A reconnaissance survey of farmers' awareness of hypomagnesaemic tetany in UK cattle and sheep farms.

Hypomagnesaemic tetany (HypoMgT) in ruminants is a physiological disorder caused by inadequate intake or impaired absorption of magnesium (Mg) in the gut. If it is not detected and treated in time, HypoMgT can cause the death of the affected animal. A semi-structured questionnaire survey was conducted from July 2016-2017 to assess farmers' awareness of HypoMgT in cattle and sheep in the UK. The questionnaire was distributed to farmers at farm business events and agricultural shows, and through a collaborative group of independent veterinary practices to their clients. Farmers were asked about (i) the incidence of presumed HypoMgT (PHT); (ii) their strategies to treat or prevent HypoMgT; (iii) mineral tests on animals, forage and soil, and (iv) farm enterprise type. A total of 285 responses were received from 82 cattle, 157 mixed cattle and sheep, and 46 sheep farmers, of whom 39% reported HypoMgT in their livestock, affecting 1-30 animals. Treatment and/or prevention against HypoMgT was reported by 96% respondents with PHT and 79% of those without. Mineral tests on animal, forage, and soil was conducted by 24%, 53%, and 66% of the respondents, respectively, regardless of PHT. There was a highly significant association between the use of interventions to tackle HypoMgT and the incidence of PHT (p < 0.01). The top three treatment/prevention strategies used were reported as being free access supplementation (149), in feed supplementation (59) and direct to animal treatments (drenches, boluses and injections) (45) although these did vary by farm type. Although some (9) reported using Mg-lime, no other pasture management interventions were reported (e.g., Mg-fertilisation or sward composition). Generally, the results indicate that UK farmers are aware of the risks of HypoMgT. A more integrated soil-forage-animal assessment may improve the effectiveness of tackling HypoMgT and help highlight the root causes of the problem.

Hypomagnesemia in dairy cattle in Uruguay / Hipomagnesemia em bovinos leiteiros no Uruguai

An outbreak of hypomagnesemia is reported in Holstein dairy cattle grazing lush oat (Avena sativa) pasture in Uruguay. Nine of 270 (3.3%) cows died in May-July (autumn-winter) 2017. These nine cows were from 2 to 9-years-old (1st-6th lactation), with 22 to 194 days of lactation and 15.8 to 31.4L of daily milk production. Two cows with acute sialorrhea, muscle spasms, lateral recumbency, weakness, opisthotonos, and coma, were euthanized and necropsied. No significant macroscopic or histological lesions were found. One untreated clinically-affected cow and eight out of 14 clinically healthy cows of the same group under similar management and production conditions had low serum levels of Mg (lower than 0.7mmol/L). Secondarily, both clinically affected cows and six out of 14 healthy cows had low serum Ca levels. The K/(Ca+Mg) ratio of two oat forages, corn silage, and ration was 5.10, 7.73, 2.45, and 0.85, respectively. A K/(Ca+Mg) ratio lower than 2.2 represents a risk for hypomagnesemia. The difference between the contribution-requirement of minerals in the diet was established and a daily deficiency of Mg (-0.36g/day), Na (-25.2g/day) and Ca (-9.27g/day) was found, while K (184.42g/day) and P (12.81g/day) were in excess. The diet was reformulated to correct the deficiencies and the disease was controlled by the daily administration of 80g of magnesium oxide, 80g of calcium carbonate and 30g sodium chloride per cow. It is concluded that hypomagnesemia is a cause of mortality in dairy cattle in Uruguay, and that the condition can be prevented by appropriate diet formulation.(AU)

