1.0 Digestive Disease of Bovine (Cattle and Buffalo)
1.1 Bovine Viral Diarrhea
Bovine viral diarrhea (BVD) is a significant disease of cattle that found endemic in most of the countries all over the world (Fray et al., 2000). It is a viral disease that arises from the bovine viral diarrhea virus (BVDV) (NYSCHAP, 2007). This virus is wide-spread and all aged cattle are found susceptible to it (NYSCHAP, 2007; Kirkland, 2015). However, the disease is rarely seen in cattle before 3 months old owing to the effectiveness of colostral antibodies work in preventing young animals from infection (NYSCHAP, 2007). Young cattle of 6 to 24 months old are most common with BVD (Gruenberg, 2018). Additionally, BVDV is found potentially cause economic losses in cattle industry majorly because of the decrement in reproductive performance. This is owing to the fact that this virus has ability crossing placenta during pregnancy leading to the birthing of persistently infected calves. The PI animals are powerful BVDV transmitters in comparison with infected animals due to their capability in shedding large amounts of viruses within their lives. Owing to the nature of this virus, no treatment can fully treat the viral infected animal. Therefore, control programs are developed in most of the countries around the world, primarily aimed to detect the PI animals, eliminate them as well as prevent them return to their herds (Khodakaram and Farjanikish, 2017).
1.2 Etiology / Causative agents
Bovine viral diarrhea virus (BVDV) is the causal agent of bovine viral diarrhea (BVD). BVDV is a single linear positive-stranded RNA virus and being classified in the genus Pestivirus of the family Flaviviridae. It is closely related to Border disease virus and also Classical swine fever (Brownlie, 1986). BVDV can be divided into 2 different genotypes which are type 1 (BVDV-1) and type 2 (BVDV-2) (Vilcek et al., 2001). Both BVDV genotypes were found can happen in biotype of cytopathogenic or non-cytopathogenic and can be distinguished via cell culture (Brownlie, 1986).
1.3 Signs and Symptoms
Clinical sign and symptoms of BVD are greatly variable; including a range from no signs to few to very severe that potentially kill the animals, all depends on the exposed animals’ immune status and also the strain of virus (NYSCHAP, 2007; APHIS, 2007). If non-vaccinated animals are infected by a virulent virus, the disease may appear as acute; otherwise the disease is chronic if the infection being acquired for months. Sign and symptoms for acute infection including high fever (41ºC-42ºC), bloody diarrhoea, rapid respiration, loss of appetite, lethargy, dehydration, mouth ulcers, excessive lacrimation, nasal discharge, decrease in milk production, leukopenia, thrombocytopenia and also pneumonia (Gruenberg, 2018; NYSCHAP, 2007; APHIS, 2007). In term of chronic infection, there might be mucosal disease. Some animals might die due to the infection, while some will recover, normally within 1 or 2 weeks. Occasionally, the infected animals are found die quickly, before other signs and symptoms apparent. High morbidity with ≥25% mortality is very common (Gruenberg, 2018). Owing to BVD is a viral disease, hence, antibiotics will not effective.
If the bovines are in second trimester of pregnancy, even they are recovered from the infection, they likely to experience abortion about two to four weeks after exposure. Early embryonic death will happen for those in first trimester. Some cows may not experienced abortion if they exposed to the infection between 60-120 days of pregnancy. Nevertheless, they rather may deliver a PI calf. Throughout its life, the PI calf will shed large quantities of BVDV. In calves herd, cerebellar hypoplasia is the most commonly recognizable birth defects where the signs including ataxia, tremors, stumbling as well as wide stance. For the cattle that are proper vaccinated and not been stressed heavily, the disease may less severe, and the visible signs and symptoms will only be the sporadic abortion and repeat breeding (NYSCHAP, 2007).
