Chapter 9 - Emergency Situations

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9.5 Guidelines for Dealing With Other Reportable Diseases in Registered Slaughter Establishments

The occurrence of any reportable disease must be immediately reported to the Terrestrial Animal Health Division. Effective action can be taken by the Veterinarian in Charge for the following diseases while awaiting the arrival of assistance from the Terrestrial Animal Health Division. A suspicion of any of the following reportable diseases at the slaughterhouse should initiate action commensurate with the disease suspected as follows:

9.5.1 Anaplasmosis

Few actions at the slaughterhouse can contribute significantly to the control of this disease. Animal-to-animal transmission is accomplished by an insect vector, blood transfusions or by fomites contaminated with infected blood. Affected carcasses should be condemned. Care should be taken to prevent the access of biting insects to fresh, possibly contaminated blood and to ensure that blood from suspicious carcasses is not salvaged. The etiologic agent Anaplasma marginale is susceptible to common disinfectants.

9.5.2 Anthrax

9.5.2.1 General

The presence of this disease in the slaughterhouse abattoir is cause for alarm because of the human health implications, the extreme resistance of the sporulated form of the etiological agent (Bacillus anthracis), and the virulence of the disease to livestock. Anthrax is a very acute infectious febrile disease caused by Bacillus anthracis. In its most common form it is a septicemia, characterized mainly by its rapidly fatal course. Remember that spores are formed within a few hours if the carcass is opened and Bacillus anthracis is exposed to air. If the carcass is not opened, the oxygen supply is insufficient for spore formation and the organisms are killed within a few days by the putrefactive process. Vegetative forms of the causative micro-organism are no more resistant than most other bacteria and are therefore much easier to destroy.

In the event of even a suspicion of Anthrax on ante mortem inspection, the animal must be held in isolation, and the program officer notified immediately. The animal will be held until released by a veterinarian of the Terrestrial Animal Health Division. In the event of a clinical diagnosis of Anthrax on ante mortem inspection, the Terrestrial Animal Health Division will take two blood samples and blood smears for confirmation in a Federal Government laboratory.

The carcass must not be eviscerated but condemned immediately. The carcass must be wrapped in a strong sheet of plastic, large enough to encase the whole carcass. The wrapped carcass must be removed from the premises to a suitable place where it will be destroyed under the supervision of an inspector from the CFIA. Again, precautionary measures must be taken to avoid distribution of the infective agent.

9.5.2.2 Pens and Area of Possible Contamination

The pens and all possible areas of the stockyards and cattle cars or trucks that may have been contaminated shall be cleaned and disinfected under the supervision of an inspector.

No animal in a lot in which Anthrax has been found on ante mortem inspection shall be presented for slaughter until it has been determined by careful ante mortem inspection that no other animal in the lot is infected. Each registered slaughtering establishment, because of size, method of operation, design of slaughtering facilities, speed of rail, etc., will have basic differences in operational procedures. Those control measures which apply in one plant may not apply in another. Therefore, it will be necessary for each plant to have its own specific procedures if an Anthrax carcass reaches the killing floor. These may be reviewed and approved by the Program officer. The following guidelines should assist in the formation of these plans.

9.5.2.3 Human Contact

All persons who have accidentally handled Anthrax infected material shall immediately be subjected to a personal decontamination. Arms and hands shall be thoroughly washed with liquid soap and hot water. It is necessary that these steps be taken immediately after discovery of exposure, before the vegetative Anthrax organisms have time to form spores. In the cleaning, a brush or other suitable appliance should be used to ensure the removal of all the contaminating material from under and around the fingernails. This process of cleaning is more effective when it is performed in repeated cycles of lathering and rinsing rather that in spending the same amount of time in scrubbing with a single lather. After the hands and arms have been thoroughly rinsed free of soap, they may be immersed for about one minute in a solution of organic iodine, Dettol, Lysol or other acceptable agents followed by a potable water rinse. A complete change of clothes should be made with the garments possibly contaminated being thoroughly cleaned and disinfected. As a precautionary measure, all persons exposed to Anthrax infection should promptly report any suspicious condition (sore or carbuncle) or symptoms to a physician.

