Clinical and microbiological study of an otitis media outbreak in calves in a dairy herd.

On a dairy farm, otitis media was diagnosed in 64 suckler calves (21.8%) during a study period of 2 years, and in 10 calves (3.4%) in the third year. The inflammation was unilateral in 63 and bilateral in 11 calves. The affected calves were dull, lacked appetite, were pyrexic and displayed drooping ear or ears and tilted heads with purulent discharge exuding from the external ear canal. Of the affected animals, 56 (87.5%) were aged between 3 and 8 weeks. Morbidity was higher during the calving season and during the autumn and winter months (October-December). Pasteurella haemolytica was isolated from 21 (32.8%), P. multocida from 20 (31.2%), Actinomyces pyogenes from 11 (17.2%) and Streptococcus pneumoniae from three (4.7%) of the clinically affected calves only during the first two study years. The exudate of the acute ear infections contained, in addition to Pasteurella spp., various bacteria and yeasts. Most of these bacteria were isolated from healthy ears as well, and are likely to be part of the normal ear flora. On the other hand most of the yeasts were isolated from otitic calves. After a short course of an appropriate treatment infections healed in all cases. Possible preventive measures are discussed.     

Mycoplasma bovis and otitis in dairy calves in the United Kingdom

Signs of severe otitis media in 20% of dairy calves on one farm were associated with Mycoplasma bovis infection, based on isolation from the external ear canal and nares. Affected calves seroconverted to M. bovis and no other significant bacteria were isolated. Infection was considered likely to have originated from cows in the milking herd based on evidence of seroconversion and detection of infection in a milk sample. M. bovis infection should be considered when investigating otitis problems in calves.     

The aerobic bacterial flora of the middle and external ears in normal dogs

The aerobic bacterial flora of the middle and external ears was elucidated in 30 normal dogs (60 ears). Bacterial swab samples were obtained by rubbing the surface of the tympanic cavity and external ear canal. In the middle ear, bacteria were cultured from 48 per cent of the total ears and mainly included Escherichia coli (8 per cent), yeasts (8 per cent), staphylococci (7 per cent) and branhamella (7 per cent). In the external ear, bacteria were found in 46 per cent of the total ears and staphylococci (19 per cent) and yeasts (7 per cent) were the main isolates. Mycoplasma was found in one external ear sample, but in no middle ear samples in an examination of 20 ears. The same type of bacterium was hardly ever found in both the middle and external parts of each ear.     

Bacteriology of the horizontal ear canal of dogs

Of 57 dogs included in a survey of the bacteriology of the horizontal ear canal, 31 showed clinical signs consistent with ear irritation. Twenty-six dogs were presented for other reasons and were asymptomatic for ear irritation. All dogs sampled were anaesthetized and sterile moistened swabs used to sample the horizontal ear canal. Swabs were introduced through a sterilized (121°C for 15 min) polypropylene otoscope cone and care was taken to prevent contamination of the cone with material from elsewhere in the ear canal. Swabs were processed within 20 min of sampling and cultures were incubated aerobically and anaerobically. Swabs from the ears of asymptomatic dogs were mixed in broth prior to plating to ensure optimal elution of small numbers of organisms from the swabs. Very small numbers of bacteria and yeasts were isolated from asymptomatic dogs while Pseudomonas spp. and Proteus spp. were frequent isolates from symptomatic dogs with chronic irritation. The significance of these findings is discussed in relation to the sampling and culturing techniques used in this and other surveys.     

The occurrence of Cryptosporidium parvum,Campylobacter and Salmonella in newborn dairy calves in the Manawatu region of New Zealand

AIM: To determine the occurrence of Cryptosporidium parvum oocysts, Campylobacter spp and Salmonella spp in faecal samples taken from newborn dairy calves on 24 dairy farms in the Manawatu region of New Zealand.

METHODS: A cross-sectional study was conducted during the 2002 calving season. Faecal samples were collected from 185 newborn calves from a convenience sample of 24 dairy farms. The samples were tested microscopically for the presence of C. parvum oocysts, and bacteriologically for the presence of Campylobacter spp and Salmonella spp.

