猪流行性腹泻或丁型冠状病毒对仔猪生长性能和机体组成的影响

猪流行性腹泻病毒(PEDV)和猪丁型冠状病毒(PDCov)都属于冠状病毒科,它们会引起仔猪腹泻、脱水的临床症状,在某些情况下还会导致死亡.本研究旨在评估PEDV和PDCov对仔猪感染后42 d的生长性能和组织增生的影响.将断奶后14 d、平均体重为(10.82±0.78)kg的225头仔猪随机分为3组,每组5个重复,每...     

Activity of an anti-inflammatory drug against cryptosporidiosis in neonatal lambs

The efficacy of the anti-inflammatory drug Bobel-24 against experimental infection by Cryptosporidium parvum was evaluated in neonatal lambs. The animals were treated by oral administration of the drug at 50 or 500 mg/kg of body weight. The prophylactic/therapeutic treatment was started 4 h before inoculation of the lambs with oocysts and was continued for eight consecutive days. The therapeutic treatment was initiated at the onset of diarrhoea, after confirmation of infection, and was continued for six consecutive days. Infection was monitored by daily examination of faecal samples from the first day until 30 days post-inoculation. The criteria considered in evaluating development of the infection and the drug activity were: oocyst shedding, presence of diarrhoea and weight gain at 15 and 30 days post-inoculation. Bobel-24 was effective as a prophylactic/therapeutic treatment at the lowest dose (50 mg/kg of body weight); in the group treated with this dose of drug there was a longer prepatent period, a shorter patent period and a lower intensity of oocyst excretion than in the untreated control group, and the differences were all statistically significant (P<0.05). Moreover, one animal did not excrete oocysts, and two lambs had diarrhoea, for only 1 and 2 days. In the group treated with the higher dose of the drug, the diarrhoea lasted for a significantly shorter period (P<0.05) than in the untreated group.     

THE EFFECTIVENESS OF LEVAMISOLE HYDROCHLORIDE IN THE TREATMENT OF ADULT DIROFILARIA IMMITIS

Dogs infected with D. immitis were treated with oral levamisole hydrochloride at various dose rates over different durations. Clinical toxicity, haematological and biochemical parameters, body weight and food intake were recorded and filarial mortality estimated at autopsy. All filariae were dead in dogs treated at 10 mg/kg body weight twice daily (12 hourly) for 14 days, with minimal clinical toxicity being seen during the treatment period.     

Water intake of weaned piglets from three to seven weeks old

One hundred and two large white cross landrace piglets weaned at 21 (+/- 1) days old were randomly allocated to one of two commercial early weaning diets for a four week growth trial. The piglets were housed in groups of between six and 10. After initial moderate restriction the piglets were fed ad libitum. Food intakes and weight gains were recorded weekly. Water consumption of individual pens of piglets was recorded daily. Dietary treatment had no significant effect on mean daily feed intake, daily liveweight gain or food conversion ratio. The relationship between water and food intake, piglet weight and daily gain was examined using regression and multiple regression analyses. Water intake was related to all these parameters, with daily feed intake being the best single predictor of water intake. The relationship was described by the equation: water intake (litres/day) = 0.149 + 3.053 feed intake (kg/day).     

Gastrointestinal motor disturbance in rabbits experimentally infected with Strongyloides papillosus

Strongyloides papillosus is a common nematode in ruminants, and the rabbit is the only susceptible experimental animal that has been identified to date. It is known that heavy infection with S. papillosus causes death in a number of animals. However, even though a number of fatal cases have been reported, the mechanism by which S. papillosus infection leads to death remains unknown. In this study, the pathogenic effect of S. papillosus infection on gastrointestinal motility in infected rabbits was investigated by radiographic means. Gastrointestinal motility in rabbits experimentally infected with S. papillosus was assessed by contrast radiography after oral administration of barium sulfate on days 11 (group A) and 13 (group B) of infection. Body weight, food intake, fecal weight and egg count per gram of feces (EPG) were examined in order to investigate the effect of infection on gastrointestinal motility. Seven rabbits from each S. papillosus-infected and uninfected group were examined. Significant declines in body weight, daily food intake, and fecal weight, as well as gastrointestinal motor disturbances, were observed in association with elevated EPG counts in infected rabbits. This was only observed during the intestinal phase of S. papillosus infection. These results suggest that gastrointestinal motor disturbances underlie the anorexia, weight loss and subsequent death observed in rabbits infected with adult stage S. papillosus.     

