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History A flock of mixed Sasso and Redbro broiler chickens raised in Pennsylvania and destined for sale to live bird markets experienced respiratory distress and a sudden increase in mortality of 0.17% overnight at 55 days of age. Daily

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in Journal of the American Veterinary Medical Association

Introduction Fungal infections of the lower respiratory tract, usually caused by Aspergillus spp, are frequently seen in psittacine patients, with certain species, such as African grey parrots, being more commonly affected. 1 Aspergillosis

Open access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine effects of intranasal inoculation with porcine reproductive and respiratory syndrome virus (PRRSV) or Bordetella bronchiseptica on challenge with nontoxigenic Pasteurella multocida in pigs.

Animals—Seventy 3-week-old pigs.

Procedure—In experiment 1, pigs were not inoculated (n= 10) or were inoculated with PRRSV (10), P multocida (10), or PRRSV followed by challenge with P multocida (10). In experiment 2, pigs were not inoculated (n = 10) or were inoculated with B bronchiseptica (10) or PRRSV and B bronchiseptica (10); all pigs were challenged with P multocida. Five pigs from each group were necropsied 14 and 21 days after initial inoculations.

ResultsPasteurella multocida was not isolated from tissue specimens of pigs challenged with P multocida alone or after inoculation with PRRSV. However, in pigs challenged after inoculation with B bronchiseptica, P multocida was isolated from specimens of the nasal cavity and tonsil of the soft palate. Number of bacteria isolated increased in pigs challenged after coinoculation with PRRSV and B bronchiseptica, and all 3 agents were isolated from pneumonic lesions in these pigs.

Conclusion and Clinical Relevance—Infection of pigs with B bronchiseptica but not PRRSV prior to challenge with P multocida resulted in colonization of the upper respiratory tract and tonsil of the soft palate with P multocida. Coinfection with PRRSV and B bronchiseptica predisposed pigs to infection of the upper respiratory tract and lung with P multocida. Porcine reproductive and respiratory syndrome virus and B bronchiseptica may interact to adversely affect respiratory tract defense mechanisms, leaving pigs especially vulnerable to infection with secondary agents such as P multocida. (Am J Vet Res 2001; 62:521–525)

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in American Journal of Veterinary Research

Respiratory diseases are recognized health problems in camelids 1 and cause for referral to specialized veterinary hospitals. The basis of high-quality care is a firm understanding of the underlying mechanisms of disease. However, a paucity of

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in American Journal of Veterinary Research

Abstract

Objectives

To determine whether intrauterine inoculation of porcine reproductive and respiratory syndrome virus (PRRSV) interferes with conception and whether exposure to one strain of PRRSV provides protection against challenge-exposure (CE) with homologous or heterologous strains of PRRSV.

Animals

40 gilts.

Procedure

Gilts were inoculated by intrauterine administration of a PRRSV isolate (nadc-8) at breeding. Inoculated and noninoculated gilts were exposed oronasally to homologous (nadc-8) or heterologous (European isolate) PRRSV during late gestation. Specimens from gilts and fetuses were tested against CE virus. Lack of virus in gilts indicated protective immunity for the dam, in fetuses indicated protection of gilt from reproductive losses, and in both groups indicated complete protection.

Results

In the homologous CE group, interval from inoculation to CE ranged from 90 to 205 days, and protection was complete. In the heterologous CE group, interval from inoculation to CE ranged from 90 to 170 days, and protection was incomplete. The CE virus was detected in gilts necropsied 134 to 170 days after CE and in a litter necropsied 170 days after CE.

Conclusions

Homologous protection can be induced in gilts by exposure to live PRRSV. Heterologous protection from reproductive losses can be induced in gilts by exposure to live PRRSV; however, this protection is incomplete and may have a shorter duration than homologous protection.

Clinical Relevance

Exposure of swine to enzootic PRRSV will provide protection against homologous PRRSV-induced reproductive losses. Extent and duration of protection against heterologous PRRSV may be variable and dependent on antigenic relatedness of the virus strains used for inoculation and CE. (Am J Vet Res 1999;60:1022-1027)

Free access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association

As a result of CNS damage, affected foals often have an abnormally low respiratory rate or periods of apnea, resulting in severe respiratory acidosis from loss of sensitivity to carbon dioxide within the chemosensitive area of the respiratory center

Full access
in American Journal of Veterinary Research

Abstract

Objective—To examine effects of co-infection with porcine reproductive and respiratory syndrome virus (PRRSV) and Bordetella bronchiseptica in pigs.

Animals—Forty 3-week-old pigs.

Procedure—30 pigs (10 pigs/group) were inoculated with PRRSV, B bronchiseptica, or both. Ten noninoculated pigs were control animals.

Results—Clinical signs, febrile response, and decreased weight gain were most severe in the group inoculated with both organisms. The PRRSV was isolated from all pigs in both groups inoculated with virus. All pigs in both groups that received PRRSV had gross and microscopic lesions consistent with interstitial pneumonia. Bordetella bronchiseptica was cultured from all pigs in both groups inoculated with that bacterium. Colonization of anatomic sites by B bronchiseptica was comparable between both groups. Pigs in the group that received only B bronchiseptica lacked gross or microscopic lung lesions, and B bronchiseptica was not isolated from lung tissue. In the group inoculated with B bronchiseptica and PRRSV, 3 of 5 pigs 10 days after inoculation and 5 of 5 pigs 21 days after inoculation had gross and microscopic lesions consistent with bacterial bronchopneumonia, and B bronchiseptica was isolated from the lungs of 7 of those 10 pigs.

Conclusions and Clinical Relevance—Clinical disease was exacerbated in co-infected pigs, including an increased febrile response, decreased weight gain, and B bronchiseptica-induced pneumonia. Bordetella bronchiseptica and PRRSV may circulate in a herd and cause subclinical infections. Therefore, co-infection with these organisms may cause clinical respiratory tract disease and leave pigs more susceptible to subsequent infection with opportunistic bacteria. (Am J Vet Res 2000;61:892–899)

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in American Journal of Veterinary Research

-called minor species. 2 One such NRSP-7 project is extending the label claims for florfenicol in bovine respiratory tract disease to sheep and goats. Florfenicol is a broad-spectrum, primarily bacteriostatic antimicrobial with a range of activity that includes

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in Journal of the American Veterinary Medical Association

respiratory tract for thermoregulation and dissipation of excess heat. Although respiratory evaporative cooling is just as effective as sweating on the basis of the amount of heat/mL of water evaporated, thermoregulation by respiratory evaporation of water is

Full access
in Journal of the American Veterinary Medical Association