Influence of liver copper status of mare and newborn foal on the development of osteochondrotic lesions

REASON FOR PERFORMING STUDY: To elucidate the highly contentious role of copper in the pathogenesis of osteochondrosis. HYPOTHESIS: There would be no relationship between liver copper concentration of mares and foals and incidence of radiographically detectable osteochondrotic lesions in foals and yearlings was tested. METHODS: Liver copper concentration was assessed in biopsies taken within 4 days after birth from both mares and foals and from the same foals at age 5 months. Biopsies were taken in the standing, sedated animal under ultrasonographic guidance. Radiographs were taken of both hocks (lateromedial, dorsoplantar and dorsomedial-plantarolateral oblique views) and stifles (lateromedial and caudolateral-craniomedial oblique views) at ages 5 and 11 months and scored for the presence and severity of osteochondrotic lesions. RESULTS: Copper concentrations in newborn foals were high with a large variation (351 +/- 201 mg/kg DM). They declined until reaching values comparable to those in mature animals at 5 months (20 +/- 8 mg/kg DM; mares: 19 +/- 20 mg/kg DM). Radiographic osteochondrotic lesions decreased in number and severity from 5 to 11 months. This pattern was more predominant in the stifle than in the hock, as has been described previously. CONCLUSIONS: There was no relationship between foal or mare liver copper concentration and osteochondrosis status at either 5 or 11 months. However, osteochondrotic lesions in foals with low-level copper status at birth decreased significantly less in number and severity than those in foals with high-level copper status at birth. POTENTIAL RELEVANCE: It is concluded that copper is not likely to be an important factor in the aetiopathogenesis of osteochondrosis, but this study indicates that there may be a significant effect of high copper status on the natural process of repair of early lesions.     

不同铜源对大鼠生长性能及组织中铜含量和血清中抗氧化酶活性的影响

比较酵母铜作为新型铜源添加剂与硫酸铜在大鼠上的饲喂效果。选择血缘相近,体重在60～90g的Wistar健康雌鼠66只,按2因子完全随机设计,分为11个处理,每个处理6个重复,试验期10d。采用酪蛋白、玉米淀粉纯合缺铜饲粮作为基础饲粮,分别以酵母铜和硫酸铜2种不同的铜源添加10、30、60、100、250mg/kg5个水平。结果表明:不同铜源、不同铜水平、不同铜源与不同铜水平互作之间,大鼠的平均日增重(ADG)、平均日采食量(ADFI)差异均不显著(P>0.05);但是酵母铜与硫酸铜相比,ADG和ADFI分别提高了2.5%和3.5%。不同铜源、不同铜水平、不同铜源与不同铜水平交互作用,对大鼠血清铜蓝蛋白、铜锌超氧化物歧化酶(CuZn-SOD)、肝铜含量都存在极显著的影响(P<0.01)。由此可见,不同铜源和水平能够显著影响大鼠对铜的吸收利用,且酵母铜源较硫酸铜源的效果更优。     

铜的来源和水平对生长猪生长性能和粪铜排出量的影响

选用平均体重29.6kg的三元杂(杜×大×长)生长猪144头,按随机区组设计分为6个处理。饲粮中分别添加0、100、200mg/kg硫酸铜、200mg/kg碱式氯化铜、100mg/kg小肽铜、100mg/kg复合氨基酸螯合铜(以铜含量计)。结果表明:100mg/kg小肽铜和100mg/kg复合氨基酸螯合铜均能有效提高生长猪日增重和日采食量,其促生长效果与200mg/kg硫酸铜无显著(P>0.05)差异,而粪中铜含量分别下降了36.8%和48.4%(P<0.05)。     

Effect of High-Protein and All-Vegetable Diets on the Incidence and Severity of Pododermatitis in Broiler Chickens