Effects of human alpha interferon on experimentally induced equine herpesvirus-1 infection in horses

The immunotherapeutic effect of low-dose human alpha interferon on viral shedding and clinical disease was evaluated in horses inoculated with equine herpesvirus-1 (EHV-1). Eighteen clinically healthy weanling horses, 5 to 7 months old, were allotted to 3 equal groups. Two groups were treated orally with human alpha-2a interferon (0.22 or 2.2 U/kg of body weight), on days 2 and 1 before inoculation with EHV-1, the day of inoculation, and again on postinoculation day 1. The horses of the remaining group were given a placebo orally on the same days. The horses were monitored daily for changes in body temperature and for clinical signs of respiratory tract disease. Blood and nasal swab specimens were collected daily for virus isolation. Blood was also collected at intervals throughout the monitoring period for evaluation of CBC, serum IgG and IgM concentrations, and antibody titers to EHV-1. Febrile responses, nasal discharge, viral shedding, changes in CBC, and an increase in antibody titers to EHV-1 were noticed in all horses after inoculation. There was no significant difference (P greater than 0.05) in mean values of the factors measured between treatment and control groups.     

Effect of mild restriction of food intake on the speed of racing Greyhounds

OBJECTIVE: To determine whether mild restriction of food intake affects clinicopathologic variables, body composition, and performance of dogs undertaking intense sprint exercise. ANIMALS: 9 trained healthy adult Greyhounds. PROCEDURE: Dogs were offered food free choice once daily for 9 weeks until body weight and food intake stabilized. Dogs were then randomly assigned to be fed either 85% or 100% of this quantity of food in a crossover study (duration of each diet treatment period, 9 weeks). Dogs raced a distance of 500 m twice weekly. Clinicopathologic variables were assessed before and 5 minutes after racing; food intake, weight, body composition, body condition score, and race times were compared at the end of each diet period. RESULTS: Compared with values associated with unrestricted access to food, there were significant decreases in mean body weight (by 6%) and median body condition score (from 3.75 to 3.5 on a 9-point scale) and the mean speed of the dogs was significantly faster (by 0.7 km/h) when food intake was restricted. Body composition and most clinicopathologic variables were unaffected by diet treatment, but dogs given restricted access to food had slightly fewer neutrophils, compared with values determined when food intake was unrestricted. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that the common practice among Greyhound trainers of mildly restricting food intake of racing dogs to reduce body weight does improve sprint performance. A body condition score of approximately 3.5 on a 9-point scale is normal for a trained Greyhound in racing condition.     

Efficacy of alpha-cyclodextrin against experimental cryptosporidiosis in neonatal goats

The efficacy of orally administered tablets containing alpha-cyclodextrin, an excipient used in the pharmaceutical industry with demonstrated anticryptosporidial activity in vitro and in neonatal mice, was evaluated in neonatal goat kids. The formulation was evaluated for hardness and was subjected to in vitro drug release studies. Twenty goat kids were orally inoculated with 10(6) oocysts of C. parvum within the first 6 days of age. Half of the animals were treated by oral administration of four tablets of alpha-cyclodextrin/day (500 mg/kg of body weight) for six consecutive days, the treatment beginning on the day of inoculation. Infection was monitored by daily examination of faecal samples from the first day to 25 days post-inoculation. The criteria studied in evaluating efficacy were: oocyst shedding, presence of diarrhoea and weight gain at 15 and 25 days post-inoculation. alpha-cyclodextrin was effective when given at the beginning of infection: there was a longer pre-patent period, a reduction in the patent period and a decrease in the intensity of infection, these differences being statistically significant (P < 0.05) compared with untreated neonatal kids. Moreover, except in one animal, the diarrhoea was prevented in infected neonatal kids. Animals from both groups increased the body weight and no significant differences were seen between the two groups.     

