Click to return to Contents - Rabbits and their Relatives
CONTENTS

Health & Management / Rabbits and their Relatives: Disease Investigation and Management / List of hyperlinked Techniques & Protocols:

Clinical Pathology of Ferrets:

      

Introduction and General Information

Clinical pathology of ferrets follows the same general principles as for other species. However, there are some aspects in which normal findings, abnormal findings, and interpretation are different from those of other species such as cats and dogs. It is important to be aware of these differences.
Published Guidelines linked in Wildpro
  • --

Return to top of page

Haematology

Sample collection

Blood can be collected from a variety of sites: the jugular vein, cephalic vein or lateral saphenous vein, also the anterior vena cava and the ventral tail artery.

  • For further information on blood sampling and the advantages and problems associated with different sites see: Venipuncture / Blood sampling / Intravenous Catheterization in Ferrets
  • Blood volume in ferrets is 50 - 60 mL. (J213.11.w2) 6 - 7 % of body weight. (B631.20.w20) about 40 mL in the female ferret, about 60 mL in the male ferret. (B660.31.w31)
  • Note: useful information can be obtained from very small blood samples:
    • Only a few drops of blood are needed for haematocrit, total protein, white cell differential (from a blood smear) and white cell count. (J213.9.w4)
  • If taking serial blood samples, avoid taking more than 15% of total blood volume over a period of 28 days. (B232.17.w17)
  • Note:  
    • Dilution errors result from e.g. adding a small blood sample to a liquid anticoagulant. (B631.20.w20)
    • Preferably collect into EDTA tubes for haematology. (B660.31.w31)
    • Haemolysis may occur, with resultant errors, if blood samples are transferred from syringe to collection tube via a small-bore needle. (B631.20.w20)
    • Ferrets apparently do not develop a "stress haemogram" when stressed/fearful/in pain. (B631.20.w20, B660.31.w31)
    • The PCV of ferrets is quite high and the erythrocyte sedimentation rate slow; spin the sample for 20% longer than usual when measuring PCV or collecting serum or plasma. (B232.17.w17)
Haematological parameters

Published normal values for ferrets are provided in: Haem19: Normal Haematology Values for Mustela putorius furo - Ferret

  • Note: Each laboratory should establish its own reference range. (J213.2.w7)
  • In general, interpretation of haematological values is the same for ferrets as for other small species. (J213.2.w7)

Haematocrit (packed cell volume, PCV)

  • This is normally fairly high (up to 61% can be normal). (J213.2.w7)
  • It is increased in dehydrated ferrets. (J213.2.w7)

Haemoglobin

  • Normal haemoglobin is 11.1 - 17.1 (mean 14.95) g/dL in males, 13.1-16.6 (mean 14.38) g/dL in females. (B660.32.w32)

Erythrocytes

  • Erythrocytes of ferrets resemble those of other domestic carnivores: round and biconcave. (B631.20.w20, B659.5.w5, B660.32.w32)
  • Reticulocyte counts are normally 4.0- 5.3%. (B660.32.w32)
  • MCV  
  • MCH  
  • MCHC  

Platelets (thrombocytes)

  • 300,000 +/- 46,000 /L. (B660.35.w35)
  • Mean platelet volume 8.7 +/- 0.8 m. (B660.35.w35)

Leucocytes

  • Typically e.g. 4,200 - 6,500 cells/L but as high as 19,100 cells/L can be normal. (J213.2.w7)
  • A left shift (increased immature neutrophils such as band forms) may occur, as may toxic changes.  (B631.20.w20)
    • A left shift is rare. (B659.5.w5)
  • There is a small but significant decrease in WBC count by about 15 minutes of isoflurane anaesthesia. (J13.55.w2)

Lymphocytes

  • These are second only to neutrophils in the normal ferret. (B631.20.w20, B659.5.w5)
  • Lymphocyte counts as low as 3,000/L can be normal in ferrets. (B659.5.w5)

Monocytes

  • Usually present only in low numbers. (B631.20.w20)

Neutrophils

  • These are usually the predominant cell type (followed by lymphocytes) in ferrets. (B631.20.w20, B659.5.w5)

