A binocular compound microscope could help diagnose an animal disease. Microscopes, such as a binocular compound microscope, magnify a specimen and helps in the identification of a pathogenic microorganism. A binocular compound microscope has two eyepieces for the user to use. This would also aid in reducing eyestrain when using the binocular compound microscope.

Erysipelas in pigs is not ordinarily difficult to diagnose because of the characteristic clinical and necropsy findings. The acute disease may be confused with the other septicemias affecting pigs, but pigs with erysipelas usually show the characteristic skin lesions and are less depressed than pigs with-hog cholera or salmonellosis. In salmonellosis there is usually gross skin discoloration, some evidence of enteritis, and respiratory difficulty. In both hog cholera and salmon¬ellosis signs of cerebral involvement including muscle tremor and convulsions are also common.

The chronic disease occurs in pigs of all ages but less commonly in adults. Streptococcal septicemia and arthritis is almost entirely confined to sucking pigs in the first few weeks of life. Streptococcal endocarditis has a similar age distribution to erysipelas endocarditis and bacteriological examination using a binocular compound microscope is necessary to differentiate them. Glasser’s disease in pigs is accompanied by a severe painful dyspnea and at necropsy there is serositis and meningitis. Myco¬plasma hyosynoviae, a pathogenic bacterium, generally affects pigs less than 10 weeks of age and produces a polyserositis as well as polyarthritis. However, Myco¬plasma hyosynoviae, another bacterium that can be viewed under a binocular compound microscope, can produce simple polyarthritis in growing pigs. In general the periarticular, synovial and cartilaginous changes are less severe in these infections when compared to erysipelas; however, cultural dif¬ferentiation is frequently necessary. Rickets and chronic zinc poisoning produce lameness in pigs but they occur under special circumstances, are not associated with fever, and rickets is accompanied by ab¬normalities of posture and gait which are not seen in erysipelas. The swelling of the hoof and the development of discharging sinuses at the coronet easily differentiate foot rot of pigs.

In recent years there has been a marked increase in chronic osteoarthritis and various forms of ‘leg weakness’ in growing swine, probably related to the increased growth rate resulting from modern feeding and management practices. In many instances differentiation from erysipelas can be accomplished only by bacteriological methods with the use of a binocular compound microscope.

Treatment

Penicillin and anti-erysipelas serum comprise the standard treatment, often administered together by dis¬solving the penicillin in the serum. Penicillin alone is usually adequate when the strain has only mild virulence. Standard dose rates give a good response in the field but experimental studies suggest that 50,000 units/kg BW of procaine penicillin for 3 days are required for complete chemotherapeutic effect. Chronic cases do not respond well to either treatment because of the structural damage, which occurs to the joints and the inaccessibility of the organism in the endocardial lesions. Cortisone administered subcutaneously produces marked Clinical improvement of the arthritis without complete recovery but adrenocorticotrophic hormones appear to be of no therapeutic value

Control

Eradication is virtually impossible because of the ubiquitous nature of the organism and its resistance to adverse environmental conditions. Complete removal of all pigs and leaving the pens unstocked is seldom satisfactory and eradication by slaughter of reactors to the agglutination test is not recommended because of the uncertain status of the test.
General hygienic precautions should be adopted.

Clinically affected animals should be disposed of quickly and all introductions isolated and examined for signs of arthritis and endocarditis. This procedure will not prevent the introduction of clinically normal carrier animals. All animals dying of the disease should be properly incinerated to avoid contamination of the environment. Although thorough cleaning of the pre¬mises and the use of very strong disinfectant solutions are advisable, these measures are unlikely to be com¬pletely effective. Whenever practicable contaminated feedlots or paddocks should be cultivated.

Immunization

Because of the difficulty of eradication biological prophylactic methods are in common uses. Immunizing agents available include hyperimmune serum and vaccines.

Anti-erysipelas serum.

The parenteral administration of 5-20 ml of serum, the amount depending on age, will protect in-contact pigs for 1-2 weeks during an out¬break. Sucking pigs in herds where the disease is enzootic should receive 10 ml during the first week of life and at monthly intervals until they are actively vaccinated which can be done as early as 6 weeks provided the sows have not been vaccinated. Repeated administration of the serum may cause anaphylaxis because of its equine origin.

Vaccination

There is no fully satisfactory vaccine avail¬able for erysipelas. Serum-simultaneous vaccination has been largely replaced by the use of bacterins, for which lysate and absorbate preparations are available, or by the use of attenuated or avirulent live-culture vaccines that are administered orally or by injection. The use of live-culture vaccines is prohibited in many countries due to the risk of variation in virulence of the strains used and the possibility of spreading infection.

None of these vaccines gives life-long protection from a single vaccination and the actual duration of protec¬tion achieved following vaccination varies considerably. There is considerable difficulty in the experimental evaluation of the efficacy of erysipelas vaccines. Strain differences in immunogenicity, and variation in host response to vaccination due to innate and acquired factors influence this evaluation, as does variation in virulence of the challenge strain and the method of challenge. Similar factors are involved in the variations seen in field response to the use of these vaccines. Passively acquired maternal immunity may significantly affect the immune response to vaccination in the young piglet. Also the immunity engendered by standard vaccines is not uniformly effective against all strains. Nevertheless, these vaccines are valuable immunizing agents in field situations.

Following a single vaccination at 6 to 10 weeks of age significant protection is provided to market age. How¬ever a second ‘booster’ vaccination given 2-4 weeks later is advisable. In herds where sows are routinely vaccinated prior to farrowing, a persisting maternal passive immunity may require that piglet vaccination be delayed until 10-12 weeks of age for an effective active immunity.

It is also advisable to vaccinate replacement gilts and adults in the herd. Bacterins are effective, and field evidence suggests that vaccination provides immunity for approximately 6 months. Sows should be vaccinated twice yearly, preferably 3-6 weeks before farrowing, as this will also provide significant protection against the septicaemic form in young sucklers. If possible a closed herd should be maintained.

Vaccination is subcutaneous in the skin behind the ear, or the axilla and the flank. Reactions at the site of injection are not uncommon. Swelling with subsequent nodule formation and occasional abscessation may occur following the injection of bacterins, and modified live vaccines may produce hemorrhage in the skin at the injection site. There is little evidence that vaccination increases the incidence of arthritis. Read more on this subject