Therapeutic and prophylactic efficacy of imidocarb dipropionate on experimental Babesia ovis infection of lambs

The objective of this study was to evaluate the therapeutic and prophylactic efficacy of imidocarb dipropionate (IMDP) against babesiosis and to determine specific antibodies against Babesia ovis in experimentally infected lambs. Thirty-six 6-month-old splenectomized lambs were used. The lambs were randomly divided into six groups with six animals each, and were intravenously inoculated with 50 mL B. ovis-infected erythrocytes as follows: group I (therapy group) was treated with IMDP (1.2 mg/kg body weight) starting on the day of onset of clinical signs of babesiosis after the inoculation; group II (untreated control animals) was not treated with any therapeutic treatment after the inoculation; groups III, IV, V and VI (prophylaxis groups) were administered IMDP (2.4 mg/kg body weight) 1, 2, 3 and 4 weeks before the inoculation, respectively. The animals were housed in a tick-proof room with water and food ad libitum up to the 30th day post-inoculation (PI). The lambs were monitored from the first day PI by recording the manifestation of clinical disease, rectal temperature, and the degree of parasitaemia. All the lambs became infected with B. ovis, except five animals from group III, which were treated 1 week prior to experimental infection. Other animals showed signs of acute clinical babesiosis. The animals treated with IMDP (group I) were able to clear the parasite from the blood circulation after 48 h post-treatment. The recrudescence of B. ovis was observed in two lambs 7 days after treatment, and they were treated with the second similar dose of the drug. Six lambs (1, 1, 2 and 2 lambs in group III, IV, V and VI, respectively) from the prophylaxis groups died within 7-17 days after showing high parasitaemia and clinical symptoms of the disease. Regardless of the clinical symptoms, 83.30% and 66.66% of the lambs which were administered IMDP 1-2 and 3-4 weeks before, were determined to be protected against the virulent field strain of B. ovis.     

Effects of nitroscanate on adult Taenia pisiformis in dogs with experimentally induced infections.

Twenty-four specific-pathogen-free Beagles were each given 50 cysticerci of Taenia pisiformis that had been harvested from experimentally infected rabbits. Quantitative fecal egg counts and fecal screening for recovery of passed segments were performed on postinoculation days 56 through 70. Twenty-three of 24 dogs fed cysticerci developed patent infections. The 23 dogs with patent infections were assigned to 1 of 2 groups and treated with nitroscanate or a placebo 60 days after inoculation. Egg counts in the treated dogs had markedly decreased by the second day after treatment, and by the sixth day after treatment, segments were not found in the feces of any of the treated animals. The control dogs continued to pass eggs and segments in their feces throughout the 9 days after treatment. The dogs were euthanatized and necropsied 70 days after being inoculated. At necropsy, the mean number of scolices recovered from control dogs was 24.6, the mean number of scolices recovered from treated dogs was 0.25. Worms recovered from the control dogs were intact, gravid cestodes. Efficacy of treatment with nitroscanate at a mean dosage of 56 mg/kg of body weight was 98.9%.     

Efficacy of oral supplementation with L-lysine in cats latently infected with feline herpesvirus

OBJECTIVE: To examine the effects of orally administered L-lysine on clinical signs of feline herpesvirus type 1 (FHV-1) infection and ocular shedding of FHV-1 in latently infected cats. ANIMALS: 14 young adult, FHV-1-naive cats. PROCEDURE: Five months after primary conjunctival inoculation with FHV-1, cats were rehoused and assigned to receive 400 mg of L-lysine in food once daily for 30 days or food only. On day 15, all cats received methylprednisolone to induce viral reactivation. Clinical signs of infection were graded, and viral shedding was assessed by a polymerase chain reaction assay throughout our study. Peak and trough plasma amino acid concentrations were assessed on day 30. RESULTS: Fewer cats and eyes were affected by conjunctivitis, and onset of clinical signs of infection was delayed on average by 7 days in cats receiving L-lysine, compared with cats in the control group; however, significant differences between groups were not demonstrated. Significantly fewer viral shedding episodes were identified in the treatment group cats, compared with the control group cats, after rehousing but not following corticosteroid-induced viral reactivation. Mean plasma L-lysine concentration was significantly increased at 3 hours but not at 24 hours after L-lysine administration. Plasma arginine concentration was not significantly altered. CONCLUSIONS AND CLINICAL RELEVANCE: Once daily oral administration of 400 mg of L-lysine to cats latently infected with FHV-1 was associated with reduced viral shedding following changes in housing and husbandry but not following corticosteroid administration. This dose caused a significant but short-term increase in plasma L-lysine concentration without altering plasma arginine concentration or inducing adverse clinical effects.     

Resistance to Eimeria zuernii produced after chemotherapy of experimental infection in calves

Nineteen Holstein-Friesian bull calves were inoculated with 2.4 × 10⁶ sporocysts of Eimeria zuernii by stomach tube. The calves were divided into three groups 10 days after infection. The first group (seven calves) was treated with monensin (1 mg/kg body weight daily) from the 10th–20th day after infection; the second group (six calves) with amprolium (10 mg/kg body weight daily) for the same period of time and the third group (six calves) acted as infected controls. Both drugs were effective in preventing clinical signs, in reducing rates of weight gain and in suppressing oocyst production. The calves were reinfected with E. zuernii 35 days after the initial infection. The calves of all three groups were resistant to the second infection with E. zuernii as measured by rates of weight gain, fecal oocyst output and lack of clinical signs.     

