Causes of Parasitic Diseases That Make Pigs Vomit and Their Prevention and Control Measures
What are the causes of parasitic diseases that make pigs vomit? How should they be prevented and controlled?
Porcine stomach worm disease
It is a nematode disease caused by round ascarid nematodes of the genus Ascarops in the family Spiruridae, order Spirurida (the spiny spirurid stomach worm, Ascarops dentata), Hexametra species of the genus Hexametra, Simondsia paradoxa of the genus Simondsia, and Gnathostoma hispidum and Gnathostoma doloresi (pathogenic Gnathostoma) of the genus Gnathostoma, family Gnathostomatidae, parasitizing the pig stomach. This disease occurs in endemic form.
When stomach nematodes are present in small numbers, the affected pigs show no obvious symptoms. When heavily parasitized by stomach nematodes, affected pigs, especially young pigs, develop inflammation of the gastric mucosa, reduced appetite, increased thirst, abdominal pain, vomiting, emaciation, and anemia, with symptoms of acute and chronic gastritis, listlessness, nutritional disorders, and stunted growth, and feces become black or mixed with blood.
Porcine toxoplasmosis
Also known as toxoplasmosis, it is a zoonotic protozoan disease caused by Toxoplasma. In the early stage, the body temperature of affected pigs rises to 40°C-42°C and persists for 7-10 days, with listlessness and poor appetite, dry feces with mucus, and diarrhea in weaned piglets. Afterwards, affected pigs show abdominal or dog-sitting breathing, coughing, vomiting, and a small amount of nasal discharge. The superficial lymph nodes, especially the inguinal lymph nodes, are obviously enlarged. In the terminal stage, petechial spots appear on the ears, nose, and lower parts of the body, and finally the pigs lie down and cannot rise, with body temperature dropping sharply, leading to death. Affected pregnant sows abort or give birth to stillborn fetuses.
Porcine strongyloidiasis
It is caused by Strongyloides ransomi parasitizing the small intestine of piglets. This disease is most harmful to piglets, especially those aged 3-4 weeks. It occurs frequently in warm and rainy seasons and is one of the causes of diarrhea in piglets.
Affected pigs vomit, suffer from enteritis and diarrhea, and then become emaciated. When larvae cause infection through the skin, they often cause eczema. When they enter the lungs, they cause bronchitis and pneumonia, and the body temperature of affected pigs rises; if they migrate to the myocardium, brain, and spinal cord, affected pigs may die acutely, and in severe cases, affected pigs die from extreme weakness.
It is recommended to breed and raise pigs on your own
It is recommended thatpig farmsbreed and raise pigs on their own. If pigs are introduced from other places or farms, an all-in-all-out raising method should be adopted to prevent the introduction of parasites. When pigs really need to be purchased, they should be bought from areas free of the disease, and quarantine certificates should be checked before purchase. Purchased pigs should be raised in isolation for more than 2 weeks, and their feces should be examined to determine whether they are parasitized by parasites. If disease is found, deworming should be carried out 1-2 times and re-examination should be done. Only after comprehensive testing confirms that they are disease-free can they be transferred to the production area.
Formulateprevention and controlplans
Pig farmsshould, under the guidance of veterinarians, formulate parasiticdiseaseprevention and control procedures according to the epidemic situation and patterns of parasitic diseases in the local area or the farm, the farm's disease history, and the pig breed, age, and feeding management conditions. Twice a year, at appropriate times, deworming can be carried out on locally raised pigs.prevention and controlprocedures. Twice a year, at appropriate times, deworming can be carried out on locally raised pigs.Parasitic diseaseprevention and controlwork should be carried out regularly and institutionalized. Large-scalepig farmsshould do a good job of parasite monitoring before deworming, and use the monitoring results as the basis for deworming.
Eliminate intermediate hosts
Eliminating intermediate hosts and cutting off transmission vectors are effective measures to prevent the spread ofparasitic diseases. Many parasites that pigs are susceptible to (such as trematodes, tapeworms, acanthocephalans, and some nematodes) require the participation of intermediate hosts and transmission vectors during their development. Chemical drugs or biological methods (cultivating natural enemies of intermediate hosts, such as raising ducks and fish) can eliminate intermediate hosts and cut off transmission vectors.Pig farms(households) are prohibited from raising cats, dogs, and other pets and should regularly do a good job of rodent control, mosquito control, fly control, cockroach control, and insect control to reduce the chance ofparasitic diseaseoccurrence.
Environmental disinfection
The clothing and tools of keepers should be disinfected by heating; pens and transport vehicles can be spray-disinfected with fenvalerate, amitraz, monoamitraz, moxidectin, etc. Immature eggs have weak resistance to dry and high-temperature environments, so pig houses should use concrete pen surfaces, and the pens should preferably face the sun.
Immunization
Use newtechnologiesand new achievements to preventparasitic diseasesin pigs, such as porcine Toxoplasma vaccine, which can make pigs develop immunity through artificial inoculation, thereby achieving the purpose of immunoprevention of porcine toxoplasmosis.
Do a good job of regular testing
Large-scale pig farms should regularly test pigs forparasitic diseases, and keepers should also undergo regular testing or health examinations to monitor the infection status of parasites in pig herds at different stages and in different periods.
Scientific deworming
The following key points should be mastered in deworming:
First: fasting before deworming. To facilitate the absorption of deworming drugs by pigs, pigs should fast for 12-18 hours before deworming;
Second: choose deworming drugs that are highly effective, broad-spectrum, low-toxicity, palatable, convenient to administer, residue-free, and not prone to drug resistance, such as ivermectin, avermectin, deworming powder, albendazole, and levamisole. Attention should be paid to the dosage, which should not be excessive or insufficient;
Third: continuous medication. To improve the deworming effect, deworming drugs need to be used 2-3 times in succession. For some external parasites, such as sarcoptic mange mites, deworming drugs can only kill the adult mites but cannot kill the eggs. The correct medication method is to administer the drug once after the first deworming, then again after an interval of 1 week, to prevent recurrence of the disease;
Fourth: deworming should be carried out in a place with isolation conditions so that the excrement of affected pigs can be cleaned up;
Fifth: pay attention to the timing of deworming. Generally, deworming should be carried out before the worms reach sexual maturity to prevent sexually mature adults from discharging eggs and larvae. Deworming should be carried out in autumn and winter, which is conducive to the safe wintering of livestock and poultry. Autumn and winter are relatively cold, which is not conducive to the survival and development of most eggs or larvae and can reduce contamination;
Sixth: before large-scale deworming, conduct a small-group experiment first, and after gaining experience, confirming the drug efficacy, and ensuring safety, carry out whole-herd deworming;
Seventh: pay attention to observing the deworming effect. After administration, observe the reaction of the pig herd. If poisoning occurs, such as vomiting and diarrhea, corresponding measures should be taken immediately;
Eighth: strictly implement the withdrawal period regulations to prevent drug residues. Generally speaking, drugs should not be used for deworming within three weeks before slaughter.