Nematodes

Specific diseases of animals (ruminants)

 

Diseases caused by viruses

Foot and mouth disease (FMD, Aphthous fever)

Judgement : In countries or in zones within a country free or nearly free of FMD diseased or suspect animals are prohibited to be admitted in an abattoir or slaughtered. If FMD is suspected on postmortem examination the carcass and viscera are condemned and appropriate action recommended by the regulatory authorities of the country must be taken. In countries where this disease is present, the judgment should be in accordance with the current animal health requirements and consisted of effective public health protection. Particular attention should be paid to secondary bacterial infections and general findings. Sanitary measures should be taken to comply with the national animal health policy.

Remarks: Latent infections with Salmonella organisms were reported in animals affected with FMD. 

Differential diagnosis in bovine and ovine species: Vesicular stomatitis, allergic stomatitis, feedlot glossitis, photosensitization, bluetongue, rinderpest, infectious bovine rhinotracheitis, malignant catarrhal fever, bovine papular stomatitis, bovine viral diarrhea, pseudocowpox, ovine pox, contagious ecthyma, footrot, mycotoxicosis and increased salt in concentrate.

Rinderpest (RP)

Rinderpest is an acute, highly contagious, fatal viral disease of cattle, buffalo, and wild ruminants manifested by inflammation, hemorrhage, erosions of the digestive tract, wasting, and often bloody diarrhea. Some swine species are also susceptible. Man is not susceptible to the RP virus.

Judgment: The carcass derived from a feverish and debilitated animal showing the sign of acute disease on antemortem examination should be condemned. In the areas free of RP and in zones where final stages of eradication exist, the animals are also condemned. In endemic zones, if acute symptoms of the disease are not present during clinical examination, the carcass may have limited distribution. In areas affected with outbreak which are protected by vaccination, heat treatment of meat is suggested if economically worthwhile. The affected organs are condemned.

Remarks: Rinderpest virus is sensitive to environmental changes and is destroyed by heat, drying, and a great number of disinfectants.

Differential diagnosis: Bovine viral diarrhea, malignant catarrhal fever, infectious bovine rhinotracheitis, bluetongue, coccidiosis, foot and mouth disease, vesicular and necrotic stomatitis, and bovine papular stomatitis. Vesicular diseases do not have accompanying hemorrhage and blisters should be differentiated from erosions (ulcers) seen at RP.

Vesicular stomatitis (VS)

This is a viral disease of ruminants, horses, and swine characterized by vesicular lesions of the mouth, feet, and teats. VS virus has two immunologically distinct serotypes, Indiana and New Jersey.

Transmission: In susceptible animals, contamination of pre-existing abrasions with saliva or lesion material, by ingestion of contaminated pasture or during milking within dairy herds. Mechanical transmission by biting arthropods is also a possibility. The virus is isolated from mites, tropical sand flies, and mosquitos.

 Judgment: The carcass of an animal affected with vesicular stomatitis is approved if the disease is not in the acute stage and secondary changes are not present. Parts of the affected carcass and organs are condemned. A carcass showing acute changes and systemic lesions is condemned. If VS is not confirmed by laboratory examination, the judgment will be the same as for the FMD.

Malignant catarrhal fever (MCF)

An acute viral disease of cattle, deer, bison, and buffalo characterized by inflammation of mucous membranes of the nose, eyes, corneal opacity, profuse nasal discharge, and enlargement of lymph nodes. MCF is arbitrarily divided into peracute, intestinal, head-eye, and mild forms according to antemortem findings. It is not communicable to man.
 
Transmission: Close contact between cattle and wildebeest (gnu, antelope), by the common use of drinking troughs or by direct contact between cattle and newborn wildebeest and placenta of parturient dams. In American or European MCF, cattle are infected from sheep.
 
Judgment: In the early stages of the disease, when fever, emaciation, and systemic signs are lacking, the carcass of the affected animal may be approved as inferior meat. Otherwise, when fever, emaciation, and systemic signs are present, the entire carcass and viscera are condemned. The condemned material may be used for rendering.

Rabies

This is an acute infectious viral disease of the central nervous system in mammals.
Transmission: It is usually transmitted through the saliva by a bite from a rabid animal, commonly the dog or jackal. Man is infected the same way.
 
Judgment: In endemic areas, carcasses may be approved if the animal was bitten eight days before slaughter and within 48 hours of slaughter. The bite area and surrounding tissue must be condemned, and prevention is taken to prevent occupational hazards.

Lumpy skin disease

Acute pox viral disease of cattle manifested with the sudden appearance of nodules on the skin. Transmission: Insect vectors by direct and indirect transmission. Seasonal and geographic distribution.
 
