BACKGROUND: It is necessary to potentiate the immune system of fishes against stresses in farms. OBJECTIVES: This study was carried out to address the potential effect of Levamisole on immune system of rainbow trout against density stress. METHODS: 1500 fish (average weight of 50 g) were divided into 5 test groups, in which each test group was repeated three times with average density of 33 kg/m3. They were fed with commercial diet supplemented with Levamisole at concentrations of 0 (control), 100, 250, 500 and 1000 mg / kg for a period of 45 days. The fishes of all groups were then fed with Levamisole free diet and exposed to 2 and 3-fold density stress for the following 15 days. Blood samples were collected on days 0, 15, 30, 45 and 60 to evaluate the serum compliment and lysozyme activity as well as total immunoglobulins. RESULTS: The results showed that all used concentrations of Levamisole just had significant effect on compliment activity after 45 days feeding period (p<0.05). Higher levels of lysozyme and complement activity as well as total immunoglobulin were observed in 1000 mg/kg Levamisole treated group when exposed to density stresses 2 and 3-fold at the end of trial (day 60) (p<0.05). The highest overall survival was found in group which was treated with 1000 mg/kg of Levamisole. CONCLUSIONS: Our results revealed that using 0/1% Levamisole as an immunostimulator in commercial diet could potentiate rainbow trout against outbreak of high density stresses and increase its overall survival.

The control of gastrointestinal nematodes (GINs) in small ruminants is principally dependent on anthelmintic therapy, which encounters the rising problem of anthelmintic resistance (AR) development. Veterinarians reported anthelmintic failure in several sheep farms in Arbat District, Sulaymaniyah, northern Iraq, which called for a systematic study about the efficacy of three commonly used drugs: albendazole, ivermectin, and levamisole.

A female Ongole calf aged one year and nine months was found to have nodular development around the left eye and neck region. Clinical examination revealed that the calf had cutaneous papilloma (wart), which was treated with autohemotherapy, ivermectin and levamisole injections along with placement of a ligature around wart's base. On the third day of treatment, a large papilloma on the left lower eyelid dried up and sloughed off. On the tenth day of therapy, the warts on the upper eyelid and neck began to dry and flake off, leaving behind barely visible scars at the original growth sites. The animal underwent an uncomplicated recovery and completely recovered from the ailment.

A female Ongole calf aged one year and nine months was found to have nodular development around the left eye and neck region. Clinical examination revealed that the calf had cutaneous papilloma (wart), which was treated with autohemotherapy, ivermectin and levamisole injections along with placement of a ligature around wart's base. On the third day of treatment, a large papilloma on the left lower eyelid dried up and sloughed off. On the tenth day of therapy, the warts on the upper eyelid and neck began to dry and flake off, leaving behind barely visible scars at the original growth sites. The animal underwent an uncomplicated recovery and completely recovered from the ailment.

A 5-year-old neutered female Dachshund dog presented with a 3-month history of hyperthermia, skin lesions, and shifting lameness. Based on physical examination, blood tests, urinalysis, and radiographs, the dog was diagnosed with systemic lupus erythematosus. Clinical signs improved after administration of prednisolone and cyclosporine but relapsed after the prednisolone was reduced due to side effects. Oral levamisole was commenced and the other immunosuppressants were tapered over a period of 2 months and then stopped. Levamisole was retained as the sole therapy for an additional 2 months. Six months after discontinuation of all treatment, the patient remained in remission.

Nematodes resistant to anthelmintics are of increasing concern to sheep farms in Malaysia. Thus to ascertain the degree of anthelmintic resistance in the sheep population, faecal egg count reduction (FECR) trials were conducted on sheep in the Veterinary Institute, Kluang. A total of 60 weaned sheep were selected and divided into six (6) equivalent groups. Group A was treated with ivermectin, Group B with Closantel, Group C with Fenbendazole, Group D with Levamisole, Group E with Cydectin and the remaining 10 were untreated controls. Faecal samples were collected from each sheep before treatment and repeated on day 14, 30, 45 and 60 post treatment. The worm egg counts were estimated by using McMaster’s method. The population of worm was classified as resistant if the adjusted percentage reduction was less than 90%. It is concluded that only levamisole can be used for helminthiasis control. The results showed that worms at the Sheep Unit of the Veterinary Institute, Kluang was suspected to be resistant to Ivermectin, Closantel and Cydectin. The worm population showed total resistance to fenbendazole. The strongyle population is mainly made up of 80% Haemonchus contortus and 20% of species were Oesophagostomum and Bunostomum.