RESULTS: Infections with C. parvum were identified in 33/156 (21.2%) calves from 10 farms. More than 10⁶ oocysts/g (OPG) faeces were detected in calves from four farms. Campylobacter spp were isolated from 58/161 (36%) calves from 18 farms; in particular, C. jejuni subsp jejuni was isolated from 11/161 (6.8%) calves from seven farms. Salmonellae were not detected.

CONCLUSIONS: Despite the short and concentrated calving pattern and the long interval between calving seasons characterising most dairy farms in New Zealand, C. parvum is widespread among calves. Campylobacter spp, especially C. jejuni, rapidly colonise the intestinal tract of newborn calves.

RELEVANCE: This study provided an estimate of the ecological impact of newborn dairy calves with regard to the potentially zoonotic enteric pathogens most frequently isolated from human gastrointestinal infections in New Zealand.     

Treatment of feline otitis externa due to Otodectes cynotis and complicated by secondary bacterial and fungal infections with Oridermyl auricular ointment

A blinded randomized study was conducted on 24 cats to confirm the presence of bacterial and/or fungal secondary infections associated with otoacariasis and to verify the efficacy of Oridermyl, an acaricidal/antibiotic/antifungal/anti-inflammatory ointment, for treatment of the primary infestation and secondary infections. Sixteen cats were treated once daily for 10 d; 4 cats were not treated and 4 were treated with a placebo ointment. On Days 0 and 10, ears were swabbed for counts of bacteria and yeasts, for bacterial culture and sensitivity, and examined for determination of the degree of clinical otitis. Auricular secretions were removed for mite counts on Day 10, except for 8 treated cats that were done on Day 30. There was a high number of bacteria and yeasts in most cats and Oridermyl treatment significantly decreased those numbers. Staphylococci were the most frequently isolated bacteria. No live ear mites were found in cats treated with Oridermyl or the placebo ointment.     

Mycoplasma otitis in California calves.

A retrospective study of Mycoplasma otitis in California calves submitted for necropsy between 1993 and 2002 was conducted to characterize the demographic features of the disease and the pathologic findings associated with infection. Sixty-one confirmed cases of Mycoplasma otitis were identified among 20,525 necropsied cattle. All affected animals were calves, ranging in age from 2 weeks to 4 months and with a median age of 1.5 months. Ninety-two percent of the cases were dairy breeds. A higher percent of necropsied calves with Mycoplasma otitis were males (0.45%) than females (0.23%). The proportion of cases that had Mycoplasma otitis increased from 1993 to 2002, and there was a significant (P < 0.05) seasonal distribution, with the highest proportion in the spring and the lowest in the summer months. Infections involved both the middle and inner ear and were characterized by a suppurative inflammatory response with extensive bony involvement. Three species of Mycoplasma were isolated from the ears: M. bovis, M. bovirhinis, and M. alkalescens. Concurrent pneumonia occurred in 47 cases (77%), and Mycoplasma was isolated from the lungs of 30 of those cases. The increasing proportion of Mycoplasma otitis cases in the past 10 years emphasizes the importance of identifying risk factors that could be modified to lower the incidence of this disease in calves.     

P‐74 Evaluation of the in vivo effects of Tris‐EDTA and chlorhexidine digluconate 0.15% solution in chronic bacterial otitis externa: 11 cases