Eosinophils

  • Usually present only in low numbers. (B631.20.w20)

Basophils

  • Usually present only in low numbers. (B631.20.w20)
  • Rare in normal (and abnormal) ferrets. (B660.32.w32)

Clotting parameters

  • Whole-blood clotting time in glass tubes is 2.0 +/- 0.5 minutes, and in siliconised tubes 3 +/- 0.9 minutes. (B660.35.w35)
  • Clot retraction is less than e.g. in humans. 
  • Activated partial thromboplastin time: 16 -25 s in one study. (J213.2.w7) 18.4 +/- 1.4 s (B660.35.w35)
  • Prothrombin time (PT): 14.4 - 16.5 seconds in one study; 8.0 - 12.0 seconds in another study. (J213.2.w7) 10.3 +/-0.1 s (B660.35.w35)
  • Thrombin time (TT):  28.8 +/- 8.7 s (B660.35.w35)
  • Russell's Viper Venom Time 14.1 +/- 1.1 s. (B660.35.w35)
  • Bleeding time: Less than two minutes in one study (note: the small size of the ferret lip produces technical difficulties in carrying out this test). (J213.2.w7)
  • Factors V and XII are high compared with humans. (B660.35.w35)
Normal variations and non-disease factors affecting parameters
  • Juvenile hobs (male ferrets) generally have a reduced rbc count, haematocrit and haemoglobin concentration compared with adult males. (B659.5.w5, B660.31.w31)
  • In jills (females), haematocrit (PCV) often reduces with age. (B659.5.w5, B660.31.w31)
  • Lymphocyte concentrations decrease with age in ferrets in both males and females. (B659.5.w5, B660.31.w31)
  • Neutrophil concentrations increase with age in both males and females. (B659.5.w5, B660.31.w31)
  • Haematological parameters including rbc count, haemoglobin concentration, wbc count, PCV and plasma proteins may decrease by as much as 20-36% within 15 minutes of induction of isoflurane (or enflurane or halothane) anaesthesia. (B659.5.w5, J13.55.w2, J29.7.w1)
    • This is not a problem with very brief (e.g. 1-2 minute) anaesthesia. (B659.5.w5, B660.32.w32)
      • Reduced RBC counts can sometimes occur even with short anaesthetic times. (B660.32.w32)
    • The changes are associated with sequestration of red blood cells in the spleen. (J13.58.w2, J213.2.w7)
Findings associated with disease
Associated techniques linked from Wildpro

Return to top of page

Clinical Biochemistry

Sample collection

Blood can be collected from a variety of sites: the jugular vein, cephalic vein or lateral saphenous vein, also the anterior vena cava and the ventral tail artery.

  • For further information on blood sampling and the advantages and problems associated with different sites see: Venipuncture - Blood sampling - Intravenous Catheterization in Ferrets
  • Blood volume in ferrets is 50 - 60 mL. (J213.11.w2) 
  • Note: useful information can be obtained from very small blood samples.
    • Complete plasma chemistry can often be run using less than 1 mL of blood (J213.9.w4); Some in-house analysers can run using just 0.13 mL blood for a complete biochemistry panel. (B631.20.w20)
    • Preferably take blood into lithium heparin tubes for biochemistry. (B660.31.w31)
      • Lithium heparin tubes rather than plain (clot) tubes increase the volume of plasma available for tests. (J213.2.w7)
  • If taking serial blood samples, avoid taking more than 15% of total blood volume over a period of 28 days. (B232.17.w17)
Biochemical parameters

Published normal values for ferrets are provided in: Biochem19: Normal Biochemistry Values for Mustela putorius furo - Ferret

Findings associated with disease

Total Protein

Albumin

  • Hyperalbuminaemia is seen with dehydration. (B631.20.w20)

Globulins

  • Raised globulins:
    • Raised globulins are associated with inflammation. (B631.20.w20)
    • Usually, but not always, in ferrets with Aleutian Disease, hypergammaglobulinaemia is present: gamma globulin commonly more than 20% of total protein concentration. (B627.15.w15, J213.8.w3)

