pathological disease processes to help in the early detection of disease in farm animals. A study in Spain (Guiterrez et al., 2012) discovered potential salivary markers for systemic disease in pigs. Saliva samples can be obtained by allowing the pig to chew on a sponge for 2 min. Serological results can show positive results for PRRS, swine influenza virus (SIV) and porcine circovirus type 2 (PCV-2).
Fig. 3.1. The pigs need to be kept out of their house to examine them.
Table 3.1. Reference levels for the clinical examination of pigs.
| Parameter | Values |
| Body temperature | Lower critical point, 38.4°C; normal, 39°C; upper critical point, 40°C |
| Pulse | 70–80 beats/min, rising to 250 beats/min in the newborn piglet |
| Respiration rate | Adults, 10–20 breaths/min; growers, 20–30 breaths/min; newborns, 40–50 breaths/min |
Table 3.2. Normal haematological parameters in pigs.
| Parameter | Normal range |
| Packed cell volume (PCV) | 37–46% |
| Red blood cells (RBCs) | 6.5–8.0 ×1012/l |
| White blood cells (WBCs) | 10.0–23.0 × 109/l |
| Platelets | 250–700 × 109/l |
| Haemoglobin (Hb) | 11.0–14.2 g/dl |
Urine samples
Obtaining urine samples requires considerable patience by the pig keeper. If required by the practitioner, catheterization of sows restrained in a crate is not difficult with a canine oesophageal tube. It is impossible to catheterize male pigs and so practitioners have to rely on a free-flowing sample. Normal urine parameters are as follows:
• Specific gravity (SG), 1.020.
• pH, 5.5–7.5.
• Protein and sugar, none.
Bacteriological examination of the urine can also be useful. Care needs to be exercised as certain bacteria will be grown as contaminates. The clinician will have to evaluate the bacteriological findings in the light of the clinical signs to decide from where in the urinary tract the bacteria originate.
Diagnostic Imaging
Radiography
Ten years ago radiography would not have featured in a book on pig surgery. That is not the case today, when we regularly radiograph pigs’ legs. Good restraint and normally a general anaesthetic (GA) are required (Fig. 3.2). Radiographs are useful for: fractures, arthritic joints, sand cracks and septic joints. Obviously this is not in a commercial situation, but radiographs are very useful to aid not only in making a diagnosis but also in making a prognosis. The author finds the procedure extremely useful when dealing with rescued pigs in sanctuaries so that unnecessary suffering is avoided.
Head radiographs are useful for diagnosis of cheek teeth disorders. The author expects radiographs in pigs to be used more frequently in the future, particularly for pet pigs.
Ultrasonography
As yet ultrasonography has had limited use in pigs. With the advent of much loved pet pigs this may change. At the present time its use is restricted to pregnancy diagnosis and for visualization of stones lodged in the small intestine.
Table 3.3. Normal biochemical parameters in pigs.
Fig. 3.2. Adult sow under general anaesthetic restrained for radiography.
Post-mortem Examination
Equipment required
These articles are not normally carried by an ambulatory clinician:
• Large plastic bucket with disinfectant, warm water, soap and towel.
• Butcher’s knife and flaying knife.
• Scalpel and blades that fit.
• Rat-toothed forceps (15 cm).
• Fine forceps (15 cm).
• Blunt-nosed straight scissors (20 cm).
• Bowel scissors.
• Bone cutters, saw and hedge loppers.
Post-mortem sampling materials required:
• Plastic trays (50 cm × 30 cm × 5 cm).
• Plastic bags of various sizes.
• Sterile universal bottles.
• Plastic jars (1 l).
• Bottles of formalin (kept separate).
• Pots containing 50% w/w glycerol for virus isolation.
• Swabs (plain, transport media and specialized media for respiratory pathogens).
• Pasteur pipettes and rubber suckers.
• Clipboard.
• Post-mortem report form, laboratory submission form.
Specific history required for post-mortem carcasses
The clinician needs to know if the pig was found dead or whether euthanasia was performed. It is useful to know how euthanasia was performed as shooting will damage the central nervous system (CNS) and lethal injections, if given into the heart, will damage the thorax. The length of time since death should be ascertained and how the body was managed in that time, i.e. fresh, chilled or frozen. The age, breed and weight should be recorded.
Before post-mortem the outside of the pig should be examined
The general appearance and colour should be noted. Careful examination should be made for the presence of ectoparasites, mainly lice and crusts relating to mange. Lice will often leave a dead pig, so their absence does not mean they were not present in life. Any crusts should be retained and can be supplemented with deep skin scrapings and even punch biopsies to help get a diagnosis.
At the start the head should be examined; is the snout twisted? Is there ocular discharge? Then the body; are there udder swellings? Is the prepuce normal? Are the feet and coronary band normal? Is the rectum/vulva normal?