The global veterinary diagnostics market was valued at USD 6.2 billion in 2020, and it is expected to expand at a compound annual growth rate (CAGR) of 11.5% from 2021 to 2028. The growth of this market is attributed to factors such as animal health expenditure, the increase in the incidence of zoonotic diseases, the number of veterinarians, technological advancement in point of care diagnostics, and the level of disposable income in developing regions. In terms of disease type, veterinary infectious diseases have the greatest impact on market size.
Veterinary infectious diseases are factors that impact the health of livestock, domestic animals and wildlife. Intensive animal farming creates conditions for the emergence and amplification of epidemics because of the physical and genetic proximity of the billions of animals, often in frail health, that are raised indoors every year. Moreover, animal farming likely contributes indirectly to the spread of pathogens from wild animals due to deforestation and biodiversity loss associated with the expansion of agricultural land use. The social costs induced by animal infectious diseases can be significant, as the COVID-19 pandemic shows. They include both direct human and animal health costs, but also the indirect economic costs of business activity, as well as the cost of preventive measures. The research of veterinary infectious diseases focuses on infectious-disease-causing pathogens, epidemiology, diagnostic methods, molecular evolution, immune responses, treatment and prevention.
Veterinary infectious disease pathogens are viral, bacterial, or fungal. Parasitic diseases are caused by protozoa or helminths (“worms”). As we know, almost two-thirds of the pathogens that cause diseases in humans are of animal origin, such as SARS-CoV/COVID-19, avian influenza virus, rabies virus, Ebola virus, etc. In addition to those zoonoses, other animal-species-specific infectious diseases, such as Africa Swine Fever (ASF), Classical Swine Fever (CSF), Foot and Mouth Disease (FMD), Newcastle Disease (ND), Lumpy Skin Disease (LSD), African Horse Sickness (AHS), etc., are also extremely important.
Fig. 1 Geographic distribution of disease agents (Anke KW, et al. 2015)
Vector-borne diseases are transmitted via a vector organism (e.g., mosquito, tick, or rodent) that carries the pathogen from person to person. Examples of vector-borne diseases include Cattle fever ticks, Rift valley fever, Japanese encephalitis, West Nile and the equine encephalitis.
Zoonotic diseases are transmitted from an animal to a person, an infected animal becomes an intermediary host. About 75% of emerging infectious diseases are zoonotic. These diseases including the avian influenza H1N1, severe acute respiratory syndrome (SARS), West Nile virus, bovine spongiform encephalopathy (BSE) and brucellosis.
Waterborne diseases are caused by pathogens that live in contaminated water, which the human host ingests. They may be deposited in water by infected humans or animals. Cryptosporidium parvum, Giardia duodenalis, Campylobacter, Rotavirus are all waterborne diseases pathogens.
Food-borne diseases are caused by pathogens that live in contaminated food, which the human host ingests. They may or may not also be transmissible from person to person. Salmonella and Campylobacter are the main food-borne disease pathogens.
Fig. 2 Schematic of ASFV transmission cycles (Natasha NG, et al. 2020)
The detection assays used in the diagnosis of animal diseases are as follows:
There are 2 major groups of infectious disease assays: assays that confirm the continued presence of the organism (cytology, culture, fecal examination techniques, antigen assays, immunohistochemical stains, molecular diagnostic assays), and antibody assays. Documenting that an infectious agent is still present is generally the best way to make a definitive diagnosis. However, certain organism demonstration techniques have low sensitivity, are expensive, are invasive, are not adequately validated, or require specialized equipment. Antibody detection assays are commonly used to aid in the diagnosis of specific infectious diseases in these situations.
Specific diagnosis of pathogens is critical for these agents owing to the existence of dynamic host– pathogen interaction as in case of peste des petits ruminants (PPR), presence of multiple serotypes and variants as in case of foot-and-mouth disease virus (FMDV) and bluetongue virus (BTV), cross-reactivity due to antigenically closely related viruses such as sheep pox, goat pox and lumpy skin disease. Even though conventional virological methods are incredibly reliable, they are time consuming and labor-intensive procedures. Lateral flow and enzyme-linked immunosorbent assay can be used for rapid detection. Multiplex bead immuno or Luminex assay is a fluorescent beads based high-throughput quantitative technique used for the detection of multiple antibodies specific for different infectious diseases at the same time in a single reaction leading to more rapid, economical and accurate results compared with conventional ELISA. In addition, the protein chip based on surface plasmon resonance (SPR), appears to be fast valuable tool in the sero-diagnosis of infection or antibody titration. Recombinant antibodies were also able to be produced in heterologous systems by using rDNA technology and used for developing diagnostic test.
Vaccination is one of the most powerful tools to protect animals against infectious diseases, and for most viral infections, prophylactic vaccination is the only option available for efficient disease control. In the past two decades, several types of marker vaccines have been developed, which vary from subunit vaccines to modified live vaccines. Marker vaccines are used in conjunction with a companion diagnostic test that detects antibodies against a protein that is lacking in the vaccine strain. A marker vaccine (live or inactivated vaccine) is either based on isolated antigenic proteins or on deletion mutants that allows the differentiation of infected and vaccinated animals (DIVA) on the basis of detectable difference in antibody responses. Hence, DIVA vaccines and/or diagnostic tests are of immense value during a mass vaccination program.
Fig. 3 Simplified schematic representation of immune mechanisms that can act to protect animals against invading viral, bacterial, and protozoal pathogens or against multicellular helminth parasites (Els N. T. Meeusen, et al. 2020)
Creative Diagnostics offers a range of high-quality antigens and antibodies for an extensive range of viral, bacterial and protozoal veterinary diseases. These reagents have been developed for both livestock and companion animals, such as cattle, pigs, dogs and cats, and includes a range of clinically relevant pathogens, such as Adenovirus, Brucella abortus, Coronavirus, African swine fever virus, Newcastle disease virus and Parvovirus. Suitable for a wide range of applications, these reagents can be used in research, as well as the development of immunoassays for diagnostic and vaccine R&D. If you are interested in finding out more, please feel free to contact us.