Glucose

  • Normally 4.44 - 6.49 mmol/L (18-32 mg/dL). (B631.20.w20)
  • Note: The reading should be taken immediately following blood collection, in order to avoid a false decrease caused by leaving serum or plasma with red blood cells. (J213.2.w7)
  • Hypoglycaemia can be seen with:
    • Insulinoma in Ferrets (Miscellaneous Disease)
      • Suspect this if glucose is below 4.16 mmol/L (750 mg/L, 75 mg/dL).  If the level is above this in a fasting ferret, it is unlikely to have insulinoma. (B631.20.w20)
      • This can be further confirmed by measuring insulin levels: normal is 33-311 pmol/L (4/6 - 43.2 U/mL), mean 101 pmol/L (14.1 U/mL). Note: it is important to compare results to the reference ranges of the laboratory carrying out the test, as the values will vary depending on the radioimmunoassay used for measuring the insulin. Insulin and glucose should be measured concurrently: raised insulin at the same time as hypoglycaemia indicates insulinoma; normal insulin in the presence of hypoglycaemia also suggests insulinoma. Insulin: glucose range of 4.6 - 44.2 pmol/mmol (3.6-34.1 U/mg) has been measured in normal ferrets. Note: this ratio may give a false-positive result. (J213.2.w7)
        • Normal insulin 35-250 pmol/L. (B232.20.w20)
  • Hyperglycaemia may be seen with:

Blood urea nitrogen (BUN)

  • Normal levels are similar to those in other species. (J213.2.w7)
  • Blood urea nitrogen may be affected by dietary protein and nitrogen absorption from the GIT following gastrointestinal bleeding, as well as related to glomerular filtration rate. (B631.20.w20)

Creatinine

  • Normal creatinine is low and remains in a narrow range; values may be raised for ferrets while still within the "normal" range for many other species. (J213.2.w7)
  • There may be a poor correlation between renal disease and blood creatinine levels in ferrets. (B631.20.w20)
  • Creatinine greater than 0.8 mg/dL plus elevated BUN indicates moderate or severe renal disease. (J213.2.w7)

Liver enzymes

  • ALT (alanine aminotransferase) may be useful as an indicator of liver damage. It may also be increased in ferrets with gastrointestinal inflammation. (B631.20.w20)
    • This enzyme increases with hepatocellular disruption e.g. with necrosis or inflammation. (J213.2.w7)
  • In ferrets with lymphoma, liver enzymes may be elevated either due to chronically low blood levels leading to hepatic lipidosis, or metastasis of the tumour to the liver. (J213.2.w7)
  • In ferrets with Aleutian Disease in Ferrets, liver enzymes may be raised. (B232.20.w20)
  • ALT and AST (aspartate aminotransferase) may be increased in ferrets with hepatic lipidosis due to anorexia. (J213.2.w7)
Hormone assays
  • In ferrets with adrenal disease (Adrenocortical Neoplasia in Ferrets), elevated sex steroids can be detected, such as androstenedione, dehydroepiandrosterone sulphate, oestradiol or 17- α-hydroxyprogesterone. (B339.9.w9)
    • Normal ranges for sex steroid hormones: 
      • Oestradiol (pmol/L) 30-180. (B629.13.w13) 106 pmol/L (B232.20.w20)
      • 17- α-hydroxyprogesterone (nmol/L) 0.0-0.8. (B629.13.w13) 0.4 pmol/L (B232.20.w20)
      • Androstenedione (nmol/L 0.0-15.0. (B629.13.w13) 6.6 pmol/L (B232.20.w20)
        • Androstenedione is the most sensitive of these hormones. (B339.9.w9)
    • If one or more of these results are positive (raised), this confirms hyperadrenocorticism. (B629.13.w13)
  • Cortisol: males 0.22- 2.7 ug/dL; females 0.55-1.84 ug/dL (B232.20.w20)
  • T3: males 0.45-0.78 ng/mL; females 0.29-0.73 ng/mL (B232.20.w20)
  • T4: 1.01 - 8.29 ug/dL; female 0.7-3.43 ug/dL (levels are highest in entire (uncastrated) adult males). (B232.20.w20)
    • Following administration of 1.1 IU TSH, T4 should be raised significantly above baseline at one, two and six hours. (B232.20.w20)
Associated techniques linked from Wildpro

