Lameness examination in cattle

Case report: Imaging of septic arthritis in the hip joint of a calf treated with femoral head ostectomy

A 24-day-old male Japanese Black calf presented with weight-bearing lameness in the left hind limb and a swollen pelvis. Ultrasonography revealed the accumulation of fluidity materials with a mixture of hyper- and hypo-echogenicity, enclosed by 5-10-mm-thick capsular structures. On the ventral-dorsal radiograph of the pelvis, irregular and radiolucent osseous changes were evident in the femoral head and acetabulum within the swollen hip joint, with soft-tissue density. Computed tomography (CT) confirmed the relationship between the bony and soft tissue lesions, which was suspected following ultrasonography and radiography, and provided additional findings, such as intra-articular accumulation of gas and the degree of osteolytic changes. Based on the imaging findings and cytology of the arthrocentesis specimen, the patient was diagnosed with hip arthritis and osteomyelitis of the femoral head. Additionally, the severity of the lesions supported our decision to perform a femoral head ostectomy. The postoperative radiographic and CT findings of the treated pelvis were helpful in evaluating the efficacy of this technique. Following treatment, the animal could walk and showed normal development, although it was three postoperative months before weight-bearing lameness improved. To the best of our knowledge, this is the first report to describe the combined use of ultrasonography, radiography, and CT in the diagnosis, preoperative planning, and evaluation of the postoperative effects of bovine hip arthritis. Additionally, this report details the therapeutic efficacy of femoral head ostectomy for bovine hip arthritis, a technique that has not been reported previously.

The welfare of ill and injured feedlot cattle: a review of the literature and implications for managing feedlot hospital and chronic pens

By definition, ill and injured animals are on the negative valence of animal welfare. For beef cattle kept in feedlot settings, advances in cattle health management have resulted in a greater understanding and prevention of illness and injury. However, the management of cattle once they become ill and injured is an understudied area, and there are gaps in knowledge that could inform evidence-based decision-making and strengthen welfare for this population. The aim of this review is to provide a comprehensive overview of the acquired knowledge regarding ill and injured feedlot cattle welfare, focusing on existing knowledge gaps and implications for hospital and chronic pen management and welfare assurance. Ill and injured feedlot cattle consist of acutely impaired animals with short-term health conditions that resolve with treatment and chronically impaired animals with long-term health conditions that may be difficult to treat. A literature search identified 110 articles that mentioned welfare and ill and injured feedlot cattle, but the population of interest in most of these articles was healthy cattle, not ill and injured cattle. Articles about managing ill and injured cattle in specialized hospital (n = 12) or chronic (n = 2) pens were even more sparse. Results from this literature search will be used to outline the understanding of acutely and chronically ill and injured feedlot cattle, including common dispositions and welfare considerations, behavior during convalescence, and strategies for identifying and managing ill and injured cattle. Finally, by working through specific ailments common in commercial feedlot environments, we illustrate how the Five Domains Model can be used to explore feelings and experiences and subsequent welfare state of individual ill or injured feedlot cattle. Using this approach and our knowledge of current industry practices, we identify relevant animal-based outcomes and critical research questions to strengthen knowledge in this area. A better understanding of this overlooked topic will inform future research and the development of evidence-based guidelines to help producers care for this vulnerable population.

Effect of continuous or intermittent feeding of ergot contaminated grain in a mash or pelleted form on the performance and health of feedlot beef steers

