Association of age of ram with distribution of epididymal lesions and etiologic agent

A 2-year study of the frequency of isolation of various organisms from mature and yearling rams with epididymitis was conducted at the US Sheep Experiment Station at Dubois, Idaho. Investigation into the distribution of lesions in the epididymis in relation to age of the ram also was studied. Serologic or bacteriologic evidence of Brucella ovis infection was demonstrated in 79.5% of the mature rams with epididymal lesions. Actinobacillus seminis and Histophilus ovis were the 2 most frequently isolated organisms from yearling rams with lesions. The tail(s) of the epididymis was the most frequent site of lesion development in the mature rams (86.4%). Yearling rams developed lesions twice as frequently in the tail(s) of the epididymis as in the head(s) of the epididymis. When lesions were localized in the head(s) of the epididymis, an etiologic agent usually was not demonstrated.

Ovine brucellosis: repeated vaccination with Rev 1 vaccine and the prevalence of the disease in the Winburg district

The effect of repeated vaccination of ram lambs with Brucella melitensis Rev 1 vaccine was studied in relation to complement fixation titres. The presence of Brucella organisms in semen and changes in neutrophil densities of the semen were also studied. A survey of the incidence of ovine brucellosis in the Winburg district on the basis of a clinical examination of rams and the complement fixation test is also reported on. Repeated vaccination of ram lambs with Rev 1 vaccine resulted in high complement fixation titres for Brucella abortus in all cases and slight Brucella ovis titres in some cases. Neither Brucella organisms, nor increased numbers of neutrophils could be found in semen samples collected from the experimental animals. The incidence of ovine brucellosis in commercial and stud flocks in the Winburg district was in the order of 2%. As a fairly high incidence of brucellosis occurred in 2 stud Döhne merino flocks where ram lambs are vaccinated with Rev 1 at weaning, the administration thereof in this breed should take place at an earlier age. A second dosage at weaning should not have any disadvantageous effects. In order to protect newly vaccinated ram lambs from contracting brucellosis from older, infected cases, the separation of age groups is essential. The incidence of clinically detectable testicular lesions in rams from the Winburg district was in the order of 2%.

Post mortem studies on infertile buffalo bulls: anatomical and microbiological findings

Twenty-two buffalo bulls suffering from three different types of infertility were slaughtered and used for this study. Except for the reproductive system, no signs of localised or generalised disease were observed. Microbiological investigations were negative for brucellosis, vibriosis, mycoplasma and other non-specific microorganisms. Nine bulls with type 1 infertility had low bodyweights and underdevelopment of testes, accessory sex glands and endocrine glands. This picture suggests a total dysfunction of the pituitary-growth-gonadal axis. One bull of this type also showed bilateral epididymitis. Four out of 11 bulls with type 2 infertility had low bodyweights and most suffered from underdevelopment of testes, accessory sex glands and endocrine glands. Six bulls of this type had lesions of either epididymitis or orchitis or both. Two of these animals showed adhesions of periorchitis. One also showed seminal vesiculitis. In two bulls with type 3 infertility, bodyweights, reproductive organs and endocrine glands were normal. In later life, they yielded poor quality semen. Semen samples collected a few months before slaughter from nine bulls with type 2 and type 3 infertility were of poor quality and had higher percentages of abnormal spermatozoa in most cases.

Use of enzyme-linked immunosorbent assay for detection of antibodies to Brucella ovis in sheep: field trial

An enzyme-linked immunosorbent assay (ELISA), using an autoclave-extracted soluble antigen, for the detection of serum antibodies to Brucella ovis in sheep was developed. The test seemed to be both sensitive and specific, on the basis of the control groups studied. The antigen showed no deterioration in prepared plates stored at -70 C for up to a year. The ELISA was used in conjunction with palpation of rams for epididymal lesions as a means to detect and control B ovis infection in a naturally infected flock. All rams were evaluated by the ELISA. At the time that the first blood sample was obtained, all positive and suspicious reactors were removed. With subsequent blood sample collections, only the positive reactors were removed. Brucella ovis was not isolated from any rams during the following year, and none of the mature breeding rams developed epididymal lesions.

