Vanessa da Silva Mustafa

Intoxicação por Brachiaria spp. em ruminantes no Brasil

Brachiaria species are the most important grasses for cattle production in Brazil. However, a limiting factor for the use of Brachiaria spp. is their toxicity. Most outbreaks of hepatogenous photosensitization are caused by B. decumbens; however B. brizantha, B. humidicola and B. ruziziensis can also cause poisoning. The poisoning affects cattle, sheep, goats and buffalo. Sheep are more susceptible than other animal species and the young are more susceptible than adults. There are differences in susceptibility among animals of the same species and it has been suggested that this resistance is genetic. Also has been suggested that buffalo and probably some sheep are resilient, i.e. when poisoned these animals have histologic lesions and high GGT serum concentrations, but do not show clinical signs. In general, saponin concentrations are higher in growing plants, but outbreaks occur all over the year, probably due to unexplained rise in saponin concentration in the plant. A clinical syndrome of progressive weight loss and death, without photosensitization, has been reported in cattle poisoned by B. decumbens. Main preventive measures are based on the selection of resistant or resilient animals and on the development of Brachiaria species or varieties with low saponin concentration.

Intoxicação natural por Brachiaria spp. em ovinos no Brasil Central

Dissertacao (mestrado)-Universidade de Brasilia, Faculdade de Agronomia e Medicina Veterinaria, 2009.

Síndrome do abscesso pituitário em bezerros na Região Centro-Oeste

Pituitary abscess syndrome is a neurologic disease responsible for sporadic cases and outbreaks especially in calves leading to high mortality rates. This paper aimed to report the occurrence and the clinical, laboratorial and pathologic findings in three 8 to 11-month-old calves with pituitary abscess syndrome from Mid-Western Brazil. The most important clinical findings were nervous signs of cerebral and brainstem origin with clinical evolution of 7-20 days. Hematology revealed leucocytosis by neutrophilia and hyperfibrinogenemia. Cerebrospinal fluid analysis showed neutrophilic pleocytosis. Arcanobacterium pyogenes was isolated from cerebrospinal fluid. One calf recovered after antibiotic treatment. Mortality rate was 66.6% (2/3). Necropsy findings included single para-hypophyseal abscesses or located in the glandular parenchyma; one calf showed necrotizing rhinitis and another abscedative pneumonia. Histological exams of the central nervous system reveal complete absence of normal pituitary tissue due to the wide necrosis and neutrophilic inflammatory infiltrate. The authors reiterate the importance of adequate management practices to reduce incidence of several diseases especially in calves, including the pituitary abscess syndrome.

Tissue accumulation and urinary excretion of Cr in chromium picolinate (CrPic)-supplemented lambs

Chromium (Cr) concentrations in liver, kidney, spleen, heart, lymph node, skeletal muscle, bone, testis and urine of lambs were measured to trace the biodistribution and bioaccumulation of Cr after oral supplementation with chromium picolinate (CrPic). Twenty-four Santa Inês lambs were treated with four different concentrations of CrPic: placebo, 0.250, 0.375 and 0.500 mg of CrPic/animal/day for 84 days. The basal diet consisted of Panicum maximum cv Massai hay and concentrate. Cr concentrations were measured by ICP-MS measuring (52)Cr as collected mass. There was a positive linear relationship between dose administered and the accumulation of Cr in the heart, lungs and testis. Urinary excretion of Cr occurred in a time and dose-dependent manner, so the longer or more dietary Cr provided, the greater excretion of the element. As some non-carcass components (such as lungs or heart) are added to bone and visceral meal to feed animals, there is a risk of bioaccumulation and biomagnification due to Cr offered as CrPic in the diet.

Doenças da cavidade nasal em pequenos ruminantes no Distrito Federal e no Estado de Goiás

Nasal cavity diseases that affect small ruminants can cause losses to sheep and goat herds in Central Brazil. A retrospective study of the University of Brasilia´s Veterinary Pathology Laboratory autopsy reports from 2003 to 2014 was conducted to verify the occurrence of small ruminants nasal cavity diseases. Six necropsied sheep (6/463 1.29%) showed mycotic or oomicotic granulomatous rhinitis and 22 animals (22/538, 4.08%) presented oestrosis diagnosis, affecting 86.36% of sheep and 13.64% of goats. The pyogranulomatous rhinitis in sheep occurred in flooded areas with abundant plant material decomposing. Rhinofacial pythiosis infection in animals showed as major changes swelling in the nasal region due to extensive granulomatous lesions associated with tissue necrosis, characterized by numerous macrophages and polymorphonuclear cells surrounding necrotic centers containing the agent surrounded by Splendore-Hoeppli reaction. Sheep with conidiobolomycosis showed extensive areas of necrosis and pyogranulomatous inflammation associated with fungal hyphae, localized in the nasopharynx and also in peribulbar region and exophthalmia. Most animals with oestrosis showed no significant clinical and pathological changes, even with the presence of larvae mainly in the sinuses and nasal turbinates, trachea and paranasal sinus. The importance of such diseases is still unknown in the region, and the knowledge of the clinical-pathological and epidemiological conditions is of great relevance for the diagnosis, control and prevention to avoid the expansion and losses to livestock.

Forma nervosa da artrite-encefalite caprina

Two cases are described of female goats, Saanen crossbreds, two months old, with clinical signs of hind limb paresis, incoordination, difficulty breathing and cachexia, which were subjected to euthanasia due to unfavorable prognosis. At necropsy it was possible to observe that there was congestion of the central nervous system (CNS) and pulmonary consolidation in both goats. Microscopic changes were characterized by multifocal lymphoplasmacytic leucoencephalomielitis, with vacuolization of neuropile and axonal spheroids, leptomeningitis, interstitial nonsupurative pneumonia in goat A and bacterial bronchopneumonia in goat B. Immunohistochemistry (IHC) was positive for the caprine arthritis - encephalitis virus in thalamus fragments. The agar gel immunodiffusion (AGID) test was performed in sera sample of twenty animals and sixteen resulted positive. Diagnosis of the nervous form of caprine arthritis-encephalitis virus (CAEV) infection was based on clinical and pathological status, IHC and AGID. This clinical presentation of CAE could be uncommon in Brazil, but must be considered in case of neurologic diseases in small ruminants.