This study evaluated the effect of feeding ergot contaminated grain continuously or intermittently through backgrounding (BG) and finishing (FN) in a mash or pelleted supplement on the growth performance, health and welfare parameters, and carcass characteristics of feedlot beef steers. Sixty black Angus steers (300 ± 29.4 kg BW) were used in a complete randomized 238-d study. Steers were stratified by weight and randomly assigned to four different diets (15 steers/treatment) and individually housed. Treatments included: (1) control [CON; no added ergot alkaloids (EA)], (2) continuous ergot mash (CEM; fed continuously at 2 mg total EA/kg of DM), (3) intermittent ergot mash (IEM; fed at 2 mg total EA/kg of DM, during the first week of each 21-d period and CON for the remaining 2 wk, this feeding pattern was repeated in each period), and (4) intermittent ergot pellet (IEP; fed at 2 mg of total EA/kg of DM as a pellet during the first week of each 21-d period and CON for the remaining 2 wk as described for IEM). Steers were fed barley based BG diets containing 40% concentrate:60% silage (DM basis) for 84 d (four 21-d periods), transitioned over 28 d (no ergot fed) to an FN diet (90% concentrate:10% silage DM basis) and fed for 126 d (six 21-d periods) before slaughter. In the BG phase, steer DMI (P < 0.01, 7.45 vs. 8.05 kg/d) and ADG (P < 0.01) were reduced for all EA diets compared to CON. The CEM fed steers had lower ADG (P < 0.01, 0.735 vs. 0.980 kg) and shrunk final BW (P < 0.01, 350 vs. 366 kg) than CON. CEM had lower gain:feed (P < 0.07, 0.130 vs. 0.142) than CON. In the FN phase, steer DMI (P < 0.01, 9.95 vs. 11.05 kg/d) and ADG (P = 0.04) were also decreased for all EA fed steers compared to CON. Total shrunk BW gain (P = 0.03, 202.5 vs. 225.2 kg), final BW (P = 0.03, 617.9 vs. 662.2 kg), and carcass weight (P = 0.06) decreased for all EA fed steers compared to CON. The percentage of AAA carcasses decreased for all EA fed steers (P < 0.01, 46.7 vs. 93.3%) compared to CON. EA fed steers had increased rectal temperatures (P < 0.01, 39.8 vs. 39.4 °C) compared to CON. Pelleting ergot contaminated grain did not reduce the impact of ergot alkaloids on any of the measured parameters during BG or FN. Continuously or intermittently feeding ergot contaminated diets (2 mg total EA/kg of DM) significantly reduced intake, growth performance, and carcass weight, with minimal impact on blood parameters in feedlot steers. Pelleting was not an effective method of reducing ergot toxicity.

The use of infrared thermography in the early diagnosis of septic arthritis in calves

The aim of this study was to compare the usefulness of thermographic examination of calves with septic arthritis with other diagnostic techniques such as synovial fluid analysis, radiography, ultrasonography and arthroscopy. Thirteen affected joints from eleven calves were used for the trial. The noninfected joints of the trial calves were used as negative controls. Thermography findings showed that heat from 100% of the affected joints was significantly increased. Subchondral osteolysis and new periosteal bone proliferation of articular bones and widening of the intra-articular joint spaces was observed in 10 joints (76.9%) using radiography. Ultrasound examination of all affected joints showed increased effusion with moderate homogeneous echoic structure. Arthroscopic examination showed synovitis and erosion of cartilage in 61.5% and osteophytic formation in 30.7% of affected joints. All diagnostic methods could be used to diagnose joint disease but it was found that thermographic examination in calves with septic arthritis is an easy convenient method to make an earlier diagnosis, which improves treatment success rates.

Radiographic diagnosis and surgical management for successful outcomes for osteochondrosis in Japanese Black calves

Osteochondrosis (OC) is not well recognized in cattle. Japanese Black (JB) cattle are valued for their beef and studies regarding OC are scarce. Hence, the aim of this study was to retrospectively discuss clinical and radiographical findings, diagnosis and treatment options for OC in JB cattle for successful outcomes. Medical records of 11 calves affected with OC were reviewed, retrospectively. Clinical and radiographic findings, treatment and outcomes and postmortem examination findings were analyzed. All calves had lameness. Stifle (4/14) and tarsal (4/14) were the most affected joints. Subchondral bone lucencies were observed in all joints (14/14) and accompanied with sclerosis (10/14). Radiographic grading was performed in calves. Calves were treated surgically (8/11) or conservatively (1/11). Surgically treated calves were auctioned (5/8). Postmortem examination was performed (2/11). Gross findings revealed ulcerative lesion at articular surface. Histopathologically, cartilage layer was defected at lesion. Inflammation (2/2) and granulation tissue (1/2) was also observed. In conclusion, OC in JB cattle can be diagnosed on the basis of radiography with history and clinical signs in clinical setting. Surgery should be performed in mild cases for successful outcomes. A modified radiographic grading criteria for clinical cases may hold potential in evaluating prognosis and outcomes.

