Mycoplasma as a cause of canine urinary tract infection

Mycoplasmas were isolated from 60 specimens of urine obtained by cystocentesis from 41 dogs (23 males and 18 females) with urinary tract infection. Mycoplasmas were isolated in pure culture from 41 (68%) of the specimens, and were isolated in conjunction with one or more bacterial species from 19 (32%) specimens. Clinical signs of urinary tract infection were noted in 20 of 31 dogs in which mycoplasmas were isolated in pure culture, and numbers of WBC in the urine sediment were above the reported normal range in 22 of 25 urine specimens from those 20 dogs. Twenty-four of 29 mycoplasma isolates were found to be Mycoplasma canis, 4 were found to be M spumans, and 1 was identified as M cynos.     

Neospora caninum infection as a cause of reproductive failure in a sheep flock

Neospora caninum has been detected only sporadically in cases of ovine abortion, and it has therefore traditionally been considered as an unimportant parasite in small ruminants. This study was carried out with the aim of identifying the pathogen causing serious reproductive problems on a commercial sheep farm. Sera from all rams and ewes tested negative for antibodies against Border disease virus, Schmallenberg virus and Coxiella burnetii, and infections by these agents were therefore ruled out. Nevertheless, seropositivity to N. caninum and/or Toxoplasma gondii was detected, although the seroprevalence was higher in the case of N. caninum. The percentage of lambings and the number of lambs per dam were significantly lower in ewes that were seropositive to N. caninum while no effect on these parameters was detected in ewes that were seropositive to T. gondii. There was also no evidence of infection by T. gondii in the foetal/lamb tissues analyzed by PCR and/or immunohistopathological techniques. On the contrary, the DNA of N. caninum was detected in 13 out of 14 foetuses/lambs descendant from dams seropositive to this parasite. Characteristic lesions caused by N. caninum and/or its antigen were also detected. Genotyping of the N. caninum DNA revealed only two closely related microsatellite multilocus genotypes. The results clearly demonstrate that infection by N. caninum was the cause of the low reproductive performance of this sheep flock.     

母猪繁殖障碍综合征的观察与防制

1998年,我们先后对河南省周口市川汇区、商水、西华、淮阳等4个县、区8个乡和黄泛区农场两个分场的150个养猪场和养猪专业户进行了调查.在调查的基础上,进行分析研究,对病猪进行了综合诊断表明主要是由细小病毒和乙脑等传染病引起,热应激也是不可忽视的因素.在查清病因的基础上,我们制订了针对性的预防措施.1998年对这些猪场和养猪户饲养的12 000头母猪进行预防接种,使母猪发病率下降到2%,仔猪死亡率降到0.9%.取得了良好的效果,获得了显著的经济效益.     

Eperythrozoon infection in swine as a disease factor

Infection with Eperythrozoon suis (E. suis) normally takes a latent course and depends on various factors. Only animals suffering extreme stress show clinically manifest attacks with anemia, fever and occasionally jaundice. Stress in the form of high animal-concentration in the stables, poor climatic conditions, change of stables or food or chronic general diseases predispose the pigs to clinical illness. The diagnosis of E. suis infection is made difficult by the prevalence of general diseases in the stocks. Experimental infections have shown that also latent infections with E. suis cause partly significant deviations in the red and white blood cell count as well as in the glucose and acid-base balance and lead to serologically detectable immune reactions which could be used as a basis for stock-diagnosis. It is still unknown to what extent infection with E. suis represents a factor in the manifestation of other complex diseases. Some observations, however, give reason to believe that Eperythrozoonosis as a basis infection is itself a precursor for the manifestation of widespread infectious diseases.     

Cryptosporidium infection as a cause of calf diarrhea

Cryptosporidiosis is a self-limiting protozoal disease of the intestinal tract. Although identified as possible agents of calf diarrhea less than 15 years ago, Cryptosporidium spp. are now believed to be common in calves and in many other host animal species worldwide. Recent literature on all aspects of cryptosporidiosis in calves is reviewed, predicaments in diagnosis and management are discussed, and public health concerns are raised.     

Persistence of porcine reproductive and respiratory syndrome virus infection in a swine operation.

