Efficacy of moxidectin against naturally acquired nematode infections in cattle.

The efficacy of moxidectin, a new endectocide against natural nematode infections, was evaluated. Twenty-five calves were divided into two groups of eight calves each and a third group of nine calves. Moxidectin was administered s.c. to two groups (I, 0.2 mg kg-1 body weight (BW); II, 0.3 mg kg-1 BW) and the third group (III) received the vehicle (placebo) s.c. Two pre-treatment and one post-treatment faecal nematode egg count determinations were made from all calves, and they were necropsied 2 weeks after treatment for the identification and enumeration of nematode parasites. Group III calves, which received the drug-free vehicle, harboured eight species of nematodes (Ostertagia ostertagi, Trichostrongylus axei, Cooperia oncophora, Cooperia punctata, Nematodirus helvetianus, Trichuris discolor, Oesophagostomum radiatum and Dictyocaulus viviparus). The mean total worm burden for this group was 8935. There was a significant reduction in the numbers of many species of nematodes (Ostertagia, Trichostrongylus, Cooperia and Nematodirus) in both treated groups. Cooperia oncophora was reduced by 94% in Group I and by 96% in Group II, while all other nematode species were reduced by 99%. Immature stages of Ostertagia and Nematodirus were significantly reduced in the two treated groups. Two weeks after treatment, the mean faecal egg counts of both treated groups were reduced by more than 98%. There was no significant difference in mean total worm burdens or egg counts between the two treated groups.     

Efficacy of albendazole for treatment of naturally acquired nematode infections in Washington cattle.

Albendazole, methyl 5-propylthio-1H-benzimidazol-2-yl carbamate, was given as a bolus (7.68 to 8.18 mg/kg of body weight) to cattle naturally infected with gastrointestinal nematodes and lungworms in a controlled trial. Over 99% of adult Ostertagia ostertagi, Trichostrongylus longispicularis, Cooperia oncophora, Nematodirus helvetianus, and Dictyocaulus viviparus were removed by the treatment. Efficacy against immature O ostertagi, early fourth-stage O ostertagi, and Oesophagostomum radiatum was 95.2%, 86.6%, and 96.7%, respectively. In a field trial, the same compound administered in a paste formulation (at approximately 7.5 mg/kg) eliminated over 99% of strongylin and Moniezia eggs from feces of treated cattle.     

Assessment of serum protein fractions in rainbow trout using automated electrophoresis and densitometry

Background: Although rainbow trout (Oncorhynchus mykiss, Walbaum) are one of the most‐studied fish, electrophoretic techniques and classification of serum protein fractions have not been standardized, such that clinically useful values are lacking. Objective: The aim of the present study was to evaluate preliminarily the serum protein fractions of rainbow trout using automated cellulose acetate electrophoresis and densitometry. Methods: Serum samples from 25 rainbow trout (Oncorhynchus mykiss, Walbaum) were electrophoresed on cellulose acetate plates and quantified using densitometry. Results: A maximum of 6 fractions were identified and numbered, in order of decreasing mobility, as I, II, III, IV, V, and VI. In 3 of 25 (12%) samples, 6 fractions were identified; in 18 (72%) samples, 5 fractions were identified; and in 4 (16%) samples, 4 fractions were identified. Fractions I, V, and VI were always clearly identifiable, whereas fractions II and IV were frequently fused and indistinguishable from fraction III. The pattern with 5 fractions was the most probable type (χ², P<.01). The mean (±SEM) protein concentrations of the 6 fractions were I, 0.8±0.1 g/dL; II, 0.3±0.0 g/dL; III, 1.6±0.1 g/dL; IV, 0.3±0.1 g/dL; V, 0.6±0.0 g/dL; and VI, 0.2±0.0 g/dL. Based on comparison of serum and plasma electrophoretic patterns from 8 fish, fibrinogen was found in fraction V. Conclusion: Automated cellulose acetate electrophoresis and densitometry appear to be a practical method for estimation of serum protein fractions in rainbow trout.     