Closing wedge ostectomy with transfixation pin-cast stabilization for correction of angular limb deformities of the metatarsophalangeal region in four cattle

CASE DESCRIPTION

4 calves were evaluated because of lameness and an angular limb deformity of the metatarsophalangeal region.

CLINICAL FINDINGS

3 calves (ages, 5 days, 10 days, and 1 month) had a congenital varus deformity of the metatarsophalangeal region characterized by medial subluxation of the first phalanx of digits 3 and 4 at the metatarsophalangeal joints. A 6-month-old heifer had a valgus deformity of the metatarsophalangeal region secondary to a malunion of a Salter-Harris type II fracture. The degree of deformity angulation ranged from 16° to 54° for the 4 patients.

TREATMENT AND OUTCOME

A closing wedge ostectomy with transfixation pin-cast application was performed on the affected limb of all 4 patients. The ostectomy healed with only minor complications (disuse osteopenia distal to the transfixation pins [n = 4] and cast sores [1]) that were easily resolved with no long-term adverse effects. Duration of follow-up for the 4 patients ranged from 6 to 17 months, and the owners reported satisfactory ambulation with no (n = 2) or only mild (2) residual lameness in the affected limb.

CLINICAL RELEVANCE

Results suggested that a closing wedge ostectomy with transfixation pin-cast stabilization is an alternative for management of angular limb deformities of the metatarsophalangeal region in cattle. Such treatment improved the quality of life for all 4 patients. However, 2 of the 4 patients had congenital deformities confirmed to be heritable. There are ethical concerns associated with treating animals with heritable disorders, and exhibition and breeding of such animals should be avoided.

Investigation of a novel prosthesis technique for extracapsular stabilization of cranial cruciate ligament-deficient stifle joints in adult cattle

OBJECTIVE

To evaluate a novel prosthesis technique for extracapsular stabilization of cranial cruciate ligament (CCL)-deficient stifle joints in adult cattle.

SAMPLE

13 cadaveric bovine stifle joint specimens.

PROCEDURES

In the first of 3 study phases, the most isometric points on the distal aspect of the femur (distal femur) and proximal aspect of the tibia (proximal tibia) were determined from measurements obtained from lateromedial radiographs of a stifle joint specimen maintained at angles of 135°, 90°, 65°, and 35°. During phase 2, 800-lb-test monofilament nylon leader line was cut into 73-cm-long segments. Each segment was secured in a loop by use of 2, 3, or 4 crimping sleeves such that there were 12 replicates for each construct. Each loop was distracted to failure at a constant rate of 1 mm/s. Mean force at failure and elongation and mode of failure were compared among the 3 constructs. During phase 3, bone tunnels were created in the distal femur and proximal tibia at the isometric points identified during phase 1 in each of 12 CCL-deficient stifle joint specimens. The 3-sleeve construct was applied to each specimen. Specimens were distracted to failure at a constant rate of 1 mm/s.

RESULTS

Among the 3 constructs evaluated, the 3-sleeve construct was considered optimal in terms of strength and amount of foreign material. In phase 3, all replicates failed because of suture slippage.

CONCLUSIONS AND CLINICAL RELEVANCE

Use of 800-lb-test monofilament nylon leader line as a prosthesis might be a viable alternative for extracapsular stabilization of CCL-deficient stifle joints in adult cattle. Further in vivo studies are necessary.