1.4 Pathogenesis
After BVDV enter and in contact with oral mucosa, nasal cavities or reproductive tract, replication of viruses will happen in epithelial cells and has predilection in nasal mucosa and palatine tonsil. From here, BVDV will transmit to regional lymph nodes prior to the buildup of viraemia. BVDV is found can freely disseminate in blood, or in association with leukocytes, specifically monocytes and lymphocytes. After that, BVDV will access to other tissues, primarily lymphoid tissue, achieving its maximum concentration in thymus, tonsil and ileum. Intestinal mucosa and bone marrow often been infected, whereas lymphoid tissue of Peyer’s patches will deplete. Nevertheless, there is strains variation as to which specific tissues are infected and generally, a broad distribution is in association with higher virulence.
1.5 Diagnosis
There are several methods that are reliable to perform in order to detect animals with BVDV infections, but it is more important to differentiate the acutely infected animals from the persistent infected animals owing to the fact that PI animals are served as natural reservoirs, identification and elimination of these PI animals can help to prevent BVDV transmission. Therefore, detection of PI cattle can be done via virus isolation, immunohistochemistry, antigen capture-ELISA, as well as reverse transcriptase polymerase chain reaction (Khodakaram and Farjanikish, 2017). .
For virus isolation, it is known as “golden standard” diagnostic technique. Due to the replication of BVDV is the most potential in lymphoid cells, therefore consideration for samples that having this kind of cells should be made. The samples will include Buffy coat, whole blood and lymphoid tissues. Unfortunately, virus isolation is a labor intensive method, it takes time to complete and the results might be false negative because of the interference with maternal antibodies which cause the test become less sensitive, thus re-test might be required for the positive animals in 3 to 4 weeks in order to distinguish the TI and PI animals (Khodakaram and Farjanikish, 2017).
Due to cost effective and easy in sample collection, immunohistochemistry is widely used to detect PI animals. This technique involves usage of formalin to fix the sample (ear notch skin biopsy sample or tissue sample). Ear notch sample is found not only quickly and require less skill to obtain, it also capable to provide visible marker for the sampled animals, and there are high concentration of BVDV antigen can be found in the samples. Not only that, this method is highly sensitive and can test calves of all ages, even there are presence of maternal antibodies (Khodakaram and Farjanikish, 2017).
In term of antigen-capture ELISA, it provides good sensitivity, repeatability and specificity in detection of BVDV antigen. In addition, it is robust, cost effective and easy to perform during identification of PI animals. ACE is a very new method which used MAb to capture the viral antigen Erns glycoprotein. The glycoprotein is produced by infected cells during replication of virus. It can directly be detected in Buffy coat cells, blood, plasma, serum, tissue extracts and also ear notches, giving a reliable result (Khodakaram and Farjanikish, 2017).
For reverse transcriptase polymerase chain reaction, it can be used in the detection of BVDV in samples such as serum, tissues, blood, milk and nasal swab. It is a relatively reliable method that can be performed in PI animals of all ages. Not only that, even maternal antibodies present to BVDV, RT-PCR still able detect the BVDV (Khodakaram and Farjanikish, 2017).
1.6 Zoonotic Importance
Bovine viral diarrhea is not a zoonotic disease; therefore it will not transmit to human being (Jonsson, 2013). Nevertheless, immunosuppresion is one of the BVDV infection’s consequences. This possibly causing the infected animals have higher tendency exposed to other bacteria and viruses, and some of them may affected human health, for instance, rotavirus, bovine rhiotracheitis virus, coronavirus, E.coli and Salmonella. Subsequently, human being may infect due to some Salmonella and E.coli species (APHIS, 2007).
BVD is potentially transmitted within the herds. Direct contact with persistent infected animals is the main route of transmission. Transmission of BVDV can be vertically (eg: before birth) or horizontally (eg: after birth). Mechanism for vertical transmission includes embryo transfer and contaminated semen. Bulls that are infected will shed BVDV in semen for longer periods, and cattle will be infected after the frozen semen being inseminated. For horizontal transmission, common mechanism such as fomites (water, feed, needles, nose tongs and milk bottle), excretions and secretions (mucus, milk, feces and urine), and vectors such as flies have been reported having ability to transmit BVDV (Khodakaram and Farjanikish, 2017).
1.7 Treatment
Treatment specifically for anti-BVDV is limited (Gruenberg, 2018). Therefore, vaccination developed as the control program to prevent the transmission of BVDV.