Since there is no registered anthelmintic drug available for use in goats, extra-label use of drugs is a common practice in most countries. The aim of the present study was to compare the pharmacokinetic disposition of levamisole (LVM)-oxyclozanide (OXZ) combination in sheep and goats following per os administration. Goats (n = 8) and sheep (n = 8) 12- to 16-months-old were used for this study. The animals received tablet formulation of LVM and OXZ combination orally at a dose of 7.5 mg/kg and 15 mg/kg body weight, respectively. Blood samples were collected by jugular vein at different times between 5 min and 120 h after drug administrations. The plasma concentrations of LVM and OXZ were analyzed by HPLC following liquid-liquid phase extraction procedures. The plasma concentrations and systemic availabilities of both LVM and OXZ in goats were lower and the plasma persistence of LVM was shorter compared with those observed in sheep. Terminal half-lives (t1/2λz) of both molecules are shorter in goats compared with those in sheep. Goats treated with LVM-OXZ combination at the recommended dose for sheep may result in a reduced efficacy, because of under-dosing, which may increase the risk of drug resistance in parasites. Increased or repeated dose could be a strategy to provide higher plasma concentration and thus to improve the efficacy against the target parasites in goats compared with sheep. However, some adverse reactions may occur since LVM has relatively very narrow therapeutic index due to its nicotine-like structure and effect.

We studied the antibody responses to transmissible gastroenteritis (TGE) in serum, colostrum, and milk from sows vaccinated with 2 attenuated (1 IM and 1 oral-IM) and 1 nonattenuated live vaccines and the relationship of these responses with the survivability of the sow's suckling pigs after challenge exposure with virulent TGE virus. Contrary to previous studies, the anti-TGE virus-neutralizing geometric mean titers (GMT) in the milk of sows vaccinated with attenuated vaccines at 3 and 5 days of lactation were similar to that found in the colostrum. Colostral and serum antibody titers were highest in sows given 2 injections of the IM attenuated vaccine. Half of the sows given the oral-IM attenuated vaccine did not seroconvert after 2 oral doses. Only sows vaccinated with the nonattenuated live vaccine had milk GMT that remained high for 21 days after farrowing. The linear relationship between colostral GMT and percentage of survivability of suckling pigs challenge exposed at 3 days of age was significant (P less than 0.05), although the relationship between serum GMT and percentage of survivability and the relationship between milk GMT and percentage of survivability were not significant (P greater than 0.10). The linear relationship between colostral (P less than 0.10) or pre-challenge exposure milk (P less than 0.05) GMT and percentage of survivability of suckling pigs challenge exposed at 5 days of age was significant. We have no adequate explanation for the relatively low colostral GMT, the relatively high milk GMT at 3 and 5 days of lactation in vaccinated sows, or the lack of significant linear relationship between milk GMT and survivability of pigs challenge exposed at 3 days of age.

First-litter commerical cross-bred gilts were treated with levamisole (1.5, 2.5, or 3.5 mg/kg of body weight) weekly during the last 4 weeks of gestation, because similar treatment of dairy heifers had improved postpartum maternal health and neonatal survival. In the gilts, differences in reproductive performance were not found on the basis of pig survival at birth, pig survival at weaning, birth weight, or weaning weight. Also differences between treated and control gilts were not found in response of circulating lymphocytes to mitogen stimulation (phytohemagglutinin A, concanavalin A, and pokeweed mitogen). In all gilts, the lymphocyte response to mitogen stimulation was decreased during the first week after farrowing.