How to Manage Rhinitis and Pneumonia in Pigs

Enzootic Pneumonia Disease in Pigs

Enzootic pneumonia disease in pigs is a highly contagious disease manifested clinically by pneumonia of moderate severity and failure to grow at a normal rate.

Causes of Enzootic Pneumonia of Pigs

Mycoplasma hyopneumoniae is the causative agent of the disease. It is host-specific and can only survive in the environment for a short period. The extent of lesions produced is influenced by other contributing factors, such as lungworm infestations and migrating ascarids.

In many cases, Atrophic Rhinitis is present alongside Enzootic Pneumonia, and the two diseases have a greater economic impact than either one alone.

This parasite can synergistically interact with other infecting agents, resulting in significant respiratory disease.

Transmission of Enzootic Pneumonia in Pigs

The transmission of Mycoplasma hyopneumoniae occurs through direct nose-to-nose contact with infected pigs. It can be passed from sow to piglet, and it usually affects grower and finisher pigs.

This disease has a high incidence in intensive pig-rearing operations and is primarily transmitted through pig-to-pig contact.

Airborne transmission has also been documented.

Epidemiology

The highest incidence occurs during the post-weaning and growing period. Management and environmental conditions can greatly influence the severity of the disease.

Pigs kept at high stock densities and subjected to environmental temperature fluctuations and poor nutrition are more susceptible to the adverse effects of the disease.

Morbidity is high, but mortality is low, which has a significant economic impact on pig rearing by reducing feed conversion efficiency and hindering daily weight gain rates.

Clinical Signs of Enzootic Pneumonia in Pigs

A persistent dry cough, impaired growth, occasional flares of respiratory distress, and a high incidence of lung lesions are commonly observed in slaughtered pigs.

In rare cases, an acute form of the infection can lead to a severe outbreak in a susceptible stock when first introduced, causing 100% morbidity among all ages and lasting for about 3 months before subsiding to the more chronic form, which is more common in endemically infected herds.

Piglets are usually infected between the ages of 3 to 10 weeks, with clinical signs becoming more evident during the growing period.

The main manifestation of the disease is a hacking and dry cough, which is most pronounced in the mornings and at feeding time and is also elicited after exercise.

There is no fever, and appetite is usually unaffected.

The disease leads to retardation in growth, and some pigs with the chronic form may develop acute pneumonia due to secondary bacterial infections.

The disease is rarely detected in sow herds, and young sows usually carry the organism.

Postmortem Findings of Enzootic Pneumonia Disease in Pigs

Lesions are more common in the right lung and are slightly gray in color. They are scattered in certain lobes of the lung and are enlarged and oedematous, causing the affected tissue to become swollen. The bronchial lymph nodes are a characteristic feature.

Diagnosis of Enzootic Pneumonia in Pigs

1. It is the commonest respiratory infection in this species.
2. History- Clinical signs are seen in growing pigs, especially in the morning and at mealtime.
3. Postmortem- Lesions in the lungs are not pathognomic.
4. Identification of Mycoplasma hyopneumoniae is difficult.

Treatment of Enzootic Pneumonia Disease in Pigs

1. No effective treatment will eliminate it, but the severity of the clinical disease can be reduced.
2. Tetracyclines are given to the animals to prevent the disease.
3. Prophylactic treatment in stress conditions may be given in feed-tetracyclines, tylosin, or Spiramycin fed at 200mg/kg feed for 5-10 days.
4. Enzootic pneumonia can be treated using valnemulin, tiamulin, lincomycin, tylosin, and enrofloxacin or marbofloxacin. Tiamulin and valnemulin can eliminate M. hyopneumoniae from animals.

Control of Enzootic Pneumonia Disease in Pigs

The eradication of the most common diseases is mandatory for large breeding companies and herds that supply replacement stock to other herds.

