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INTERPRETING THE CHEMISTRY PROFILE o If the animal has eaten within the last 4 hours IN FERRETS and the glucose is below 90 mg/dL (< 60 mg/dL on the human glucometer) this is diagnostic for Joerg Mayer, Dr.vet.med., MSc insulinoma School of Veterinary Medicine o glucose alone is diagnostic for Tufts University, North Grafton, MA insulinoma; no other parameters need to be taken into consideration While the ferret is not considered to be a particularly o Repeated levels above 350 mg/dL might exotic pet and in general its clinical medicine is very indicate diabetes mellitus (rare in my similar to feline clinical medicine, the interpretation of the experience) ferret chemistry profile deserves special attention as x It can also develop after a partial there can be several pitfalls if ferret profiles are pancreactomy was performed. interpreted by comparing with cat or dog normal values. This article focuses on some of the most important Liver clinical pathology parameters and their interpretation. x ALT (Alanine Aminotransferase) As in other species, an exact diagnosis of a clinical o Liver specific in ferrets (not in rabbits!) is problem should never be based on blood work alone, but released when liver cells are damaged. Activity should include an evaluation of other diagnostic tools in liver is 3–10 times higher than in other tissues such as biopsies. One abnormal parameter is rarely (in ferret) pathognomic for a problem, and often two or three x Normal value 80–290 IU/L clinical pathology parameters need to be assessed in x High normal value than in other species order to better locate the potential origin of the clinical x Steroids can increase ALT very fast. problem, especially if it is subclinical. If several different x Hepatic lipidosis, lymphocytic hepatitis, parameters are significantly altered, a preliminary other forms of hepatitis often produce: diagnosis can be with a high degree of certainty and ƒ Up to 800 mg/dL then pursued with further diagnostics. Further ƒ With diagnostics approaches, eg, biopsies, should be (ALP) up to 100 mg/dL recommended. The lecture presents clinical cases, ƒ Increase in aspartate which highlight the need to harvest biopsies early on in aminotransferase (AST) as the diagnostic process in order to come to a definitive well diagnosis and to establish an accurate treatment plan ƒ Same occurs in gastritis early on. x Careful when diagnosing primary liver Recommended reading for a detailed discussion on disease on blood work alone GI and liver diseases of ferrets includes the chapter x Check for increased billirubin, low total “Ferret gastrointestinal and hepatic diseases” in the new and icterus 2 edition of Ferret Husbandry, Medicine and Surgery or x Suggest biopsy in order to the 2006 American Ferret Association (AFA) characterize liver lesion 1 proceedings. ƒ Lymphocytic hepatitis ƒ Suppurative hepatitis PARAMETERS TO EVALUATE DIFFERENT ORGAN ƒ Vacuolar hepathopathy FUNCTION ƒ Hepatic lipidosis ƒ Cirrhosis x Glucose ƒ Hepatic neoplasia o Normal values 90–200 mg/dL ƒ Billiary cystadenoma o An extremely important parameter, as insulinoma is the most common form of cancer x Gamma Glutamyltransferase (GGT) affecting the ferret in the US o The biliary system is the primary source of x Extremely common in ferrets older then plasma GGT. In addition to biliary GGT, 4 years; blood glucose should be significant levels of renal epithelial GGT can be checked at least once a year found in the urine o Care has to be taken when using a human o Normal around 5 IU/L glucosometer as these devices will artificially o Over 10 IU/L high index of suspicion for liver read out lower values then the true value, problems usually 15–20 mg/dL lower) x Need to differentiate nature of elevation x In addition, the (in)accuracy of these x Recommend abdominal ultrasound +/- units is around 20 mg/dL ultrasound-guided biopsy of liver to rule o The fasting glucose (4- to 6-hr fast) should be out primary liver pathology between 90–120 mg/dL x Liver involvement is sometimes o If animal has been fasting for longer periods of secondary to ascending inflammation time, the glucose will be low and is not from gut considered diagnostic for insulinoma 1851 NAVC Conference 2008 ______

