Blood samples may also be taken to check their fructosamine level . This gives a long-term view of blood glucose over the previous 1 – 3 weeks but should not be the sole indicator of DM ; it should be used in conjunction with the clinical history and clinical signs .
Idexx states that the fructosamine reference interval for dogs is 177 – 314 µ mol / l , and for cats it is 137 – 286 µ mol / l [ 7 ] . However , DM patients can have results within the normal range due to periods of hypoglycaemia [ 6 ] .
Treating the patient as an individual and spotting trends will aid the VS in diagnosing DM and assessing the patient ' s stability before and during insulin therapy . Table 1 details the common and uncommon causes of decreased and increased fructosamine [ 7 ] .
Fructosamine levels over 450 µ mol / l suggest poor control of DM , and in these cases a review by the VS is needed [ 7 ] . The added benefit of the fructosamine value is that it does not consider the short-term increase of blood glucose during times of stress , excitement or any intravenous dextrose administration [ 8 ] . Urinalysis can also help in the diagnosis of DM by measuring the glucose level in the urine .
Table 1 . Common and uncommon causes of decreased and increased blood levels of fructosamine [ 8 ] .
Causes of decreased fructosamine
Common : Prolonged hypoglycaemia due to insulin overdose or insulinoma . Decreased fructosamine is not diagnostic for insulinoma . Other tests , such as an ultrasound , would be needed to confirm a diagnosis
Common : Hyperthyroidism . Other tests , such as thyroxine measurement , would confirm a diagnosis
Common : Decreased albumin ( dog ) or total protein ( cat )
Uncommon : Storage of sample at room temperature Uncommon : Azotaemia
Causes of increased fructosamine
Common : Diabetes mellitus . Clinical signs are also present , as well as glucose in urine ± ketones and increased blood glucose
Common : Haemolysis ( certain methodologies )
Common : Insulin overdose with Somogyi overswing effect
Uncommon : Hypothyroidism
Uncommon : Increased albumin ( dog ) or total protein ( cat )
Treatment
DM treatment will often include lifestyle management as well as daily insulin injections . In veterinary practice , two types of insulin are predominantly used in the longterm treatment of DM : Caninsulin and ProZinc .
Caninsulin
Caninsulin is an intermediate-acting lente insulin containing 40 IU / ml of purified porcine insulin [ 9 ] . It is formulated as an aqueous suspension containing approximately 30 % amorphous and 70 % crystalline zinc insulin in a neutral buffer [ 9 ] . The amorphous fraction peaks about 4 hours post-injection and lasts for 8 hours , and the crystalline fraction is slowly absorbed with a peak activity 11 hours post-injection [ 9 ] . Caninsulin is also available in a VetPen , which is a device that can be used by owners to give insulin injections . The owner uses the dial on the device to prepare the dose , and then pushes the injection button to deliver the dose . Use of the VetPen reduces the chance of dosing errors .
ProZinc
ProZinc is a protamine zinc recombinant human insulin . It is available for cats and dogs but is mainly used to treat cats . The zinc component in ProZinc controls the rate at which insulin is released into the bloodstream , and the protamine allows delayed absorption [ 10 ] . Together , they control and extend the delivery of purified insulin into the bloodstream [ 10 ] . ProZinc can be given to dogs once a day but cats require twice-daily injections . When preparing a dose , it is important that the vial of ProZinc is rolled rather than shaken , as shaking may reduce the effectiveness of the insulin by breaking the insulin molecules apart [ 10 ] .
Diet and weight management
Diets formulated for DM can help to regulate blood sugar as well as manage weight . During a consultation , VNs should discuss how many times a day the owner currently feeds their pet and whether it prefers wet or dry food . If a cat needs to lose weight , it is important to explain to the owner that weight management is a gradual process and should include short-term targets . If weight loss is too rapid , cats can develop a life-threatening disease known as hepatic lipidosis , where fat cells are laid down in and around the liver . Dogs may develop this condition too , but it is more commonly seen in cats . If weight and blood glucose in cats with DM are well managed , the diabetes could go into remission .
A new diet should be introduced slowly , over 7 – 10 days . For example , on the first day a cat ' s meal could comprise 10 % new food and 90 % current food . The proportion of new food can be increased by 10 % each subsequent day until the new diet comprises 100 % of every meal . Dogs with DM require a diet that is high in fibre , medium in protein and low in fat . By contrast , for
54 Veterinary Nursing Journal