Production and preliminary characterization of monoclonal antibodies to Actinobacillus sp isolated from epididymitis lesions in a ram

A panel of 55 monoclonal antibodies to an Actinobacillus sp isolate (As8C strain) cultured from the epididymides of an infected ram was produced. Cell lines producing 5 of these antibodies were cloned and expanded by hybridoma tumor production in Balb/c mice. An isotype profile revealed that 1 cloned antibody belonged to the immunoglobulin (Ig) M class and the 4 remaining antibodies belonged to the IgG class. Within the IgG class, 1 clone produced IgG1, 1 clone produced IgG2a, and 2 clones produced IgG2b. Ascites fluid antibody titers from the cloned hybridomas ranged from 6,400 to 51,200, as determined by enzyme-linked immunosorbent assay. Specificity of the antibodies to target As8C antigens could be demonstrated by enzyme-linked immunosorbent assay inhibition. Ascites fluid from 2 clones contained antibodies that agglutinated As8C. Two additional clones produced antibodies capable of only partial agglutination, whereas 1 clone produced antibody that did not agglutinate As8C. The indirect fluorescent antibody test revealed that target antigens for at least 4 of the 5 monoclonal antibodies were most likely located on the bacterial cell surface. Antigens were extracted from As8C, using 5 surface active chemicals. An attempt to immunoprecipitate these antigens in agarose by reacting individual extracts with each of the antibodies was unsuccessful.

Prevalence and causes of ram epididymitis in Utah

Palpation of the testicles and epididymides was used to determine the prevalence of ram epididymitis (RE) in Utah range flocks over a 5-year period. Of 62 range flocks examined, 58 had rams with palpable lesions. A comparison was made of prevalence by right vs left testicle involvement, but no significant difference was found. Culling all rams with palpable lesions from the flock progressively reduced the annual incidence, but did not eliminate RE from any flock. Semen and specimens of reproductive tract tissue were obtained from representative flocks for bacterial culture. Brucella ovis was found commonly in range flocks, but was not isolated from RE-affected rams in virgin, ram-producing flocks. In the ram-producing flocks, a gram-negative, pleomorphic rod-type organism was found. It was concluded that RE should be considered as 2 disease entities, based on the finding of 2 causative organisms and the management systems under which those organisms are found. Brucella ovis was the major cause in persistently infected range flocks, whereas the gram-negative pleomorphic rod-type organism is the apparent cause of RE in virgin, ram-producing flocks.

The acquisition of immunity to Histophilus ovis by sheep in nature

It was demonstrated that skin wound infection with Histophilus ovis elicits an immune response which can protect a ram against a challenge injection of the same organism into its epididymis.

Epididymitis of rams in the central and southern districts of the Orange Free State

Scrotal palpation, microscopical examination of semen smears and the application of bacteriological techniques, revealed the incidence of Actinobacillus seminis and Brucella ovis infection of rams in the central and southern districts of the Orange Free State to be 2,9% and 4,3%, respectively. More Dorper than Merino rams were affected. Although clinically detectable epididymitis was found in 5,9% of rams examined, infection with A. seminis and B. ovis, as measured by the presence of neutrophils in semen and positive semen cultures, could only be demonstrated in a small minority of affected cases. These organisms were found more regularly in clinically negative rams excreting neutrophils in their semen. Possible reasons for the high incidence of sheep brucellosis in rams in the particular area as well as the higher incidence of infection in Dorper rams are discussed.

Characterization of Brucella ovis lipopolysaccharide and its use for diagnosis of ram epididymitis by enzyme-linked immunosorbent assay

Rough lipopolysaccharide, extracted by a mixture of phenol, chloroform, and petroleum ether from freeze-dried Brucella ovis cells with a yield of 0.71%, contained relatively small amounts of protein and nucleic acid contaminants as compared with lipopolysaccharides from other Brucellae. The crude lipopolysaccharide was suitable as a diagnostic antigen in an enzyme-linked immunosorbent assay for the sensitive and specific detection of ram epididymitis caused by B. ovis infection. In comparative serological tests, the enzyme-linked immunosorbent assay with B. ovis lipopolysaccharide gave better identification of infections and fewer false-negative results than the enzyme-linked immunosorbent assay with sonicated antigen or the complement fixation test.

