Brown recluse spider (Loxosceles reclusa) envenomation in small animals

Objective – To provide a comprehensive review of relevant literature regarding the brown recluse spider (BRS) and to define those criteria that must be satisfied before making a diagnosis of brown recluse envenomation.
Etiology – The complex venom of the BRS contains sphingomyelinase D, which is capable of producing all the clinical signs in the human and some animal models.
Diagnosis – There is no current commercially available test. In humans there are many proposed guidelines to achieve a definitive diagnosis; however, there are no established guidelines for veterinary patients.
Therapy – Currently, no consensus exists for treatment of BRS envenomation other than supportive care, which includes rest, thorough cleaning of the site, ice, compression, and elevation.
Prognosis – Prognosis varies based on severity of clinical signs and response to supportive care.     

Experimental Mycotoxic Nephropathy in Pigs Provoked by a Diet Containing Ochratoxin A and Penicillic Acid

Mycotoxic nephropathy was induced in 18 young pigs by diets contaminated with strains of Aspergillus ochraceus containing ochratoxin A (OTA) and penicillic acid (PA) at levels corresponding to those naturally encountered in animal feeds in Bulgaria. Haematological and biochemical parameters, as well as the morphological and ultrastructural changes in various internal organs, and especially in the kidneys, were examined at different stages of development of the disease. A mottled surface of the kidneys was only seen in pigs exposed to a mouldy diet containing 180 ppb OTA for 3 months, but microscopic lesions, as well as changes in various haematological and biochemical parameters, were observed in all groups exposed to the same mouldy diet containing only 90 or 180 ppb OTA. Histological examination showed two types of change: degenerative changes affecting the epithelial cells of the proximal tubules, which predominated at the initial stage, and proliferative changes in the interstitium, which predominated at the later stage of the disease. Telangiectasis and lymph stasis were also seen, as well as degenerative changes in the capillary endothelium. The characteristic renal lesions were similar to those observed in spontaneous cases of mycotoxic porcine nephropathy in Bulgaria, but they were a little different from the classic Danish porcine nephropathy. The enhanced toxicity of OTA in our study may be due to a synergistic effect between OTA and PA or to some other unknown metabolites produced by the same ochratoxinogenic strains of A. ochraceus.     

Fumonisin B1 Metabolism by Bovine Liver Microsomes

Only limited and contrasting information is available about the metabolic fate in cattle of fumonisin B₁, a mycotoxin produced by moulds of Fusarium. This study was carried out to evaluate the hepatic metabolism of fumonisin B₁ by bovine liver microsomes. No biodegradation or metabolization of the mycotoxin by liver microsomes was detectable after incubating fumonisin B₁ with bovine microsomes in the presence of a regenerating system for 1 h. No aminopolyol 1, aminopolyol 2 or aminopentol, metabolites of fumonisin B₁, were detected in any of the incubated samples. The tolerance of ruminants to fumonisin B₁ is apparently not dependent on its detoxification in the rumen.     

The Effect of Management Factors on the Seroprevalence of Anaplasma marginale in Bos indicus cattle in the Mexican Tropics

A cross-sectional study with a two-stage design and proportional distribution was carried out to determine the effect of management factors on the seroprevalence of Anaplasma marginale in Bos indicus cattle in the Mexican tropics. Serum was obtained from 384 cattle aged 1-2 years on 92 farms. The number of samples was proportionally distributed according to the number of farms in eastern Yucatan. Antibody activity against A. marginale was assessed using the card agglutination test. A primary screening using a 2 x K contingency table of the exposed variables with the outcomes was performed. All variables for which p < 0.20 were included in a fixed-effects log regression. The seroprevalence in the cattle was 69.75% (SE +/- 0.02). Sixty-four per cent of the farms had a seroprevalence > or = 75%. The risks related to managemental factors were stocking density ( > or = 1 animal/ha, OR = 10.94), type of acaricide (pyrethroids, OR = 3.8), dipping interval ( > 60 days, OR = 0.13) and type of veterinary instruments used (needles, scalpels, ear tattoos, and dehorners, OR = 0.17).     