Return to top of page

Urinalysis

Urine collection
  • Cystocentesis (Cystocentesis of Ferrets) is preferred for collection of an uncontaminated urine sample for culture and sensitivity testing. (B631.20.w20, B660.41.w41) The ferret shoulld be sedated or anaesthetised. (J15.24.w5)
  • Samples can also be collected by catheterisation (Urethral Catheterization in Ferrets), although this is not easy in ferrets (B232.17.w17, B660.38.w38) and is usually carried out only when there is a lower urinary tract obstruction. (B660.38.w38)
  • If culture is carried out, the urine sediment should be examined also. (B660.41.w41)
  • A naturally-voided sample can be collected by placing the ferret into a cage with a grid floor and placing a tray underneath. (B232.17.w17, J15.24.w5)
  • The bladder can be expressed manually, gently. (B232.17.w17, J15.24.w5)
Normal urine values
  • Total bladder capacity (low pressure) is about 10 mL in a large ferret. (B660.38.w38)
  • Normal ferret urine is pale to yellow, and clear. (B631.20.w20)
    • Note: urine can be dark and dark urine may give a false-positive reading for ketones. (J213.2.w7)
  • Volume per 24 hours: 
    • 8-48 mL (male); 8-140 mL (female). (B232.20.w20, J213.2.w7)
    • 26 mL per 24 hours (male), 28 mL per 24 hours (female). (B626.App.w22)
  • Sodium: 
    • 0.4-6.7 mmol/24 hours (male); 0.2-5.6 mmol/24 hours (female). (J213.2.w7)
    • 1.9 mmol/24 hours (male); 1.5 mmol/24 hours (female). (B626.App.w22)
  • Potassium:
    • 1.0-9.6 mmol/24 hours(male); 0.9-5.4 mmol/24 hours(female). (J213.2.w7)
    • 2.9 mmol/24 hours (male); 2.1 mmol/24 hours (female). B626.App.w22
  • Chloride: 
    • 0.7-8.5 mmol/24 hours (male); 0.3-7.8 mmol/24 hours (female). (J213.2.w7)
    • 2.4 mmol/24 hours (male); 1.9 mmol/24 hours (female). (B626.App.w22)
  • pH
    • 6.5-7.5 (male); 6.5-7.5 (female). (B232.20.w20, B626.App.w22, J213.2.w7)
    • Varies with diet e.g. lower (pH 6.0) on a high-quality meat diet. (J213.2.w7)
  • Protein (mg/dL): 
    • 7-33 (male); 0-32 (female). (J213.2.w7)
    • 70 - 330 mg/L (male), 0 -230 mg/L (female). (B626.App.w22)
  • Ketones +. (B232.20.w20)
  • Protein: trace is common. (B232.20.w20)
  • Blood: may be present in females during oustrus. (B232.20.w20)
  • Occasional hyaline casts are normal. (B660.38.w38)
Abnormal findings
Associated techniques linked from Wildpro
  • --

Return to top of page

Cerebro-spinal Fluid

CSF collection
  • CSF is collected from the anaesthetised ferret. (J13.65.w3)
  • CSF can be collected from the cerebellomedullary cistern using a percutaneous approach with a 25-gauge 1.6 cm hypodermic needle in an anaethetised ferret in lateral recumbency. This allowed collection of 0.25 - 0.45 mL of CSF without adverse effects; it was suggested that 0.26 mL could be collected safely. (J13.65.w3)
  • A lumbar approach can be used but allows only very small samples to be taken.
Normal  CSF constituents

Collection of CSF from cisternal puncture in an adult ferret should provide sufficient CSF (0.26 mL can be collected safely) to allow determination of WBC and RBC numbers as well as protein levels and cytological evaluation. (J13.65.w3)

