Managing Reproduction Emergencies in the Field: Part 2: Parturient and Periparturient Conditions.

Selected conditions affecting broodmares are discussed, including arterial rupture, dystocia, foal support with ex utero intrapartum treatment, uterine prolapse, postpartum colic, the metritis/sepsis/systemic inflammatory response syndrome complex, and retained fetal membranes. Postpartum colic beyond third-stage labor contractions should prompt comprehensive evaluation for direct injuries to the reproductive tract or indirect injury of the intestinal tract. Mares with perforation or rupture of the uterus are typically recognized 1 to 3 days after foaling, with depression, fever, and leukopenia; laminitis and progression to founder can be fulminant. The same concerns are relevant in mares with retention of fetal membranes.

[Etiology, therapy and prophylaxis of bovine parturient paresis (hypocalcaemia)]. / Wesen, Ursachen, Therapie und Prophylaxe der hypokalzämischen Gebärparese beim Rind.

Due to the sudden increase of calcium demand at the onset of lactation many high yielding dairy cows experience a certain level of hypocalcaemia following parturition. The incidence of hypocalcaemia (parturient paresis) increases with age but also depends on many other factors such as the acid-base status and the availability of calcium as well as other minerals and trace elements. Hypocalcaemia can easily be treated by supplementation of calcium parenterally or orally, nonetheless, prophylaxis of the condition should be the main focus in modern dairy farming, in order to avoid its negative effects. Oral administration of calcium around parturition is the simplest way of prophylaxis, but results in a high work load and requires exact knowledge of the date of parturition. The latter also applies for the parenteral administration of vitamin D3, which should be injected 1 week before parturition. Additionally, repeated treatment with vitamin D increases the risk for calcinosis. Reducing the calcium concentration of the ration fed during the late dry period also decreases the risk for hypocalcaemia by activating the mechanisms for calcium homeostasis within the body. The induction of a mild (compensated) metabolic acidosis to increase the sensitivity of parathormone receptors and enhance intestinal calcium uptake may also be employed to prevent milk fever. For this purpose, a DCAD (dietary cation anion difference) diet is fed during the late dry period, in which the concentrations of strong cations (potassium and sodium) as well as strong anions (sulfate and chloride) are altered. This may either be achieved by reducing the potassium concentration (partial-DCAD) or by adding anionic salts (full-DCAD). This method, especially the full-DCAD variant, requires a substantial level of surveillance and monitoring. Suitable prophylactic measures for the prevention of hypocalcaemia must be chosen individually for each farm, depending on the incidence of hypocalcaemia as well as personnel and structural resources.

[Diagnosis, therapy and prophylactic measures of parturient paresis in dairy cattle: results of an online survey for Swiss veterinarians]. / Diagnose, Therapie und prophylaktische Massnahmen der Gebärparese beim Rind: Ergebnisse der Online-Umfrage bei Schweizer Tierärzten.

INTRODUCTION: The aim of this study was to obtain the diagnostic, therapeutic and prophylactic approach among Swiss veterinary practitioners in cows with parturient hypocalcemia. All members of the Association for Ruminant Health were contacted per e-mail. The survey was completed by 108 (28%) of 393 that were contacted. According to the questionnaire responses, the typical presentation of a parturient paresis cow is a pluriparous middle-yielding dairy cow one day post-partum in sternal recumbency with normal consciousness. The diagnosis is usually based upon the medical history. Therapy of parturient paresis consists of mixed infusions (with calcium, phosphorus, magnesium or glucose) as well as oral preparations with calcium. The veterinarians estimate that 25-50% of the cows treated for parturient paresis need more than one treatment and that one case of parturient paresis costs CHF 200-300. Prophylactic treatments are usually used for cows, which have suffered from parturient paresis in the previous lactation, elder cows (≥ 3 lactations) as well as cows with a high body condition score (> 3.25). Prophylactic measures used by the veterinarians are vitamin D3 injections and oral preparations with calcium. They recommended a special diet, for example a low calcium diet ante-partum.

INTRODUCTION: Le but de la présente enquête en ligne était de relever les méthodes de diagnostic, de traitement et de prophylaxie utilisées en pratique en matière de parésie puerpérale hypocalcémique. Tous les membres de l'Association suisse pour la santé des ruminants ont été contactés par courriel. Sur les 393 questionnaires envoyés, 108 (28%) ont été remplis complètement et exploités. L'anamnèse typique est un animal pluripare avec une production de parésie puerpérale, il est mentionné des animaux pluripares avec une production laitière moyenne, incapables de se lever un jour après le vêlage et présentant un état de conscience normal. Le diagnostic est fréquemment posé sur la base de l'anamnèse. Les vaches laitières concernées sont traitées avec des perfusions mixtes (produits à base de calcium et de phosphore, parfois avec du magnésium et du glucose) et des préparations de calcium orales. Les vétérinaires estiment que 25 à 50% des vaches nécessitent plusieurs traitements et que les coûts totaux par animal de l'ordre de CHF 200 à 300. Du point de vue prophylactique, ce sont principalement les animaux ayant déjà souffert d'une parésie lors de la lactation précédente ainsi que les vaches plus âgées (3ème lactation et plus) et celles présentant un indice de condition élevé (> 3.25) qui sont traitées. Les vétérinaires utilisent pour cette prophylaxie des injections de vitamine D3 ainsi que des préparations orales de calcium et/ou conseillent aux propriétaires une alimentation pauvre en calcium ante partum.