Prevalence and lameness-associated risk factors in Alberta feedlot cattle

Lameness in cattle is a health and welfare concern; however, limited information is available on risk factors and the relationship between lameness and common diseases like bovine respiratory disease (BRD). Therefore, the objectives of this study were to: 1) identify prevalence of lameness in feedlot cattle and related risk factors of cattle diagnosed as lame; and 2) determine associations between BRD occurrence and lameness. Feedlot cattle health records were available from 28 feedlots for 10 yr. The data set consisted of 663,838 cattle records, with 13.9% (92,156) diagnosed with a disease, including 32.3%, 46.0%, and 22.0% with lameness, BRD, and other diagnoses, respectively. Lameness was classified into four categories: foot rot (FR), joint infections (JI), lame with no visible swelling (LNVS), and injuries (INJ), with a prevalence of 74.5%, 16.1%, 6.1%, and 3.1%, respectively. Lameness was compared across cattle types (arrival date and weight) as well as age classification (calf vs. yearling), gender (steer vs. heifer), and season of placement in the feedlot (spring, summer, fall, and winter). Within the disease-diagnosed population, lameness represented 28.5% of treated fall-placed calves, 38.5% of winter-placed calves, and 40.8% of treated yearlings. Foot rot was the most common diagnosis with 74.5% of all lameness diagnoses, with winter- and fall-placed calves more likely to be diagnosed with FR compared to yearlings (OR: 1.19, 95% CI: 1.10–1.30 and OR: 1.46, 95% CI: 1.38–1.55, respectively). Joint infections were the second most common diagnosis (16.1%). Compared to yearlings, fall-placed calves had a higher odds (OR: 3.64, 95% CI: 3.12–4.24) for JI. Injuries and LNVS were the least common but again fall-placed calves had higher odds of this diagnosis compared to yearlings (OR: 2.26, 95% CI: 1.70–2.99 and OR: 9.10, 95% CI: 6.26–13.2, respectively). Gender was significantly different for JI as steers were less likely affected compared to heifers (OR: 0.687, 95% CI: 0.545–0.867), and more likely affected by LNVS (OR: 2.46, 95% CI: 1.57–3.84). Of all lameness-associated deaths, JI accounted for almost 50%. Finally, cattle diagnosed with BRD were subsequently more likely to be diagnosed with INJ, JI, or LNVS (P < 0.001 for all comparisons). In conclusion, animal type and gender were associated with type of lameness diagnoses, allowing feedlots to allocate resources to groups at highest risk and focus on early intervention strategies.

PEDOMETRIA APLICADA A ESTUDO COMPARATIVO ENTRE MORFINA E TRAMADOL EM BOVINOS

Resumo A analgesia com opioides é limitada ou indefinida em ruminantes. Neste trabalho, objetivou-se a realização de um estudo comparativo entre dois analgésicos opioides: a morfina e o tramadol, com base nas avaliações clínica e pedométrica de animais submetidos a artrite e sinovite experimental transitórias, desenvolvidas na articulação interfalângica distal, após administração intra-articular de anfotericina B. Utilizou-se seis animais, em dois tratamentos distintos, com morfina, na dose de 0,5 mg/kg e 20 dias depois com tramadol, na dose de 1,8 mg/kg, ambos via intramuscular. Os animais foram avaliados em intervalos de três horas, num total de 27 horas, observando-se parâmetros fisiológicos, deambulação e atividade pedométrica. Claudicação e alterações pedométricas foram observadas para ambos os fármacos. Por meio das variáveis da atividade pedométrica, observou-se um padrão de inquietação compatível com nocicepção podal, não havendo a interferência dos fármacos sobre a claudicação. Concluiu-se que a morfina e o tramadol, nas doses testadas, foram incapazes de interferir na atenuação do grau de claudicação no momento de máxima estimulação dolorosa, frente ao modelo experimental de dor ortopédica.