The incidence and severity of pododermatitis in broiler chickens is of great concern to the broiler industry, both from product quality and animal welfare standpoints. A total of 1,600 birds were raised in floor pens in a design involving a 2 × 2 × 2 arrangement of protein level [high or low], protein source [all vegetable (VEG) or vegetable plus animal (VEG + ANI)], and sex (male and female) on a 4-stage feeding program (50 birds per pen; 4 pens of males and 4 pens of females per treatment). In addition to live performance, the feet were scored on all birds on 29, 43, and 54 d of age, and the severity of lesions was recorded as none, mild, or severe. A subsample of birds was processed at the end of the experiment to evaluate carcass yields. Pooled litter samples were collected on 29, 43, and 54 d of age for total and NH₃-N analysis. Protein level had a significant (P < 0.05) effect on BW on 14, 29, and 43 d of age. At 43 and 54 d of age, BW was significantly influenced by protein source and sex. Chilled carcass yields did not differ between the treatments (P > 0.05). Footpad lesions were significantly affected by protein level, protein source, and sex. At 29 d of age, all lesions were mild in severity and varied significantly in incidence by protein source (31% for VEG vs. 41% for VEG + ANI). At 54 d of age, both protein level and protein source significantly increased the incidence and severity of footpad lesions. Incidence of pododermatitis was higher for males (61%) than females (55%). Litter total N was significantly affected by protein level and protein source. The litter NH₃-N content, although not significant, except for 29 d of age, showed an increasing trend for each feeding period. The incidence and severity of pododermatitis was significantly affected by protein level, protein source, sex, and age. Hence, nutritional factors play a significant role in the etiology of pododermatitis in broilers.     

Use of taste repellants and emetics to prevent accidental poisoning of dogs

Twelve taste repellents and 3 oral emetics were tested. The taste repellents were capsaicin, capsicum, oleoresin, sucrose octaacetate, quinine tonic, quassia wood extract, vanillamide, horseradish extract, caffeine, pepperoni enhancer, acorn extract, and commercially available bitter and hot flavors. The emetics tested were: antimony potassium tartrate, apomorphine, and copper sulfate. Intake of a 20% sucrose solution by Beagles was significantly depressed by addition of vanillamide at concentrations greater than 0.001%, by capsicum and capsaicin at concentrations greater than 0.01%, and by horseradish extract, pepperoni enhancer, and a commercially available hot flavor at concentrations greater than 0.1%. Antimony potassium tartrate, when added to the 20% sucrose solution at a concentration of 0.1%, produced emesis as did apomorphine at a concentration of 0.005% and copper sulfate at 1%. When the emetic antimony potassium tartrate was combined with vanillamide in a 20% sucrose solution, intake was reduced to less than 20 ml, and vomiting occurred within 15 minutes. Capsaicin (0.02%) inhibited intake of ethylene glycol to less than the lethal dose in 5 dogs tested. Incorporation of such taste repellents and/or emetics into potentially poisonous substances would reduce accidental poisoning of animals and children.     

Effects of Daily Oral Administration of Copper to Goats

Three goats were dosed orally with a 0.2 % aqueous copper sulphate solution. The dosing was 20 mg copper sulphate/kg body weight twice a day for 56 to 113 days. One of the goats accumulated substantial amounts of copper in the liver and developed two haemolytic crises. The two other goats showed only increased liver copper concentrations before they were killed. The results indicate that the goats were susceptible in varying degrees to repeated oral copper dosing, and that two of the goats were significantly less susceptible to copper than sheep. The goat that turned into a haemolytic crisis showed changes similar to those seen in sheep as far as blood and plasma parameters are concerned. The gross and histological lesions were also mainly of the same type as described in sheep. The hepatic lesions found in the goat differed to some degree from those found in sheep as the necroses were more distinctly located to the centrilobular area, and as the iron pigments were mainly located in phagocytes in the hepatic sinusóides.     

Effects of dietary copper on elemental balance,plasma minerals and serum biochemical parameters of growing-furring male mink(Mustela vison)

The objectives of this study were to study the effects of different levels of dietary copper on copper and zinc balance, plasma minerals and serum biochemical parameters of mink in the growing-furring periods. One hundred and five standard dark male mink were randomly assigned to seven groups with the following dietary treatments: basal diet with no supplemental Cu(Control); basal diet supplemented with either 6,12, 24, 48, 96, or 192 mg/kg Cu from copper sulfate,respectively. The average daily gain(ADG) linearly(P = 0.0026, P = 0.0006) responded to increasing levels of Cu; maximal growth was seen in the Cu24 group. Feed efficiency tended to improve with the increase of dietary copper level(linear P = 0.0010, quad, P = 0.0011). Fecal copper, urinary copper, retention copper responded in a linear(P 0.05) fashion with increasing level of Cu. The effect of level of Cu was linear(P 0.001) for plasma Cu concentration. The serum glutamic-oxalacetic transaminase(GOT) and glutamic-pyruvic transaminase(GPT) activities were increased linearly(P 0.05) with dose of Cu, but serum total protein(TP) and albumin(ALB) concentrations decreased linearly(P 0.05) as dietary copper levels increased. Effect of level of Cu was linear(P 0.001) for serum ceruloplasmin(CER) concentration or Cu-Zn superoxide dismutase(Cu-Zn SOD) activity. Supplemental dose of Cu linearly decreased serum triglyceride(TG)(P = 0.011) and total cholesterol(TC)(P = 0.007). Our results indicated that the activity of Cu-dependent enzymes was enhanced by increasing dietary Cu concentration and that supplementation of Cu in the diet of mink could alter the plasma lipid profile and copper concentration.     

