Bovine mastitis

It is a multifactorial process with many causes which is defined as an alteration of the mammary gland that leads to the alteration of production, qualitative and cuantitavimente, ie, milk production decreases in quality and quantity.

The presentation can be clinical, abnormalities of the breast and the production perfectly detectable or subclinical, with hardly any manifestations in the breast or in production, although in the milk.

There are several classifications of mastitis based on various criteria:

- Depending on location may be galatoforitis (affecting canals and pipes), parenchymal (glandular acini are affected) or interstitial (affects the supporting tissue). The development may lead to involvement of all the breast tissue forming.

- According to the clinic can be clinical, subclinical or latent.

- According to the source can be divided into endogenous (secondary infection of the breast from other organs), exogenous (infection of the breast directly from the outside skin, environment, etc..) Or idiopathic (the causative agent is within the own breast).

- Depending on the type of exudate to produce mastitis may be catarrhal, serous, fibrinous, purulent or bloody

- Depending on the time of onset can differentiate postpartum mastitis during lactation or during drying.

- According to the etiology may be divided into bacterial, viral or fungal infections.

Many factors influence the occurrence of mastitis in a flock, among which may be mentioned race (Frisian are more sensitive), genetic characteristics, age of animal (between the 3rd and 4th lactation are more likely), nutrition, housing, milking system, milking management, milking hygiene, etc. The sources of infection by infectious mastitis are usually the soil, rags, bedding, milking equipment, and any other contaminated instrument that comes into contact with cattle, the infection usually occurs via canalicular, but there are also cases traumatic mastitis.

The clinical diagnosis of mastitis should be based on two fundamental points: the study of breast milk production studies, both quantitatively and qualitatively.

In acute mastitis can see swelling, redness, heat, edema, swollen glands and changes in milk vary according to the agent, but usually processes tend to be produced by several species of bacteria, viruses and / or fungi at the same time. There may be mild acute mastitis, in which only affect a quadroon, or severe acute mastitis affecting the entire breast.

In subclinical mastitis cróncas or alterations are not apparent from the breast, only changes in the milk.

In the study of milk, you should pay attention to the decline in production, which affect one or more quarters but eventually result in the decrease of total production, and the qualitative changes that may be of the physico-chemical of milk (clots or filaments, color changes, odor and flavor, jelly-like, etc..) and cellular content (increase in cellular levels, which in normal conditions is 100000 cells / mL.). For the rapid diagnosis of mastitis is used Mastitis Test Californian (MCT), which consists of an indirect method of detecting alterations of the cellular content, based on the existence of diagnosing abnormalities in the viscosity of the milk.

It is recommended to collect samples and send them to the laboratory to establish an etiologic diagnosis and make an antibiogram to administer the most effective treatment against the causative agent.

Prophylaxis of mastitis is twofold: to reduce the rates of occurrence of new infections and reduce the time of presentation. Eradication is almost impossible, as a multicausal disease and multifacotorial. Treatment is applied according to the antibiogram performed in the laboratory with the antibiotic of choice, and usually involves a combination of b-lactams and aminoglycosides (penicillin + streptomycin, ampicillin + gentamicin, etc..). must take into account the blanking periods in milk after giving any kind of treatment.

The imunoprofilaxis is based primarily on the use of autogenous vaccines against common pathogens. General measures are recommended on-farm hygiene, pre and post milking, breeding, control of the milking machine, milking order of status: healthy animals, animals with subclinical mastitis and animals with clinical mastitis, periodic monitoring, etc..

Bovine brucellosis

Contagious disease that affects cattle, pigs, sheep, goats and dogs. It is caused by bacteria of the genus Brucella in cattle mainly B. abortus, although in some cases also been isolated B. melitensis. Processes are often acute and chronic tendency to have abortion as most common symptom and can cause infertility, and orchitis and infection of the accessory sex glands in the male.