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.

Strategies for preventing milk fever in dairy cattle.

Milk fever is a complex metabolic disorder that occurs at the onset of lactation. Clinical symptoms of this disease include inappetence, tetany, inhibition of urination and defecation, lateral recumbency, and eventual coma and death if left untreated. The hallmark of this disease is severe hypocalcemia, which probably accounts for most of the clinical signs associated with a milk fever episode. Several factors have been consistently associated with increased incidence of milk fever, including parturition and initiation of lactation, advancing age, breed, and diet. Of the various methods used in attempts to control the disease, the most progress has been made in dietary management. Until recently, most attention has focused on manipulating the levels of dietary calcium to control milk fever incidence; results, however, have been inconsistent, except for those diets containing very low (8 to 10 g/d) concentrations of Ca. During the past decade, there has been renewed interest and research in the use of dietary anions (Cl- and SO4(2-) in controlling milk fever. An outgrowth of this research has been the surprising realization that dietary K is significant (perhaps more significant than Ca) in determining the susceptibility of dairy cows to milk fever. This knowledge has expanded the understanding of the pathogenesis of milk fever and has focused attention on research designed to study methods for neutralizing the detrimental effects of dietary K excess on periparturient animal health. This report discusses various practical strategies and potential research areas for managing the dietary forage components to minimize the effects of K on milk fever incidence.

Calcium metabolism in hypocalcemic cows with myocardial lesion.

This paper deals with blood levels of calcium (Ca), inorganic phosphorus, parathyroid hormone and 1,25-dihydroxyvitamin D in 6 cows treated for milk fever. Four of the cows stood within 1 day after Ca therapy, whereas 2 other cases showed an unsatisfactory response to Ca therapy and did not rise. The necropsy revealed microscopic necrotic myocardial lesions scattered in the heart of these 2 unrecovered cows. The degree of hypocalcemia and hypophosphatemia were similar in the 6 cows. However, the recovery from hypophosphatemia was markedly delayed in the cows will an unsatisfactory response.

Aspectos clínicos, epidemiológicos e terapêuticos da hipocalcemia de vacas leiteiras / Hipocalcemia in a Brazilian dairy cattle herd: some epidemiological, clinical and therapeutical considerations

No decorrer de 1987 e 1988 acompanhou-se o aparecimento de casos clínicos de hipocalcemia, durante o puerpério, em vacas leiteiras da raça Holandesa ou mestiças Gir-Holando, de uma propriedade do Vale do Paraíba, Estado de Säo Paulo. A incidência de hipocalcemia foi de 4,25 por cento. Näo se observou influência do grupo genético e da época do ano (seca ou chuva) no aparecimento da afecçäo. Quanto maior a ordem de lactaçäo maior a incidência de hipocalcemia, näo ocorrendo a enfermidade em vacas com menos de três lactaçöes. A hipocalcemia foi mais frequente no decorrer do primeiro dia pós-parto, 64,10 por cento, que no segundo 30,80 por cento, e após, 5,10 por cento. A maioria dos casos, 84,10 por cento, foi detectada em animais que apresentavam o segundo estádio clínico da afecçäo (depressäo, paralisia flácida etc.), mais do que no terceiro (comatose, depressäo da consciência etc) ou no primeiro (tetanias, hiperexcitabilidade etc) estádios. Todas as vacas acometidas foram tratadas com doses crescentes de cálcio injetável, num máximo de nove gramas, até a recuperaçäo do animal. Quanto maior a dose de cálcio empregada maior o sucesso acumulado no tratamento. O exame laboratorial do soro sanguíneo revelou que vacas com afecçäo apresentaram hipocalcemia, hipofosfatemia e hipermagnesemia quando comparadas com vacas parturientes hígidas

Treatment and control of an outbreak of fat cow syndrome in a large dairy herd.

An outbreak of fat cow syndrome occurred in a herd of 300 Friesian and Friesian/Holstein dairy cows calving predominantly between January and May. The herd came in off grass in good condition despite a long and hot summer. The dry cows received a diet of grass silage, brewing waste and minerals until the end of December, but the grass silage was butyric and was partially replaced by maize silage. By January 23, 16 of 70 calving cows (23 per cent) had appeared to suffer milk fever. Subsequent blood tests revealed that the cows may have been ketotic, and clinical and post mortem examination showed that they were probably suffering from fat cow syndrome. The freshly calved sick cows were treated with glucose, and corticosteroids were injected every second day into those which remained ill. The cattle had received a high energy diet, but the cows still to calve were placed on a diet of low metabolisable energy (77 MJ/cow) but adequate levels of undegradable protein. The problem was associated with a possible clostridial infection in two cows and with reduced fertility.