  • CSF is normally clear (blood tinged or turbid in5/42 clinically normal ferrets). (J13.65.w3)
  • RBC counts 
    • In 27/42 samples, RBC counts were below 100 cells/L (0-94, mean 20.3 +/- 28.8, 95% confidence interval 14.8-25.8). (J13.65.w3)
    • In samples with RBC counts above 100 cells/L, RBC counts were 103-11,550 (2,879 +/- 3,699, 95% CI 1,923-3,835). These samples were considered to be contaminated with blood. (J13.65.w3)
  • WBC counts 
    • In 15 samples with RBC counts below 100 cells/L (i.e. uncontaminated by blood) WBC counts were 0-6 cells/L (mean +/- SD 1.0 _/1 1.3; 95% CI 0.75-1.25). (J13.65.w3)
    • In samples with RBC counts above 100 cells/L (i.e. contaminated with blood), WBC counts were 0-8 (2.7 +/- 2.1; 95% CI 2.2-3.2), slightly (but sisnificantly) higher than in uncontaminated samples. (J13.65.w3)
  • Protein
    • In samples uncontaminated with blood, protein was 20-43 mg/dL (28.5 +/- 6.2 mg/dL, 95% CI 27.3-29.7 mg/dL). (J13.65.w3)
    • In samples with RBC counts above 100 cells/L, protein was 20-68 mg/dL (36.6 +/- 14.5 mg/dL, 95% CI 32.8-40.3 mg/dL). The difference from uncontaminated samples was not statistically significant, but all four samples with protein over 40 mg/dL had RBC counts of over 2,000 cells/L and the highest protein level was found in the sample with the highest RBC count. (J13.65.w3)
    • Overall, protein was 20-68 mg/dL (31.4 +/-10.6 mg/dL; 95% CI 28.8 - 34.0 mg/dL). (J13.65.w3)

Sedimentation can be used to determine percentages of each WBC type. (J13.65.w3)

  • Neutrophils: In with RBC counts below 100 cells/L, no neutrophils were present. (J13.65.w3)
    • In samples with RBC counts above 100 cells/L, neutrophils were 0-38% of leucocytes, mean 4.7+/- 13.4%, 95% CI 1.3-8.2%. (J13.65.w3) Neutrophils were found in only one sample, one with a RBC count of 11,560 cells/uL.  (J13.65.w3)
  • Lymphocytes: In with RBC counts below 100 cells/L, lymphocytes were 0-100% of leucocytes, mean 55.4 +/- 35.0%, 95% CI 44.3-66.5% . (J13.65.w3)
    • In samples with RBC counts above 100 cells/L, lymphocytes were 52-100% of leucocytes, mean 91.4 +/-16.6%, 95% CI 87.1-95.7%. (J13.65.w3)
  • Monocytes: In with RBC counts below 100 cells/L, monocytes were 0-100% of leucocytes, mean 44. +/- 35.0%, 95% CI 33.5-55.7% . (J13.65.w3)
    • In samples with RBC counts above 100 cells/L, monocytes were 0-13% of leucocytes, mean 3.6 +/- 5.2%, 95% CI 2.3-4.9%. (J13.65.w3)
  • No macrophages, eosinophils or degenerate cells were seen in the samples. (J13.65.w3)
Abnormal findings
  • Detection of macrophages or eosinophils in CSF [or neutrophils in the absence of large numbers of RBCs indicating blood contamination] would indicate CNS disease. (J13.65.w3)
Associated techniques linked from Wildpro

Return to top of page

Bone Marrow 

Bone marrow aspiration is used to collect a sample for cytology; bone marrow biopsy is used to collect a sample for histopathology.
  • Bone marrow may be collected from the proximal femur, proximal humerus, or iliac crest. (B602.2.w2, B660.34.w34, P120.2006.w6)

Bone marrow aspiration is used in the diagnosis of anaemia, thrombocytopaenia, pancytopaenia, suspected haematopoitic malignancies or proliferative abnormalities, and to evaluate prior to chemotherapy. (B602.2.w2, J29.6.w3)

  • Bone marrow evaluation should be carried out in any ferret with PCV under 35% and decreasing on serial testing. (B660.34.w34) 
  • Diseases to consider include hyperoestrogenism, chronic gastro-intestinal bleeding, flea infestation, neoplasia (particularly Lymphoma in Ferrets), immune-mediated disease and bleeding dyscrasias (may occur with Aleutian disease). (B660.34.w34)