Animals are the most important source of infection and maintaining the Brucella and removed without the disease. In addition, by eliminating the bacteria, they pollute the environment so that water, pasture or bedding can also act as sources of infection. Usually the disease enters the animal farm from new infected neighboring farms and less frequently from rare hosts that may come into contact with livestock.

The sensitivity of the animals depends on several factors, including age, race ( breeds selected are more sensitive) and the state of gestation are the most important.

In cattle there is no previous symptoms of abortion. If infection occurs early in gestation, the fetus is expelled from the 4 th and 6 th month, no serious injuries or alterations, only suffering from anoxia. If the infection occurs before mating, while the fetus is expelled from the 6 th and 8 th month, looking hemorrhagic and generalized edema or calf births occurring weak. The mother may develop reactions severe placental bleeding, hemorrhagic and necrotic placentitis and withholdings.

Bovine brucellosis is subject to the National Campaign for Eradication, so that treatment and vaccination are banned unofficial, and when an animal is found positive, we proceed to isolation, repeating checks and / or sacrifice in terms of results. There is established a rating system based on exploitation of the annual checks in:

- Herd officially free of brucellosis

- Brucellosis-free herd

For each of these ratings the herd must satisfy requirements for minimum clinical and serological results, the rating may be lost if any of the controls are not maintained the conditions of grant.

Bovine Tuberculosis

It is a disease of chronic course, characterized by nodules or follicles tuberculosis as main lesion. Mainly affects the respiratory system and is producidad by bacteria of the genus Mycobacterium, mainly in cattle M. bovis.

The sources of contagion of the disease are affected animals, inhalation and digestive, basically. Younger animals are more sensitive to race and the most selected and immunocompromised animals.

The most frequent clinical manifestations are the presenting respiratory symptoms, initially unapparent and ending with intense cough and severe dyspnea. You can also give the digestive form with specific symptoms: cramping, bloating, ascites, etc.. Other possible forms include meningeal, neurological symptoms, and bone or reproductive forms.

The most characteristic lesions, when found, is the granuloma or tubercle, very variable in size, morphology, number and arrangement. They usually appear in the viscera and often accompanied by lymph node lesions.

Tuberculosis, like brucellosis, a disease under national eradication campaign, so that treatment and vaccination are banned unofficial, sanitation campaigns are based on early diagnosis and slaughter of positive animals. Herds can be officially tuberculosis request and conducting the tests and controls established by law. The loss of the conditions for granting the classification determines the suspension or revocation of the classification.

Enzootic Bovine Leukosis

Enzootic bovine leukosis (EBL) is a worldwide disease, with an incidence higher in milk production systems, mainly from cows 3-4 years old.

The causative agent is a virus of the genus Oncornaviridae belongs to the family of retroviruses. Generally, only a small number of animals in a herd affected, usually over three years, may develop clinical symptoms of the disease, characterized by the presence of tumors (lymphosarcoma). The rest of infected cattle do not develop clinical disease are the main source of spread of infection because they carry the virus for the rest of his life. The infection can be

The transmission of the disease can be horizontal (bovine to bovine) or vertical (mother to child). The infected cattle is the source of virus spread, horizontal transmission being the most important and which produces as many new infections. When the number of infected cattle and animals per unit area is high, horizontal transmission is favored as the Crowding of physical contact and transmission of the virus.

When the infection is widespread, the clinic is characterized by the so-called multicentric lymphosarcoma with lymphosarcomas throughout the body, nervous symptoms, ocular signs consequence of the condition of the fundus, digestive signs of retropharyngeal node involvement and edema due to heart failure right to determine the occurrence of edema.

The EBL is part of a National Campaign for Eradication, based on early detection and slaughter of seropositive animals. Establishments that manage certain conditions of absence of illness, absence of compatible clinical and animal tests negative for two consecutive official obtained the qualification of herd officially free of EBL. Failure to comply with the conditions for granting or existing legislation in this regard, will the suspension or revocation of the classification.

LSD

Viral disease caused by a virus of the family Poxviridae, genus Capripoxvirus, surviving long periods at room temperature, especially in dry scabs, is resistant to a wide range of pH. The disease has a mortality rate varies. Notifiable disease, belonging to List A of the OIE.