[The frequency of individual methods of treatment for health disorders in north German dairy herds]. / Zur Häufigkeit von Eigenbestandsbehandlungen bei Gesundheitsstörungen in norddeutschen Milchviehbeständen.

Disease data were recorded in 143 north German dairy herds including cows of three breeds: Angler, German Red and White and German Black and White. The following disease complexes were analysed: retained placenta, sterility, mastitis, milk fever and claw disorders. Data recording was performed by the herdsman and included date and type of disease per cow and a note, by whom the medical therapy was conducted (veterinary or herdsman). A comparison of both, therapy performed by veterinary or by herdsman, indicated that 75% of all cases of mastitis, 48% of all claw disorders and 25% of all cases of retained placenta were treated by the herdsman, whereas concerning milk fever and sterility only 10 resp. 8% of all cases were treated by the herdsman. An analysis was performed to investigate which factors of region, farm and herd may be related to the extent, in which disorders are treated by the herdsman. The results indicated that region, housing system, herd size and herd milk (kg) and fat (%) were affecting at least two of the five parameters which were formed to describe the herdsman's willingness to conduct medical therapy himself.

Parturient paresis and hypocalcemia in ruminant livestock.

Parturient paresis (hypocalcemia) is most likely to affect dairy cattle around the time of parturition. It causes progressive neuromuscular dysfunction and flaccid paralysis. Older dairy cows, cows with a history of parturient paresis during a previous lactation, high-producing cows, and cows from the Jersey and Guernsey breeds are at highest risk for developing parturient paresis. Nonparturient hypocalcemia may also occur and is related to events other than parturition, such as severe stress, that temporarily overwhelm the mechanisms of calcium homeostasis. Beef cattle, sheep, and goats are affected less frequently by hypocalcemia than are dairy cows. Because these species are not as stressed for milk production as dairy cattle, nonparturient hypocalcemia makes up a higher proportion of cases in nondairy ruminants. Clinical signs of hypocalcemia in beef cattle, sheep, and goats tend toward hyperesthesia and tetany rather than the classic flaccid paralysis that occurs in dairy cattle with parturient hypocalcemia. Prompt and effective treatment of hypocalcemia helps to reduce the incidence of secondary complications, such as muscle damage or mastitis. The standard treatment regimen of 500 ml of 23 per cent calcium gluconate, administered intravenously, will elicit a favorable response in approximately 75 per cent of recumbent cows within 2 hours of treatment. Relapses following successful initial therapy are common and may be prevented in part by supplementation of intravenous treatment with an additional 500 ml of 23 per cent calcium gluconate administered subcutaneously. Proper nursing care following treatment speeds recovery and reduces the incidence of secondary complications owing to hypocalcemia.

The relationship between certain clinical characteristics and course of disease in milk fever in dairy cows.

Recovery rate after one treatment and mortality rate in cows with clinical milk fever were related to several clinical characteristics recorded immediately prior to first treatment, namely: Appetite, mobility, demeanour, whether or not hyperhidrosis was present, pulse quality, pulse rhythm, pulse rate and rectal temperature. Furthermore, the same symptoms at second treatment and subsequent course of disease in milk fever cows which received at least two treatments were found to be related. Recovery rate after first treatment was lower in cows which had been recumbent for more than one hour before treatment than in those which had been down for a shorter period. As regards cows which received at least two treatments, the recovery rate after second treatment was higher in those which had been on their feet for a shorter or longer period between first and second treatment than in those which has been recumbent during this period.

The relationship between packed cell volume and the course of disease in milk fever in dairy cows.

Results from a field investigation involving 1086 cows with clinical milk fever, revealed a clear relationship between PCV at the time of first treatment and the subsequent course of the disease. Average PCV was progressively higher as the cows required one, two, or more than two treatments before recovery, and was highest in cows which subsequently failed to recover. PCV in healthy, periparturient cows was considerably lower than in cows with milk fever. PCV was negatively correlated with plasma Ca, and varied, moreover, with the time of first treatment in relation to calving, and also with the length of time the cow had been recumbent before being treated for the first time. PCV was also measured during the further course of the disease in cows which received more than one treatment (2nd to 6th treatments).

Pathogenesis of the downer cow syndrome.

A historical review of the downer cow literature is presented in order to provide a background for understanding current research. Initially thought to be an entity separate from parturient paresis, the condition has eventually come to be regarded as a complication of parturient paresis. Since many other factors also contribute to the syndrome, it is difficult to define precisely what is meant by the term 'downer cow'. A hypothesis that many primary factors, including parturient paresis, may cause the initial stage of recumbency is presented. This is followed by secondary muscle and nerve damage caused by tissue compression. This damage leads to permanent recumbency even if the primary factors have been ameliorated by therapeutic measures. Support for this hypothesis is given from the literature on cattle and other species and from recent experiments on cows. The concepts are applied to a discussion of prevention and therapy of downer cow cases.