Descreve-se um surto de hipomagnesemia em bovinos leiteiros da raça Holandês com alimentação a base de pastagens de aveia (Avena sativa) em crescimento no Uruguai, nos meses de maio a julho (outono-inverno) de 2017. De um rebanho de 270 vacas em ordenha, nove (3,3%) morreram. As nove vacas tinham entre dois e nove anos, estavam entre a primeira e a sexta lactação e a produção diária era de 15,8 a 31,4 litros de leite. Duas vacas que apresentaram sialorreia, espasmos musculares, decúbito lateral, debilidade, opistótono e posteriormente, estado comatoso foram eutanasiadas e necropsiadas. Não foram observadas lesões macroscópicas ou histológicas significantes. Uma vaca com sinais clínicos, não tratada, e oito de 14 vacas sem sinais clínicos, do mesmo rebanho, apresentaram baixos níveis séricos de Mg (menos de 0,7mmol/L). Adicionalmente, as duas vacas com sinais clínicos e seis das 14 vacas sem sinais clínicos apresentaram baixos níveis de Ca sérico. A relação do risco tetanizante K/(Ca+Mg) de duas pastagens de aveia, silagem de milho e ração concentrada foi estimada em 5; 10; 7,73; 2,15 e 0,85, respectivamente. Uma relação K/(Ca+Mg) maior de 2,2 é um indicador do potencial tetanizante da forragem, A diferença entre o aporte e os requerimentos dos minerais foi estabelecida constatando-se deficiência diária de Mg (-0,36g/dia), Na (-25,2g/dia) e Ca (-9,27g/dia). O potássio (K) (184,42g/dia) e o fósforo (P) (12,81g/dia) estavam em excesso. A dieta foi reformulada para corrigir as deficiências e a doença foi controlada mediante a administração diária de 80g de MgO, 80g de CaCO3 e 30g de NaCl por vaca. Conclui-se que a hipomagnesemia é uma doença de importância crescente em gado leiteiro no Uruguai e que deve ser prevenida mediante a formulação correta da dieta.(AU)

[Magnesium in dogs and cats - physiology, analysis, and magnesium disorders]. / Magnesium bei Hund und Katze ­ physiologische Aspekte, Messung und Störungen im Magnesiumhaushalt.

Magnesium is the second most abundant intracellular cation after potassium. It plays a vital role in almost every metabolic process in the body and is important for bone mineralization, muscle contraction and relaxation, and neuronal signal transduction. Because of its expanding role in intensivecare medicine, there has been a significant increase in knowledge during recent years regarding the functions of magnesium in the body, problems leading to magnesium disorders, and limitations of laboratory testing. Alterations of serum magnesium constitute one of the most prevalent electrolyte abnormalities in critically ill patients and can lead to lifethreatening complications. In addition to human literature, most of the information regarding the role of magnesium is derived from buiatrics. In recent years, a few studies in veterinary medicine have also started to consider the importance of magnesium in dogs and cats.

[Unusual case of struvite urolithiasis in a dog. A case report]. / Ungewöhnlicher Fall von Struvit-Urolithiasis bei einem Hund. Ein Fallbericht.

A dog was referred for nutrition consultation after surgical removal of struvite uroliths from the bladder. Inspection of the dog's current ration revealed a pronounced vitamin-A deficiency together with a marked deficiency of protein, phosphorus and magnesium. Therefore, a supersaturation of the urine with ammonium, magnesium and phosphate, the three constituents of struvite, as a cause of struvite calculi formation appears rather unlikely. Vitamin-A deficiency can promote urinary infections and consequently struvite stone formation because of the lack of the protective effect of vitamin A on the epithelia of the urinary tract. Not only common causes for struvite urolith formation, including urinary supersaturation with stone-forming constituents and urinary tract infection, but also less common causes, including vitamin-A deficiency, which was the presumed trigger in the present case study, have to be taken into consideration. Dietetic measures appear to be a useful tool in such cases to prevent uroliths from reoccurring.

A Quick Reference on Magnesium.

This article serves as a quick reference on the distribution, handling, and supplementation of magnesium. It also lists the manifestations and causes of magnesium deficit and provides criteria for the diagnosis of a magnesium deficit.