Low-level disease control must be implemented to limit the effects of the disease in the herds. In this case, individual litters are reared separately, with a low stocking density of fewer than 25 pigs per pen, and stress should be avoided by purchasing pigs from disease-free herds.

Atrophic Rhinitis Disease in Pigs

Atrophic rhinitis disease primarily affects young pigs (piglets) but causes anatomical lesions that may persist for life. Atrophic rhinitis disease is characterized by acute rhinitis followed by chronic atrophy of the turbinate bones and facial deformity.

Causes of Atrophic Rhinitis Disease in Pigs

Atrophic rhinitis is caused by an infection with the toxigenic bacterium, Pasteurella multocida. It can also be caused by any early-life infection of the nostrils that results in persistent, severe inflammatory reactions.

Other bacteria of the genus Bordetella, as well as Corynebacterium pyogenes and Haemophilus species plurimae, have also been associated with the disease as secondary infections contributing to inflammatory rhinitis.

Transmission of Atrophic Rhinitis Disease in Pigs

The transmission of Atrophic Rhinitis in pigs occurs through the respiratory route. Carrier sows transmit the disease to their piglets. Poor management and husbandry practices can exacerbate the disease.

Outbreaks usually occur after the introduction of infected pigs or the mixing of pigs from various sources. The primary impact of the disease is on the growth rate.

Clinical Signs of Atrophic Rhinitis Disease in Pigs

Coughing, sneezing, and in severe cases, nasal bleeding and poor growth are common symptoms. Sneezing reduces the feed conversion ratio, and in acute cases, swelling of the nasal mucosa can obstruct breathing, resulting in a watery nasal discharge, sneezing, and rubbing of the nose against objects or the ground. This can lead to deformities in the face, caused by the arrested development of bones.

In pigs 8 to 10 weeks old, wrinkling of the skin may follow facial distortion. Piglets may experience retarded growth and unthriftiness.

Although appetite may not be affected, much food is lost through spillage. The post-mortem findings, in this case, are restricted to the nasal cavities.

Diagnosis of Atrophic Rhinitis Disease in Pigs

Sneezing in the early stages and facial deformity later are characteristics of the disease.

Treatment of Atrophic Rhinitis Disease in Pigs

Treatment is useful in the early stages, but it is of little value in chronically affected pigs due to persistent poor growth and high food conversion, so culling is the best solution.

Treat with Tylosin (20mg/kg), oxytetracycline (20mg/kg), or sulphadoxine (40mg/200mg per ml) at 0.1ml/kg, either parenterally or in feed. Give three injections.

Control of Atrophic Rhinitis Disease in Pigs

Use of bacterin-toxoid mixtures. Bacterins against toxigenic P. multocida and B. bronchiseptica have been developed.

Prophylactic treatment decreases the severity and adverse effects of the disease.

Worm Infestation in Pigs

These worms include: Metastrongylus, Oesophagostomum, Ancylostoma, and the Kidney worm, among others.

Parasitism in pigs. Pigs are mostly affected by ectoparasites such as Sarcoptic mange, lice infestation, and Haematopinus.

As mentioned, these diseases are not caused by bacteria or viruses but may be caused by nutritional deficiencies or inherited factors that can occur independently and frequently as a result of other diseases. For example, Agalactia (lack of milk) may occur due to repeated cases of mastitis on the farm.

a) Piglet Anemia

Piglet anemia is a common cause of pre-weaning losses among housed pigs. It results from a direct lack of iron when penned sows are not allowed to forage and are not given iron supplements.

Iron deficiency is aggravated by cold and damp conditions. Copper and cobalt deficiency may also occur.

Clinical Signs of Piglet Anemia

The condition is commonly called “thumps” because of the labored, spasmodic breathing seen in affected piglets.

Anemic piglets look pale and accumulate fluid around the throat, brisket, and internal body spaces. Scouring (diarrhea) is common, and resistance to other conditions and diseases is weaker.

Pale, whitish skin, the parlor of the mucous membrane, anemic.

