Annex A: Ante-mortem Examination (Screening) - A Training Guide for Plant Employees
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Humane Handling of Animals
Livestock handling facilities in registered establishments must be properly designed, maintained and operated. The benefits gained will be efficient and humane handling resulting in a steady flow to the dressing operation, reduced injury (such as bruises) and increased safety for employees and inspection staff. Generally, the design of the facilities should correspond to the physical characteristics and behaviour traits of each species handled in an establishment.
It is important that the truck be flush with the receiving dock to preclude openings or unevenness that may result in injury to livestock as they are being off-loaded. Different levels of receiving docks might be needed to match the varying heights of livestock vehicles.
Livestock pens are to be kept reasonably clean. Cleaning and disinfecting with an approved disinfecting agent should be done regularly, or whenever it is feasible to do so.
Clean water must be provided in all livestock pens, including the isolation or suspect pen. In addition, animals kept for more than 24 hours must be supplied with food.
No food animal shall be handled in a manner that subjects the animal to avoidable distress or avoidable pain. Animals must be protected from inclement weather, heat and frostbite. No goad or electrical prod shall be applied to the anal, genital or facial region of a food animal. An electric prod must use a reduced voltage obtained from a stepdown transformer. The use of slappers made of a canvas-like material is to be kept to an absolute minimum. Their use; however, is preferable to canes and sticks in handling livestock. Unnecessary use or abuse of electric prods or any other type of physical abuse of animals submitted for slaughter will not be tolerated.
Animals of one species must be penned separately from animals of other species. Pen separately animals which might injure each other (i.e. fractious animals, adult boars and bulls and horned cattle) or which are vulnerable to injury from others (younger animals, sick or disabled animals). For more details on humane handling of food animals see Chapter 12 of this manual.
Purposes of Ante mortem Examination (Screening)
Ante mortem examination (screening) is to be performed on all animals within 24 hours of slaughter. If for some reason they have not been slaughtered within that period, they are to be re-examined prior to slaughter.
There are some very important reasons for performing ante mortem examination (screening) on animals and you should keep them in mind when performing your examination. These reasons are to:
- Identify animals showing clear evidence of being affected with a disease or condition that could render the carcass unfit for human consumption. This also allows you to identify animals affected with disease showing no evidence or post-mortem lesions (e.g. a rabid animal would have characteristic signs on ante mortem but no lesions on regular post-mortem inspection).
- Identify animals which could pose a threat to the health of personnel handling the carcass (e.g. ringworm).
- Identify animals which are suspected of being affected with a disease or condition that might render the carcass unfit for human consumption.
- Identify animals which are suspected of having been treated with antibiotics or other chemicals.
- Alert the inspection staff when diseased animals are found in a herd as the rest of the herd could be affected by the same disease (e.g. respiratory disease in swine).
- Identify heavily contaminated animals that could lead to problems during the dressing procedures.
- Identify animals which are suspected of having a reportable or exotic disease (e.g. Tuberculosis is a reportable disease and Foot and Mouth disease is an exotic disease as it does not exist in Canada). This also includes animals ordered to be slaughtered.
- Make a disposition regarding the suitability of animals for slaughter so that dead or dying animals do not enter the slaughter floor.
- Identify animals requiring special handling for humane reasons (e.g. animals with fractures).
Examination of the Animals
Your initial examination is the process of observation and detection of animals with noticeable abnormalities. So you must first learn to recognize normal animals. The following section will tell you how to identify animals which must be segregated from others.
How to conduct your examination
The animals should be observed at rest and in motion. Both sides, the head and rear of each animal, should be examined. It is of the utmost importance that you develop a standardized approach for your examination so that all animals are observed completely and in a consistent manner. When possible, the animals should be checked upon arrival.
In-pen screening should take into account the requirements for observation while maintaining safety considerations. An alternative to examining animals on arrival is to observe the animals in motion as they leave the holding pens.
Signs you should look for
What types of abnormalities should you be looking for when performing the initial ante mortem examination (screening)? In general anything that deviates from normal should be segregated during initial ante mortem examination (screening). There are some exceptions of minor significance such as cow with one horn or with an extra teat, a hog with no tail, minor cuts, etc.
Your job is to recognize abnormalities. It is therefore extremely important to recognize what is normal when examining an animal. This takes some time and with experience you will be able to judge which conditions require a detailed inspection by an official veterinarian.