Hypomagnesaemia in suckler cows.

Hypomagnesaemia in housed and grazing suckler cows. Coronavirus infection in cows. Suspected nitrite toxicity in lambs associated with feeding broccoli. Maedi visna in ewes. Mycotic pneumonia in a wildcat. These are among matters discussed in the disease surveillance report for November 2015 from SAC Consulting: Veterinary Services (SAC C VS).

Seizure disorders in 43 cattle.

BACKGROUND: Large animals have a relatively high seizure threshold, and in most cases seizures are acquired. No published case series have described this syndrome in cattle. OBJECTIVES: To describe clinical findings and outcomes in cattle referred to the Veterinary Teaching Hospital of the University of Turin (Italy) because of seizures. ANIMALS: Client-owned cattle with documented evidence of seizures. METHODS: Medical records of cattle with episodes of seizures reported between January 2002 and February 2014 were reviewed. Evidence of seizures was identified based on the evaluation of seizure episodes by the referring veterinarian or 1 of the authors. Animals were recruited if physical and neurologic examinations were performed and if diagnostic laboratory test results were available. RESULTS: Forty-three of 49 cases fulfilled the inclusion criteria. The mean age was 8 months. Thirty-one animals were male and 12 were female. Piedmontese breed accounted for 39/43 (91%) animals. Seizures were etiologically classified as reactive in 30 patients (70%) and secondary or structural in 13 (30%). Thirty-six animals survived, 2 died naturally, and 5 were euthanized for reasons of animal welfare. The definitive cause of reactive seizures was diagnosed as hypomagnesemia (n = 2), hypocalcemia (n = 12), and hypomagnesemia-hypocalcemia (n = 16). The cause of structural seizures was diagnosed as cerebrocortical necrosis (n = 8), inflammatory diseases (n = 4), and lead (Pb) intoxication (n = 1). CONCLUSION AND CLINICAL IMPORTANCE: The study results indicate that seizures largely are reported in beef cattle and that the cause can be identified and successfully treated in most cases.

Perfil mineral de vacas mestiças Girolanda no período de transição em sistema semi-intensivo em duas estações do ano / Serum mineral profile of Girolanda cows during transition period in semi-intensive system in two seasons

Neste estudo foi avaliado o perfil metabólico de vacas leiteiras no período de transição durante o verão e o inverno. Foram utilizados 31 animais pluríparos mestiços girolando em cada estação, totalizando 62 vacas. No verão permaneciam em pasto com suplementação de silagem de milho e concentrado. No inverno, a exigência nutricional era suprida apenas com silagem de milho e concentrado. Foram feitas um total de 11 coletas de sangue de cada animal segundo o seguinte protocolo: quatro coletas pré-parto espaçadas semanalmente, no dia do parto e com 2, 5, 10, 15, 21 e 30 dias pós-parto. Foram avaliadas as concentrações de cálcio, fósforo e magnésio. Todos os analitos variaram em função do estatus fisiológico. As concentrações médias de cálcio e magnésio foram maiores no verão do que no inverno. Em ambas as estações, as menores concentrações médias de cálcio ocorreram próximas ao parto, sendo que 75% dos animais no inverno e 35,48% dos animais no verão estavam hipocalcêmicos. Apenas no décimo dia as concentrações de cálcio voltaram aos níveis do pré-parto, demonstrando que esse tempo é necessário para a adaptação da nova condição de lactante. As concentrações de magnésio foram menores no pós-parto do que no pré-parto nas duas estações, demonstrando a necessidade desse mineral para a produção de leite. As concentrações médias de magnésio permaneceram sempre dentro dos valores de referência, porém 19% dos animais aos dois dias pós-parto no inverno e 7% dos animais aos 10 dias pós-parto no verão tinham concentrações inferiores a esses limites. As concentrações de fósforo sofreram grande variação ao longo do peri-parto, porém sempre em níveis elevados, sendo que 49,8% dos animais no inverno e 37,3% no verão tinham níveis de fósforo acima dos valores de referência.