In term of vaccination, there are inactivated virus vaccine and modified-live virus vaccine. Proper vaccination of bovine by using either inactivated virus vaccine or modified-live virus vaccine needed instruction from the manufacturer. Since BVDV is immunosuppressive and fetotropic, therefore, the use of modified-live virus vaccine for pregnant cattle or cattle that have signs of being infected is not recommended. Otherwise, this kind of vaccine generally is recommended for every animal at least once in lifetime, and 3 to 6 months old is the most preferable ages (NYSCHAP, 2007). Inactivated virus vaccines possibly used for the pregnant cattle, but this kind of vaccines only provide short-term protection, thus frequent vaccination is required to prevent the disease (Gruenberg, 2018).
2.0 Respiratory Disease of Bovine (Cattle and Buffalo)
2.1 Shipping Fever Pneumonia
Shipping fever pneumonia, also known as bovine pneumonic pasteurellosis, is one of the complex respiratory diseases that lead to morbidity and mortality in cattle and buffalo (Rehmtulla and Thomson, 1981). This disease has caused a great impact in livestock industry, including decreased in weight and meat production in affected bovine as well as increased in feeding period and death in infected bovine. In fact, shipping fever pneumonia often affects cattle and buffalo during transportation. The infected bovine is found to have high fever, difficulty in breathing and inflammation in lung (Friend et al, 1977; Yates, 1982). In Colorado, there were about 64% of the cattle died due to this disease in 1974 (Jensen et al, 1976).
According to Canadian Journal of Comparative Medicine in 1980, stress in bovine can lead to spread of virus and respiratory tract infection due to Pasteurella which causes fatal pneumonia (Hoerlein, 1980). The impact of this disease has encouraged the authorities involved to use modern management in infectious agents and vaccination programs to increase the defense mechanisms in bovine as well as to encourage modern diagnostic tools and antibiotic treatments to stop this contagious disease (Storz et al, 2000). Therefore, more efforts and time needed to be allocated to understand the etiology, epidermiology and immunology of this disease to reduce the morbidity and mortality rate of bovine due to shipping fever (Hamdy et al, 1965).
2.2 Etiology / Causative agents
Virus, which is bovine herpesvirus-1 (BHV-1), is considered as a causative agent of bovine shipping fever. Besides, bovine parainfluenza type-3 virus (PI-3), bovine respiratory syncytial virus (BRSV) and bovine viral diarrhoea virus (BVDV) can contribute to shipping fever pneumonia in cattle and buffalo (Jericho and Langford, 1978; Woolums et al, 1999).
Bacteria that results in shipping fever including Pasteurella haemolitica, Pasteurella multicida and Haemophilus somnus. These are the bacteria that cause the cattle and buffalo to develop bacterial pneumonia infection which compromise their respiratory tract at most cases. Even worst, it is fatal to some cattle and bovine due to untreated condition (Currin and Whittier, 2009).
2.3 Signs and Symptoms
The signs of developing shipping fever can appear in 2-21 days, but most commonly within 5-14 days. Increase tiredness and loss of appetite are the first signs that can be observed in infected cattle and buffalo. Besides, the infected animals will show depression by hanging their heads and isolated themselves from the herds. Fever may also show in affected animals and it is the earliest signs of bovine shipping fever.
For the latter signs, watery nose and eye may be observed in which the mucus discharge is commonly start from nose of the affected animals, then affects the eyes when the disease become progress. Furthermore, the affected animals may experiences rapid breathing, decreased in body weight and soft coughing. Rapid breathing occurs when large amount of blood is travelled to the infected part of the lung, which leads to obstruction in airflow. As a result, the animal needs to breathe more quickly and harder in order to allow sufficient air exchange due to reduced in efficiency of lung function. Besides, the affected animals tends to clear their airways by producing mild and soft coughing because the affected lungs is damaged and painful to that animals. Because the affected cattle and buffalo are observed to be decreased in appetite, therefore, eventually, their weight tends to be reduced after a few days (Hamdy et al, 1965). During weaning, the animals have higher risk to get infected with shipping fever, therefore, the farmers should monitor for any sign and symptom of shipping fever in animals by monitoring each and every calf twice a day for first few weeks after weaning to prevent any occurrence of this disease. If this action is not performed by the farmers, it can lead to death in calves due to severe pneumonia (Kasimanickam, 2010).