Effects of milbemycin oxime on adult hookworms in dogs with naturally acquired infections

Previous work indicated that adult Ancylostoma caninum can be removed from experimentally infected dogs, using a formulation of milbemycin oxime at dosage of 0.5 mg/kg of body weight. To determine the efficacy of this treatment in dogs naturally infected with adult hookworms, 24 mixed-breed dogs with patent hookworm infections were purchased from an out-of-state vendor, and 6 male and 6 female dogs were assigned to either a control group or a group that would be treated. Dogs were treated 10 days after their arrival and were euthanatized 1 week after treatment. Beginning 3 days before treatment, fecal samples were collected daily from all dogs, and the number of Ancylostoma eggs per gram of dry weight of feces was determined from each sample. By 1 week after treatment, the mean number of eggs being passed by the treated dogs had dropped from 12,700 to 10 eggs/g of dried feces; there was no apparent change in fecal egg counts for dogs of the control group. At necropsy, the mean number of adult A caninum in dogs of the treated and control groups was 1.3 and 56, respectively; in these naturally infected dogs, efficacy of treatment was calculated to be 97.8%. The mean number of adult Trichuris vulpis recovered in dogs of the control and treated groups at necropsy was 24 and 0, respectively, which yielded treatment efficacy of 100%. Although Uncinaria stenocephala and Toxocara canis appeared also to be removed by use of this dosage, too few dogs were in the study to calculate meaningful efficacies.(ABSTRACT TRUNCATED AT 250 WORDS)     

Resistance of Santa Ines and crossbred ewes to naturally acquired gastrointestinal nematode infections

This trial was carried out in Piracicaba, São Paulo State, Brazil, to comparatively evaluate the degree of resistance to naturally acquired gastrointestinal nematode infections in sheep of the following genetic groups: purebred Santa Ines (SI), SI crossbred with Dorper (DO × SI), Ile de France (IF × SI), Suffolk (SU × SI), and Texel (TE × SI). Fifteen ewes from each group were raised indoors until 12 months of age. At this age, they were moved to pasture that was naturally contaminated by nematode infective larvae and were evaluated from December to May, 2007. Rainfall ranged from 267 mm in January to 37 mm in April. Maximum and minimum mean temperatures ranged from 32.5 °C to 19.0 °C in March and from 25.9 °C to 12.8 °C in May. There was an increase in the mean number of eggs per gram of feces (EPG) after animals were placed on pasture with significant difference between the SI (80 EPG) and IF × SI (347 EPG) groups in January; and the DO × SI (386 EPG) and TE × SI (258 EPG) groups in May. The highest mean fecal egg count (FEC), 2073 EPG, was recorded for the TE × SI group in February. All groups showed a progressive reduction in body weight throughout the experiment of 12.0% (TE × SI) to 15.9% (SU × SI). In general, the animals with the highest FEC presented the lowest packed cell volumes (PCV); the highest correlation coefficient between FEC × PCV occurred in the SU × SI sheep in January (r = −0.70; P < 0.01). Similarly, there was an inverse relationship between FEC and blood eosinophil values, with the highest correlation coefficient in the TE × SI sheep in February (r = −0.64; P < 0.05). Immunoglobulin G (IgG) levels against Haemonchus contortus antigens increased in all groups as a result of the exposure to parasites and remained relatively constant until the end of the study, with the exceptions of SU × SI and TE × SI, which showed a rise in IgG levels during the last sampling that coincided with a reduction in mean FEC. In conclusion, crossbreeding Santa Ines sheep with any of the breeds evaluated can result in a production increase and the maintenance of a satisfactory degree of infection resistance, especially against H. contortus and Trichostrongylus colubriformis, the major nematodes detected in this flock.     

Determination of serum organic acids in puppies with naturally acquired parvoviral enteritis

The purpose of the present study was to investigate the acid-base status and the serum concentration of organic acids in puppies with naturally occurring canine parvoviral enteritis. Between July 1999 and July 2000, 25 client-owned puppies admitted to the St. Louis Animal Emergency Clinic South for treatment of enteritis caused by parvovirus infection were used in our study. Control blood samples were collected from 22 healthy puppies less than 9 months of age. Serum organic acid concentrations were quantitatively determined by HPLC. Puppies infected with parvovirus had significantly lower plasma concentrations of sodium, potassium, chloride, and bicarbonate than controls. Although serum L-lactate tended to increase in some puppies with canine parvoviral enteritis, our study demonstrated that most affected puppies developed only mild compensated metabolic acidosis. None of the affected puppies had an elevated serum D-lactate concentration at admission.     

Assessment of an immunoturbidimetric method for measuring equine serum haptoglobin concentrations.