x Suggest exploratory with multiple o Lab artifacts biopsies (GI tract, liver, lymph node) x Elevated levels: False-high test values can result when using Jaffe’s reaction, a chromogen color reaction x Blood Nitrogen (BUN) when the sample contains non- o BUN measures the amount of urea nitrogen, a chromagens, such as waste product of protein , in the ketones, glucose, fructose, ascorbic blood. acid, protein, urea, and ascorbic acid o Normal range 10–40 mg/dL x Decreased levels: Creatinine o I consider BUN a relatively insensitive test for deteriorates in plasma samples older evaluating renal disease in ferrets due to: than 24 hours leading to unreliable o Pre-renal factors influencing the BUN in ferrets results. can also cause include sampling errors. x High-protein diet x Phosphorus, Calcium, Potassium x Tendency to develop gastric ulcers very o These three parameters can be used to assess fast renal function in conjunction with BUN and o Post-renal elevations include urinary tract creatinine problems such as o Suspect true renal failure if: x Urinary obstructions. x Phos > 10 mEq/L AND x Infections (prostatitis, etc.) x Cal < 8 mg/dl AND x Often due to adrenal disease!! x Potas > 6 mEq/L o Might go up to 200–300 mg/dL with normal or mildly elevated creatinine Gastrointestinal Tract o Drug interaction x x Drugs such as steroids or NSAIDs may o Enzyme that breaks down into cause GI ulcers, therefore increasing monoglycerides and free fatty acids the BUN value o Normal values 0–200 U/L x Levels have been shown to decrease o While in other species, lipase is primarily with the administration of diuretics, produced in the pancreas, with a small amount aminoglycosides, amphotericin B, and being produced by the gastric mucosa, it chloramphenicol (not a ferret-specific appears that the ferret produces more lipase in fact) the stomach than in the pancreas x Creatinine x Therefore, elevations of lipase appear o Creatinine is a nitrogenous waste product more diagnostic for GI problems than produced by the breakdown of creatine, which is for pancreatic problems. an important part of muscle. A serum creatinine o Elevated if > 500 IU/L from commercial labs or > test measures the amount of creatinine in the 1000 IU/L from the IDEXX Vet-test) blood and is an indirect indicator of renal o Significant elevation most commonly seen cases glomerular filtration rate and can estimate renal of mild to severe GI disease like inflammatory function. bowel disease (IBD) and/or eosinophilic o It has been demonstrated that creatinine is an granulomatous disease insensitive indicator of renal failure in ferrets x Check globulin for evaluation as well perhaps related to their capacity for extrarenal x Run CBC to check for peripheral elimination of creatinine. Ferrets also have a eosinophilia considerably lower and narrower range of o In my opinion, lipase is one of the most creatinine in the blood than other mammals. commonly underused clinical pathology o Narrow range at normal 0.2–0.6 mg/dL parameters o Is considered relatively insensitive as an o Steroids will increase lipase levels in other indicator of renal failure species (dogs, etc) o The normal creatinine level averages x Most likely in ferrets as well. approximately half the level of the dog and cat x Globulin o If > than 0.8 mg/dL, then renal suspect o Globulins are that are mostly involved x Elevations of BUN up to 300 mg/dL the immune defense system. Any protein that is have been seen with a mild increase of not albumin is classified as a globulin creatinine. to 2–3 mg/dL o Normal values 2–2.9 mg/dL x Three-fourths of renal function must be o Often elevated with chronic inflammatory lost before abnormalities in creatinine conditions such as IBD concentration are seen x Check lipase for elevation in cases of x In contrast to BUN, creatinine is not IBD influenced by diet or GI ulcers

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x Most confirmed cases of IBD have high total protein. Any error in the measurements of levels (> 3–5 mg/dL) albumin or total protein will give you erroneous x Consider Aleutian disease if elevation globulin levels goes beyond 6 mg/dL x Increases in dehydration REFERENCES x Decreased globulins are generally the 1. Burgess M. Gastrointestinal and hepatic diseases. result of decreased production (ie, liver In: A Comprehensive Veterinary Symposium, failure) or increased loss Advanced Course. Management of the Ferret. AFA x Lipase and globulin should always be Meeting, Pittsburgh, Pennsylvania. 2006, pp 79-97 interpreted with each other to check for signs of (order online at www.ferret.org). IBD 2. Lewington J. Ferret Husbandry, Medicine and x I usually recommend GI biopsies to diagnose Surgery, 2nd ed. St. Louis, MO: Saunders/Elsevier, IBD in these cases 2007. 3. Hamosh M, Henderson TR, Hamosh P. Gastric x It has been speculated that chronic unmanaged cases of IBD might develop into GI lymphoma lipase and pepsin activities in the developing ferret: nonparallel development of the two gastric digestive x Potential laboratory error: Globulin levels are enzymes. J Pediatr Gastroenterol Nutr. 1998;26(2): often calculated by subtracting albumin from the 162-166.

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