Judgment: Carcass of an animal showing mild cutaneous lesions and no fever associated with general signs of infection is conditionally approved pending heat treatment. The affected parts of the carcass and organs are condemned, Carcass of an animal show, on antemortem examination, generalized acute infection accompanied by fever, is condemned.

Bovine herpes dermophatic disease (BHD)

A herpes virus infection of cattle and sometimes sheep and goats manifested by cutaneous lesions and fever.
 
Transmission: Biting insects, mechanical milking
 
Judgment: Carcass of an animal affected with BHD is disposed of similarly to an animal affected with lumpy skin disease

Infectious bovine rhinotracheitis (IBR)

IBR is a highly infectious viral respiratory disease of cattle, goats, and pigs manifested by inflammation of respiratory passages and pustular lesions on the male and female genital organs. Generally, four forms of the disease are recognized; the respiratory form, the genital form, the enteric form, and the encephalitic form.
 
Transmission: Respiratory droplet and nasal exudate in the respiratory form of IBR. Obstetrical operations, coitus, and licking of the genitalia of affected animals in the genital form of the disease.
 
Judgment: Carcass of an animal affected with IBR is approved if signs of acute infection are not present and the animal is in good body condition.

Bovine viral diarrhea (BVD)

This is an infectious viral disease of cattle manifested by active erosive stomatitis, gastroenteritis, and diarrhea.
 
Transmission: Direct contact with clinically sick or carrier animals, indirect contact with feedstuffs or fomites contaminated with urine, nasal and oral secretions or feces, and contact with aborted fetuses. Transmission through aerosol droplet dispersion or by insect vector may also be a possibility. The virus may persist in recovered and chronically ill cattle which are considered a potential source of infection.
 
Judgment: Carcass and viscera of an animal, which on antemortem examination showed generalized signs of acute infection accompanied by fever and/or emaciation, are condemned. Chronic cases of BVD with no systemic involvement have a favorable judgment of carcass, viscera, and organs.

Bovine leukosis

Bovine leukosis is a persistent and malignant viral disease of the lymphoreticular system. It occurs in all breeds and in both sexes. Bovine leukosis is observed in two forms: a) the sporadic and b) the enzootic form. The sporadic form is rare and occurs in cattle under three years of age. The enzootic form is most commonly found in adult cattle, particularly in cull cows.
 
Judgment: Carcass of an animal affected with leukosis (lymphosarcoma) is condemned. When a diagnosis cannot be made by postmortem findings, a laboratory diagnosis should be performed. If lymph node hyperplasia is the histological diagnosis, the carcass is approved for human consumption. Depending on disease prevalence, leukosis reactors may be totally approved or conditionally approved pending heat treatment.

Bovine spongiform encephalopathy (BSE, “Mad cow disease”)

BSE is a progressive and fatal disease of adult cattle characterized by progressive degeneration of the central nervous system causing neurological signs in animals. Some scientists suspect that an unusual and atypical virus-like transmissible agent called a prion is associated with the etiology of BSE. Prion is the term currently used in literature.
 
Transmission: The ingestion of protein feed supplements prepared from sheep meat or sheep by products contaminated with scrapie virus. Diagnosis can be confirmed only on the postmortem histological examination of brain tissue. Microscopic lesions include degenerative lesions of the cerebral cortex, medulla and central grey matter of the midbrain.
 
Judgement : Carcass is condemned.

Diseases caused by Rickettsia and Mycoplasma spp.

Heartwater (Hydropericardium)

“Black dung” when affecting African cattle and buffalo
“Sheep fever” when seen in sheep
Heartwater is an acute, non-contagious disease of cattle, sheep, goats, antelopes, and wild ruminants. It is caused by the rickettsial organism Cowdria (Rickettsia) ruminantium.
 
Transmission: Heart-water is transmitted by various species of Amblyomma ticks. Transtadial transmission of the organism occurs in vector ticks.
 
Judgment: Carcass of an animal affected with heartwater is condemned in the acute stage of the disease. In a chronic case, the carcass may be approved if adequately bled and muscles are wholesome in color and texture. The affected organs are condemned.

Q fever (Queensland fever, Nine-mile fever, American Q fever, Australian Q fever)

Q fever is a disease of cattle, sheep, goats, donkeys, camels, fowl, dogs, cats, pigeons, and humans. It is caused by Coxiella burnetii. Q fever is an occupational disease of livestock personnel. farmers and laboratory personnel.
No gross lesions are reported in cattle.
 