Slide preparation

  • Forcibly expel the aspirated sample onto a clean slide held vertically; let the contaminating blood run off the slide. (B660.34.w34)
  • Press another clean glass slide onto the slide holding the bone spicules and allow the marrow to spread between the slides. (B660.34.w34)
  • Holding the two slides horizontally, pull them apart horizontally, smoothly. Four to eight slides can be prepared. (B660.34.w34)
  • Let the slides air-dry. (B660.34.w34)
  • Stain one or more slides with a Romanowski or Wright's stain e.g. DiffQuick (Baxter Scientific Products, McGaw Park, Illinois USA). (B660.34.w34)
    • Keep some slides unstained in case staining is poor or special stains are needed. (B660.34.w34)
    • Stain for about twice as long as when staining a peripheral blood smear. (B660.34.w34)
  • Alternative stains include Giemsa or Leishman's. (B660.34.w34)

Evaluation

  • Slides should be evaluated at low power initially (x4 - x10) to assess adequacy of the smear, cellularity, polymorphogeneity of cells, numbers of megakaryocytes and amount of marrow iron, then at x40. (B660.34.w34)
  • Bone marrow is more highly cellular in young animals; in adults it is normal to have about 50% fat. (B660.34.w34)
  • If the smear is solidly cellular with all cells having a similar morphological appearance, and little sign of peripheral blood, neoplasia is likely. (B660.34.w34)
  • In ferrets with Hyperoestrogenism in Ferrets, the bone marrow will be hypocellular; only 10 to 20% of cells will be haematopoietic cells, the remainder being adipocytes, red blood cells, lymphocytes and hemosiderin-containing macrophages. (B627.10.w10)
  • Bone marrow dysplasia (defective maturation of cell lines) has not been reported in ferrets. (B660.34.w34)
  • With Hyperoestrogenism in Ferrets (Miscellaneous Disease) initially there may be hyperplasia of bone marrow, but later there is preogressive granulocytopaenia, thrombocytopaenia and normochromin, normocytic anaemia evident in peripheral blood and bone marrow. (B660.34.w34)
  • Lymphosarcoma (Lymphoma in Ferrets) is the haematopoietic malignancy most likely to be seen. (B660.34.w34)
  • Elevated plasma cell numbers (e.g. >10%) are seen with Aleutian Disease in Ferrets. (B660.34.w34)
Associated techniques linked from Wildpro

Return to top of page

Faecal Analysis

Faecal analysis is useful for detection of helminth and protozoal infections, and for investigation of gastrointestinal disease which is not responding to therapy.

  • Faeces are easy to collect. Most ferrets will defecate after having a rectal temperature taken. Ferrets have a rapid gut transit time, therefore if they do not defecate in response to this, simple place them in a cage for a short while and wait. (J213.2.w7)
Worm eggs
Coccidia
Abnormal bacteria
  • In ferrets with diarrhoea, faeces should be cultured. Aerobic and anaerobic cultures should be carried out, including checking for Salmonella spp. (J213.2.w7)
Faecal occult blood test
Associated techniques linked from Wildpro
  • --

Return to top of page

Skin Testing

Prior to any specific skin testing or even examination of the skin, a history should be taken, the ferret's environment and husbandry assessed, and a thorough physical examination carried out, including observing the ferret for any scratching, rubbing, excessive grooming etc. (B232.10.w10, B602.10.w10, B631.24.w24, J16.30.w1, P120.2008.w3)
Direct and magnified visual examination
Coat brushing
  • Detection of fleas (Flea Infection in Mammals)(B631.24.w24)
    • Brushing the coat over a piece of wet paper assists in detection of flea faeces (turning red in contact with water). (B232.10.w10)
Adhesive tape
Skin scraping

Skin scrapings are examined under the microscope either in potassium hydroxide (KOH) or liquid paraffin. (B631.24.w24)