Economic impacts of lameness in feedlot cattle

Lameness is an important health issue in feedlot cattle; however, there is a paucity of information regarding its economic impact. Decision tree models are excellent tools for assessing costs of disease such as the net return (net return = benefit – cost). Models were developed using expert opinion, literature and retrospective feedlot data provided by Vet-Agri Health Services (VAHS, Airdrie, Alberta, Canada) collected from 2005 to 2015 on individually treated cattle (n = 30,940) from 28 feedlots. The objective was to estimate net return of various lameness diagnoses and impacts of cattle type, season of treatment, and extreme high and low cattle prices. Cattle were diagnosed as lame according to the following categories: foot rot, foot rot in heavy cattle (BW > 363 kg at treatment), injury, lame with no visible swelling, and joint infection. Records consisted of arrival and treatment weight, cost of treatment, and cattle deaths. Records included cattle types classified as: fall calves (heifer and steer), winter calves (heifer and steer) and yearling cattle (heifer and steer). Lastly, variables ADG, days on feed (DOF), and Season (spring, summer, fall, and winter) were created. Models estimated net return using cattle slaughter prices for healthy cattle that reached a slaughter weight of 635 kg and for three possible outcomes for each diagnosis after final treatment: cattle that recovered after treatment and reached a slaughter weight of 635 kg; cattle that were removed before they reached slaughter weight; or cattle that died. Compared to undiagnosed cattle with 1.36 kg/d ADG, cattle diagnosed with foot rot and foot rot heavy cattle had the highest ADG until first treatment (1.14 and 1.57 kg/d, respectively) and differed significantly (P < 0.05) compared to cattle diagnosed with injuries (0.87 kg/d), lame with no visible swelling (0.64 kg/d), and joint infections (0.53 kg/d). Yearling steers had the most positive returns compared to all other cattle types. Cattle with lighter arrival weight had lower ADG and increased economic losses after treatment compared to heavier weighted cattle on arrival. Based on average slaughter prices over a 10-yr period for healthy cattle, return was $690. Return after final treatment for cattle with foot rot was $568, foot rot in heavy cattle was $695, and injury was $259. However, joint infections and lame with no visible swelling had negative returns of –$286 and –$701, respectively.

Growth Plate Lesions of Fattening Bulls

Lameness related to growth plate lesions is an important problem in the beef industry. This article describes the macroscopic and microscopic lesions in the distal metatarsal physis of bulls from an association of farmers in northeastern Italy. The metatarsal bones of 62 bulls (12 with severe lameness and 50 without lameness), average age 16.44 ± 1.72 months, were examined at the abattoir. The animals came from the same geographic area and shared intensive husbandry practices and a diet based on maize starch. A total of 124 metatarsal bones were sectioned, and the distal metaphyseal growth plate was grossly examined. Twenty-three cases, including 12 lame and 9 nonlame animals with visible lesions on macroscopic examination, and 2 controls (a total of 46 physes) were examined microscopically. Eight of 12 bulls with severe lameness had a chronic purulent physitis in at least 1 limb. Segmental thickening of the hypertrophic zone, consistent with osteochondrosis (OC), was present contralaterally ( n = 3 cases) and bilaterally ( n = 3 cases) in 6 of these animals. In the group of nonlame bulls, 19 of 50 (38%) had similar segmental thickening of the physis consistent with OC. In the remaining bulls, minor findings included partial closure of the physis and a variable degree of metaphyseal hyperemia. A high incidence of OC was found in both lame and nonlame fattening bulls. It is likely that lame animals were clinically more severe due to secondary hematogenous implantation of bacteria, resulting in a purulent physitis and severe lameness that required emergency slaughter in some cases.

Trailer temperature and humidity during winter transport of cattle in Canada and evaluation of indicators used to assess the welfare of cull beef cows before and after transport

The current study evaluated 17 loads of cull beef cows transported in Canadian winter conditions to assess in-transit temperature and humidity, evaluation of events during loading and unloading, and animal condition and bruising. Regardless of the use of boards to block ventilation holes in trailers, temperatures were higher within trailers than at ambient locations during both travel and stationary periods (P < 0.01). Boarding was associated with smaller differences in trailer temperature, compared with ambient conditions, while the trailer was traveling at highway speeds versus when trailers were stationary (P < 0.01). Moisture levels within trailers were not different from ambient conditions when loads using boarding were traveling (P < 0.01), whereas loads without boarding had a larger difference (P < 0.01). The moisture within trailers relative to ambient conditions increased when trailers were stationary compared with traveling when boarding was used (P < 0.01). The majority of cattle transported were in good body condition (97.4% within BCS of 2 to 3.5) and had calm temperaments (96.7%). Although all comparisons were made, only the doghouse compartment had an increased risk of severe bruising compared with all other compartments (odds ratio [95% confidence interval]: 3.0 [1.6–5.5], 3.7 [2.1–6.4], 2.2 [1.3–3.7] and 3.8 [1.5–9.6] in comparison with the back, belly, deck, and nose compartments, respectively; P < 0.05). Increasing the duration of waiting to unload 30 min relative to a 1 h duration increased the odds of severe bruising by 1.18 times (95% confidence interval: 1.09–1.29; P < 0.01). Scoring systems that have been developed for auditing unloading of cattle had limited variation across loads at both loading and unloading. Pretransport assessment of animal condition using the American Meat Institute’s compromised animal score was the only scoring system that was consistent with posttransport scores. We inferred from the temperature and humidity data in the current study that under commercial conditions, boarding may increase ventilation within trailers during travel and decrease ventilation during stationary periods. The current study provides the first indication that issues in Canadian cull cow transport may be related to pretransport animal condition and management of unloading.

