Other minerals are also affected by magnesium deficiency in dogs
Sure, there are other electrolyte minerals required by both humans and dogs. We need sodium, potassium and calcium as well, but these are all dependent to some degree on the action of the magnesium. Magnesium underpins and leverages their effect. And our main electrolyte team in addition to magnesium – sodium, potassium and calcium – are necessary for some very important functions, including muscle movement, proper heart function and nervous system signalling. For example, if you have plenty of magnesium, your body doesn’t need quite as much calcium to get the calcium jobs done because magnesium organises and controls calcium’s use in the body. It turns out that magnesium is the ‘Master Mineral’ electrolyte regulator in the electrical system. If it drops too low, calcium can cause a lot of havoc as free calcium depositing where it shouldn’t, or over-stimulating muscle cells. Therefore, as magnesium drops lower, it can lead to the other three minerals losing effect. Studies have shown that potassium suffers when magnesium is too low, as we can lose too much potassium due to membrane ‘leakiness’ when magnesium is deficient. If you lose too much potassium from inside the cell it can cause heart attacks. The potential knock-on effects are muscle weakness and tremors, as well as heart arrhythmias. As these issues escalate they can become fatal. I have a customer that regularly applies Magnesium Oil to the legs of his racing dogs so they can recover better from their events. Without the extra magnesium the dogs develop intense and involuntary muscle tremors and spasms. This is also a helpful strategy for all athletes who undertake extreme sports and gruelling training. If your dog is behaving strangely and seems to be in pain or having trouble walking, take your pet to a vet straight away so they can check exactly what’s happening. Sometimes it might be a toxin from a tick or snake bite that is causing these issues, because that type of toxin blocks the electrical system. Magnesium deficiency is something that tends to grow over time. You will be able to notice symptoms creeping in slowly, and escalating if left untreated. If you’re worried about your dog’s health because he/she is behaving strangely with symptoms like sensitivity to stress or noises, anxiety, muscle weakness and changes to gait, or skin issues with constant scratching not due to fleas, then your vet will likely order a blood electrolyte test. This measures the amount of minerals such as magnesium, potassium, calcium and sodium in your pet’s blood, in addition to some other common electrolytes.
Ron Hines DVM PhD
After sodium (Na+), potassium (K+) and calcium (Ca2+), magnesium (Mg2+) is the most common positive ion (cation), in your dog or cat’s blood stream. Magnesium is required for many enzyme-based reactions that occur in your pet’s body. Within the animal’s cells, magnesium it is second only to potassium in abundance. The normal commercial diets for dogs and cats contain plenty of magnesium because meat and meat byproducts are rich magnesium sources.
Approximately fifty percent of the magnesium in your dog and cat’s body is found in its bones. Most of the other half is found inside the cells of its body. Only about 1% of your dog or cat’s magnesium is found in its blood. The pet’s body works hard to keep that amount constant. So, when your veterinarian says that your pet is deficient in magnesium based on a blood test, that doesn’t necessarily mean that all its body magnesium reserves are low.
Too little blood magnesium (hypomagnesemia) is considerably more common in dogs and cats than too much blood magnesium (hypermagnesemia).
Experiment 1; Seasonality of serum Mg2+ levels
To examine the serum Mg2+ levels of dogs with very few individual differences due to their environments and foods, we used guide dog candidates with the agreement of The Eye Mate Inc., a Japanese public incorporated foundation that raises guide dogs. Since serum Mg2+ levels are influenced by temperature and the seasons in humans (Owaki et al., 1996), we first assessed seasonal variations of serum Mg2+ levels in dogs. We collected blood samples from the guide dog candidates in the advanced class in January (winter, average temperature for the last five years in Tokyo, Japan is 5.7°C), May (spring, 19.4°C), and August (summer, 28.6°C). The serum Mg2+ levels of January, May, and August were 16.7 ± 0.2 μg/mL (the median is 16.9 μg/mL), 20.7 ± 0.3 μg/mL (the median is 21.0 μg/mL), and 21.2 ± 0.2 μg/mL (the median is 21.7 μg/mL), respectively ( ). Serum Mg2+ levels of dogs in the advanced class were significantly lower in winter. On the other hand, serum Mg2+ levels increased in summer.
In the previous studies, it mentioned that intravenous injection of adrenaline decreased blood levels of Mg2+ in humans (Joborn et al., 1985) and ewes (Rayssiguier, 1977), and that the consequent increase in adrenaline induced magnesium loss (Seelig, 1994). Therefore, we examined adrenaline and noradrenaline levels in winter and summer ( , ). Plasma adrenaline and noradrenaline levels were higher in winter; on the other hand, they became lower in summer, showing the inverse correlation with serum Mg2+ levels.
Magnesium Deficiency in Dogs | Wag!