Response of Corriedale and Crioula Lanada Sheep to Artificial Primary Infection with Haemonchus Contortus

Clinical, parasitological and biochemical parameters were evaluated in Corriedale and Crioula Lanada sheep after a single experimental infection with Haemonchus contortus. Ten 4-month-old worm-free lambs, of each breed, were infected with 200 L₃ H. contortus per kg live weight and four uninfected animals of each breed were used as controls. Every week, the animals were weighed and blood and faecal samples were collected for measurement of packed cell volume (PCV), total serum protein (TSP) and albumin (ALB), and the number of eggs per gram of faeces (EPG), respectively. Twelve weeks after infection, the animals were slaughtered. The worm burden was determined and samples of the abomasal mucosa were processed for determination of the number of eosinophils, mast cells and globule leukocytes. No significant differences in PCV, TSP, ALB, parasite burden or the cell populations of the abomasal mucosa were observed between breeds, but Crioula lambs had a lower EPG count. The comparison of the infected groups with their respective controls revealed significant alterations in PCV, TSP and ALB in the Corriedale lambs and in PCV, TSP, ALB and the density of eosinophils and mast cells in the Crioula lambs.     

The effects of low doses of Senna occidentalis seeds on broiler chickens

The effects of 0.5%, 0.3% and 0.1% w/w concentrations of Senna occidentalis (So) seed mixed with commercial ration were studied in 18 groups of 32 broiler chicks each, from 1 day to 49 days of age. Three groups were fed one of the rations throughout their lives (TL). Three other groups were fed one of the rations from the 1st to the 28th day of life (starter phase, SP), and the final 3 groups were fed one of the rations from the 29th to 49th day (finisher phase, FP). Each experimental group was matched by a control group fed the same diet over the same period but without the inclusion of So. All the animals were killed at 49 days of age, and blood was collected from 10 birds in each group for biochemical studies (ALT, AST, GGT, LDH, UA). A complete necropsy was performed on 3 birds from each group. No significant differences in the biochemical parameters in the serum were found between the control and experimental chicks, but animals treated with 0.5% So in groups FP and TL, gained less weight and chicks that received 0.3% So or 0.5% So in the ration throughout life (TL) had a larger feed conversion ratio. Besides this, degenerative changes were found in the striated skeletal muscle in the chest, in the myocardium and in the liver in the animals that received the higher concentrations of So seeds.     

Daily basking patterns of the fresh-water turtle

Basking activity in the turtle Pelomedusa subrufa L. apparently is initiated by the presence of a suitable heat source, whereas subsequent basking is largely determined by prevailing environmental temperatures as well as requirements for avoiding overheating.     

Pubertal development of male African catfish,Clarias gariepinus. In vitro steroidogenesis by testis and interrenal tissue and plasma levels of sexual steroids

In fish, sex steroids initiate and/or accelerate the maturation of the brain-pituitary-gonad axis. In order to obtain information on the steroid milieu during the pubertal development of male African catfish, we have monitored the conversion of [³H]-pregnenolone and [³H]-androstenedione by testis and [³H]-pregnenolone by interrenal tissue fragmentsin vitro. Pubertal development occurs between two and six months of age. Testicular development proceeds through four main stages that are characterised histologically by the presence of spermatogonia (stage I), spermatogonia and spermatocytes (stage II), spermatogonia, spermatocytes and spermatids (stage III), and all germ cells including spermatozoa (stage IV). 11β-Hydroxyandrostenedione and cortisol were the main products of testes and interrenal tissue, respectively, in all stages of the pubertal development; a change in the steroidogenic pattern was not observed during this period. The interrenal tissue displayed no significant conversion of [³H]-pregnenolone to 11-oxygenated androgens. Blood plasma was analyzed for the presence of five androgens; testosterone, 11β-hydroxytestosterone, 11β-hydroxyandrostenedione, androstenetrione, and 11-ketotestosterone. 11-Ketotestosterone was the quantitatively dominating androgen in the circulation at all stages of development, which was more pronounced in stages III and IV. The obvious differences between thein vitro andin vivo results, namely 11β-hydroxyandrostenedione being the main testicular productvs. 11-ketotestosterone dominating in the blood, may indicate that 11β-hydroxyandrostenedione is converted to 11-ketotestosterone at extratesticular sites.