Serum haptoglobin was measured by immunoturbidity in Thoroughbreds stabled in three Newmarket yards for nine months. The mean serum haptoglobin value for horses housed in Stable 1 was 1.43 +/- 0.68 g/litre, similar to values in grazing adult ponies. The mean monthly haptoglobin values remained constant. For horses in Stable 2 there was an increase in serum haptoglobin values in June and July whereas, in Stable 3, the increases early in the training season were associated with an increase in serum viral titres. In equine serum, haptoglobin values estimated in g/litre by immunoturbidimetry were twice the haemoglobin binding capacity (HbBC). The correlation coefficient, between the methods, exceeded 0.96. Surgical interference caused a 2- to 3-fold increase in serum haptoglobin, with levels peaking between three and five days post surgery. The concomitant presence of haematomata following surgical interference (castration) resulted in the disappearance of haptoglobin from the circulation. There was no significant increase in serum haptoglobin levels following vaccination of Thoroughbreds against influenza and tetanus. However inhalation of influenza virus by vaccinated and non-vaccinated ponies resulted in a 2- to 3-fold increase in both groups of ponies, peaking seven to 10 days post infection. Serum haptoglobin proved to be a useful indicator of infection/inflammation and haemolytic disease in the horse and could be used to monitor the health status of stabled Thoroughbreds.     

Resistance to moxidectin and abamectin in naturally acquired Ostertagia circumcincta infections in sheep

AIM: To investigate the occurrence of resistance to macrocylic lactone (ML) anthelmintics by Ostertagia circumcincta in lambs on a sheep and cattle property in the North Island of New Zea- land.

METHODS: Thirty lambs were randomly allocated to one of five equal-sized groups, consisting of an untreated control and four treatment groups. The treatments, which were administered at the manufacturer's recommended dose rates, included oral moxidectin, oral abamectin (both at 0.2 mg/kg), an albendazole-levamisole combination, and an albendazole-levamisole-ivermectin combination. Post mortem worm counts were undertaken 7 days after treatment to determine the efficacy of each anthelmintic.

RESULTS: The albendazole-levamisole and albendazole-levam-isole-ivermectin combinations both reduced O. circumcincta burdens to zero whereas for moxidectin and abamectin efficacies of only 72% and 29%, respectively, were recorded.

CONCLUSIONS: These results clearly demonstrated the occurrence of resistance to MLs by O. circumcincta. Although this is not the first occasion where resistance to this anthelmintic family has been detected in this parasite in sheep in New Zealand, it is the first instance that resistance to either moxidectin or abamectin has been reported.     

Resistance to moxidectin and abamectin in naturally acquired Ostertagia circumcincta infections in sheep

AIM: To investigate the occurrence of resistance to macrocyclic lactone (ML) anthelmintics by Ostertagia circumcincta in lambs on a sheep and cattle property in the North Island of New Zealand. METHODS: Thirty lambs were randomly allocated to one of five equal-sized groups, consisting of an untreated control and four treatment groups. The treatments, which were administered at the manufacturer's recommended dose rates, included oral moxidectin, oral abamectin (both at 0.2 mg/kg), an albendazole-levamisole combination, and an albendazole-levamisole-ivermectin combination. Post mortem worm counts were undertaken 7 days after treatment to determine the efficacy of each anthelmintic. RESULTS: The albendazole-levamisole and albendazole-levamisole-ivermectin combinations both reduced O. circumcincta burdens to zero whereas for moxidectin and abamectin efficacies of only 72% and 29%, respectively, were recorded. CONCLUSIONS: These results clearly demonstrated the occurrence of resistance to MLs by O. circumcincta. Although this is not the first occasion where resistance to this anthelmintic family has been detected in this parasite in sheep in New Zealand, it is the first instance that resistance to either moxidectin or abamectin has been reported.     

A review of feline serum protein electrophoresis

A review of the current literature available on feline serum proteins is presented. Early studies concentrated on comparative aspects of species variations in the electrophoretic pattern. The feline electrophoretogram was divided into five basic regions: albumin, alpha-1, alpha-2, beta and gamma. Different subdivisions of these areas were recognized depending on the support medium used. Current papers have compared the relative migration distances of each globulin peak to the migration of albumin. This "Rf" value enables reliable peak identification. To date, no data exists identifying the individual proteins responsible for the peaks in the alpha and beta regions. The only feline globulin to be studied is haptolobin; however its precise location on the electrophoretic strip was not identified.     