2.4 Pathogenesis
Stress factor is involved in the development of shipping fever pneumonia. It can lead to decrease in defense mechanism of cattle and buffalo. When the immune system of the affected animals is compromised, it results in growth and proliferation of bacteria such as Pasteurella haemolitica in the upper part of the respiratory tract. Then, when the disease progresses, the bacteria colonize and infect the lower part of the respiratory tract. As a result, it leads to bronchopneumonia with distribution in cranioventral region of the lung. Besides, long distance transportation of cattle and buffalo also can be seen as a pathogenesis of shipping fever pneumonia. As stress can be produced during the transportation, the animals are more prone to get infected. Stress level may be increased when the animals experience tiredness, dehydration, unstable weather conditions and starvation during the transportation process (Whiteley et al, 1992).
Besides, the major virus that contributes to shipping fever pneumonia is bovine herpesvirus-1 (BHV-1) and bovine viral diarrhea virus (BVDV). For BHV-1, it leads to infection in respiratory tract as well as genital tract. Due to infection in genital tract, it caused abortions in cows during pregnancy or the disease may infect the fetus. Since BHV-1 results in reduced in immune response, the affected animals are more prone to secondary bacterial infections which are fatal to them. This virus resides in the host, primarily in trigeminal ganglia in latent state after the primary infection. When the affected animals are exposed to stress, such as transportation and weaning, the virus becomes activated and start to colonize to infect the animals. On the other hand, BVDV contributes to fever, rapid breathing, and diarrhoea and decreased in leukocytes level. Persistent infections may be resulted in fetus especially during the early stages of pregnancy. Most of the infected calves are found death after the infection, but some of the calves may survive with stunted growth or birth defects (Hurk et al, 2018).
2.5 Diagnosis
Necropsy on the dead cattle and buffalo may be recommended and performed by the veterinarians and researchers in order to confirm the diagnosis on shipping fever pneumonia. Besides, by doing the necropsy, types of virus or bacteria can be identified which allows the researchers to develop the treatment plans such as development of vaccination to treat this disease. Apart from that, necropsy also can give the nutritional status of the affected animals and determines the most appropriate antibiotics treatment to the affected animals (Kasimanickam, 2010).
2.6 Differential diagnosis
Since diagnosis of the shipping fever pneumonia may be difficult, therefore, it is important to differentiate shipping fever pneumonia from other types of bovine respiratory disease in order to provide appropriate treatment to the affected animals. Therefore, researchers can perform tissue culture, bacteriological and serological techniques to effectively differentiate this disease from other types of similar diseases. In order to have a more accurate diagnosis, laboratory testing and postmortem examinations can be conducted with closely monitoring of the affected animals. When the signs and symptoms such as loss of appetite, fever or rapid breathing are seen in the cattle and buffalo, especially within 2-21 days after transportation, it allows the researchers and veterinarians to conduct further diagnosis to confirm this disease. Besides, postmortem examination can also be conducted in which the affected animals will show changes in pathological aspect in respiratory organs. This includes bronchopneumonia associated with congestion of affected lung as the early stage of this disease. Furthermore, the researchers may notice that there is presence of blood and fibrin in the alveoli of the affected animals, some parts of the lung can also found to have edema. In the latter stage of this disease, which is secondary bacterial infection, bacteria tend to enter into the tissues as well as bloodstream to produce bacteremia. This leads to small hemorrhage in various organs which can be observed. Lungs abscesses and swollen, blocked lymph nodes in thoracic region may also be observed (Hamdy et al, 1965).
2.7 Zoonotic Importance
According to WHO 2016, zoonosis is the ability of disease or infection in animals to transmit to humans. Zoonoses can be transmitted in the form of bacteria, virus or parasites. However, shipping fever pneumonia is not transmissible to human; therefore, humans will not get infected with the agents that leads to shipping fever pneumonia. Besides, according to a study in The Canadian veterinary journal, the chance of getting infected by shipping fever pneumonia is not significant. It explained by placing sick, infected cattle into a herd of calves, but the risk of getting infected is not increased. Therefore, it concluded that this disease is not that contagious (Taylor et al, 2010).