Effect of environmental stress on the responses of ascorbic-acid-treated chickens to Escherichia coli challenge infection

As the stressfulness of the environment increased (measured as increasing heterophil/lymphocyte [H/L] ratios), resistance of chickens to Escherichia coli challenge infection increased. At a relatively low level of environmental stress (H/L ratio = 0.33), the incidence of severe lesions was 22% in chickens fed diets containing 330 mg of ascorbic acid (AA)/kg and 80% in undosed controls. As the level of environmental stress increased, the dose of AA required for maximum reduction of the incidence of severe lesions increased, and the difference in lesion incidence between AA-dosed and undosed chickens decreased. When environmental stress resulted in H/L ratios of 0.53 or more, AA did not ameliorate the severity of infection. At levels of stress characterized by H/L ratios between 0.39 and 0.44, increasing doses of AA resulted in increased susceptibility to E. coli until a dose associated with maximum susceptibility was reached. Further increases in the dose of AA resulted in decreased susceptibility until a dose associated with maximum resistance was reached. In chickens fed feed containing 15 mg corticosterone/kg, increasing doses of AA resulted in increasing susceptibility to E. coli.     

Oral Lesions Associated with Orotracheal Administered Mechanical Ventilation in Critically III Dogs

The incidence and clinical progression of oral lesions in a cohort of critically ill patients administered mechanical ventilation via orotracheal intubation were observed prospectively in the Intensive Care Unit (ICU) of the University of California, Davis Veterinary Medical Teaching Hospital. Oral cavities of these patients were examined within 24 hours of being placed on the ventilator and at least daily thereafter during ventilator therapy. As part of the study protocol, any lesion noted was treated. Twenty-one critically ill canine patients (median age of 7 yrs; range <1 to 19 yrs) were observed from 1 January 1995 through 31 August 1995. Over ninety percent (90.5%) of the observed patients developed oral lesions subsequent to being mechanically ventilated. Erosive and ulcerative mucosal lesions were the most frequently observed (15/43) with the tongue being the most frequently involved oral structure. Most of the observed soft tissue oral lesions appeared secondary to persistently applied pressure from teeth, mouth gags, endotracheal tubes, and other monitoring devices. Efforts taken to prevent persistently applied trauma, such as periodic positional changes of equipment and padding of susceptible structures, apeared effective in preventing oral lesions. There were indications of gastric reflux in 6 patients (28.6%), as evidenced by secretions in the oral cavity with a pH of <6 and containing digested blood. Ulcerative lesions in the subset of patients with gastric reflux seemed to worsen in severity with exposure to the low pH secretions. Over the course of the study, the ICU nursing staff developed an effective protocol for the care of the oral cavity: treating mucosal erosions and ulcers topically8 with a dilute chlorhexidine solution (0.05%), removing oral secretions via suction as needed, and padding persistently traumatized tissues with glycerin moistened gauze. Oral lesions in orotrachealy intubated and mechanically ventilated patients are predictable, preventable, and treatable. Most lesions are pressure induced, associated with monitoring/therapeutic equipment, and appear to be preventable with appropriate nursing protocls. Most observed oral lesions clinically improved with routine, periodic dilute chlorhexidine rinses and relief of applied pressure.     

Efficacy in turkeys of spray vaccination with a temperature-sensitive mutant of Bordetella avium (Art Vax)

Broad-breasted white turkeys were vaccinated with a temperature-sensitive mutant of Bordetella avium (Art Vax) at 2 and 15 days of age and challenged at 22 days of age by contact with infected birds. Necropsy was performed at 35 days of age. Two vaccination protocols (eyedrop/oral and spray cabinet/spray bottle) and two challenge isolates (Arkansas 105 and North Carolina [NC] isolates) were used. Neither the spray nor the eyedrop/oral methods of vaccination prevented infection of the anterior trachea with either of the virulent challenge strains. The spray and eyedrop/oral methods of vaccination were equally effective in reducing the severity of gross lesions in the trachea. The vaccine reduced the severity of gross lesions in the tracheas of turkeys challenged with the NC isolate to a level approximately equal to that observed in unchallenged vaccinated controls, but the vaccine only moderately reduced the severity of lesions in birds challenged with the 105 isolate.     