The objectives of this study were to evaluate in vivo tolerance, and antimicrobial and clinical activities of a topical otic preparation containing EDTA tromethamine (Tris) and chlorhexidine digluconate 0.15% solution (Otodine^®) in dogs with chronic bacterial otitis externa. Eleven dogs were included. The affected ears were filled with the solution once daily during a 2‐week period. Dogs were evaluated on days 0, 14 and 28. Three clinical parameters (exudate, erythema, pain) and three cytologic parameters (Malassezia, cocci, rods) were scored (0–4 scale) by otoscopic and cytological examinations of otic exudate. Bacterial cultures were performed at each time point. If there were bacteria on cytological examination on day 14, the dogs were treated with the original product, with the addition of enrofloxacin (5%) applied 10 min after the original product, for a further 2 weeks. All 11 cases yielded isolates of resistant gram‐negative bacteria; gram‐positive bacteria were also isolated from six of 11 dogs. On day 14, six of 11 dogs were negative on culture examination; on day 28, 10 of 11 were negative and only one case had a positive culture. On day 14, clinical and microbial scores (cytology) were reduced by 54.6 and 71.1%, respectively, and by 85.7 and 94% on day 28. All cases reported good tolerance of the treatment. The results show that this ear solution was helpful in the management of chronic bacterial otitis externa in dogs and was well tolerated. There seems to be a synergistic effect of the combination of Tris‐EDTA/chlorhexidine digluconate 0.15% solution, and an antimicrobial agent (enrofloxacin) against resistant gram‐positive and gram‐negative bacteria. Funding: Self‐funded.     

Effects of a prebiotic supplement on health of neonatal dairy calves

Calf morbidity and mortality represent major financial losses for many dairy producers. The primary cause of calf mortality in the U.S. is diarrhea caused by intestinal bacterial infections. Traditionally, formulated antibiotics in milk replacer have been used as preventive treatments. However, as consumer concern about antibiotic resistance has increased, interest in alternative supplements has grown. Prebiotics, which are food ingredients not digestible by animal enzymes, and probiotics, which are beneficial bacteria, are two proposed alternatives for antibiotics to reduce diarrhea and improve immunity in calves. In this trial 75 Holstein heifer calves were randomly assigned to one of 3 treatments: control (C; no additive), antibiotic treatment (A; oxytetracycline 0.220 g/kg and neomycin base 0.441 g/kg), and prebiotic supplement (PB; 20 g/day Prebio Support™, Meiji Feed Co., Ltd. Tokyo, Japan). Calf scours, respiratory, and general appearance scores were not affected by treatment. No statistical differences were detected in any of the health data collected; however, treatment C had nearly twice as many calves that scoured and refused feed than treatments A and PB. Populations of beneficial and pathogenic bacteria in feces were generally not affected by treatments. However, PB treatment calves had an overall trend for more Lactobacilli in their feces than calves fed A (P = 0.08), and Enterobacter population was greater in C calves than in calves on treatment A in week 4 (P < 0.05). There was a tendency for the PB treatment to have elevated populations of beneficial species of bacteria during week 2. Populations of lymphocytes carrying CD4 and CD8 markers were not affected by treatment. Fecal IgA concentration decreased as calf age increased, with the greatest concentration in week 2 (P < 0.01) for all calves. Fecal IgA levels were numerically greater for the PB group in weeks 2 and 4. Both PB and A treatments affected fecal parameters with PB having positive effects in several areas. Since calves in this study were generally healthy, observable benefits from the treatments were likely minimized.     

A syndrome of facial paralysis of dairy calves in the Franklin district of New Zealand

AIM: To determine the aetiology of a syndrome characterised by facial paralysis in calves (facial paralysis syndrome; FPS); describe the epidemiology of the syndrome on an affected case farm; and define the intra-farm prevalence of affected calves, and inter-farm prevalence of affected dairy farms, in the Franklin district of New Zealand.

CASE HISTORY AND CLINICAL FINDINGS: An investigation was carried out on a town-supply dairy farm experiencing an outbreak of FPS in calves during the autumn of 2007, following a previous outbreak during the spring of 2006; 21 calves were affected in both outbreaks. Post-mortem examinations of three affected calves revealed no infectious aetiological agent in neurological tissues despite tests for viruses, bacteria and Mycoplasma species. Tests on hepatic tissues for vanadium toxicity were inconclusive.