Generally abnormalities that require segregation of animals at the time of initial ante mortem examination fall into the following categories:
- abnormalities in breathing;
- abnormalities in behaviour;
- abnormalities in gait;
- abnormalities in posture;
- abnormal discharges or extrusions from body openings;
- abnormal colour;
- abnormalities in appearance; and
- abnormal odour.
We will discuss each of these in more detail with some examples.
Do not hesitate to ask for assistance so that you can develop a proper judgement and recognize abnormal conditions.
Abnormalities in breathing
Usually this refers to frequency of respiration but there are also other abnormalities such as frequent coughing and difficulty in breathing. The main point for you to remember is that if the breathing pattern differs from normal, the animal should be screened out.
Abnormalities in behaviour
Abnormalities in behaviour can be significant in some very serious diseases such as rabies and lead poisoning. Examples of abnormal behaviour are:
- an animal pushing its head against the wall;
- an animal walking in circles;
- an animal charging at various objects;
- an animal with an anxious expression in its eyes;
- an animal with a dull expression in its eyes; and
- an animal that is acting very aggressively.
Animals that behave in an abnormal way should be segregated at the time of ante mortem examination. Special attention should be taken so the animal will not be a danger to other animals or to humans.
Abnormalities in gait
When an animal has an abnormal gait or is reluctant to move, it usually indicates that there is pain somewhere. The animal may be suffering from abnormalities anywhere it its legs or may have pain in the chest or abdomen. It may also indicate nervous disorders.
Abnormalities in posture
An animal with abnormal posture:
- may stand with the abdomen tucked in;
- may lie with its head turned and along its side;
- may stand with its feet stretched out in front;
- may stand with its head and neck extended; and
- may be unable to rise.
These are examples of abnormal posture. With experience you will soon learn the normal posture of an animal. Sometimes normal animals may temporarily assume posture that may be mistaken for abnormal postures e.g. a cow that has rested a long time may stretch and stand with its legs out front as in some disease conditions; also, resting cattle sometimes have their head turned along their side. In normal animals this posture disappears when the animal is stimulated.
The most frequently observed abnormal posture is of course the "downer". "Downers" are any animals that cannot stand or can only stand for short periods. Such animals must be handled without causing undue suffering and are usually segregated on initial ante mortem examination. If they cannot be segregated, operations should cease so that they may be dealt with. After veterinary inspection "downers" must be stunned in the yard if moving them causes undue pain and sent directly to the appropriate bleeding area.
Abnormal discharges or protrusions from body openings
The normal animal has no discharges or protrusions from its body openings. Examples of abnormal discharges or protrusions from the body are:
- discharge from the nose;
- bloody diarrhea;
- excessive saliva coming out of the mouth;
- afterbirth hanging out of the vulva;
- calf leg protruding from vulva;
- intestine protruding from rectum;
- uterus protruding from vulva; and
- growth protruding from eye.
Abnormal colour is generally not as important as the other abnormalities; however, you must be on the lookout for this. Examples are:
- black areas on the skin of swine;
- red areas in light coloured skin (inflammation);
- dark blue areas e.g. gangrenous udder; and
- yellow coloration of the sclera of the eye or skin (jaundice).
Abnormalities in appearance (conformation)
You will see many of these. Whenever there is a change in the normal conformation of an animal, a disease process should be suspected. Examples are:
- swelling of the skin (abscesses);
- enlarged joints;
- swelling of the umbilicus;
- udder greatly enlarged;
- abdomen bloated;
- swollen legs;
- enlarged jaws ("lumpy jaw");
- lower abdomen pendulous (hanging down); and
- swelling of subcutaneous lymph nodes.
In some instances it is helpful to compare both sides of the animal to find discrepancies. Any animal affected with the above abnormalities or other abnormalities of conformation should be segregated for veterinary inspection.
This is often difficult to detect on ante mortem. Examples of odours found at ante mortem examination are stinkweed, medicinal or punctured abscess odours. Your duty will be to hold the animals for veterinary inspection anytime you suspect an animal is affected with an abnormal odour.
What should you do when you see an abnormality?
In the event that you are confronted with an animal showing one or more of these abnormalities you should:
- segregate the animal; and
- inform the veterinarian on duty.
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