Discussions: Coxiella burnetii is highly resistant and was isolated from farm soil 6 months after the removal of animals. It may persist in the udder for up to 3 years. The temperatures of milk pasteurization (in bulk at 63°C for 30 minutes or the common method at 72°C for 15 seconds) kill this agent in milk. Vaccination will reduce the shedding of organisms in milk.
This disease in humans has a sudden onset and is characterized by loss of appetite, weakness, and generalized malaise lasting from 1 – 2 weeks. Pneumonia may also be present. Death may be caused by endocarditis in older people. More severe symptoms of Q fever are noticed.

Contagious bovine pleuropneumonia

This is an acute, subacute, or chronic highly infectious disease of cattle caused by Mycoplasma mycoides var, mycoides.
 
Transmission: Aerosol and droplet infection from infected animals. The recovered animal called “lungers” act as carriers and shedders, especially under stress.
 
Judgment: Carcass of an animal affected with contagious bovine pleuropneumonia is condemned if the disease is associated with fever, inadequate bleeding of the carcass, serous infiltration of the brisket, and emaciation. Recovered animals showing no generalized signs of the disease are approved and the affected organs are condemned.

Diseases caused by bacteria

A black quarter (Blackleg)

The black quarter is an acute infectious disease of cattle and sheep manifested by severe inflammation of the muscle with high mortality. It is caused by Clostridium chauvoei.

Transmission: The organisms of blackleg are found in the soil. During grazing, organisms may enter the digestive tract of a susceptible animal. Clostridium chauvoei is also found in the digestive tract of healthy animals. In sheep, the agent is transmitted through wounds at shearing, docking, and castration and during lambing in ewes.
 
Judgment: Carcasses of animals affected with black leg should be condemned. It is prohibited to slaughter and dress an animal diagnosed with this disease at an antemortem examination.

Botulism

Botulism is a disease manifested by progressive muscular paralysis. It is seen in humans, animals, birds, and fish and is caused by various strains of Clostridium botulinum.
 
Transmission: Decomposed flesh and bones are the sources of infection for animals. Incubation period 12 – 24 hours. However, 2 hours up to 14 days incubation period has been recorded.
 
Judgment: Total condemnation of carcass because of human hazards.
 
Differential diagnosis: Parturient paresis, paralytic rabies, equine encephalomyelitis, ragwort poisoning in horses, miscellaneous plant poisoning.

Malignant edema

Malignant edema is a bacterial disease of cattle, sheep, goats, swine, horses, and poultry. It is caused by Clostridium septicum and is manifested by a wound infection. The infection is commonly soil-borne. Deep wounds associated with trauma provide the ideal conditions for the growth of this agent.
 
Judgement : Carcasses of animals affected with malignant edema are condemned.

Tuberculosis

Tuberculosis is a chronic disease of many animal species and poultry caused by bacteria of the genus Mycobacterium. It is characterized by the development of tubercles in the organs of most species. Bovine tuberculosis is caused by Mycobacterium Bovis. It is a significant zoonotic disease.
 
Judgment: Carcass of an animal affected with tuberculosis requires additional postmortem examination of the lymph nodes, joints, bones, and meninges. It is suggested that the Codex Alimentarius judgment recommendations for cattle and buffalo carcasses be followed.
Carcasses are condemned 

1. where an eradication scheme has terminated or in cases of residual infection or re-infection.
2. in final stages of eradication - natural prevalence low
3. during early stages in high prevalence areas

The carcass of a reactor animal without lesions may be approved for limited distribution. If the economic situation permits, this carcass should be condemned. Heat treatment of meat is suggested during early and final stages of an eradication program: in low and high prevalence areas where one or more organs are affected, and where miliary lesions, signs of generalization, or recent hematogenous spread are not observed. If the economical situation permits, then the carcass is condemned.
 
In some countries, the carcass is approved if inactive lesions (calcified and/or encapsulated) are observed in organs and without generalization in lymph nodes of the carcass.

Johne's disease (Bovine paratuberculosis)

Johne's disease is a chronic, infectious bacterial disease of adults wild and domestic ruminants such as cattle, sheep, and goats. It is characterized by the thickening and corrugation of the wall of the intestine, gradual weight loss and chronic diarrhea and is caused by Mycobacterium paratuberculosis

Judgment: Carcass of an animal affected with Johne's disease is approved when generalized systemic signs of disease are not present. A poor, thin, and slightly moist carcass should be held in the chiller and assessed after 24 or 48 hours. If the dryness and setting of the carcass improve during this time it can be released. The carcass with associated edema and emaciation is condemned.