SURVEY OF DAIRY FARMS: Results from a postal survey of 177/325 (54%) farms established the yearly prevalence of affected farms, based on farmer diagnosis, was 11%, and there was a median two (range 1–25) affected calves on those farms. There was no evidence of spatial clustering of affected farms after accounting for the underlying farm density, or of an increase in the number of affected farms between 2003 and 2007.

CLINICAL RELEVANCE: Facial paralysis syndrome is an unusual condition that has not been reported in other districts of New Zealand or in other countries. It is probable that this syndrome will continue to occur at a low to moderate prevalence, and have a significant impact on a small number of farms.     

Enteric infections in veal calves: A longitudinal study on four veal calf units

Summary

Forty‐five calves on four veal calf units were monitored during the first four weeks after their arrival. Faecal samples were collected on alternate days and screened for the presence of rotaviruses, bovine coronavirus, Cryptosporidium oocysts, K99 positive strains of E. coli and Salmonella spp. Rotaviruses and Cryptosporidium were the most commonly detected agents (78% and 60% respectively of the calves). Bovine coronavirus was detected in the faeces of 18% of the calves, whilst K99 positive E. coli was only found in 2 samples from one calf. Salmonella spp. were not isolated from any of the 646 faecal samples examined. Shedding of rotaviruses occurred in a bimodal pattern beginning in the first week of the survey. Cryptosporidium oocysts were detected most frequently in the interval between the two peaks of rotavirus shedding. The presence of rotaviruses or Cryptosporidium oocysts in faeces was not strongly associated with scour, nor were combined infections with these agents or the cases of bovine coronavirus infection. The condition of the calves throughout the survey was generally satisfactory.     

Evaluation of an ear cleanser for the treatment of infectious otitis externa in dogs

Thirty-one ears (16 dogs) with otitis externa originating from bacterial or yeast infections were enrolled in a study to evaluate the in vivo efficacy of an ear cleanser containing 2.5% lactic acid and 0.1% salicylic acid for the treatment of infectious otitis externa. The affected ears were treated with the ear cleanser twice daily for 2 weeks and evaluated after 1 and 2 weeks of treatment. The ear cleanser was effective in resolution of infection in 67.7% of the ears, and clinical signs of infectious otitis externa were significantly reduced within 2 weeks.     

Evaluation of fungal flora in normal and diseased canine ears

This study was undertaken to characterize otic fungal flora encountered in normal dogs, atopic dogs with no clinical or cytological evidence of otitis and dogs with otitis externa. Forty‐two normal dogs, 23 atopic dogs and 32 dogs with otitis were included in the study. Samples for otic fungal culture and cytology were obtained from all animals, for a total of 194 ears. Sixty‐seven ear samples (34%) were culture positive for saprophytic fungal organisms, as follows: 43 (64%) Penicillium species, 13 (19%) Aspergillus species and the remaining 17% comprised of various other saprophytic fungal organisms. Cytological evidence of saprophytic fungal colonization or infection was not found in any animal. There was no relationship between positive saprophytic fungal culture and any study group. Thirty‐three ear samples (17%) were positive for Malassezia pachydermatis. Cytological findings of Malassezia were significantly associated with positive culture for Malassezia (P = 0.006 left ear; P = 0.019 right ear). Furthermore, increased numbers of Malassezia led to a higher chance of positive culture (P = 0.003 left ear; P = 0.008 right ear; McNemar’s test). Malassezia pachydermatis was more likely to be cultured from ears with increased cerumen. Ear type (erect or pendulous) was not significantly associated with positive culture for Malassezia or saprophytic fungal organisms. There was no relationship between positive Malassezia culture and any study group; however, Malassezia was more likely to be cultured from individual dogs in the atopic or otitis groups that also had other dermatological signs consistent with allergic dermatitis and/or pyoderma (P = 0.031 left ear; P = 0.005 right ear).     

