Organ-specific Parasites in Cattle

Bovine parasitism presents a complex and variable disease condition affecting grazing cattle, encompassing both internal and external parasites. Internal parasites reside within the animal, while external parasites inhabit the animal's exterior. Both types can significantly impact cattle health. Understanding internal parasites and their control in natural field conditions necessitates awareness of external parasites and their role in cattle production cycles. The economic significance of different parasitic worms in cattle hinges on factors such as parasite species, the damage they cause, and parasite numbers within the animals at any given time.

Gastrointestinal parasites pose a significant threat to cattle health, welfare, and productivity worldwide. This chapter describes the major gastrointestinal parasites affecting cattle, their impact on the industry, current management strategies, and potential future directions for effective control. The economic implications of parasite infections in cattle production systems are explored, highlighting the need for integrated approaches to combat these parasites. Key aspects, such as grazing management, anthelmintic treatment, genetic selection, and emerging research, are discussed in the context of sustainable parasite control. The chapter underscores the importance of continued research and collaboration to mitigate the impact of gastrointestinal parasites on cattle populations.

Gastrointestinal parasites pose a significant threat to cattle health, welfare, and productivity worldwide. This chapter describes the major urogenital parasites affecting cattle, their impact on the industry, current management strategies, and potential future directions for effective treatment and control measures. The economic implications of parasite infections in cattle production systems are also elaborately explored by highlighting the need for integrated approaches to combat parasitic diseases. Key aspects including proper grazing management, treatment of anthelmintic drugs, selection of genetic variables, and emerging research, are properly discussed in the chapter. The chapter also underscores the importance of continued updated research and collaboration to mitigate the impact of urogenital parasites on cattle populations

Parasitic diseases affecting the circulatory system of cattle are a significant concern in veterinary medicine. The impact of these parasites on cattle health can be significant, resulting in decreased productivity, anaemia, and, in extreme cases, death. Haemoprotozoa like Trypanosoma, Theileria, Babesia, and Anaplasma, as well as helminths like Schistosoma and Onchocerca, are among the parasites that impact cattle's circulatory systems. Because the majority of these diseases are transmitted by invertebrate vectors, a comprehensive approach comprising vector control targeted medicine administration, and biosecurity measures is required to ensure cattle health and productivity. Regular monitoring and early action are critical for reducing the parasites' influence on cattle herds. 

The integumentary system is the largest organ system in the body and a physical barrier to the external environment. This intricate system maintains the animal's body in a state of homeostasis thanks to its many vital activities and complex structure. Worldwide, a wide range of parasitic diseases significantly increase the morbidity and mortality rate of cattle. Through the various ways that parasitic illnesses infect their host to collect nutrients and complete their lifecycle, as well as the possibility of becoming infection vectors, they have an impact on the health and productivity of cattle. Numerous protozoa, ectoparasites, and helminths mostly affect the integumentary system. A number of diseases have the potential to seriously affect both public and animal health; some are notifiable, while others are zoonotic.

Parasitic disease of the nervous system of cattle is generally caused by migrating nematodes, cestode cysts, or protozoa in the central nervous system. The parasites namely Hypoderma larvae cause neurological diseases. The toxins liberated by Dermacentor ticks, and metabolic changes associated with intestinal coccidiosis are the key factors for neurological complications.

The eye and earworms are responsible for ocular infections and ear infections in cattle. Larva can migrate the anterior chamber of the eye and can cause severe ocular inflammation in cattle. The antigen present on the surface of the parasite can cause an immune-mediated response with uveitis and keratoconjunctivitis. The transmission occurs through a housefly which feeds on the excretions/ lacrimal/ear discharge and the larva develops in the fly and lodges in mouthparts and when the same fly feeds another animal, the infestation is established. Proper anthelmintic treatment with correct management protocol is needed to combat the parasitic diseases of the eye and the ear.