1Cooperative Major in Advanced Health Science, Graduate School of Bio-Applications and System Engineering, Tokyo University of Agriculture and Technology, Tokyo 183-8509, JapanFind articles by
1Cooperative Major in Advanced Health Science, Graduate School of Bio-Applications and System Engineering, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
2Laboratory of Comparative Animal Medicine, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, JapanFind articles by
3Laboratory of Veterinary Molecular Pathology and Therapeutics, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, JapanFind articles by
1Cooperative Major in Advanced Health Science, Graduate School of Bio-Applications and System Engineering, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
3Laboratory of Veterinary Molecular Pathology and Therapeutics, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, JapanFind articles by
1Cooperative Major in Advanced Health Science, Graduate School of Bio-Applications and System Engineering, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
2Laboratory of Comparative Animal Medicine, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, JapanFind articles by
Magnesium ions (Mg2+) are essential for various enzymatic reactions in the body associated with energy production and activation of the muscles and nerves. Mg2+ is also involved in blood pressure regulation, maintenance of body temperature, and glucose metabolism. Although various factors including foods and physical conditions have been reported to change serum Mg2+ status in humans, serum Mg2+ in dogs exposed to external stress has been unclear. In this study, we examined serum levels of Mg2+ in dogs at different conditions using the guide dog candidates for the blind. Serum Mg2+ was decreased in winter and increased in summer. Guide dog candidates in an elementary class of the training showed markedly lower levels of serum Mg2+, compared with that of dogs in an advanced class. When healthy adult dogs were subjected to forced exercise using a treadmill, a significant reduction in serum Mg2+ levels was observed, particularly in winter. These findings suggest that serum levels of Mg2+ may be influenced by weather fluctuation such as air temperature, nervousness in unaccustomed situations, age, and physical stress induced by exercise. The results indicate that Mg2+ supplementation should be considered for working dogs, dogs moving or traveling to a new environment, and dogs during winter.
Magnesium ions (Mg2+) are one of the essential minerals necessary to maintain life. Most Mg2+ is stored in the cells of organs and tissues, particularly in the bones and teeth. Small amounts of Mg2+ are present in extracellular spaces, where Mg2+ binds with either proteins or anions. Mg2+ is needed to generate energy by assisting in the reaction of various enzymes with Mg2+ binding sites in their active region (Cowan, 2002). Mg2+ is necessary for the synthesis of proteins, energy metabolism (Pfeiffer and Barnes, 1981; He et al., 2006), contraction of the muscles (Altura and Altura, 1981), blood pressure regulation (Resnick et al., 2000; He et al., 2005), and modulating blood glucose levels (Dominguez et al., 1998; Singh et al., 1998), as well as a considerable number of enzymatic reactions within the body (Cowan, 2002). Lack of Mg2+ induces deterioration in energy production, leading to fatigue (Lukaski and Nielsen, 2002). Mg2+ deficiency also causes poor concentration, chronic fatigue, loss of appetite, and cardiovascular abnormalities in humans (Bohl and Volpe, 2002). Concentration of Mg2+ in blood is regulated by the interaction of several hormones, including, noradrenaline, parathyroid hormone, glucagon, and cortisol (Soria et al., 2014). Intravenous injection of catecholamine induced a marked increase of Mg2+ excretion in the urine (Rayssiguier, 1977; Joborn et al., 1985), suggesting catecholamine may reduce blood Mg2+ levels.
In humans, abnormalities in serum Mg2+ levels have been reported in various diseases (Elin, 1988; Rude and Gruber, 2004; Sinert et al., 2005; Baltaci et al., 2013), and, interestingly, the morbidity of these diseases has been reported to correlate with Mg2+ intake (Elin, 1988; Singh et al., 1997; Eby and Eby, 2006). However, the dietary intake of Mg2+ reduces with age (Bazzarre et al., 1993; Durlach et al., 1993; Tucker et al., 1999). The market for Mg2+ supplements has expanded for prophylactic amelioration of lifestyle related diseases (Seelig and Altura, 1997). In addition, Mg2+ supplementation in training athletes has also increased (Haymes, 1991). Moreover, reduction in Mg2+ intake has been reported to be associated with severity of depression and anxiety in community-dwelling adults, and administration of Mg2+ to patients improved their conditions (Jacka et al., 2009).
Changes in the serum Mg2+ levels of dogs have not been fully explored. The aim of this study was to analyze changes in serum Mg2+ levels of dogs before and after a training or exercise load.
All animal experiments complied with the standards specified in the guidelines of the University Animal Care and Use Committee of the Tokyo University of Agriculture and Technology as well as the guidelines for the use of laboratory animals provided by the Science Council of Japan. The procedures conducted were approved by the University Animal Care and Use Committee of the Tokyo University of Agriculture and Technology (No. 27-62; July, 27, 2015). For blood collection from guide dog candidates, all procedures were informed approved by The Eye Mate Inc. (Tokyo, Japan). Young Labrador retrievers (aged from 17 to 35 months, mean age was 23 ± 0.8 months old.) that had been selected as candidates for guide dogs for the blind were subjected to the measurement of serum Mg2+ in the experiment 1 (12 dogs) and 2 (24 dogs). They were housed in individual cages in a room illuminated daily from 6:00–21:00 with a temperature of 15–25 ± 3°C. The room temperature of the kennel was set according to that of the outside, because the training of the dog was carried out in city areas. They were fed with appropriate food once a day at 7:00 and were given water ad libitum. They were all neutered and belonged to The Eye Mate Inc. The Eye Mate Inc. has the longest history of dog training in Japan and provides the largest number of well-trained guide dogs to the blind. Healthy Labrador retrievers that worked as guide dogs for the blind (mean age was 6.9 ± 0.4 years old, 6 neutered males and 8 neutered females) were subjected to the measurement of serum Mg2+ in the experiment 2 (14 dogs). They were all neutered and belonged to their user. They were fed by their users. Three of them were fed in the morning and 11 of them were fed in the night. All the guide dog candidates and guide dogs were fed with the same food.