Effect of epididymitis on semen quality of rams

To better document the detrimental effect of ram epididymitis (RE) in large range flocks, a study was conducted to determine the correlation of palpable RE lesions and semen quality. Presence of leukocytes in the semen of rams affected with RE also was evaluated and found to correlate positively with RE lesions and inversely with semen quality. Rams with palpable RE lesions usually produced semen of reduced quality; however, some affected rams did produce good quality semen. The mean scrotal circumference varied significantly when rams were analyzed by breed, but not when grouped by RE status or classified by semen quality.

Protection of rams against epididymitis by a Brucella ovis-vitamin E adjuvant vaccine

Rams vaccinated at 7 and 8 months of age with a B. ovis-vitamin E adjuvant vaccine had increased antibody titers compared with Freund's incomplete adjuvant or commercial bacterin vaccinated rams. The percent overall infectivity in an experimental infection of B. ovis-vitamin E adjuvant vaccinated rams was 22% compared to 44% for B. ovis-Freund's incomplete adjuvant or bacterin vaccinated rams and 67% for control.

The epidemiology of bacterial infection of the genitalia in rams

The interrelationship between the various bacteria isolated from the genital tract of rams and their host animals was studied. The pathogenicity of the different isolates varied. Several of these bacteria could be cultured in a medium consisting of a suspension of pen floor debris solidified with agar, while many organisms survived in the suspension for 10 days. Epidemiological investigations showed that rams kept under intensive systems were subjected to large-scale invasion of their genitalia by bacteria which led to infection of the accessory glands and orchitis and epididymitis. Apart from the preputial cavity, some rams kept on open range were entirely free of bacterial infection of their genitalia, and those that did have bacteria in the deeper parts of their genitalia had a very significantly lower incidence of pathological lesions of their genitalia. Finding bacteria and neutrophils in semen is consistent with the epidemiological findings.

Clinical findings and pathological changes in Histophilus ovis infections of sheep

The Gram-negative pleomorphic bacterium Histophilus ovis was incriminated as the cause of natural cases of epididymitis in rams, polyarthritis in lambs, mastitis and abortion in ewes. Epididymitis was sporadic in occurrence, unilateral in distribution and varied from acute to chronic in degree. Polyarthritis affected recently born lambs and resulted in acute lameness and subsequent debility. Mastitis was rare in occurrence, unilateral in distribution, acute and gangrenous in type. Abortion was also rare and manifested by a specific haemorrhagic placentitis. These four conditions were reproduced experimentally. The clinical, pathological and histopathological changes associated with field and experimental cases are described.

Association of sexual experience with isolation of various bacteria in cases of ovine epididymitis

Testicles from rams in flocks experiencing ram epididymitis in Idaho and eastern Oregon were cultured. Twenty-six breeding rams from 6 flocks were cultured and only Brucella ovis was isolated. Virgin rams (65) harbored numerous species of small fastidious gram-negative rods, including Actinobacillus actinomycetemcomitans, Haemophilus spp, Moraxella spp, and Pasteurella spp. Thus, there appeared to be 2 separate disease entities, dependent on sexual experience of the animal.

Ovine contagious epididymitis: a review

Ovine contagious epididymitis is predominantly associated with Brucella ovis, Actinobacillus seminis and a variety of organisms including Histophilus ovis. Transmission occurs venereally or by homosexual activity and, in the case of Actinobacillus seminis, ewe to lamb transmission is probably important. A chronic infection, mainly in the cauda epididymis may result in formation of spermatic granulomata and a reduction in ram fertility. Eradication of ovine brucellosis can be achieved by serological testing using a complement-fixation test in conjunction with palpation of lesions and removal of reactors. Vaccination to control ovine brucellosis is advocated in some countries. The nomenclature of the group of Gram-negative pleomorphic organisms to which Actinobacillus seminis and Histophilus ovis belong is urgently in need of review. This paper reviews the organisms capable of producing ovine contagious epididymitis, the pathogenesis of the condition as well as methods of diagnosis and control.

Epidemiological studies on ovine brucellosis in selected ram flocks

The epidemiology of ovine brucellosis was investigated in 6 ram flocks in which anomalous reactions to the complement fixation test was recorded. It was shown that rams can become infected as young as 4 months of age. Naturally infected animals have an epididymitis and excrete Brucella ovis in their semen or they may only show a serological response for a short time then recover. The base line titres of chronically infected animals stay relatively constant. The importance of abortive infection and possible reinfection is discussed.