Four-year survey of urinary tract infections in calves in Israel

The prevalence of urinary tract infections in calves aged seven days to three months in three dairy cattle herds ranged from 0.5 to 1.6 per cent, with an average of 1.1 per cent. The mortality rate reached 16.1 per cent. The morbidity rate of the female calves was 1.4 per cent and that of the male calves 0.8 per cent. The bacteria isolated from urine, and from vaginal and preputial swabs were Escherichia coli (35 per cent), Corynebacterium renale (14 per cent), plasma coagulase-negative Staphylococcus species (12 per cent), Pseudomonas aeruginosa (12 per cent), Proteus species (12 per cent) and Arcanobacterium pyogenes (5 per cent). The affected calves had a significantly lower serum concentration of inorganic phosphorus (P < 0.01).     

Clinical efficacy of florfenicol in the treatment of calf respiratory tract infections

This paper reports on a study of the aetiology of calf pneumonia and the clinical efficacy of florfenicol, a new antibiotic in Turkey. Twenty-seven weaned and unweaned calves (13 males and 14 females) between 1 and 16 months of age brought to the clinics of Sel?uk University, Faculty of Veterinary Science. Broncho-alveolar lavage (BAL) fluid samples were taken from the animals diagnosed to have upper respiratory tract infection associated with bronchitis (N=2), bronchitis (N=5), bronchopneumonia (N=4), pneumonia (N=3), pleuropneumonia (N=11), bronchopneumonia plus pulmonary oedema (N=2) based on the results of the clinical and laboratory examinations. Then microbiological isolation and antibiotic culturing were performed. The animals were treated with 1 ml/15 kg (20 mg/kg) florfenicol (Nuflor, DIF) twice within 48 hours via intramuscular injection. At the end of the treatment, 23 of the weaned and unweaned calves were completely healed, 1 calf had died and 3 calves showed no healing. The results of BAL samples and microbiological examinations of the 3 calves that did not respond to the treatment indicated that these cases were affected by mixed infections of yeasts, fungi, and bacteria. Widespread pleuropneumonia was observed. According to the results of the microbiological examination of the BAL samples, Mannheimia (Pasteurella) haemolytica had the highest isolation rate (25%) compared with the other isolated bacteria, namely, Klebsiella pneumonia (20%), Actinomyces pyogenes (15%), beta-hemolytic streptococci. (10%), Staphylococcus spp. (5%), and E. coli (5%). The study also revealed fungi [Penicillum spp. (5%) and Aspergillus spp. (5%)] and two calves (10%) had a yeast infection.. We conclude that florfenicol has a high bacteriological and clinical efficacy (100% and 96% respectively) in the treatment of calf respiratory tract diseases.     

Use of ImageJ software for histomorphometric evaluation of normal and severely affected canine ear canals

Morphological studies comparing normal and diseased ear canals use primarily subjective scoring. The aim of this study was to compare normal and severely affected ears in dogs with objective measurements using ImageJ software. Ear canals were harvested from cadavers with normal ears and from dogs that underwent total ear canal ablation for unresolved otitis. Histopathology samples from ear canals were evaluated by semi-quantitative scoring and also by using ImageJ-software for histomorphometric measurements. The normal ears were compared to the severely affected ears using the 2 methods. The 2 methods were significantly (P < 0.0001) correlated for epidermal hyperplasia, ceruminous gland dilation, and hyperplasia and tissue inflammation, which were significantly greater in the severely affected ears (P < 0.0001). This study demonstrated that there is a very high correlation between the 2 methods for the most markedly affected components of otitis externa and that ImageJ software can be efficiently used to measure and evaluate ear canal histomorphometry.     

Comparative study of the microbial profile from bilateral canine otitis externa

Fifty dogs with bilateral otitis externa were studied over a 10-month period. The exudates of both external ears were obtained, using sterile swabs, and microorganisms were isolated according to standard microbiological techniques. Antimicrobial susceptibility testing of Staphylococcus intermedius was done by the agar diffusion method. There was bacterial and/or fungal growth in all of the samples. These were all polymicrobial infections. Anaerobic bacteria were not isolated in any sample. The most common pathogens isolated were S. intermedius and Malassezia pachydermatis. A statistically significant difference (P < 0.05) was observed in the isolation pattern between the right and left ears in 34 of the 50 animals (68%). High resistance rates of S. intermedius strains to penicillin, ampicillin, erythromycin, tetracycline, and clindamycin were found. The results suggest that in bilateral canine otitis externa, each ear should be cultured separately and considered as separate units.     