Leptospirosis

Leptospirosis is an important and relatively common disease of domestic and wild animals and humans. In cattle, it is manifested by interstitial nephritis, anemia and mastitis and abortion in most species. Leptospira spp. are the causative agents.
 
Transmission: Animals contract the disease by eating and drinking leptospira-contaminated urine, water, or by direct contact of broken skin or mucous membranes with mud, vegetation, or aborted fetuses of infected or carrier animals. Recovered animals and animals with unapparent (subclinical) leptospirosis frequently excrete billions of leptospira 
 
Judgment: Carcass of an animal affected with acute leptospirosis is condemned. A chronic and localized condition may warrant an approval of the carcass.

Brucellosis (contagious abortion, Bang's disease)

Brucellosis of cattle is an infectious, contagious disease caused by Brucella abortus and is characterized by abortion in late pregnancy and a high rate of infertility. B. melitensis affects goats, B. ovis sheep, and B. suis swine. B. abortus may occur in horses.
 
Judgment: Cattle and horse carcasses affected with brucellosis are approved (after removal of affected parts), as Brucella bacteria remain viable for only a short period in the muscles after slaughter. In acute abortive form (after the miscarriage), cattle carcasses are condemned. Pig, sheep, goat, and buffalo carcasses require total condemnation. Heat treatment may be recommended in some areas for these species due to economic reasons. Affected part of the carcass, udder, genital organs and corresponding lymph nodes must be condemned.
 
Reactor animals should be carefully handled during slaughter and dressing procedures. Gloves and goggles should be worn when known reactors are being slaughtered and hygroma lesions should be sprayed liberally with 1 % lactic acid at meat inspection.
 
In humans, brucellosis is called “Undulant Fever”. The general population is not at risk with this disease if high levels of hygiene and sanitation are practiced. Pasteurized milk is brucella-free. Affected humans will suffer from intermittent high fever, headache, and generalized malaise.
 
Brucellosis is an important zoonosis in particular in rural areas in developing countries and is an important occupational hazard for veterinarians, meat inspectors, farmers, animal health inspectors, and butchers.

Anthrax

Anthrax is a peracute disease of ruminants manifested with septicemia, sudden death, and carry blood from the body openings of the cadaver. It is caused by Bacillus anthracis.

Judgment: Condemnation of the carcass and its parts by burning or burial. If disposed of by burial, the carcass should be buried at least 6 feet below ground. The site should be surrounded by a foot thick layer of quicklime.

Salmonellosis in bovine

Salmonellosis is a disease that occurs in all animals and humans. In animals, salmonellosis is characterized clinically by one of three syndromes:

1. peracute septicemic form
2. acute enteritis
3. chronic enteritis.

The young, old, debilitated and stressed animals are at greater risk. More than 200 antigenically different serotypes of Salmonella have been identified and all of these possess pathogenic potential. 

The most frequently identified serotypes of the organisms which cause the disease in cattle are S. typhimurium, S. dublin, S. muenster, and S. Newport. Salmonellosis in stressed animals is frequently associated with inadequate diet, irregular feeding, water deprivation, overcrowding, parasitism, weather extremes, pregnancy, parturition, intercurrent diseases, etc. The calving complications which may predispose the disease include abortion or early termination of pregnancy, retained placenta, endometritis, and post-parturient metabolic conditions.
 
Judgment: Carcass affected with Salmonellosis is condemned.

Hemorrhagic septicemia

Hemorrhagic septicemia is a systemic disease of cattle, buffalo, pigs, yaks, and camels. It is caused by Pasteurella multocida type B of Carter. Outbreaks of this disease are associated with environmental stresses such as wet chilly weather and overworked, exhausted animals. It is a specific type of pasteurellosis distinct from other forms of Pasteurella infections.
 
Judgment: Carcass of an animal affected with hemorrhagic septicemia is condemned. If the disease is diagnosed on antemortem examination, an animal should not be allowed to enter the abattoir. Dressing of such a carcass would create a potential danger for the spread of infection to other carcasses.

Calf diphtheria

Calf diphtheria is an acute oral infection of calves less than 3 months old. It is caused by Fusobacterium (Sphaerophorus) necrophorum. This agent also causes liver abscesses and “foot rot” in cattle.
 
Judgment: Carcass of an animal affected with local lesions is approved. Generalized diphtheric lesions associated with pneumonia or toxemia require the carcass condemnation. The carcass is also condemned if lesions are associated with emaciation.

Actinobacillosis

Actinobacillosis is a chronic disease of cattle caused by Actinobacillus lignieresi. It is manifested by inflammation of the tongue and less frequently lymph nodes of the head and of even the viscera and carcass.
 