The metabolic profile of dairy cows in the transition period during summer and winter was evaluated. Were used 31 crossbred Holstein/Gir cows at each season, totaling 62 cows. During summer they remained in pasture with supplementation of corn silage and concentrate and in the winter, corn silage and concentrate was offered to furnish the nutritional requirements. A total of 11 blood samples from each animal were taken according to the following protocol: four collections weekly antepartum, at birth and at 2, 5, 10, 15, 21 and 30 days postpartum. Concentrations of calcium, phosphorus and magnesium were evaluated. All analytes varied according to the physiological status. The average concentrations of calcium and magnesium were higher in summer than in winter. In both seasons, the lowest mean calcium concentrations occurred near calving, and 75% of the animals in winter and 35.48% of the animals in the summer were hypocalcemic. Only on the tenth day postpartum, the calcium concentrations returned to levels of prepartum, demonstrating that this time is necessary for the adaptation of the new condition of lactating. Magnesium concentrations were lower postpartum than prepartum in both seasons, demonstrating the need for this mineral for the production of milk. The average concentrations of magnesium remained always within the reference values for the species, but 19% of the animals at two days postpartum in winter and 7% of the animals at 10 days postpartum in summer had concentrations below these limits. Phosphorus concentrations suffered large variation along the peri-partum, but always at high levels, with 49.8% of the animals in winter and 37.3% in summer had phosphorus levels above the reference range of the species.

Hypomagnesemia in brachycephalic dogs.

BACKGROUND: Brachycephalic dogs are at risk for arterial hypertension and obstructive sleep apnea, which are both associated with chronic magnesium (Mg) depletion. HYPOTHESIS/OBJECTIVES: To compare the period prevalence of hypomagnesemia between Boxers and Bulldogs presented to a referral teaching hospital. To screen a group of Bulldogs for evidence of hypomagnesemia, and to obtain pilot data regarding the utility of parenteral Mg tolerance testing (PMgTT) in the diagnosis of whole-body Mg deficiency. ANIMALS: Chemistry laboratory submissions were retrospectively analyzed for serum total Mg (tMg) in Boxers and Bulldogs. Prospectively, 16 healthy client-owned Bulldogs were enrolled. METHODS: Retrospective case study. tMg concentrations were compared between Boxers and Bulldogs. Dogs with low serum albumin or high serum creatinine concentrations were excluded. Prospectively, ionized Mg (iMg), tMg, and arterial blood pressure were measured and iMg-to-tMg ratio (iMg : tMg) was calculated. Parenteral Mg tolerance testing (PMgTT) was performed in 3/16 dogs. RESULTS: In the retrospective study, period prevalence of hypomagnesemia was 4.7% in Boxers and 15% in Bulldogs (P = .02). The risk ratio for hypomagnesemia in Bulldogs was 1.8 when compared to Boxers (CI: 1.3-2.7). In the prospective study, iMg was [median (interquartile)] 0.43 (0.42-0.46) mmol/L (reference range 0.4-0.52), tMg was 1.9 (1.8-1.9) mg/dL (reference range 1.9-2.5). iMg : tMg was [mean (±SD)] 0.59 ± 0.04. Percentage retention after PMgTT were 55%, 95%, and 67%, respectively. CONCLUSIONS AND CLINICAL IMPORTANCE: Mg deficiency is common in Bulldogs and could contribute to comorbidities often observed in this breed. iMg : tMg and PMgTT might prove helpful in detecting chronic subclinical Mg deficiency.

Magnesium disorders in horses.