The role of restricted food intake in the pathogenesis of cachexia in severe combined immunodeficient beige mice infected with Mycobacterium paratuberculosis.

A paired feeding experiment was conducted to investigate if reduced food intake is a reason for the body weight loss previously observed in severe combined immunodeficient beige (SCID bg) mice infected with Mycobacterium paratuberculosis. Mice were paired on the basis of age, litter and sex. One of each pair was injected intraperitoneally with 10(5) viable M. paratuberculosis organisms. The remainder served as uninfected pairfed mates. Each uninfected mouse was restricted to the amount of food (per gram body weight) that its infected paired mate ate in the previous 24 hour period starting at four weeks postinfection until 12 weeks postinfection when the mice were necropsied. The mean body weights of the two groups were not significantly different (p < 0.05) at the start of the experiment (infected 27.6 +/- 2.1 g, pairfed 27.3 +/- 3.4 g) but the pairfed group weighed less after 12 weeks of restricted food intake. Mycobacterium paratuberculosis was isolated from the spleen, liver, gut and fecal pellets of the infected but not the uninfected mice. Acid-fast bacilli were seen histologically in the liver, spleen and intestines of the infected mice only. Analysis of carcass compositions indicated that both infected and pairfed mice lost dry matter. Despite the loss in dry matter, the infected mice appeared to have maintained their body weights due to an increased retention of body water (presumably due to edema of inflammation). These results suggest that infection of SCID bg mice with M. paratuberculosis causes a reduction in their food intake (presumably due to reduced appetite) which, in turn, contributes to a loss in dry matter. We suggest that this loss in dry matter is one of the initial events that eventually lead to cachexia, and that it precedes the body weight loss that inevitably occurs in SCID bg mice chronically affected with M. paratuberculosis.     

Black tea reduces diarrhoea prevalence but decreases growth performance in enterotoxigenic Escherichia coli-infected post-weaning piglets

Enterotoxigenic Escherichia coli (ETEC) is a main cause of diarrhoea in humans and piglets. In vitro, black tea extract (BTE) has anti-pathogenic properties. Anti-diarrhoeal properties of BTE were assessed in a pig model of gastrointestinal infection. At weaning (day 0), piglets (n = 96) were randomly assigned to a diet containing 0% (control), 0.4% or 0.8% (wt/wt) BTE during 27 days. Piglets were orally infected with 6.4 × 10(6) cfu of ETEC on day 6. Faecal consistency, feed intake and body weight were measured. In a sub-study (n = 30 piglets), the effect of BTE palatability on feed intake was assessed. Additionally, the effect of BTE on ETEC growth in the presence or absence of iron was studied in vitro. The 0.8% BTE diet reduced diarrhoea prevalence by 20% but also decreased feed intake by 16% and feed efficiency by 12% over the total period. The 0.4% BTE diet decreased feed efficiency and weight gain from day 13 onwards. The palatability study demonstrated that piglets preferred the control to the BTE diets. In vitro, BTE delayed ETEC exponential growth, which was reversed by iron addition. Although BTE had anti-diarrhoeal properties, this effect was accompanied by impaired performance. The absence of a correlation between diarrhoea prevalence and feed intake suggests that reduced diarrhoea directly results from BTE rather than from reduced feed intake caused by BTE astringency.     

Central effects of rat versus mouse leptin: ingestive behavior and adipose apoptosis

Leptin decreases food intake, body weight and fat mass while sparing lean mass. Although mouse leptin (ML) and rat leptin (RL) are 95.9% identical, our impression from previous studies was that they were not equally potent in rats. Thus, in the present study, 0 microg (vehicle) or 10 microg of ML or RL was injected into the lateral ventricle of rats (eight per treatment) once a day for four consecutive days. Body temperature, body weight, food intake and water intake were measured daily. Intrascapular and perirenal brown fat pads, white fat tissues (retroperitoneal, epididymal and inguinal fat pads) and the gastrocnemius muscle were collected and weighed 24h after the last treatments. Body temperature was not affected by either ML or RL. Both ML and RL caused significant reductions in food intake (P<0.05), and there was no difference between them. ML and RL also similarly inhibited water intake on days 2 and 3 (P<0.05). By day 5 both ML- and RL-treated rats had lost weight (11.6 and 15.4 g, respectively), while vehicle-treated rats gained weight (6.8 g). Weights of retroperitoneal and epididymal fat pads, but not other tissues, were reduced similarly by both leptin treatments (P<0.05). However, an increased apoptotic response was detected in the retroperitoneal fat tissue of RL- but not ML-treated rats (P<0.05). These results suggest that RL is more effective than ML in inducing apoptosis in retroperitoneal fat tissue after i.c.v. injection in rats.     