不同来源日粮铜水平对肉鸡肝线粒体H_2O_2 生成变化的研究

本研究旨在探讨不同来源日粮铜水平对肉鸡肝线粒体H_2O_2生成变化的影响.选用硫酸铜、蛋氨酸铜作为源铜,每种源铜均设4个浓度梯度.288只1日龄科宝商品代肉鸡随机分为8组,每组36只,分别喂以对照日粮(Cu 11 mg·kg~(-1),Ⅰ组)和高铜日粮(Cu 110 mg·kg~(-1),Ⅱ组;Cu 220 mg·kg~(-1),Ⅲ组;Cu 330 mg·kg~(-1),Ⅳ组)60 d,并于12、36和60日龄取样,观察肉鸡肝线粒体H_2O_2生成速率变化.结果:与对照组相比,2种来源的高铜Ⅱ组、Ⅲ组和Ⅳ组肉鸡肝线粒体H_2O_2生成速率显著加快(P＜0.05或P＜0.01);试验第36和60天时,蛋氨酸铜各组肉鸡肝线粒体过氧化氢生成速率均高于相应的硫酸铜各组(P＜0.05或P＜0.01),并且,高铜日粮饲喂的肉鸡肝线粒体H_2O_2生成部位主要集中在线粒体呼吸链复合体Ⅳ.结果表明:高铜日粮可诱导肝脏的氧化应激损伤;同剂量的有机铜螯合物比无机铜更易加快肝脏线粒体H_2O_2生成速率,并可推测,线粒体呼吸链复合体Ⅳ是机体在高铜刺激下攻击的靶部位之一.     

Natural Resolution of Air Sac Lesions Caused by Mycoplasma meleagridis in Turkeys

Lesions caused by Mycoplasma meleagridis were followed in one hatch of turkeys from one day to 20½ weeks of age. Air sac lesion incidence increased from 20% at one day to 44% at six weeks of age with a slow decline to 10% at 10 weeks of age. Lesions were detectable on careful examination at 10-20% level to 20 weeks of age on laboratory examination, but at 20½ weeks only 0.07% lesions were found in 1000 turkeys from the same hatch.

Air sac lesion severity, based on an arbitrary 0.5,1,2,3,+scale, increased in intensity and spread of air sac involvement from a mean of 1.5 at day old to 2.5 at five weeks of age. This declined to 1.0 at 10 weeks of age and lesions became progressively more faint until careful examination was necessary to detect them in birds 15 weeks and older. The latter would not be considered as a cause of total condemnation.

The percentage of Mycoplasma isolations from the respiratory tissues were much higher in birds exhibiting air sac lesions than those in which no typical air sac lesions were visible, as follows. air sacs 51.6 vs. 2.9, lungs 43.3 vs. 4.0, trachea 47.2 vs. 4.6, sinus 38.5 vs. 19.0.

     

What is your diagnosis? Particulate material in peritoneal fluid from a dog

9-year-old castrated male Greyhound dog was presented for evaluation of vomiting and lethargy of 1-week duration. On physical examination, the dog was febrile and dehydrated with a tense abdomen and petechial hemorrhages. Clinicopathologic abnormalities included relative polycythemia, mild lymphopenia with reactive lymphocytes, hypoalbuminemia, hypocholesterolemia, hyperbilirubinemia, increased ALP, mild hypokalemia, hyperamylasemia, hyperlipasemia, increased D-dimer concentration, and hyperfibrinogenemia. Cytologic evaluation of peritoneal fluid revealed marked suppurative inflammation with intracellular barium sulfate particles. The day before presentation, the referring veterinarian had administered oral barium sulfate in an upper gastrointestinal contrast study. Radiographs revealed free contrast material in the peritoneal cavity, consistent with gastrointestinal perforation, and leakage of contrast material. Abdominal exploratory surgery revealed a mid-jejunal perforation and a hepatic nodule. Histopathologic diagnosis of the jejunal and liver lesions was T-cell lymphoma. The patient recovered well postoperatively and received chemotherapy for treatment of lymphoma. Most commercial barium sulfate preparations contain relatively uniform, weakly birefringent, pale yellow particles <1 microm in diameter. Because barium sulfate is found occasionally in clinical specimens, cytopathologists should be familiar with its cytologic appearance.     