Judgment: Carcass of an animal affected with active progressive inflammatory lesions of actinobacillosis in lymph nodes and lung parenchyma is condemned. Condemned material should be sent to an authorized rendering plant. If the disease is slight and confined to lymph nodes, the head and tongue and whole carcass are approved after the condemnation of lymph nodes. If the tongue is diseased and no lymph nodes are involved the head and carcass are approved. The tongue is condemned.

Actinomycosis (“Lumpy Jaw”)

Actinomycosis is a chronic granulomatous disease of cattle and pigs and rarely in sheep and horses. It is caused by Actinomyces bovis which is an obligatory parasite in the mucous membrane of the mouth and pharynx. Infection occurs following injury with a sharp object or hard feed pieces to the oral mucosa.

Pyelonephritis (Contagious Bovine Pyelonephritis)

Pyelonephritis is a purulent and inflammatory bacterial disease of the kidney pelvis and parenchyma caused by Corynebacterium renale. This disease is essentially observed in adult cows and sows. A predisposing factor for developing a kidney infection is trauma to the bladder and urethra during parturition.
 
Judgment: It depends on the infection of one or both kidneys and/or the presence of a urine odor. The carcass of an animal affected with pyelonephritis or nephritis is condemned if: 1) renal insufficiency is associated with uremia; 2) acute infection of the kidney is accompanied by systemic changes in the organs and lymph nodes, and/or degeneration of body tissues. Borderline cases with uraemic odors should be kept in the chiller for 24 hours. They are subjected to a boiling test. If a urinary odor is not present after detention, the carcass may be approved. Subacute or chronic kidney infections with no systemic changes allow for a favorable judgment of carcass. Only the affected parts are condemned. Pyelonephritis associated with kidney stones often has a favorable judgment of the carcass.

Metritis

Metritis is inflammation of the uterus. This condition is of bacterial origin. It occurs as a result of calving problems such as retention of the placenta, abortion, twin births, abnormal labor, and traumatic lesions of the uterus cervix, and vagina.
 
Judgment: Carcass of an animal affected with acute metritis is condemned if it is associated with septicemia or toxemia. In chronic cases, when toxaemic signs are lacking, the carcass may be approved if no antibiotic residues are found.

Mastitis

Mastitis is inflammation of the udder caused by bacteria, fungi, and yeasts. Depending on the virulence of the agent and resistance of the udder, mastitis is manifested in acute or chronic forms.
 
Judgment: Carcass and viscera are condemned if acute or gangrenous mastitis is associated with systemic changes. If the infection has spread from the supramammary lymph nodes via the iliac lymph nodes to the lumbar lymph nodes, this can be taken as evidence of the spread of infection from its primary location. The condemnation of the carcass may then be warranted. A localized condition of the udder has a favorable judgment of the carcass.

Endocarditis

Endocarditis is an inflammation of the endocardium of the heart. The lesion is most commonly seen in the valves. It may be the result of bacteremia caused by an infection in some remote organs such as the udder, uterus, or other sites.
 
In cattle, the organisms most commonly associated with endocarditis are Actinomyces pyogenes and Streptococcus spp. Strains of Escherichia coli are also frequently found. The lesion is most commonly found on the valves. Portions of vegetation may become detached and released into the bloodstream as emboli which may lodge in other organs. They may be septic or aseptic. The latter contains thrombotic material. Emboli, brought from the right heart to the lungs by blood vessels may cause pulmonary abscesses, or pulmonary thrombosis and the emboli brought from the left heart to the spleen and kidneys may cause septic or aseptic infarcts in these organs. Abscesses in the heart may also be observed.

Judgment: Carcass of a debilitated animal is condemned for verrucose endocarditis if it is associated with lesions in the lungs, liver, or kidneys. Carcass affected with ulcerative or verrucose endocarditis with no signs of systemic changes and the negative bacteriological results may be approved after heat treatment is applied. Endocarditis showing scar tissue is approved. The heart is condemned.

Traumatic reticuloperitonitis (TRP, hardware disease, traumatic gastritis, traumatic reticulitis)

TRP is caused by the perforation of the reticulum by a metallic foreign body. It is mostly seen in adult dairy cattle and can occur in beef cattle.
 
Judgment: Viscera and carcass are condemned

1. if the animal is affected with acute diffuse peritonitis or acute infectious pericarditis associated with septicemia
2. carcass with traumatic pericarditis associated with fever, a large accumulation of exudate, circulatory disturbances, degenerative changes in organs, or abnormal odor.
3. carcass with chronic traumatic reticulo-peritonitis and/or purulent pericarditis with associated pleuritis, abscessation, and edema of the chest.