Magnesium (Mg) is an essential macroelement that is required for cellular energy-dependent reactions involving adenosine triphosphate and for the regulation of calcium channel function. Subclinical hypomagnesemia is common in critically ill humans and animals and increases the severity of the systemic inflammatory response syndrome; worsens the systemic response to endotoxins; and can lead to ileus, cardiac arrhythmias, refractory hypokalemia, and hypocalcemia. This article discusses the clinical signs, consequences, and treatment of hypomagnesemia in horses and describes the association of Mg and endotoxemia, insulin resistance, and brain injury.

Treatment and control of peri-parturient metabolic diseases: pregnancy toxemia, hypocalcemia, hypomagnesemia.

The paper reviews treatment and control of pregnancy toxaemia, hypocalcaemia, hypomagnesaemia, the important peri-parturient diseases of small ruminants. Treatment of pregnancy toxemia benefits from early instigation, ie, upon timely diagnosis and is based on administration of energy sources to sick animals. Removal of fetuses, by induced parturition or caesarean section, should also be carried out. Individual cases within a farm require close monitoring of other animals and measures to avoid development of further clinical cases. Treatment of hypocalcemia is based on administration of calcium solution. Finally, hypomagnesemic animals need urgent treatment with calcium and magnesium solutions.

Indication of intracellular magnesium deficiency in lactating dairy cows revealed by magnesium loading and renal fractional excretion.

Nine non-pregnant, lactating dairy cows were used to study plasma and urinary magnesium concentrations ([Mg]pl; [Mg]u), and the urinary fractional excretion of magnesium (FE(Mg)) before, during and after an 120 min intravenous magnesium (Mg) administration (2.5 mg/kg body weight). Animals received a total mixed ration, and Mg content of the diet was within recommended range. Basal mean [Mg]pl, [Mg]u and FE(Mg) were 0.89 +/- 0.09 mm, 5.92 +/- 2.99 mm and 8.3 +/- 9.7% respectively. For all parameters, a substantial inter-individual variation was observed. Three cows showed suboptimal [Mg]pl and/or [Mg]u as well as low FE(Mg) values of approximately 2% indicating an insufficient Mg supply to these animals (depressed feed intake, reduced absorption of Mg). The applied Mg challenge induced no significant change of mean [Mg]pl in the cows because part of the excess Mg was excreted in the urine. But in five out of nine cows, a decrease of the FE(Mg), during and after an intravenous Mg load was observed showing that part of the infused Mg is used to replenish intracellular Mg pools. Thus, the existence of an intracellular Mg deficiency in these cows was unmasked by performing the Mg loading test only. Because a reduced free intracellular [Mg] impairs cell and tissue functions, the results highlight the importance of an accurate definition of the intracellular Mg status. The Mg loading test is a suitable procedure, however, for practical purposes less expensive and time consuming methods must be developed.

Magnesium: a quick reference.

This article serves as a quick reference for the distribution, handling, and supplementation of magnesium. It also lists the manifestations and causes of magnesium deficit and provides criteria for the diagnosis of a magnesium deficit.

Therapeutic approach to chronic electrolyte disorders.

Chronic disorders of sodium and potassium occur and occasionally need symptomatic therapy. Hypernatremia primarily indicates loss of free water, whereas hyponatremia may be attributable to various problems. It is important not to correct major aberrations of serum sodium concentrations too quickly lest the therapy be more detrimental than the electrolyte abnormality. In distinction, hypokalemia and hyperkalemia may be corrected quickly. Hypomagnesemia is relatively common, but its clinical significance is still being determined.

The monitoring, prevention, and treatment of milk fever and subclinical hypocalcemia in dairy cows.

The periparturient cow undergoes a transition from non-lactating to lactating at calving. The animal is tremendously challenged to maintain calcium homeostasis. Those that fail can develop milk fever, a clinical disorder that is life threatening to the cow and predisposes the animal to a variety of other disorders. Guidelines for monitoring the incidence of hypocalcemia and methods for treating milk fever are reviewed. The physiological factors that cause milk fever and strategies for prevention of milk fever are discussed, focusing on the effects diet cation-anion difference can have on tissue sensitivity to parathyroid hormone. Another major risk factor for milk fever is hypomagnesemia, which is observed when animals are fed inadequate amounts of magnesium, or some factor is present in the diet that prevents adequate absorption of magnesium. Moderate hypomagnesemia impairs the ability of the cow to maintain calcium homeostasis and hypocalcemia occurs.