Studies on Haemoglobin Polymorphism of Two Breeds of Iranian Sheep and Its Relationship to Concentrations of Iron,Copper, Haemoglobin,Haematocrit and RBC number

After electrophoresis on cellulose acetate, two haemoglobin phenotypes were detected in Baloochi and Kordi breeds: AA and AB phenotypes. AA was commonest in two breeds. The incidence of type AB haemoglobin in Baloochi and Kordi breeds was 26.5% (9/34) and 9.5% (2/21), respectively. BB phenotype was not seen in Baloochi and Kordi breeds. In sheep with AB phenotype, haemoglobin B was dominant. The mean +/- SD of the two kinds of haemoglobin in sheep with AB phenotype were haemoglobin B percentage 60.5% +/- 9.04%, haemoglobin B absolute 73.84 +/- 5.44 g/L, haemoglobin A percentage 39.5% +/- 9.04%, haemoglobin A absolute 32.88 +/- 2.89 g/L. There were no significant differences for total haemoglobin, haematocrit, red blood cell (RBC) number, iron and copper levels between breed, sex and age groups and also between sheep with AA phenotype and AB phenotype. Pearson's method showed significant correlations for total haemoglobin with packed cell volume (PCV), RBC number, copper concentration and RBC number with PCV, copper level and PCV with copper amount and copper concentration with iron level (p<0.05). In the Kordi breed, significant correlations were seen for total haemoglobin with PCV, RBC number, copper concentration and PCV with RBC number and RBC number with copper level and copper concentration with iron amount (p<0.05). In the Baloochi breed, significant correlations were detected for total haemoglobin with PCV, RBC number and PCV with RBC number (p<0.05).     

Treatment of Trichophyton mentagrophytes infection in rabbits

Copper sulfate and a metastabilized chlorous acid/chlorine dioxide (MECA) compound were evaluated for efficacy in treating Trichophyton mentagrophytes infection in rabbits. Forty rabbits naturally infected with T mentagrophytes were allotted to 5 treatment groups: nontreated control, sham dip, 1% copper sulfate dip, MECA dip, and MECA spray. Results of lesion culture, regression of gross lesions, and histopathologic findings were documented. Copper sulfate and MECA were effective in treating clinical dermatophytosis and in decreasing T mentagrophytes carrier status in rabbits.     

The effect of an acidified, ionized copper sulphate solution on digital dermatitis in dairy cows

Digital dermatitis (DD) is the most important infectious claw disorder in dairy cattle and herd-based foot bathing with antibacterials, such as 4% formalin, is often used to prevent it. However, there is a lack of long-term studies of the effectiveness of such regimes and in this study the preventive and curative effect of 4% formalin was compared with that of an acidified, ionized copper sulphate solution over a 4-month period on a commercial 120-cow dairy farm. The cows were walked through a split-leg footbath where left claws were treated with an acidified copper solution twice daily for 5days/week, while right claws were treated with 4% formalin twice daily for 1day/every second week. Hind claws were scored for the presence and severity of DD in a trimming chute at the start of the study and every 4weeks throughout the study period. At the start of the study 21/110 cows had ulcerative DD lesions with 10 on the left hind foot, 8 on the right and 3 on both. These lesions, as well as any new lesions which arose during the study, were treated with chlortetracycline spray. During the study 440 observations were made and seven new DD lesions were recorded on left feet (copper treated) and 20 on right feet (formalin treated). Based on survival analysis, the risk of developing a new ulcerative DD lesion on copper-treated (left hind) feet was almost three times less (RR=0.37, 95% CI 0.16-0.91) than formalin-treated (right hind) feet. Cure rates of DD lesions were not different between copper and formalin.     

The Incidence of Lymphoplasmacytic Gastritis in the Fundus and Antrum of Cynomolgus Monkey ( Macaca fascicularis ) Stomachs

Lymphoplasmacytic gastritis is a concern for toxicological pathologists reading preclinical, non-human primate toxicity studies because subtle gastric changes which could be treatment-related may be masked and gastritis lesions may be confused with treatment-related effects and thus a gastric finding may be incorrectly assigned as a treatment-related lesion. This paper discusses the incidence of lymphoplasmacytic gastritis in cynomolgus monkeys at a contract research organization. The incidence of lymphoplasmacytic gastritis in the fundus and antrum of control cynomolgus monkeys on 18 non-gastric compound studies, was scored. The average fundus score ranged from 0.3 to 1.5 and the average antral score ranged from 0.9 to 3.5 in the cynomolgus monkey stomachs examined. The number of affected control animals in a study ranged from 0 to 5 control animals. No correlation between the route of vehicle administration and the severity or incidence of the lesions was noted. The percentage incidence of affected animals ranged from 0 to 100%. An increased incidence lymphoplasmatic gastritis from 2000 to 2004 was noted. The implications of lymphoplasmacytic gastritis in cynomolgus monkeys used for acute toxicity studies are discussed.     