Piglets are unthrifty, anorexic, and death may occur.

The growth rate is slow; piglets may not grow at all.

 Postmortem Findings For The Case of Piglet Anemia

Paleness-all tissues are anemic.

Heart greatly dilated, with excess pericardial fluid.

Oedema of the lungs.

Why do Piglets Usually Show More Profound Anemic Effects Than Other Species?

Piglets grow extremely rapidly. Of other species, they can reach 5 times their birth weight in 3 weeks and 10 times their birth weight in 8 weeks (so increased nutrient requirement or sow's milk) is paramount because it may not be sufficient to cope with the demand, and they do not have a very high reserve of iron in their tissues at birth.

Placental transfer of iron from the sow to offspring is very poor, though the sow may be getting a high intake of iron during pregnancy.

Treatment And Control of Piglet Anemia

The easiest method is to give the piglet an injection of 150- 200mg of iron dextran in either a 1 or 2ml dose. Iron is best given from 3 to 5 days of age and not at birth.

A 2ml dose at birth causes considerable trauma to the muscles. The sites of injection are either into the muscles of the hind leg or into the neck.

b) Mastitis And Agalactia (Lack of Milk)

1. These are difficult to control.
2. They cause starvation of piglets.
3. Agalactia is influenced by an inherited factor, but it may also occur independently but it frequently results from mastitis.
4. It is manifested by the failure of the sow to produce milk.
5. The multiple bacterial agents causing mastitis may enter the teats as a result of bites from the piglet's teeth.
6. Dirty and damp furrowing pens provide a favorable environment for infection of injured teeth or mammary glands.
7. If mastitis is acute, the udder is swollen, congested, hot, and painful.
8. Sows may not allow piglets to suckle even from normal (healthy) glands if 1 or 3 glands are suffering from mastitis.
9. If chronic glands are swollen to firm, cold, and painless, there is the production of little milk, which is mainly watery and sometimes contains clots.
10. In some cases, problems of agalactia may arise from nonspecific causes.
11. Environmental factors, for example, poor nutrition, high ambient temperatures, and poor genetic makeup, such as inherent - inject oxytocin in prolactin, such sows should be culled after weaning their piglets.

Treatment of Mastitis And Agalactia (Lack of Milk) in Pigs

Antibiotic infusion into the udder and external application of a hot compress and mild antiseptics help to relieve the condition. Penicillin and streptomycin can also be used.

Agalactia is treated by the injection of oxytocin to release retained milk.

Conclusion

In conclusion, enzootic pneumonia disease in pigs, caused by Mycoplasma hyopneumoniae, is a highly contagious and economically impactful respiratory disease. Its transmission primarily occurs through direct pig-to-pig contact and airborne transmission. The disease leads to clinical signs such as a persistent dry cough, impaired growth, and lung lesions.

While there is no effective treatment for eliminating the disease, its severity can be reduced through the use of antibiotics. Implementing low-level disease control measures, such as rearing individual litters separately and avoiding stress, can help limit the effects of enzootic pneumonia.

Atrophic rhinitis disease, characterized by acute rhinitis followed by chronic atrophy of the turbinate bones and facial deformity, primarily affects young pigs. It is caused by an infection with Pasteurella multocida and can result in symptoms like coughing, sneezing, and poor growth. Treatment is most effective in the early stages, and culling chronically affected pigs is often the best solution. Prophylactic measures, including the use of bacterin-toxoid mixtures, can help decrease the severity and adverse effects of atrophic rhinitis.

Parasitic infestations and other conditions like piglet anemia and mastitis with agalactia also pose challenges in pig farming. Piglet anemia, resulting from iron deficiency, can be treated through iron supplementation. Mastitis and agalactia can cause starvation of piglets and are influenced by factors like bacterial infections and environmental conditions. Treatment options include antibiotic infusion, hot compress, and oxytocin administration.