Shipping fever pneumonia can be transmitted through aerosol or direct contact. Cattle and buffalo can get infected by breathing in causative agents of this disease from the cough of affected animals. Besides, saliva, urine or feces of infected animals can be the medium of transmission in which the animals can get infected by direct contact with any of these secretions or fecal materials of infected animals (Thomas et al, 2006).
Shipping fever pneumonia is not transmissible to humans; however, preventive measures should be taken to prevent secondary bacterial infection. For examples, always make sure that stress is reduced to minimal in cattle and buffalo during transportation and travel by not travelling to long distance. Adequate hydration and feeding should be provided during transportation and before weaning. Besides, vaccination should be given to bovine before weaning; booster should be given later at weaning. If any animals show sign of sickness or fever, sufficient treatment should be given promptly and that particular sick animal should be isolated from the herd (Grooms and Urban-Chmiel, 2012).
2.8 Treatment
In order to achieve better treatment outcome, early recognition of shipping fever pneumonia should be identified in affected cattle and buffalo. Antibiotics are the major treatment options in treating affected animals with pneumonia. Veterinarians may prescribe antibiotics that specifically target the bacteria involved in shipping fever pneumonia found in parts of lung tissue. Subcutaneous dosing of antibiotics can be used and found to be effective against this disease. Some of these antibiotics have shorter or no withdrawal periods. Besides, anti-inflammatory medication can help to reduce fever and decrease in the lung damage. It can also help to increase appetite in affected animals. In this case, vitamin B and probiotics, which leads to stimulation of appetite, can be added in the treatment plans of sick animals due to shipping fever pneumonia (Kasimanickam, 2010).
Example of anti-inflammatory drugs:
- Flunixin meglumine (Banamine® injectable solution) – Slowly inject intravenously with a single dose or 2 divided doses of 1.1 to 2.2 mg/kg of body weight for 3 days.
Examples of antibiotics:
- Tilmicosin (Micotil®) – Inject subcutaneously with a single dose of 10 to 20 mg/kg of body weight.
- Enrofloxacin (Baytril® 100) – Inject subcutaneously with a single dose of 7.5-12.5 mg/kg of body weight.
For shipping fever pneumonia caused by virus, modified-live and inactivated vaccines should be used for prevention. It is available in intramuscular administration. Example of vaccination is PI-3 vaccines. Besides, administration of vaccines via intranasal route also available which is suitable for temperature-sensitive mutants (Campbell, 2018).
Examples of vaccines:
- IBR vaccine (Bovi-Shield Gold®) – Inject a single dose of 2 mL subcutaneously or intramuscularly before the age of 6 months, after the age of 6 months or at weaning.
- PI-3 vaccine (Rispoval ®) – Inject a single dose of 2 mL intranasally from the age of 9 days.
- BVD vaccine (One shot®) – Inject a single dose of 2 mL to healthy cattle and buffalo.
3.0 Nervous System Diseases of Bovine (Cattle and Buffalo)
3.1 Bovine Babesiosis (Redwater, Tick Fever)
The disease is transmitted by ticks which are by the Babesia genus. It is from the protozoans. The negative consequences are where this caused a huge loss in the economy in which the production beefs and meat is greatly reduced due to the death of the animals. This disease is arthropod-born and many countries such as Australia, Central America as well as United States were greatly affected. This disease is the first that transmitted to mammals from arthropods (Friedhoff, 1988).