9.5.2.4 Cattle and Sheep

1. In the event that Anthrax is detected on the killing floor, all operations must cease. All parts of an affected carcass including the hide, horns, hooves, hair, viscera and contents, and blood must be condemned. All tissues from an infected carcass should, if they can be identified, be collected and placed in plastic bags. Blood may be handled through the usual blood cooking and drying process. The plastic bags containing the infected tissue shall be removed from the plant for destruction under the supervision of an inspector.
2. Any other carcass or parts that may have been contaminated with Anthrax material through possible contact with contaminated equipment must be condemned and disposed of under the strict supervision of an inspector.
3. That portion of the establishment that has been contaminated with Anthrax infected material shall be cleaned and disinfected immediately with an approved disinfectant such as 5% solution of sodium hydroxide or commercial lye. A solution of sodium hypochlorite (bleach) containing approximately one half of one percent (5,000 ppm) of available chlorine may be used. The solution shall be freshly prepared. Water at 82°C will destroy vegetative organisms.

9.5.2.5 Swine

The same procedures as for cattle should be followed. In addition the scalding tank, if contaminated, should be brought to a boil before being drained.

9.5.3 Bluetongue

The transmission of this disease requires insect vectors - biologically by Culicoides spp., and mechanically by the sheep ked (Melophagus ovinus). Therefore, there is little that can be done at the slaughterhouse to aid in control measures. Affected carcasses should be condemned and exposed animals in the yards should be slaughtered in order to limit the contact of Culicoides or infected sheep keds to live infected animals. The virus is susceptible to a 3% solution of sodium hydroxide but special disinfection measures would not appear to be warranted.

9.5.4 Brucellosis

Brucellosis has been eradicated from Canada except for geographically restricted wildlife reservoirs in northern Canada. It is therefore unlikely that animals affected with brucellosis will be presented to an abattoir except for those animals licensed to slaughter as serological reactors or their contacts. Because of the serious consequences of human infection, precautions should be taken.

9.5.5 Cysticercosis

The human health implications of bovine and porcine cysticercosis makes its detection in and elimination from meats essential. Ovine cysticercosis is not a human health risk. As with any reportable disease, you must report the occurrence. (See Chapter 5, section 5.5.)

9.5.5.1 Bovine and Ovine Cysticercosis

The larval form of the human tapeworm Taenia saginata is found in the connective tissue separating skeletal muscle fibre bundles and in the cardiac lymphatic spaces of the bovine. The cysts of Taenia ovis are similarly distributed in sheep and goats. Contrary to previously published reports, there are no sites of predilection for the cysts in a carcass, especially in lightly infected animals. Meat inspection procedures are designed, however, to find the cysts in areas in which they commonly occur and which can be examined with a minimum of carcass mutilation. For more details on bovine cysticercosis see Chapter 5, section 5.5.

9.5.5.2 Porcine Cysticercosis

Since auto-infestation of infested humans with cysts of T. solium in other than muscle tissues is possible, all swine carcasses with any evidence of Cysticercus cellulosae must be condemned. For further information see Chapter 5, section 5.5.

9.5.6 Pullorum Disease

This disease occurs only rarely in Canada and mainly in chicks and turkey poults in small farm flocks. The etiologic agent, S. pullorum is susceptible to most disinfectants. While infected eggs are the primary vehicle for transmission, fomites may be involved and plant workers should disinfect equipment and rinse hands and arms in a disinfectant solution.

9.5.7 Fowl Typhoid

Mechanical dissemination of the etiologic agent S. gallinarum is possible although egg transmission is the primary means of spread.

Therefore, a good disinfection routine for workers contacting infected birds is essential especially if they will be contacting live birds. Care should also be taken that wild birds do not have the opportunity to contact carcasses or offal from infected birds.

9.5.8 Glanders

This disease is rarely seen outside Eastern Europe, Asia, and North Africa. The etiologic agent Burkholderia mallei is capable of inducing a fatal pyemic condition in man. Therefore, strict personal sanitation is required to prevent human infection. Suspect horses should be isolated. The agent is susceptible to common disinfectants.

9.5.9 Dourine

Now found only in Asia, Africa, the United States and Central and South America, Trypanosoma equiperdum is transmitted primarily by coitus and probably by biting flies and through ocular infection from discharges. Since the organism cannot survive outside a living hose and dies quickly upon slaughter of infected horses, control at the abattoir would consist mainly of controlling the movement of contact horses until the Terrestrial Animal Health Division assumes control.