The breeding of livestock, particularly cattle, is one of the oldest agricultural activities that have been used to raise farmers' living standards all over the world, particularly in developing nations, however, this activity faces a number of challenges, one of which is the risk of disease transmission to the cattle. Numerous diseases can reduce an animal's productivity; harm its overall health, or even cause their death. Parasites are one of the greatest challenges to the development of cattle husbandry. One of these diseases is caused by parasitic agents, especially respiratory tract disease. There are numerous ways that these parasites can spread from one animal to another and affect cattle both internally and outwardly. In this section of the book, parasites that affect the respiratory system are discussed from the aspect of clinical, treatment, and control measures. These parasites can be classified as primary parasites that directly infect the respiratory system, secondary parasites that infect other parts of the body but also cause respiratory problems, or tertiary parasites that cause respiratory problems while they are passing through or developing. Parasites are considered the most challenging infections because the clinical symptoms are typically subclinical.

Infestation with parasites is incredibly widespread on a worldwide scale. Nematodes, cestodes, and trematodes are three types of helminths (parasitic worms) that can infect the liver and hepatobiliary systems. The host immunological response to the larvae or adult worms is the main source of morbidity and mortality from these infections. Asymptomatic carriage to cirrhosis and decompensated liver disease are the two extremes of parasitic disease presentations. Improvements in medical therapy, widespread screening and chemoprophylaxis, and the creation of preventative vaccination techniques are the main topics of current basic science and clinical research. This chapter discusses the general morphology, pathology, clinical symptoms, diagnosis, and treatment aspects of liver and pancreas-associated parasites of cattle.

Parasitic diseases are still a common occurrence in cow herds, both in conventional and organic systems, and understanding these diseases is a prerequisite for putting in place effective management measures and boosting farm profitability. The evolution of diagnostic techniques has allowed for a deeper understanding of the aetiology through the identification of parasite strains. Their epidemiology has altered over time in response to factors that are both human and environmental in origin. A reappraisal of the zoonotic danger of consuming beef has also been prompted by the recent rise of parasitic diseases including cysticercosis, sarcocystosis, toxoplasmosis, hydatidosis neosporosis, besnoitiosis, hypodermosis, toxocarosis, hookworm, and aberrant ascarid infection. The purpose of this book chapter is to focus on parasites that can directly or indirectly affect the musculoskeletal system, which can update our understanding of the state of parasite infections in cattle today.

In veterinary medicine, faecal examination is an important technique for detecting parasite infections. It is a basic marker for the parasitic infection in cattle. It is an affordable and non-invasive method that helps detect parasites across different body systems. Parasites residing in the digestive tract release eggs, larvae, or cysts in faeces, while adult helminth parasites may be visible during enteritis. Additionally, parasites such as worms, eggs, or larvae can be expelled from the respiratory system through coughing and subsequently swallowed, appearing in faeces. Mange or scab mites may be ingested through licking or nibbling, also manifesting in faeces. Various parasite forms with distinct morphological features can be identified in faeces, serving as diagnostic markers for specific species. However, some parasites may produce similar eggs or oocysts, making species-level detection challenging. Overall, faecal examination is a fundamental diagnostic tool for identifying parasitic eggs.

In the bovine industry, histopathological diagnosis plays a crucial role in the identification and characterization of parasitic diseases. Parasites can infect various organs and tissues in the cattle body, causing a wide range of pathological changes. This manuscript aims to provide an overview of the histopathological techniques employed in the diagnosis of parasitic diseases of cattle. It discusses the common parasites encountered, the associated histopathological findings, and the methods used to identify and differentiate these parasites. Understanding the histopathological features of parasitic infections is essential for accurate diagnosis and appropriate management of these diseases.