Efficacy of Copper Sulfate for the Treatment of Ichthyophthiriasis in Channel Catfish

Abstract

Ichthyophthirius multifiliis is a protozoan that may infest and significantly damage cultured fish species. The purpose of this study was to measure the efficacy of copper sulfate in treating ichthyophthiriasis. Fingerling channel catfish Ictalurus punctatus exposed to at least 2,000 theronts of I. multifiliis per liter of water developed consistent infestations of I. multifiliis (20 or more trophonts on the dorsal surface of the head of the fish). Infestation was observed in untreated controls at day 5 after exposure and mortality occurred after day 10. Coexposure studies with theronts and different concentrations of copper sulfate revealed that all theronts were killed at concentrations greater than 0.05 mg/L. To determine the effect of copper sulfate in the treatment of ichthyophthiriasis, fish were exposed to the parasite until trophonts were observed (day 5), and they were subsequently treated with copper sulfate. The lowest effective concentration of copper sulfate for treatment of ichthyophthiriasis (i.e., after infestation was observed in the fish) was 0.4 mg/L. To assess the effects of various water quality conditions on copper treatment, total suspended solids (TSS) and pH were varied during treatment of ichthyophthiriasis. Concentration of TSS was inversely correlated to the efficacy of copper sulfate for I. multifiliis infestations, whereas no relationship was observed between pH and efficacy of a single copper sulfate dose. The results indicated that copper sulfate can be used to treat ichthyophthiriasis at concentrations of 0.4 mg/L for at least 5 d under the specific water conditions used in this study (pH, 7.45 ± 0.27; temperature, 20.5 ± 0.7°C; alkalinity, 176.6 ± 28.1 mg/L as CaCO₃) and that efficacy of copper sulfate was affected more by TSS concentration than by pH.     

不同形态的铜对猪生长性能及血清GH、血浆NPY水平的影响

将75头体质量约20kg的“军牧1号”白猪，分成A、B、C、D、E组。A组为对照组，饲以基础日粮，B、C2组分别饲以添加122．5、250mg／kg铜(硫酸铜)的日粮；D、E2组分别饲以添加122．5、250mg／kg蛋氨酸铜的日粮，观测不同形态的铜对仔猪生长性能以及血液GH、血浆NPY水平的影响。结果显示：日粮中添加2种铜均能促进仔猪的生长，提高饲料利用率，升高血液中GH和血浆NPY水平，但对采食量没有显著影响，2种铜源在相同浓度下对猪的促生长性能无差异。     

Comparison of topical application of oxytetracycline and four nonantibiotic solutions for treatment of papillomatous digital dermatitis in dairy cows

OBJECTIVE: To compare efficacy of topical treatment with oxytetracycline solution or 1 of 4 nonantibiotic solutions among dairy cows with papillomatous digital dermatitis (PDD). DESIGN: Randomized field trial. ANIMALS: 66 cows in a single herd. PROCEDURE: Cows were randomly assigned to be treated with oxytetracycline solution; a commercial formulation of soluble copper, peroxide compound, and a cationic agent; 5% copper sulfate solution; acidified ionized copper solution; hydrogen peroxide-peroxyacetic acid solution; or tap water. Cows were examined 14 and 30 days after initial treatment. During each examination, pain and lesion scores were recorded. RESULTS: On the basis of pain and lesion scores, oxytetracycline and the commercial formulation appeared equally effective for treatment of PDD and significantly more effective than 5% copper sulfate solution, acidified ionized copper solution, hydrogen peroxide-peroxyacetic acid solution, and tap water. Proportions of cows with signs of pain or visible lesions after treatment were significantly lower for cows treated with oxytetracycline or the commercial formulation than for cows in the other groups. CLINICAL IMPLICATIONS: Oxytetracycline and a commercial formulation of soluble copper, peroxide compound, and a cationic agent appeared to be effective for treatment of PDD in dairy cows.