases. From the 69.1% of dogs already presenting with dermatitis, 50% also presented external otitis and 28.9% self-inflicted alopecia. "Intense itching" was found in 10.5%, "medium itching" in 81.6% and “mild itching” in 5.26% of the patients. Prevalence of positive IDT was 37.3 % to Lep d, 29.41% to Der f, 27.5% to Der p, 25.5% to Dac g and 21.6% to Malassezia sp. From the 37 dogs submitted to food IDT, 40.5% revealed positive to beef, 27% to chicken, 27% to porc and 5.4% to lamb. Specific IgE > 150 EAU was found in 84% of dogs to indoor allergen sources and in 68% to pollens. A negative correlation was found between an outdoor life and the intensity (p = 0.033) and precocity (p = 0.026) of clinical signs. Sensitization to pollens was found positively correlated with the seasonality of clinical signs (p = 0.001) and the positivity for Dac g (p = 0.007). The prevalence of chronic otitis correlated positively with alopecia and reactivity to Lep d (p = 0.008), Plantago lanceolata (p = 0.026) and Platanus acerifolia (p = 0.017). There was no correlation between the results of ITD and specific IgE. Conclusion: We can conclude that correlation between different clinical signs and positive testing for some allergenic sources may occur, as well as between sensitization to pollens and the beginning, the intensity and the seasonality of dog patient clinical signs.

Sewage disposal and wildlife health in Antarctica

Sewage and its microbiology, treatment and disposal are important to the topic of Antarctic wildlife health because disposal of untreated sewage effluent into the Antarctic marine environment is both allowed and commonplace. Human sewage contains enteric bacteria as normal flora, and has the potential to contain parasites, bacteria and viruses which may prove pathogenic to Antarctic wildlife. Treatment can reduce levels of micro-organisms in sewage effluent, but is not a requirement of the Environmental Protocol to the Antarctic Treaty (the Madrid Protocol). In contrast, the deliberate release of non-native organisms for any other reason is prohibited. Hence, disposal of sewage effluent to the marine environment is the only activity routinely undertaken in Antarctica knowing that it will likely result in the release of large numbers of potentially non-native species. When the Madrid Protocol was negotiated, the decision to allow release of untreated sewage effluent was considered the only pragmatic option, as a prohibition would have been costly, and may not have been achievable by many Antarctic operators. In addition, at that time the potential for transmission of pathogens to wildlife from sewage was not emphasised as a significant potential risk. Since then, the transmission of disease-causing agents between species is more widely recognised and it is now timely to consider the risks of continued discharge of sewage effluent in Antarctica and whether there are practical alternatives.

Rural Poultry in the Developing world

In 2007 I travelled to Mozambique and Tanzania to photographically document the work undertaken by a group of Australians who are working to bring a self sufficient lifestyle back to the HIV Aids stricken communities of Africa. University of Queensland veterinary researchers have developed a vaccination that can eradicate disease from local rural poultry. The Kyeema Foundation is working in country to supply this vaccine to families battling HIV AIDS and to teach local residents how to successfully implement it. QUT, AusAID and the Kyeema Foundation funded the trip.

Transcutaneous immunization with novel lipid-based adjuvants induces protection against gastric Helicobacter pylori infection

The development of vaccines to combat pathogens that infect across mucosal surfaces has been a major goal of vaccine research. Successful mucosal vaccination requires the co-administration of adjuvants that can overcome the state of immune tolerance normally associated with mucosal application of proteins. In the case of oral immunization, delivery systems are also required to protect vaccine antigens against destruction by gastric pH and digestive enzymes. Furthermore, adjuvants used for mucosal delivery must be free of neurotoxic effects like those induced by the commonly used experimental mucosal adjuvant cholera toxin. Maintenance of the "cold chain" is also essential for the effectiveness of any vaccine and adjuvants/delivery systems that enhance the stability of a vaccine would offer a significant advantage. Needle-free methods of vaccination that induce protective immunity at multiple mucosal surfaces are also desirable for rapid vaccination of large populations. In the present study we show that transcutaneous immunization (TCI) using Lipid C, a novel lipid-based matrix originally developed for oral immunization, containing soluble Helicobacter sonicate significantly reduces the gastric bacterial burden in mice following gastric challenge with live Helicobacter pylori. Protection is associated with the production of splenic gamma interferon and gastric IgA and was achieved without the co-administration of potent and potentially toxic adjuvants, although protection was further enhanced by inclusion of CpG-ODN and cholera toxin in the lipid delivery system.

Influence of biochars on flux of N2O and CO2 from Ferrosol

Biochars produced by slow pyrolysis of greenwaste (GW), poultry litter (PL), papermill waste (PS), and biosolids (BS) were shown to reduce N₂O emissions from an acidic Ferrosol. Similar reductions were observed for the untreated GW feedstock. Soil was amended with biochar or feedstock giving application rates of 1 and 5%. Following an initial incubation, nitrogen (N) was added at 165 kg/ha as urea. Microcosms were again incubated before being brought to 100% water-filled porosity and held at this water content for a further 47 days. The flooding phase accounted for the majority (<80%) of total N₂O emissions. The control soil released 3165 mg N₂O-N/m², or 15.1% of the available N as N₂O. Amendment with 1 and 5% GW feedstock significantly reduced emissions to 1470 and 636 mg N₂O-N/m², respectively. This was equivalent to 8.6 and 3.8% of applied N. The GW biochar produced at 350°C was least effective in reducing emissions, resulting in 1625 and 1705 mg N₂O-N/m² for 1 and 5% amendments. Amendment with BS biochar at 5% had the greatest impact, reducing emissions to 518 mg N₂O-N/m², or 2.2% of the applied N over the incubation period. Metabolic activity as measured by CO₂ production could not explain the differences in N₂O emissions between controls and amendments, nor could NH₄⁺ or NO₃^– concentrations in biochar-amended soils. A decrease in NH₄⁺ and NO₃^– following GW feedstock application is likely to have been responsible for reducing N₂O emissions from this amendment. Reduction in N₂O emissions from the biochar-amended soils was attributed to increased adsorption of NO₃^–. Small reductions are possible due to improved aeration and porosity leading to lower levels of denitrification and N₂O emissions. Alternatively, increased pH was observed, which can drive denitrification through to dinitrogen during soil flooding.