Wood's lamp examination 
  • This is used in diagnosis of Ringworm caused by Microsporum canis only however, only some strains will fluoresce.  (B631.24.w24)
Fine needle aspirate 
  • This is used to collect samples from nodular lesions.  (B631.24.w24)
  • Cytological examination of material from a fine needle aspirate can be useful in initial assessment of cutaneous or subcutaneous masses. (B602.10.w10)
  • If neoplastic cells are detected, excisional biopsy should be carried out. (B232.17.w17)
Bacterial culture 
  • A Gram stain can be carried out on exudate to guide therapy prior to culture and sensitivity results being available. (B602.10.w10)
  • Swabs of skin lesions can be taken. (J16.30.w1)
  • From abscesses, swabs should be taken from the wall of the abscess; the central pus may be sterile. (B232.10.w10)
  • Intact pustules can be sampled for bacterial culture and sensitivity testing in ferrets with dermatitis. (B631.24.w24, B660.41.w41) For deep dermatitis/cellulitis, a skin biopsy should be taken and culture made from the subcutis (which should ebe sterile in the normal animal). (B660.41.w41)
Fungal culture 
  • Fungal culture (on dermatophyte culture medium) is used in the diagnosis of Ringworm. (J213.6.w3)
    • Hairs should be plucked from the edge of the lesion. (B232.17.w17)
Skin biopsy
Associated techniques linked from Wildpro

Return to top of page

Serological and Specific Disease Tests

Aleutian Disease in Ferrets
  • Counterimmunoelectrophoresis (CEP, CIEP) (United Vaccines, Madison, Wisconsin, USA) or ELISA (Avecon Diagnostics, bath, Pennsylvania, USA) can be used to detect antibodies; this ELISA has not been tested for sensitivity and specificity in ferrets. (J213.8.w3)
    • This test is inexpensive, rapid, and can be run on plasma from a microhaematocrit tube. (B660.41.w41)
  • IFA (immunoflorescent antibody test) can also be used to detect antibodies. (B627.15.w15, B660.41.w41)
  • Note: Antibodies may be present for a long time without the development of clinical disease due to this infection. (B627.15.w15, J213.8.w3)

Canine Distemper

  • Fluorescent antibody tests can be run on antemortem samples including peripheral blood smears, buffy coat preparations, conjunctival swabs or mucous membrane scrapings to test for viral antigens. (B660.41.w41)
Heartworm Infection
  • An ELISA antigen test which is commonly used is the SNAP heartworm Antigen Test Kit (Idexx Laboratories) or the DiroCHEK Heartworm Antigen Test (Synbiotics Corporation, San Diego, USA), however if there are only male worms or only a single female worm this may give a false negative result. (B150.w4, B602.6.I.w6a, B631.26.w26, P120.2006.w4, J213.2.w6)
  • Antigens detected in the ELISA are shed only by adult female worms. (B602.6.I.w6a)
  • The modified Knott technique for detection of microfilaria in the blood should be carried out also. (J213.2.w7)
    • Often no microfilarea are present in the circulation in ferrets with this infection. (B660.44.w44)

Helicobacter mustelae Gastritis in Ferrets

  • Examination of a biopsy of the pylorus of the stomach, using silver stain, for the presence of the helical bacteria. (B660.41.w41)
  • Testing for urea production from a biopsy sample. Various tests take as short as one hour or as long as 24 hours. (B660.41.w41)
  • Measurement of circulating antibodies in whole blood (using a test against the human pathogen Helicobacter pylori); since many ferrets carry Helicobacter mustelae without clinical signs the usefulness of this test is uncertain. (B660.41.w41)

Influenza in Ferrets

  • Usually diagnosed by clinical signs and history of exposure. (B660.41.w41)
  • Virus can be isolated from nasal secretions. (B660.41.w41)
  • Rising antibody titre in paired serum samples (haemagglutinin-inhibition antibodies) can be used to confirm diagnosis. (B660.41.w41)

Proliferative Bowel Disease in Ferrets (Lawsonia intracellularis (Desulfovibrio sp.) Infection)

  • Colonic biopsy; silver stain for the bacilli, which are within the epithelium. (B660.41.w41)

Rotavirus Infection

  • Fresh or frozen faeces can be examined for negatively stained virus particles with electron microscopy (clarified faecal suspensions from affected ferrets). (B627.15.w15, B660.41.w41)
  • Note: commercially-available rotavirus immunoassays do not detect this atypical rotavirus. (B627.15.w15, B660.41.w41, J213.8.w3)