It affects cattle, the oryx, giraffe and impala are susceptible to experimental infection, the virus replicates and also in sheep and goats after being inoculated.

Not transmitted in the absence of an insect vector, and although not set any particular vector, mosquitoes (eg Aedes and Culex mirificens natrionus) and flies (eg Stomoxys calcitrans and Biomyia fasciata) may play a role. Source of the virus are skin and skin lesions, scabs, saliva, nasal secretions, milk, semen, etc..

Symptoms of LSD range from inapparent to the most severe such as fever of up to two-week appearance of lumps or nodules on the skin, from 1 to 5 cm. in diameter, sometimes generalized, painful, particularly appearing on the skin of the snout, the nostrils, back, legs, scrotum, perineum, eyelids, the base of the ears, oral mucosa and tail. Also observed depression, anorexia, excessive salivation, runny oculonasal, agalactia and emaciation. If nodules deeper levels affect the skin, appears limp caused by inflammation and necrosis of the tendons and edema in the chest and legs. Superficial lymph nodes that drain the infected areas of skin can multiply its normal size from four to ten times

Some complications may arise from secondary bacterial infection of the nipples, causing severe dermatitis that can even lead to loss of affected quarter, or secondary bacterial infection of the tendon and the joint may cause permanent limp. Another complication is the emergence of abortion by intrauterine infection, which causes temporary sterility in bulls and cows.

The differential diagnosis of nodular seudodermatosis against contagious bovine mastitis herpes, Dermatophilosis, ringworm, insect bites or ticks, Besnoitiosis, Rinderpest, Demodicosis, Hypoderma bovis infection and other diseases with similar symptoms and injuries.

No particular treatment but using strong antibiotics to prevent secondary infection. Prophylaxis in non-infected health control is recommended the importation of cattle, carcasses, hides, skins and genetic material. In infected countries must make strict quarantine and isolation and prohibition of animal movement at the onset of an outbreak, with slaughter of all infected animals and patients (as far as possible), proper disposal of dead animals, disinfection of premises and of the instruments and vector control at the premises and animals

There is an attenuated virus vaccine confers homologous immunity up to 3 years. You can also use an attenuated virus vaccine heterologous vaccine as sheep pox, although it can cause severe local reactions.

Rinderpest

Rinderpest is a highly contagious acute viral disease mainly of cattle and secondarily may affect sheep, goats and wild ruminants. Asian pigs seem more susceptible than Europeans and Africans. Notifiable disease, belonging to List A of the OIE.

The disease is caused by a virus belonging to the family Paramyxoviridae, immunologically related to the measles virus is sensitive to the action of strong acids and alkalis. The disease is spread by contact with infected animals or indirectly by secretions, excretions and slurry. The virus appears in the blood and secretions before the onset of signs, so it can spread from inapparent on farms. Animals that recover develop a strong immunity, but whether they can be carriers.

Clinical signs after an incubation period of 3 to 10 days, longer in places where the disease is endemic. The most obvious symptoms are high fever, nasal discharge, erosions of the oral mucous membranes, constipation followed by diarrhea, dehydration, rough hair coat and dirty. Death occurs in 7-12 days. As gross lesions observed erosion-like lesions on the inner surfaces of the lower lip, gums, ventral surface of the tongue and soft palate. The course of the disease may be acute or subacute treble

The classic form has three stages or acute after the incubation period, beginning with a period of depression accompanied by fever, anorexia, reduced rumination, rapid breathing and heart rate. Then there is a second phase of 2 or 3 days, in which there is congestion of the mucous oral, nasal, ocular and genital intense mucopurulent lachrymation profuse salivation, anorexia - necrosis and erosion of the oral mucosa. Finally, gastrointestinal symptoms, when fever reducer: profuse bloody diarrhea containing mucus and necrotic debris, dehydration and abdominal pain, abdominal breathing, weakness, pitch position. Death occurs within 8-12 days. In rare cases, clinical signs regress at 10 days and recovery occurs between 20 and 25 days. In the peracute form no prodromal symptoms, only fever (> 40-42 ° C), and sometimes mucous congestion and death. This form occurs in young animals and infants are very susceptible. The subacute clinical symptoms limited to one or more of the classic symptoms and a low mortality rate. There is also an atypical form characterized by irregular pyrexia and mild diarrhea or no rare.