Bacteria of Pathogenic Importance in Faeces from Cadavers of Free-ranging or Corralled Semi-domesticated Reindeer in Northern Norway

There is little information on bacteria that have the potential to cause disease in reindeer husbandry. In this project, faecal samples from 35 free-ranging or corralled reindeer, adults and calves, that died in the winter of 2000 in northern Norway, were examined for the occurrence of Campylobacter spp., Clostridium perfringens, Listeria spp., Salmonella spp. and Yersinia spp. to evaluate the role of these microrganisms in loss and mortality in reindeer husbandry. In addition, 31 of these samples were examined for the occurrence of bacteria producing shigatoxin-1 and 2. C. perfringens was isolated in 20 (57.1%) of the faecal samples. In the free-ranging reindeer, 44% were positive carriers of C. perfringens and 90% of the corralled ones were positive for C. perfringens. In addition, the gene encoding for shigatoxin-1 was detected in one of the samples derived from a corralled reindeer. The other bacteria investigated were not found. Shigatoxin-1-producing bacteria were isolated for the first time from reindeer in Norway. However, no correlation between C. perfringens or shigatoxin-1-producing bacteria and mortality in the reindeer could be established.     

A retrospective study of 29 cases of otitis media/interna in dairy calves

Epidemiological data, clinical findings, laboratory data, medical imaging, and outcomes were reviewed in 29 dairy calves with otitis media/interna. Age at admission ranged from 1 to 24 wk. The majority of calves were referred during winter. Clinical signs included drooping ear, ptosis, head tilt, abnormal nystagmus, strabismus, dysphagia, regurgitation, stiff neck, opisthotonos, facial hyperesthesia, and purulent aural discharge. Intranasal endoscopic examination of 5 animals revealed nasopharyngeal collapse in 4. Cerebrospinal fluid (CSF) was abnormal in all of 7 cases. Mycoplasma bovis was cultured from all but 1 case with external ear or tympanic bullae samples (n = 12), and Mycoplasma arginini was cultured from the remaining ear sample. Radiographs of the tympanic bullae were performed in 24 calves, tomodensitometry (CT) in 3 calves and ultrasound in 4 calves. According to medical imaging techniques or necropsy, 69% of the cases were classified as chronic. Mean duration of treatment was 23.3 d. The rate of clinical recovery was 75%.     

Cow–Calf Herds in Eastern Germany: Status Quo of Some Parasite Species and a Comparison of Chemoprophylaxis and Pasture Management in the Control of Gastrointestinal Nematodes

Infections with gastrointestinal parasites (Eimeria spp., Cryptosporidium spp., Buxtonella sulcata, Fasciola hepatica, Moniezia spp. and trichostrongyles) and lungworms were monitored in five cow–calf herds in the north German lowlands. Estimated prevalences of infections with Eimeria spp. (predominantly Eimeria bovis) ranged between approximately 2 and 48 %. The highest prevalences were found during late summer and autumn. On one farm Cryptosporidium spp. were detected in July and August (prevalence: 8.5 ± 2.7 % and 6.7 < 2.0 %). The latter finding coincided with diarrhoea in many calves. Buxtonella sulcata was found during the entire study period in highly variable estimated prevalences ranging between zero and 73 %, but without any obvious association with clinical disease. Fasciola hepatica was detected on four out of five farms at estimated prevalences of approximately 1–20 %. Lungworm infections played a minor role in at least three of five study herds. The estimated prevalence of trichostrongyle infections rose from August until November whereas the intensity of infection did not change significantly. No difference in the intensity of infection could be detected between one farm on which infections with gastrointestinal nematodes were controlled only by moving the animals to an uninfected pasture in July, and three other herds on which strategic anthelmintic control was in place.