Gastrointestinal parasites pose a significant threat to cattle health, welfare as well as productivity throughout the globe. This chapter describes the major gastrointestinal parasites that affect cattle, their impact on the industry, proper management strategies, and also potential future directions for effective control and preventive measures. The economic upliftment of parasite infections in cattle production systems is generally explored, highlighting the major need for integrated approaches to combat these potential parasites. Key and major aspects including grazing management, proper anthelmintic treatment, genetic selection criteria as well as emerging research, are elaborately discussed in the context of sustainable parasite control strategies. The chapter magnifies the importance of continued updated research with major collaboration to mitigate the impact of gastrointestinal parasites on cattle populations. 

 Resistance to parasitic infections falls under two main domains. The first is known as innate resistance, it comprises age resistance, breed resistance, and in some situations, species resistance which does not have an immunological basis. The second category is termed as acquired resistance and it depends on humoral and cell response. However, for reasons elaborated in this chapter, parasitic diseases can be countered by a few vaccines. The main role of protecting animals against infections and modulating the spread of parasitic diseases is contributed by the natural expression of acquired resistance. Host-parasite relationships are mostly perceived as a defense race, where parasites are continuously trying to take over host machinery. A common source of parasite spread is herbivory, which constitutes the most prevalent challenge to mammalian growth and reproduction. Factors affecting the immune response against infection include (a) genetics, (b) host status at the time of exposure comprising age, disease, and underlying illness, and (c) transmission and population of parasite loading dose.). The immune system works in the same fashion against parasites as for other pathogens, but there are some major changes depending upon the nature of the response. Different antigens show up as a parasite develops through certain stages of its life cycle. This results in the occurrence of many antibodies dependent and independent responses. The immune system of the host becomes confused in certain infections, progressing to conditions where the host is targeted rather than supported.

Cattle farming plays a vital role in global agriculture, providing meat and dairy products to meet the growing demand for protein. However, the industry faces significant challenges posed by parasitic infections that lead to economic losses, reduced productivity, and compromised animal welfare. To combat these issues, researchers have been exploring the development of antiparasitic vaccines for cattle. In the realm of helminths, efforts have been made to identify specific antigens from nematodes, trematodes, and cestodes that can stimulate protective immune responses in cattle. The transition from whole-organism vaccines to subunit vaccines has shown promise, with several candidates in various stages of development. Protozoal infections, including Neospora caninum and Theileria species, have been targeted with vaccines designed to reduce abortions and mortalities in cattle. Live-attenuated and subunit vaccines have been explored with varying levels of success. Achieving consistent protection across diverse parasite strains remains a challenge. Ectoparasitic arthropods like ticks and flies have also been the focus of vaccine development. Bm86- based vaccines for ticks have shown partial success but face limitations in terms of tick species and strains. Combinatorial vaccines and in silico approaches offer potential solutions for broader protection. Despite these advancements, several challenges persist in the development of antiparasitic vaccines for cattle. These include the need for rigorous field testing, addressing antigenic diversity, optimizing vaccine formulations, and ensuring cost-effectiveness for widespread adoption.

Parasitism is one of the greatest challenges faced by the cattle industry worldwide. Parasites and parasite-borne infections not only pose various adverse impacts on the health of cattle but also affect the marketing and import-export of animals and their products, which lead to the loss of billions of dollars on an annual basis. Therefore, devising appropriate preventive measures and control strategies is direly needed in order to fight against these devils that affect cattle health. As the kinds of parasites and the degree of their impacts on cattle vary significantly according to climatic conditions, geography, genotype of cattle, production environment, cattle age, and management approaches, precise and suitable preventive and control measures must be adopted according to faced factors and situations. Nowadays, many approaches are extensively utilized for parasitic control, like pasture management, waste management, deworming, grazing management, nutritional management, management of dwelling places or sheds, immunization, and biological control. It is not possible to issue general guidelines and recommendations for parasitic control in cattle due to diverse geo-climatic conditions and methods opted for rearing the cattle. Due to the increasing incidence of anti-parasitic drug resistance in animals, it is crucial to design a sustainable parasite control approach, which must involve the host as well as the host control measures to achieve maximum productivity from cattle for an indefinite time period.