Effect of flunixin meglumine on the amelioration of lameness in dairy steers with amphotericin B-induced transient synovitis-arthritis

OBJECTIVE

To characterize amphotericin B-induced lameness in cattle and to ascertain the analgesic effects of flunixin meglumine by use of multimodal assessment.

ANIMALS

10 healthy Holstein steers free from musculoskeletal disease.

PROCEDURES

Steers were randomly allocated to a treatment or negative control group. Amphotericin B was injected into the distal interphalangeal joint of the lateral claw of the left hind limb of all steers. Treatment steers received flunixin meglumine at the time of synovitis-arthritis induction and at 12 hours after induction. Control steers received no medication. Multimodal analysis included vital parameters, visual lameness score, behavioral monitoring with accelerometers, pressure mat analysis, and plasma cortisol determination before and after induction. Data were analyzed by use of linear mixed models with treatment and time designated as fixed effects, accounting for repeated measures on individual calves.

RESULTS

Amphotericin B injection induced moderate, transient lameness. Control steers were more than twice as likely to be lame as treatment steers (mean ± SD lameness score, 92.2 ± 8.1 % vs 40.7 ± 2.5%). Treatment steers placed significantly greater force and contact area on the affected foot and greater force, impulse, and contact area on the paired claw, compared with control steers. Furthermore, treatment steers spent considerably less time in recumbency than controls.

CONCLUSIONS AND CLINICAL RELEVANCE

Amphotericin B successfully induced synovitis-arthritis in dairy steers that was transient in nature. Flunixin meglumine was efficacious in providing analgesia for these steers.

Pharmacokinetics of tetracycline in plasma, synovial fluid and milk using single intravenous and single intravenous regional doses in dairy cattle with papillomatous digital dermatitis

The purpose of this study was to compare the pharmacokinetics of tetracycline in plasma, synovial fluid, and milk following either a single systemic intravenous (i.v.) injection or a single i.v. regional antibiosis (IVRA) administration of tetracycline hydrochloride to dairy cattle with papillomatous digital dermatitis (PDD). To this end, plasma and synovial fluid tetracycline concentrations were compared with the minimal inhibitory concentration (MIC) values of the major bacteria, which are known to cause digital diseases and thus assess its efficacy in PDD. Residual tetracycline concentrations in milk from cows treated by both methods were also determined. Twelve Holstein cows with various stages of PDD were randomly assigned to two groups of six animals. Group 1 received a single systemic i.v. injection of 10 mg/kg of tetracycline hydrochloride. Group 2 received 1000 mg of tetracycline hydrochloride by IVRA of the affected limb. Blood, synovial fluid and milk samples were taken prior to tetracycline administration (time 0 control), and then at 22, 45 and 82 min, and 2, 3, 4, 6, 8, 12, 24, 48, 72, 96, and 120 h following drug administration. Tetracycline concentrations were determined by high-performance liquid chromatography. Mean tetracycline plasma and milk concentrations in Group 1 were higher than Group 2. The opposite was observed for synovial fluid concentrations. Group 2 synovial fluid concentrations were higher than the MIC value over 24 h for the bacteria most frequently responsible for claw disease. Compared with i.v. administration, IVRA administration of tetracycline produced very high synovial fluid and low plasma and milk concentrations.