Rabies

  • An indirect fluorescent antibody test on brain tissue is the test of choice; tissue can be fresh or frozen. (B660.41.w41)
Associated techniques linked from Wildpro
  • --

Return to top of page

Microbiological Investigation

  • Ideally, choice of antibiotics should always be based on culture and sensitivity testing. (B602.4.w4, B602.10.w10, B626.8.w8, B627.14.w14, B631.27.w27,  P120.2007.w4)
    • It is particularly important to test samples when initial therapy has been unsuccessful.
    • Preferably, samples for bacteriological testing and culture are taken before antimicrobial therapy is initiated. (B660.41.w41)
Samples 
  • In taking samples from an abscess, take from the wall of the lesion; the central pus may be sterile. (B232.17.w17)
  • Needle aspirates also can be sent for microbiological examination. (B232.17.w17)
  • For faeces, always send at least 1 g faeces if bacteriological testing is required. Preferably send in specific transport medium. (B660.41.w41)
  • For detection of bacteraemia/septicaemia, several blood samples should be taken over a period of 24 hours and the skin should be prepared aseptically for the blood draw to avoid surface contaminants. (B660.41.w41)
  • Urine samples for culture preferably are taken by cystocentesis. (B660.41.w41)
    • Examination of urine sediment should be carried out also. (B660.41.w41)
Sample handling & transport

Preferably check with the laboratory regarding sample handling and transport. (B232.17.w17)

  • Transport media should always be used if transit time is more than three hours. (B660.41.w41)
  • A swab from the lesion should be placed into appropriate transport medium. (B232.17.w17)
  • After taking a swab, wait one hour, allowing the bacteria to colonise the swab, before refrigerating it. (B232.17.w17)
  • All samples must be labelled properly with the patient and owner's name, date, name of the veterinary surgeon/clinic and the source/type of the specimen. (B660.41.w41)
    • This information (or sufficient for positive sample identification) should be included on all syringes, slides etc. (B660.41.w41)
  • Clinical history should be sent with samples. (B660.41.w41)
    • If any antibiotics have already been given to the patient, these should be listed. (B660.41.w41)
  • If Actinomyces infection in Lagomorphs and Ferrets is suspected, submit the exudate or biopsy sample of the nodule anaerobically and inform laboratory personnel that an actinomycete is suspected(B660.41.w41)
Initial examination
  • In conjunction with culture, cytological examination of e.g. air dried smears, stained with Wright's and Gram stains are useful. These provide information not only on the presence (or absence) of bacteria, and whether they are Gram-positive or Gram-negative, but also the cytoloical characteristics of the exudate. (B660.41.w41)
  • Initial examination may confirm the presence of e.g. bacteria or fungi, and show the cellular characteristics of an exudate (e.g. neutrophils with bacterial infection, lymphocytes and plasma cells with viral infection, multinucleate giant cells with fungi) as an initial guide to therapy while waiting for furtehr results. Note: bacteria are commonly present and should only be considered relevant if there are signs of an immune reaction, such as bacteria present within neutrophils, or neutrophil death. (B660.41.w41)
  • Kinyoun carbolfuchsin staining is useful for diagnosis of Actinomyces infection in Lagomorphs and Ferrets, and Ziehl-Neelsen staining for mycobacteria. (B660.41.w41)
Associated techniques linked from Wildpro

Return to top of page

Cytological Investigation

In addition to blood, bone marrow, urine and CSF, cytological investigation can be carried out on samples obtained from the live ferret by abdominocentesis, thoracocentesis, tracheal lavage or fine needle aspirate from organs or lesions. (B602.2.w2, J29.6.w3, P120.2006.w6)
  • Impression smears or fine needle aspirates can be examined cytologically.
  • For an impression smear, place a clean glass slide onto the cut surface of the tissue.
  • Note: when aspirating lymph nodes care is required to ensure the lymph node is sampled, not the surrounding fat pad. (B232.17.w17)
    • Excisional biopsy may be preferable for lymph node examination. (B232.17.w17)
Associated techniques linked from Wildpro

Return to top of page

Authors & Referees

Authors Debra Bourne MA VetMB PhD MRCVS (V.w5)
Referee  

Return to top of page