Magnesium disturbances in critically ill patients.

Magnesium alterations can have a noticeable effect on the neuromuscular cardiovascular, and metabolic systems. With recent advances in point-of-care testing, it is now easier to monitor for changes in the serum magnesium concentration and implement therapies in the critical care setting. This article reviews the normal homeostatic mechanisms, clinical abnormalities, and therapeutic strategies for magnesium disturbances in critically ill patients.

Influence of balance of protein and energy metabolism in rumen on hypomagnesaemia in cows.

This study was carried out in order to determine the influence of nitrogen excess in rumen and deficit of digestible organic matter in a feed ration for dairy cows on hypomagnesaemia at the beginning of green forage feeding. The balance of nitrogen and energy metabolism in rumen was determined using the rules of evaluation of the nutritional value of fodder (PDI system) according to the Institut National de la Recherche Agronomique (INRA), taking into consideration a potential protein synthesis from nitrogen by microorganisms in rumen (MPRN) and microbial protein synthesized from digestible organic matter (MP(RE)). It was found that an increase in the amount of rumen degradable protein (RDP) and MPRN-MPRE balance leads to a significant increase of urea nitrogen in serum (p < 0.05). An increase of total MPRN-MPRE balance in rumen results in a decrease of Mg concentration in serum. It has been demonstrated that in cows fed green forage at the end of spring (2nd half of May to 1st half of June) when the MPRN-MPRE balance is not higher than 187 g, adding 7 g or 25 g of MgO/cow/day to the same extent successfully prevents hypomagnesaemia.

Grass tetany in a herd of beef cows.

Five cows in a herd of 15 cattle that had just been turned out onto lush pasture after having over-wintered on poor quality hay died suddenly. Biochemical profiles collected from the cadavers revealed reduced serum levels of magnesium, urea, and beta-hydroxybutycate. Classical grass tetany (hypomagnesemia) was diagnosed on postmortem examination.

Evaluation of plasma-ionized magnesium concentration in 122 dogs with diabetes mellitus: a retrospective study.

The goal of this study was to evaluate plasma-ionized magnesium (iMg2+) concentration in a large group of dogs with naturally occurring diabetes mellitus and to determine whether dogs with diabetes mellitus have hypomagnesemia, as reported in diabetic humans and cats. Plasma iMg2+ concentrations were retrospectively evaluated at the time of initial examination of 122 diabetic dogs at the Matthew J. Ryan Veterinary Hospital of the University of Pennsylvania. Diabetic dogs were defined as having uncomplicated diabetes mellitus (DM, 78 dogs) diabetic ketoacidosis (DKA, 32 dogs), or ketotic nonacidotic diabetes mellitus (DK, 12 dogs) on the basis of presence or absence of metabolic acidosis or ketonuria. Twenty-two control dogs were used to determine reference values for plasma iMg2+ concentration in healthy dogs. Plasma iMg2+ concentration also was evaluated in 19 nondiabetic dogs with acute pancreatitis because many of the dogs with DKA had concurrent acute pancreatitis. Plasma iMg2+ concentration was significantly higher in dogs with DKA (median 0.41 mmol/L, reference range 0.14-0.72 mmol/L) than in dogs with DM (0.33 mmol/L, 0.17-0.65 mmol/L; P = .0002) or the control group (0.32 mmol/L, 0.26-0.41 mmol/L; P = .006). There were no significant differences between plasma iMg2+ concentrations in dogs with DM or DK compared with control dogs. We conclude that dogs with naturally occurring diabetes mellitus do not have marked hypomagnesemia on initial examination at a tertiary care center.