In sheep, goats and pigs pyrexia and anorexia observed variables, sometimes diarrhea. Finally, the pigs have pyrexia, prostration, conjunctivitis, erosions in the oral mucosa, and finally death

The clinical history, signs and lesions can help determine a diagnosis, however, the similarity of these features with those of other diseases, you need a confirmation by laboratory diagnosis.

The differential diagnosis in cattle is due to face Foot and mouth disease, bovine viral diarrhea / mucosal disease, infectious bovine rhinotracheitis, malignant catarrhal fever, vesicular stomatitis, salmonellosis, necrobacillosis, paratuberculosis and arsenic poisoning. In small ruminants should be differentiated from Peste des petits ruminants

There is no treatment. The sanitary prophylaxis is based on isolation or sacrifice of sick animals or contact with them, the destruction of the bodies, disinfection of holdings and protection of unaffected areas. As for medical prophylaxis, attenuated virus vaccines in cell cultures are very effective. The commonly used vaccine is an attenuated strain of rinderpest virus to confer immunity for 5 years. Annual revaccination is recommended for a high percentage of immunized animals in an area.

Plerineumonia contagious bovine

It is an infection of cattle caused by Mycoplasma mycoides spp mycoides SC (short colonies). Mycoplasmas are microorganisms deprived of cell walls and are therefore resistant pleomorphic and beta lactam antibiotics. Notifiable disease, belonging to List A of the OIE.

This is a serious disease that causes necrotic fibrinous bronchopneumonia with pleuritis and kills more than 50% of affected animals, which may be cattle, zebu and water buffalo. Cattle and wild camels are not susceptible. This process is eradicated from our cabin, but its importance lies in the possibility of the existence of carrier animals. The causative agent is not resistant in the environment and transmission requires close contact, the air is usually transmitted through droplets emitted by coughing animals, saliva and urine. Also transplacental infection can occur.

The incubation period is 1-3 months. During an outbreak of the natural disease, only 33% of animals showing symptoms (hyperacute or acute forms), 46% are infected but asymptomatic (subclinical) and 21% appear to be resistant. The symptoms in adults presents with mild fever with respiratory symptoms, pulmonary and pleural: tachypnea, characteristic attitude (elbows out, back arched, neck extended), and cough (initially dry, light and without access later wet). A percussion mates can hear sounds in the lower chest. In calves need not cause respiratory signs and infected calves present arthritis with swelling of the joints. The coexistence of pulmonary symptoms in adults and arthritis in young animals should alert the clinician to a diagnosis of CBPP.

It should establacer differential diagnosis with East Coast fever, bovine pasteulerosis acute bronchopneumonia and pleuropneumonia resulting from mixed infections. The chronic form of hydatid cyst should be differentiated, actinobacillosis, bovine tuberculosis and glanders (farcinosis).

No effective treatment and treatment with antibiotics should be banned to prevent the emergence of resistance and carrier animals. Health prophylaxis in areas free of the disease is based quarantine, serological tests (complement fixation) and slaughtering of all animals from herds in which appear positive. Controlling the movement of cattle is the most effective in limiting the spread of CBPP.

As medical prophylaxis in infected areas using a vaccine containing T1 strain and sometimes a combination vaccine against CBPP and rinderpest.

Sources:

Sheets OIE www.oie.int
Rebhun, William C., 1999. Diseases of dairy cattle
Sainsbury, David, 1998. Animal Health: health, deseases and Welfare of farm livestock.
Mandell, Gerald, N. 1997. Infectious Diseases: Principles and Practice