Comparação entre as administrações tópica e sistêmica de oxitetraciclina no tratamento de vacas com dermatite digital papilomatosa

Comparou-se a eficiência dos tratamentos tópico e sistêmico com oxitetraciclina em vacas com dermatite digital papilomatosa (DDP) e determinaram-se a presença de resíduos desse antimicrobiano no leite e sua concentração no líquido sinovial e no plasma. Utilizaram-se o tratamento tópico com oxitetraciclina em pó (grupo 1) e o sistêmico de longa ação (grupo 2) em 16 vacas holandesas em lactação, acometidas por DDP. Obtiveram-se amostras de plasma, líquido sinovial e leite nos momentos: M0, antes dos tratamentos; M1, seis horas após o tratamento e em intervalos de 12 horas até M23 (264 horas pós-tratamentos). Avaliaram-se o grau de claudicação, a extensão da lesão e a concentração da oxitetraciclina pela cromatografia líquida de alta eficiência. Nas vacas do grupo 1, ocorreu redução das lesões e da claudicação, quando comparadas com as do grupo 2. Nenhuma das amostras de leite, de líquido sinovial e de plasma nos animais do grupo 1 foi positiva para oxitetraciclina. As amostras de leite dos animais do grupo 2, entre M1 e M23, apresentaram valores acima do limite máximo residual permitido para esse antimicrobiano. O tratamento tópico foi eficiente no tratamento de DDP, sem produzir resíduos no leite ou concentrações no plasma e no líquido sinovial. O tratamento sistêmico foi ineficiente para DDP, resultando em resíduos no leite, durante a avaliação.

Synovial fluid changes in induced infectious arthritis in calves

The objective was to develop an experimental model of septic arthritis in calves and to evaluate the effect of treatment on cytologic and bacteriologic variables of synovial fluid. The right tarsus of 7 healthy Holstein bull calves were inoculated with 10⁸ colony‐forming units of viable Escherichia coli of a pap‐positive strain (day 1). On day 2, joint lavage was performed and antibiotic treatment was instituted. Cytologic examinations, bacterial cultures, and pap factor determinations by polymerase chain reaction (PCR) were performed on synovial fluid samples that were collected daily until day 4, then every 4 days until day 24. Results of physical examination, the severity of lameness, and swelling were recorded. Clinical signs of septic arthritis appeared on day 2 and persisted until day 9 for all calves. Bacterial cultures from all calves were positive for E coli on day 2, and remained positive until day 3 for 1 calf and until day 4 for 5 calves. In addition, PCR results were positive for all calves, with 6 positive through day 3 and 1 positive through day 4, after which a positive result was again obtained on day 24. Synovial fluid neutrophil counts and white blood cell counts were significantly increased on days 2–4; however, synovial total protein concentrations were increased (P < .05) throughout the experiment in comparison to day 1. Results of all bacterial cultures were negative on day 8, although clinicopathologic signs of inflammation persisted until day 20. This model successfully induced acute septic arthritis in calves. Rapid recovery occurred within 1 week when an appropriate treatment was instituted early in the course of the disease

Synovial fluid changes in induced infectious arthritis in calves

The objective was to develop an experimental model of septic arthritis in calves and to evaluate the effect of treatment on cytologic and bacteriologic variables of synovial fluid. The right tarsus of 7 healthy Holstein bull calves were inoculated with 10(8) colony-forming units of viable Escherichia coli of a pap-positive strain (day 1). On day 2, joint lavage was performed and antibiotic treatment was instituted. Cytologic examinations, bacterial cultures, and pap factor determinations by polymerase chain reaction (PCR) were performed on synovial fluid samples that were collected daily until day 4, then every 4 days until day 24. Results of physical examination, the severity of lameness, and swelling were recorded. Clinical signs of septic arthritis appeared on day 2 and persisted until day 9 for all calves. Bacterial cultures from all calves were positive for E. coli on day 2, and remained positive until day 3 for 1 calf and until day 4 for 5 calves. In addition, PCR results were positive for all calves, with 6 positive through day 3 and 1 positive through day 4, after which a positive result was again obtained on day 24. Synovial fluid neutrophil counts and white blood cell counts were significantly increased on days 2-4; however, synovial total protein concentrations were increased (P < .05) throughout the experiment in comparison to day 1. Results of all bacterial cultures were negative on day 8, although clinicopathologic signs of inflammation persisted until day 20. This model successfully induced acute septic arthritis in calves. Rapid recovery occurred within 1 week when an appropriate treatment was instituted early in the course of the disease.