A herd of Quebec seedstock pigs experienced in early 1992 a typical outbreak of porcine reproductive and respiratory syndrome (PRRS) associated with lesions of interstitial, proliferative and necrotizing pneumonia in weaned piglets. The nature of the infection was confirmed by serology using indirect immunofluorescence (IIF) and virus isolation in primary cultures of porcine alveolar macrophages (PAM). Farm production recovered after eight weeks of losses. In order to evaluate the persistence of infection in the herd, five SPF-piglets were introduced in two different sections of the PRRS-affected barn four months after the disappearance of clinical symptoms, and two others were placed in a neighboring building with apparently healthy farrow-to-finnish pigs. Clinical signs, body temperature, humoral immune response, virological and histopathological findings were recorded over a 42-day period. Clinical signs were evident in all of the sentinels and prolonged fever (> or = 40 degrees C) was recorded one day post-exposure (PE). Antibody titers to PRRS virus could be detected by IIF on PAM seven days PE, and reached 1:1024 by day 21 PE. Three of the sentinels developed significant virus neutralizing antibody titers (> 1:8 to < or = 1:128) by day 35 PE. In all cases, the virus could be isolated from the serum between day 7 and 42 PE. Thus, the virus and specific antibodies coexisted for several weeks. Lesions of interstitial pneumonia was demonstrated in few animals. In experimental inoculation studies, the viral strain isolated from the sentinel pigs produced severe reproductive disorders in two sows inoculated at 95 days of gestation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Early platelet aggregation as a cause of thrombocytopenia in classical swine fever

Twenty pigs were inoculated with a virulent classical swine fever virus isolate to determine the mechanism responsible for thrombocytopenia using histopathologic, ultrastructural, and immunohistochemical (detection of viral antigens gp55 and FVIII-rag) techniques. In animals euthanatized at 2, 4, and 6 days postinoculation (dpi), clusters of granular material staining positive for FVIII-rag were observed in splenic cords, the marginal zone, hepatic sinusoids, and the perisinusoidal space. Moreover, numerous macrophages in these areas were swollen and displayed an intensely positive granular and cytoplasmic reaction. Cell alterations indicative of platelet activation and secretory and phagocytic activation of resident macrophages were also observed in these sites at 2 and 4 dpi. These results suggest that the thrombocytopenia observed in pigs is caused in the first instance by massive activation and subsequent phagocytosis of platelets secondary to the release of platelet-activating factors by activated macrophages.     

Anastomoses of intestinal tract as a sequela to rectal stricture in swine.

Rectal stricture with anastomoses of colon and/or small intestine to a spherical dilatation of the descending colon proximal to the stricture was observed in six swine. In three of these swine, feces bypassed most of the colon in passage from the small intestine to the dilated colon. Rectal stricture with an anastomosis of a loop of colon to the rectal stricture was observed in one pig where feces bypassed much of the stricture.     

猪消化道传染病的鉴别与防治

猪消化道传染病是养猪生产中比较常见的疾病,尤其是对仔猪危害较大,因此,必须掌握这类疾病的临床识别要点,以准确诊断,避免较大的经济损失。常见的猪消化道传染病有仔猪黄痢、仔猪白痢、仔猪红痢、仔猪副伤寒、猪痢疾、猪传染性胃肠炎、猪流行性腹泻、猪轮状病毒病。     

Bartonella spp infection as a possible cause of uveitis in a cat

A 6-year-old castrated mixed-breed cat was evaluated because of unilateral anterior uveitis. The cat was seronegative for antibodies to Toxoplasma gondii, coronaviruses, and feline immunodeficiency virus, and antigens for FeLV p27 and Cryptococcus neoformans. Antibodies to Bartonella spp were detected in serum and aqueous humor. The antibody coefficient (C value) for IgG antibodies to Bartonella spp in the aqueous humor was 4.42; values > 1 suggest ocular production of antibodies and supports a diagnosis of ocular infection. Topical administration of prednisolone and oral administration of prednisone failed to induce a response; however, the uveitis resolved rapidly after the cat was given doxycycline orally. Clinical or laboratory evidence of immunodeficiency in this cat was not detected. Detection of a serum IgG antibody titer to Bartonella spp and ocular production of IgG antibodies to Bartonella spp, exclusion of other causes of uveitis, and response to doxycycline suggests that the cat may have had bartonellosis resulting in uveal tract inflammation.     

Parvovirus infection of keratinocytes as a cause of canine erythema multiforme

Erythema multiforme major was diagnosed in a dog with necrotizing parvoviral enteritis. Skin lesions consisted of ulceration of the footpads, pressure points, mouth, and vaginal mucosa; vesicles in the oral cavity; and erythematous patches on the abdomen and perivulvar skin. Microscopic examination of mucosal and haired skin specimens revealed lymphocyte-associated keratinocyte apoptosis at various levels of the epidermis. Basophilic cytoplasmic inclusions were seen in basal and suprabasal keratinocytes. Immunohistochemical staining, performed with canine parvovirus-2-specific monoclonal antibodies, confirmed the parvovirus nature of the inclusions in the nucleus and cytoplasm of oral and skin epithelial cells. This is the first case of canine erythema multiforme reported to be caused by a viral infection of keratinocytes. This case study indicates that the search for epitheliotropic viruses should be attempted in cases of erythema multiforme in which a drug cause cannot be identified.