Other Common Ills; Molds, Chemicals

By James McKean.

Agalactia

A common disease of swine is the MMA (Mastitis, Metritis, Agalactia) syndrome. This problem generally occurs at or several days after farrowing. Incidence of reduced milk flow (hypogalactia) or complete milk stoppage (agalactia) will vary between herds and between farrowing within herds.

Agalactia may be a primary disease or be secondary to a disease or environmental problem. Clinical signs in sows include depression, reluctance to eat or drink, high temperature, rapid breathing, and reluctance to move around or allow pigs to nurse. Affected pigs are hungry, weak, and appear restless. The entire udder or individual glands may be affected. Affected glands are usually warmer, firmer and more sensitive than normal glands.

There is no specific cause for agalactia or hypogalactia. Bacterial endotoxins, hot environmental temperatures, constipation, poor sanitation, weak nursing action by sick pigs, hormonal imbalances, genetic predisposition, secondary effects of other infectious diseases, and management techniques contribute to MMA signs. Because of this diversity of causes, no treatment is uniformly successful.

Oxytoxin should be administered at 2 to 4 hour intervals to stimulate milk letdown and "milk out" diseased fluid. An injectable antibiotic and possibly anti-inflammatory drug should be administered to the affected sow. Milk replacer should be offered to pigs to supplement milk received from the mother.

Prevention must be based on determining the cause on each farm. Careful investigation by the producer and attending veterinarian should yield indications for preventive actions. Ration or feeding changes may be needed to reduce sow constipation. Laxative feedstuffs or additions of chemical laxatives to lactation feedstuffs may be beneficial. Temperatures above 80 to 85 F where the sow lays will reduce milk flow. Clean, dry farrowing crates or pens will result in less mastitis.

E. coli, Streptococcus, Staphylococcus sp. and, occasionally, Klebsiella are bacteria commonly found in affected glands. Very few cases of agalactia are the result of uterine infections (metritis). Routine use of uterine douches or infusions, intrauterine pills or boluses should be resisted unless a herd metritis problem is diagnosed by the attending veterinarian.

Some herds have a higher resistance to MMA than others. Whether this resistance is due to a genetic strength or to the absence of an immune-suppressing bacteria or virus is unknown.

Strep Infections

Streptococcus organisms are identified in several swine diseases. Besides their activity in the MMA syndrome, Streptococcus sp. have been associated with arthritis, jowl abscesses, meningitis, and pneumonia.

Streptococcus arthritis is discussed later, in the chapter dealing with lameness.

Jowl absesses and puncture wound abscesses were once a major swine disease problem. With confinement rearing and better sanitation, these problems have been reduced greatly. But because pus from a swollen jowl abscess can contaminate feeders and waterers and infect normal swine, strict equipment sanitation and infected animal segregation must be practiced. The strep organisms can survive on the tonsils for long periods before producing abscesses.

Until recently, meningitis was an uncommon effect of strep infections. In the past 3 to 4 years, however, a strain of streptococcus Strep suis Type II has been identified in an increasing number of swine meningitis cases. Incidence of this disease has been predominantly in confinement situations, although a few outbreaks have been found in open air systems.

Clinical signs are sudden onset of depression, convulsions, involuntary paddling, coma and death. Pigs from 3 to 12 weeks are affected most commonly. They generally have just been through a stressful situation such as movement, weaning, commingling, overcrowding or poor sanitation conditions.

Most pigs in a group are infected but only a few develop meningitis. Without prompt treatment, mortality will approach 100 percent. The organism is probably spread by "aerosol" transmission (via breathing, coughing, sneezing) and spreads very rapidly.

Treatment consists of injecting large doses of effective antibiotics. All animals in an affected group should be treated initially. Treatment of pigs already exhibiting meningitis signs is generally not successful.

In herds with a persistent problem, medication and vaccine usage may be required for prevention. Reduction of stresses will help reduce incidence of the problem.

Pseudorabies or PRV

Pseudorabies (Aujeszky's Disease, Mad Itch, Herpes suis, PRV) is a herpes virus infection of swine and other mammals. Pseudorabies is completely different from rabies, but derived its name pseudo (false) rabies because of signs of mouth frothing, teeth grinding, changes in temperament, a choke-like spasm of the esophagus and other signs which may be seen with both diseases.

Swine are the reservoir host for this virus and may exhibit mild to severe signs when infected. All other mammals, except humans and horses, are susceptible to the virus.

In almost all cases of non-swine disease, death occurs soon after signs appear. Sheep, dogs and cats are the domestic animals most easily infected by PRV. Cattle are less readily infected. Raccoons, skunks and opossum are easily infected wildlife.

Swine pseudorabies may show mild signs of appetite suppression, fever and general reluctance to move for 3 to 4 days; or have more severe signs with abortions, high rates of stillbirths, weak pigs at birth, rhinitis and pneumonia in sows. Shaking, convulsions, coma and death are clinical signs in young pigs.

Generally, severity of death loss is age-related. Pigs under 4 weeks of age are most susceptible. Young pigs are more likely to be affected with convulsions and other central nervous signs, while older pigs may develop respiratory disease.

Recovered swine are the primary host and the most common method of spread to new farms. Aerosol transmission is the primary route of infection. Consumption of internal organs from infected wildlife by swine may lead to infection. Non-swine carriers can mechanically carry virus-containing material from farm to farm locally.

Regulations controlling swine movement between States have helped keep the number of PRV infected herds from rising, since swine must test negative or originate from negative-tested herds before being allowed to move interstate.