3.2 Etiology/ Causative Agents
Bovine Babesiosis (BB) can be known as tick-borne diseases. The causative and principle microbial strains included are known as Babesia bovis and Babesia bigemina with Rhipocephalus as the main vector (Ueti MW, 2015). Besides that, Babesia divergens is also being found and the main vector is lxodes Ricinus. BB can be identified in places where the arthropod vector can be found. BB can normally be found in tropical and subtropical (Zhang B, 2016). Babesia bovis and B. bigemina majorly distributed in Africa, Australia, South America, Asia and Central. Babesia divergens is also significant in some of the Europe parts and possibly Northern Africa. B bovis is transmitted through the engorgement of adult female ticks when they have the infection. Moreover, the infection can be passed on to their progeny through the eggs (Ros-García A, 2008). The larvae or seed ticks will be transmitted to others when fed to other animals. B bigmina is also passed from one generation to the next (Vannier E, 2009). On the next generation, the infection is passed to other cattles through engorgement of adult ticks, nymphal and adult stages but not during larval stages. The mortality rates and morbidity rates are largely affected by the availability of the treatments in an area, the exposure before this to the specific parasite strain and the presence of vaccination. Cattles at young age which become infected will develop lifetime immunity in the endemic areas (Wiegmann L, 2015). The disease outbreaks however can occur in the endemic areas if it is exposed to ticks when interrupted or the introduction of young cattle id been done. Moreover, the disease also can be due to outbreaks of ticks infected by Babesia (Ohta M, 1996).
3.3 Signs and Symptoms
The signs persist for about 7 days. The first clinical sign is fever that is for during the acute babesiosis phase. Then, the cattle or buffalo will experience anorexia, which is then followed by increase in the breathing or inspiration rate if they are moving. The first acute phase ends with muscle tremors and pipe-stem diarrhea. During the intermediate stage, the animals experience hemoglobinemia and haemoglobinuria (red urine). Jaundice will then occur. In late stage, constipation occurs and followed by unable to stand (Yang Y, 2013). When the weather is cold, death will occur as shock is worsen. The cows which are pregnant in late stages may experience abortion while the bulls become infertile. For the urine to become normal in color instead of red, several days is needed. For those who heal from acute stages will still be infected for some time. Tachycardia, hemolytic anemia and icterus will happen in acute Babesiosis. For chronic Babesiosis, it happens without hemoglobinuria. Acute Babesiosis bovis normally grow in life-threatening cerebral babesiosis with hyper-aesthesia. There will also be seizure and convulsions as well as paralysis as the red blood cells will aggregate (World Organization for Animal Health (OIE), 2018). This will cause damage in endothelial cells. The animals heal and will become carrier with no obvious symptoms.
3.4 Pathophysiology
Bovine Babesiosis is one of the zoonotic diseases that is caused by tick vectors interactions, the host transportation and the source of animals. The genus Ixodus ticks are primary factor of this disease. Ixodus scapularis or Ixodus dammini can be found in the United States. In Europe, Ixodus Ricinus can be found (Cooke BM, 2013). All of these primary vectors actually transmit the factors that exacerbate Lyme diseases. The factor that transmitted is known is Borrelia burgdorferi.
Ixodus scapularis has a total of three stages of growth. For example, larva, followed by nymph and then grow up to be adults. In order for them to proceed into next level, a meal with blood is needed. When the tick is still larva or nymph, they take the blood from the white-footed mouse or from rodents such as Peromyscus leucopus. When they reach adult level, they prefer taking blood from deer with white colored tails (Skerrett HE, 2003). When taking blood from these deers, the ticks actually transmitting and penetrating into the deer. They actually can grow and divide up to twenty thousand of eggs. However, in the Europe, the primary animal chosen is cattle (Yoshinari T, 2013).
The complete life cycle of the Ixodus scapularis takes two years. The cycle first started in spring, in which eggs are accumulated. They feed primarily in the white-footed mouse. After this, B. microti is now impregnated into ticks at larvae stage (Desoutter D, 2011). After one year, the tick larvae will develop into nymphal phase from the larva phase completely. Then, the B. microti will spread Babesia to human or rodents. After three to four days of consuming blood from rodents, human and mouse, the nymphs will develop into adults. The population for adult ticks will be sustained in the deer (Ishihara C, 2012). They will leave their eggs accumulated in deer in spring time and then die. Hence, it can be said that the larva, nymphs and adult ticks all can spread to humans.
2019-1-4-1546594264
...(download the rest of the essay above)