Effects of sequential treatments with eprinomectin on performance and grazing behaviour in dairy cattle under daily-paddock stocking management

To evaluate the effect of gastrointestinal parasites on grazing behaviour, herbage intake and milk production in spring calving dairy cows, 12 naturally infected control cows were compared with 12 similar animals treated on three occasions (June, July and September) with eprinomectin. The cows were blocked according to calving date, parity, live weight and milk yield during week 2 after turnout and then allocated to the treatments. The grazing area was sub-divided into two sets of 12 replicated paddocks of equivalent size and topography. Pairs of either control or treated animals were randomly assigned to graze each paddock over the duration of the study. Within each plot, the pair of cows grazed a series of 1-day paddocks, of areas calculated to provide 72 kg of herbage dry matter measured to ground level. Faecal samples were collected from each cow in April, prior to allocation, and every 28 days thereafter. Samples were submitted for counts of nematode eggs (sensitivity 1 epg) and the presence of Dictyocaulus viviparus larvae. Additional faecal samples were taken on each occasion for culture and nematode identification. Pasture samples for direct larval counts were collected at the same time as faecal sampling. Behaviour measurements on all cows were made during three periods, once before the first treatment with eprinomectin and thence after the 2nd and 3rd treatments. During each behaviour measurement period, grazing and ruminating behaviour were recorded over two 24-h periods and measurements of components of short-term intake rate were made during a morning and a late afternoon grazing meal. Milk yield was recorded daily and milk quality was recorded weekly. Live weight and body condition score were recorded on the day of allocation, the day of initial treatment and thereafter at weekly intervals until the end of the trial. The parasitological results showed low levels of faecal egg output throughout the study with group arithmetic means ranging from 0 to 6.8 epg. Faecal culture yielded predominantly larvae of the genus Ostertagia, but the following genera were also identified: Cooperia, Oesophagostomum and Trichostrongylus. Pasture larval levels were also low with peak values of 135 and 58 L3/kg DM herbage (7 August) in the paddocks grazed by the control and treated cattle, respectively. Thereafter, larval counts on paddocks grazed by treated cows declined to undetectable levels by October, while control paddocks remained at approximately 40 L3/kg DM. There was no effect of treatment on components of grazing or ruminating behaviour recorded over 24 h or on short-term intake rates. There were significant differences between components of short-term intake rates measured during the morning and afternoon grazing meals. The overall milk yield response to treatment with eprinomectin was +1.68 kg/day solids-corrected milk (SCM) (P=0.026). The overall response included significant (P<0.050) increases in mean daily SCM yield following each of the three treatments, indicating a positive response to repeated treatments at several different stages of lactation. There were no significant differences in the overall percentages of fat, protein or lactose between control and treated groups. The differences in live weight were not significant, although there was a consistent pattern throughout for the treated cows to be heavier than the controls.     

Effect of treatment with oxytetracycline during the acute stages of experimentally induced equine ehrlichial colitis in ponies.

Eighteen ponies were inoculated IV with Ehrlichia risticii-infected P388D1 mouse monocyte cells. Twenty-four hours after onset of fever (rectal temperature > 38.8 C), 9 ponies were treated with oxytetracycline (6.6 mg/kg of body weight, IV, q 24 h) for 5 days. The remaining 9 ponies served as infected nontreated controls. Mean scores of the following variables were not significantly different between groups on the day treatment was begun: rectal temperature, diarrhea, borborygmal sounds, feed intake, mental attitude, and evidence of a hyperresonant area in the abdomen. All ponies were observed for progression of clinical signs typical of ehrlichial colitis. Within 12 hours of initiation of treatment, only 1 treated pony had a rectal temperature > 38.8 C and most rectal temperatures were < 38.3 C. In contrast, only 2 control ponies had rectal temperatures < 38.8 C (mean rectal temperature values were significantly, P = 0.01, different between groups). In the treatment group, 4 ponies had no signs of depression after the first day of treatment, and only 1 had signs of depression after the second day of treatment (mean scores between groups were significantly different, P = 0.01). Feed intake remained normal in 4 treated ponies and improved in 4 of the remaining 5 after treatment began. Most of the control ponies had a progressive decrease in their feed intake during the observation period (mean scores between groups were significantly, P = 0.01, different). Three ponies in the control group and 2 ponies in the treatment group developed diarrhea before the treatment observation period began.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of T. vivax infection in west African dwarf goats on energy and nitrogen metabolism.