An evaluation of apramycin soluble powder for the treatment of naturally acquired Escherichia coli infections in broilers

During 1983, a series of trials was carried out in Greece, Italy and Jordan, to test the efficacy of the aminocyclitol antibiotic apramycin as a treatment for naturally acquired Escherichia coli infections in broilers. The trials involved a total of 40,389 broilers, 27-39 days of age, in twelve houses at eight different production sites. Three levels of apramycin medication were evaluated: 125, 250 and 500 mg activity/litre drinking water, administered for five consecutive days. Treatment was only initiated after disease had been confirmed by laboratory examination of dead birds. Not all treatments were evaluated in every house. However, each house contained a group of unmedicated birds as controls, while the remaining birds were allocated to one or more apramycin treatment groups. There was a reduction in mortality and an improvement in the final weight and the economic feed conversion ratio in all three treatment groups. The data presented provide support for the use of apramycin sulphate administered in the drinking water for the treatment of E. coli infections in broilers.     

Ivermectin treatment of naturally acquired and experimentally induced Strongyloides stercoralis infections in dogs.

Treatment of Strongyloides stercoralis infection was investigated in 2 dogs with naturally acquired, chronic-active infections, and in 3 dogs with corticosteroid-enhanced, experimentally induced hyperinfections. A single oral dose of ivermectin was given to naturally infected (200 micrograms/kg of body weight) and experimentally infected (800 micrograms/kg) dogs. Five dogs with experimental hyperinfections served as controls. Dogs with naturally acquired infections ceased to shed first-stage larvae in the feces 1 week after treatment, but 1 dog had recrudescence and required a second dose. Ivermectin was 100% effective in removing adult S stercoralis from the intestinal tract of the experimentally infected dogs, but it was not effective in removing third-stage larvae from parenteral sites. Ivermectin-treated dogs had few intestinal parasites of any stage, whereas at necropsy, 4 of 5 experimentally infected dogs not treated had massive infections (greater than 100,000 adults, greater than 92,000 larvae) in the intestinal tract, and 3 of 5 had larvae (greater than 2,500) in parenteral sites.     

Fenbendazole as a therapy for naturally acquired Stephanurus dentatus and gastrointestinal nematodes in feral swine

Adult feral swine, naturally infected with kidney worms (Stephanurus dentatus) and gastrointestinal nematodes, were divided into two groups of 10 pigs each. One group was treated with fenbendazole (Panacur, Hoechst AG, Frankfurt am. Main) mixed in feed at the rate of 3 mg kg-1 body weight for 3 days. The second group received feed only and was designated as non-treated controls. The animals in both groups were necropsied 3 weeks post-treatment and examined for the presence of live and dead adult kidney worms in the perirenal and ureteral area, ureteral penetration, the presence of kidney worm larvae in the liver, hepatic scars due to kidney worm larval migration, and for liver fibrosis. No live adult kidney worms were found in the perirenal and ureteral areas of treated pigs, and the non-treated pigs harbored an average of 42.8 live worms. No liver kidney worm larvae were found in the livers of treated pigs, and the non-treated pigs averaged 6.7 live larvae. At necropsy, urine samples from 8 of the 10 treated pigs contained no kidney worm eggs, and only 2 eggs were found in samples from each of the remaining 2 pigs in this group. In contrast, urine samples from 8 of the non-treated pigs contained numerous kidney worm eggs. Reductions in ascarid (Ascaris suum) and nodular worm (Oesophagostomum dentatum) egg counts were also observed in treated pigs.     

The diagnostic utility of serum protein electrophoresis.

Routine serum protein electrophoresis is recognized as the most reliable assessment of avian protein profiles in health and disease and has replaced biochemical determination of albumin and A:G ratio in the ability to predict abnormalities of clinical significance. The importance of considerable species differences to the overall interpretation of avian electrophoresis is well established and constitutes a continued challenge to the avian specialist and to the providing laboratories to continue the pursuit of species-specific, even age- and gender-specific, reference ranges. Patterns for various diseases continue to emerge as more scrutiny is applied to the use of this tool in avian diagnostics for overall health assessment as an adjunct to specific disease diagnosis and for both prognostic and therapeutic monitoring.