9.5.10 Rabies

Quick action at the slaughterhouse is necessary to limit human contact with suspected rabid animals. Under no circumstances should such animals be brought onto the killing floor. Contact of yard personnel with suspicious animals must be avoided. All contact animals should be detained and not slaughtered until the Animal Health representative arrives. Warning signs should be applied to the pen. Names of those individuals who may have contacted the suspicious animals should be collected. Any person in contact with rabid animals is strongly advised to consult a physician. Bovines sampled for rabies must have the obex tested for BSE as well.

9.5.11 Trichinosis

In the unlikely event that trichina are uncovered through trichinoscopic or muscle digestion examination at the abattoir, the infested carcass shall be put under detention and condemned after laboratory confirmation of the infestation. The program chief must be informed of the origin of trichina-infested hogs. Any further action regarding investigation and depopulation of the herd of origin is carried out by the Terrestrial Animal Health Division. Hogs presented for slaughter from an infested herd must be held and laboratory-tested for trichina infestation. See Chapter 5, section 5.5.

9.5.12 Tuberculosis

It is not necessary to report suspected cases of porcine tuberculosis to the Terrestrial Animal Health Division unless carcass condemnation is involved, nor is it necessary to report tuberculosis in poultry. In cases where swine carcasses are condemned for granulomatous lymphadenitis, typical lesions shall be sent for examination

However, our meat inspection system plays a very important role in the eradication program for bovine tuberculosis. All thoracic granulomas and any tuberculosis-like lesions found elsewhere in the bovine carcass (including single mesenteric lesions) must be forwarded for laboratory analysis. It is imperative that all forms of identification associated with carcasses bearing these lesions be recorded to facilitate herd trace backs. Even if a number of herds or feedlots need to be investigated, the effort is considered to be worthwhile. Specimens should be submitted in the tuberculosis specimen submission kits provided to inspectors at beef slaughter plants.

Based on the experience of others, it is expected that, over the long term, inspectors at beef slaughter plants will submit lesions at the rate of one lesion for every 2,000 cows slaughtered.

Herd trace backs will be conducted by Animal Health on all histopathology-positive lesions. The inspection staff submitting such lesions will be informed of the results of the investigation.

9.5.13 Bovine Spongiform Encephalopathy, Scrapie, and Chronic Wasting Disease

These three diseases are all classed as Transmissible Spongiform Encephalopathies (TSE). TSEs are believed to be caused by a conformational change to the normal protein particles called prions. Animals affected by TSEs experience progressive degeneration of the nervous system as the normal prion protein is transformed to the abnormal isoform. Thus the diseases are marked by a long incubation period, and are inevitably fatal.

Cattle with BSE may display changes in temperament, such as nervousness or aggression, abnormal posture, incoordination and difficulty in rising, decreased milk production, or loss of body weight despite continued appetite. Given the lengthy incubation period, BSE would most likely be found in older dairy cattle.

Scrapie usually manifests in sheep between two and five years of age. Most of the symptoms involve the nervous system. Early on, animals may display a change in their behaviour, becoming either aggressive or apprehensive. Owners often notice that sheep with scrapie seem disoriented and do not remain with the flock when it is herded. Later on, infected animals may start grinding their teeth, nibbling with their lips, or biting at their feet and limbs. Affected animals often seem itchy, and will scratch against objects and rub their wool off. They may also develop an unusual "bunny hopping" or high-stepping gait. Affected animals often lose weight and may appear in poor condition. Animals with scrapie can appear normal when standing quietly, but when stimulated or startled they may begin to tremble or appear to be having a seizure.

Chronic Wasting Disease (CWD) is a disease of cervids, both wild and domestic. Affected animals are poor doers, lose weight and go down.

All animals showing central nervous system signs require careful veterinary examination. TSEs should be considered among the rule-outs and appropriate samples taken (the obex from the brain stem). Samples for BSE and CWD must be forwarded to the lab with clear indication that the carcass is being held pending test results (unless condemned for other reasons). All carcasses and edible parts of carcasses must be detained pending the receipt of CWD or BSE lab results. Sampling an edible carcass for scrapie does not necessitate the holding of a carcass. Samples for scrapie, even from edible carcasses, can be frozen and held and sent to CFIA labs in periodic batches (e.g. monthly) to reduce associated courier costs. If found positive, carcasses sampled for CWD may go for rendering as SRM. Carcasses sampled for BSE and found positive must be buried or incinerated. (See Chapter 17, Annex D)

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