To investigate how T. vivax affects metabolism in dwarf goats, nine wethers (infection group) given alfalfa pellets ad libitum were infected intravenously and food intake was recorded up to 49 days after infection in the infection group and in the control group (n = 9). Controls received the same diet, ad libitum before infection and in restricted amounts after infection in order to obtain similar intakes in the two groups. Digestible organic matter intake (DOMI) and nitrogen balance (NB) were determined during four balance trials. All animals were bled regularly to measure parasitaemia, packed cell volume (PCV) and a number of serum metabolites. All infected animals showed symptoms typical for T. vivax infection as judged by parasitaemia, PCV and rectal temperature. Infection had a non-uniform negative effect on food intake. Compared with controls at equal DOMI, NB was lower in infected animals, the difference being significant 4 weeks after infection. This was caused by a gradual increase in NB at equal DOMI of the control group. The NB of the ad libitum fed infected animals 2 and 4 weeks after infection was comparable to values normally found in healthy ad libitum fed dwarf goats with an equal DOMI. NEFA values in serum were significantly elevated after infection. Except for two infected animals with an extremely low food intake towards the end of the experiment, no rise in serum ketone bodies was evident. After infection, serum protein increased, differences with controls being significant 4 and 7 weeks after infection.(ABSTRACT TRUNCATED AT 250 WORDS)     

A 90-day Feeding Toxicity Study of l-Serine in Male and Female Fischer 344 Rats

A subchronic feeding study of l-serine (l-Ser) was conducted with groups of 10 male and 10 female Fischer 344 rats fed a powder diet containing 0, 0.06, 0.5, 1.5 or 5.0% concentrations of l-Ser for 90 days. There were no toxicologically significant, treatment-related changes with regards to body weight, food intake, water intake or urinalysis data. In several of the hematology, serum biochemistry and organ weight parameters, significant changes were observed between some of the treated groups and the controls. All these changes, however, were subtle and lacked any corresponding pathological findings. In addition, the increased or decreased values remained within the range of the historical control values. In fact, histopathological assessment revealed only sporadic and/or spontaneous lesions. In conclusion, the no-observed-adverse-effect-level (NOAEL) for l-Ser was, therefore, determined to be at least a dietary dose of 5.0% (2765.0 mg/kg body weight/day for males and 2905.1 mg/kg body weight/day for females) under the present experimental conditions.     

Evaluation of dirlotapide for sustained weight loss in overweight Labrador retrievers

The effects of dirlotapide on body weight (BW) reduction were investigated in overweight Labradors in two parallel-design studies. Study A involved 42 dogs randomized to 0.0, 0.025, 0.05, 0.1, 0.2 or 0.4 mg dirlotapide/kg/day orally for 4 weeks. Study B involved 72 dogs randomized to nine treatments: placebo (24 weeks); dirlotapide (24 weeks) followed by placebo (28 weeks); or dirlotapide (52 weeks); on diets containing 5%, 10% or 15% fat. Dirlotapide dose (initially 0.1 mg/kg) was adjusted monthly during 24-week weight-loss and subsequent 28-week weight-stabilization phases. Food was offered above maintenance energy requirements (MER× 1.1–1.2) based on initial BW. Body composition (body fat, lean tissue and bone mineral content) was monitored using dual-energy X-ray absorptiometry. After treatment, dogs that had received dirlotapide for 52 weeks were fed 90% of quantity consumed at week 52. In study A, BW and food intake decreased asymptotically with dose: mean weekly weight loss exceeded 1% at 0.1–0.4 mg/kg. In study B, dirlotapide resulted in significant mean weekly weight loss (>0.8%) and decreased food intake over 24 weeks compared with placebo ( P  = 0.0001) for all diets. Food restriction minimized post-treatment weight rebound. Dirlotapide administered daily to dogs for up to 52 weeks was clinically safe and resulted in sustained weight reduction.