3 Diagnosis and Differential Diagnosis
Transcript
So today, we are going to see about lesson-3, before that in the previous lesson, we have seen about the Pathogenesis of Hypermagnesaemia and the various risk factors, How it causes hyper magnesium and the Clinical manifestation that is a major form is Acute Hypermagnesaemic characterized by neurological signs, tonic-clonic convulsion Tetany, and a Subacute form that is a more gradual onset of clinical signs, and the common Chronic form which is only unthriftiness and reduced appetite and milky and this form is always accompanied with hypocalcemia and most of the time it will predispose the cattle to go far downer cow syndrome.
And today in lesson-3, here we are going to see about How to diagnose the Hypermagnesaemic based on the various laboratory techniques at the field level.
The major pathogenic in Hypermagnesaemia is reduced serum magnesium level, so estimation of Magnesium from the blood is an important diagnostic too, normal value is 1.7 to 3 milligram per deciliter. So in Hypermagnesaemic, the levels will be less than 1.7.
To occur Tetany and convulsion the value should be too low, that is less than 1.2 and since most of the time Hypermagnesaemi concurrently there will be hypocalcemia, estimation of Calcium is also important, always there will be Subclinical hypercalcemia that is less than 7.5-milligram deciliter of calcium will be estimated apart from this there will be release or increased Acute-phase inflammatory response you can see, that is a severe leukocytosis also you can appreciate in a Hypermagnesaemic animal. So in addition to serum analysis of magnesium since the main Homeostasis is the kidney, whenever there is Hypermagnesaemia, you may expect a reduction of magnesium in the urine, so the filter useful is a Xylidel test, so the urine magnesium decreases that indicates the animal is having Hypermagnesaemia.
So, one challenge is that field the animal is given is on grazing land and the animal shows severe neurological signs, you cannot collect even a blood sample, and most of the time the animal may be found dead. So if the animal is found dead, the diagnosis purpose will be to collective various samples and if you have a suspicion of Hypermagnesaemic here we need to collect the CSF fluid and we need to estimate the magnesium level, because CSF is a predictor for a Hypermagnesaemia and we can collect CSF up to 12 hours of death, that is reliable so you can estimate the magnesium till the even after 12 hours of the death of carcass animal and so the collection of magnesium from atlantooccipita region is more reliable than the Lumbar puncture. So the values are less than like it’s almost equal to serum magnesium, if the values are too low 0.4 or 0.5 milligrams it could have died of convulsion and other severe neurological signs.
If the animal doesn’t have a convulsion, then it is in subacute form, you can estimate the magnesium from even Vitreous humor, so you can use a 14 gauge needle to collect CSF from Vitreous humor, even in a dead animal also Vitreous humor sampling is useful to estimate the magnesium level and to prove Hypermagnesaemia and by adding formaldehyde to the sample we can estimate the still prolong the estimation of magnesium level in the prosumer fluid. Since Hypermagnesaemia occurs mainly it is manifested as a neurological disease as I said earlier mainly Tetany is stiffness of limb and the excitatory signs like prickly ears and that is an uncontrollable neurological sign like frenzy expression and then very difficult to control so these are exciting neurological signs should be differentiated from similar diseases like mainly the common neurological adult dairy cattle acute Lead poisoning, there also you will get neurological signs and another important thing in a high yielding dairy cattle- nervous signs of like the frequent licking of body, frenzy behavior, and pica and other signs, that is a nervous form of ketosis is also important.
And another important this is to be differentiated that is an important neurological disorder at the field level is Rabies; in Rabies also you will get excitatory signs, like attacking others and the animal is uncontrollable and it’s very difficult to restrain frequent getting up and walking. In addition to the neurological sign, each disease will have the Pathogens based on that we need to differentiate and mostly in western countries other important neurological signs to be differentiated are moments of spongy form Encephalopathy.
In this lesson, we have seen how to Diagnose Hypermagnesaemia by various laboratory techniques by estimation of Magnesium from the serum and then the estimation of Magnesium in the urine and then in dead animals especially CSF fluid and Vitreous humor.
How they are useful in the Diagnosis of Hypermagnesaemia as well as What are all the Diseases to be differentiated from Hypermagnesaemia especially Rabies, Lead poisoning, and Ketosis?