In the experiment 3, we used 6 laboratory dogs. They were housed in individual cages in a room illuminated daily from 7:00–19:00 with a temperature of 21 ± 4°C. They were fed with appropriate food once a day at 19:00 and were given water ad libitum. They were allowed to take a walk or free exercise at the outside of their facilities with animal care staffs for 30–60 min in one day for their welfare, except the day of the experiment. They were all neutered, fed with the same food, and managed in the same circumstances.
Foods supplied to dogs used in the current study are shown in . Natural Harvest Maintenance (13–15 g/kg body weight/day) (Vanguard International Foods Co., Chiba, Japan) was given to guide dog candidates and guide dogs for the blind, and Acana Pacifica for dogs (15–20 g/kg body weight/day) (Champion Pet Foods Ltd., AB, Canada) was given to laboratory dogs.
In the experiment 1, 12 guide dog candidates in the advanced classes (aged from 21 to 35 months) were used to confirm seasonal changes of serum Mg2+ levels. The advanced class is a final stage of their training. Blood samples collected in January, May, and August from different dogs in the advanced class at each month, and serum Mg2+ levels were analyzed. Each group was consisted of 4 dogs (1 neutered male and 3 neutered females). In Eye Mate Inc., 4 dogs finish their trainings every month and start working as mature guide dogs for the blind.
In the experiment 2, the total of 24 guide dog candidates and 14 working guide dogs were used to measure serum Mg2+ levels. Training phases of those candidates are divided into three classes as described below. The elementary training class included dogs that could walk with their instructor on their leads for 10–15 min. The intermediate class included dogs that could wear harnesses to walk under the simple commands of their instructor on an empty street for 20–30 min. The advanced class included dogs that could wear harnesses to walk under the commands of their instructor on a busy street for 40–50 min. Six dogs (the mean age was 19.8 ± 0.8 months old, 1 neutered male and 5 neutered females) in the elementary class, 10 dogs (the mean age was 21.1 ± 0.9 months old, 4 neutered males and 6 neutered females) in the intermediate class, and 8 dogs (the mean age was 26.5 ± 1.5 months old, 2 neutered males and 6 neutered females) in the advanced class were subjected to the study. Fourteen healthy Labrador retrievers that worked as guide dogs for the blind (mean age was 6.9 ± 0.4 years old, 6 neutered males and 8 neutered females) were subjected to the measurement of serum Mg2+ in the experiment 2 under the informed consent of their owners as adult controls.
In the experiment 3, we used a treadmill to test the effects of forced exercise. In this experiment, three healthy mixed breed dogs (aged from 5 to 6 years), one Beagle dog (6 years old), one Jack Russell Terrier (6 years old) and one Miniature Dachshund (9 years old), belonging to the colony of our laboratory were used. They included 3 neutered males and 3 neutered females. Before and after the treadmill training performed in January and August, blood samples were collected. To assess the effects of forced exercise on serum Mg2+ levels, laboratory dogs undertook 20 min of physical exercise on a treadmill that was set at 3–6.5 km/h. The speed of the treadmill was set according to the physical ability of each dog.
To investigate serum Mg2+ levels of dogs, guide dog candidates at different phases of training were examined. We collected blood samples from dogs in the elementary and intermediate classes on the first day of their training. We collected blood samples from dogs in the advanced class on the day that the training was completely over. Blood samples (1.5 mL/dog) of laboratory dogs were collected at each time point of their exercise. Samples were taken from the cephalic vein by experienced veterinarians and were collected into serum-separator tubes (SST II; Becton, Dickinson & Co.). The tubes were allowed to stand for 30 min at room temperature and were then centrifuged for 10 min at 425 g. Separated serum was collected and stored at -30°C until use.
Serum Mg2+ was measured by the quantitative colorimetric determination method using the QuantiChrom Magnesium Assay Kit (DIMG-250; BioAssay Systems, Hayward, CA), according to the manufacturer’s protocol. Using the assay kit, we can directly measure magnesium ions in serum samples without any pretreatment. All assays were performed in flat-bottom 96 well plates (Nunc PolySorp®; Thermo Fisher Scientific, Inc., Tokyo, Japan). A calmagite dye used in the assay kit forms a colored complex specifically with magnesium ions. The absorbance values were measured at 500 nm using a micro plate reader (ImmunoMini (NJ-2300); BioTec, Suffolk, UK). Serum Mg2+ values were expressed as the mean of triplicate measurements.