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Diagnosis

  • Adrenocorticotropic hormone is produced in the brain and regulates the production of cortisol. When blood cortisol levels are low it is secreted to stimulate more production and when cortisol is high it will suppress the production of ACTH. Cushing’s disease caused by a pituitary tumor will result in elevated ACTH levels in the blood, whereas Cushing’s disease caused by an adrenal tumor will result in lower ACTH blood levels as production will be suppressed by the cortisol released from the adrenal tumor. Endogenous ACTH cannot be used alone to diagnose Cushing’s disease, but can help determine what type of Cushing’s disease the patient has.

  • Serum biochemistry measures the amount of enzymes, proteins, sugar, electrolytes, minerals, and hormones found in the liquid portion of the blood. Determining the amount of these factors in the blood can provide evidence of dysfunction or disease in certain organs or metabolic pathways indicative of certain diseases. This article provides general information on the most routinely measured factors in serum and common reasons for abnormal readings.

  • Electrolytes are the salts and metallic components that are dissolved within the blood serum (serum is the liquid portion of blood). The electrolytes of greatest clinical importance are sodium, potassium, chloride, bicarbonate, phosphorus, and calcium. It is important to detect changes in electrolyte concentrations so that these alterations can be treated prior to the situation becoming severe or life threatening.

  • Serum iron tests are indicated when the results from a complete blood count indicate that your pet is anemic and that the red blood cells are microcytic and hypochromic. Because blood is a rich source of iron, chronic external blood loss can lead to iron deficiency anemia. Tests to assess iron deficiency require a single blood sample that is sent to a veterinary referral laboratory. Additional tests such as serum biochemistry profile, urinalysis, and fecal evaluation are also used as screening tests to determine the cause or source of the chronic blood loss.

  • Serum contains a large number of proteins that perform diverse functions which include providing cellular nutrition, defending against infections, playing a role in inflammation, and acting as hormones or enzymes. Protein electrophoresis is a specialized test that analyzes specific groups of proteins in the blood serum and measures how much of each group of protein is present. The results of the analysis help diagnose specific diseases, such as infection and some types of cancer.

  • A biopsy is one of the more common diagnostic procedures performed in cats. Biopsies provide valuable insight into the type of cells in an abnormal area of skin or a skin growth and whether the growth poses a more serious health threat to your pet. Either the entire mass or a small representative section of skin is removed and submitted to a veterinary pathologist, who will perform a histopathology analysis. The pathologist will attempt to determine the nature of the lesion, identify the type of cells and their relationship to each other, as well as any evidence of malignancy.

  • A biopsy is one of the more common diagnostic procedures performed in dogs. Biopsies provide valuable insight into the type of cells in an abnormal area of skin or a skin growth and whether the growth poses a more serious health threat to your pet. Either the entire mass or a small representative section of skin is removed and submitted to a veterinary pathologist, who will perform a histopathology analysis. The pathologist will attempt to determine the nature of the lesion, identify the type of cells and their relationship to each other, as well as any evidence of malignancy.

  • Wellness testing, performed routinely on apparently healthy birds, screens for underlying, inapparent problems. Veterinarians also use test results in conjunction with physical examination findings and the owner’s account of the bird’s history to diagnose illnesses. Blood tests include the complete blood count and chemistry profile. Other tests your veterinarian may use to assess your bird’s health and diagnose disease include Gram’s stain, culture and sensitivity testing, parasitology, X-rays, laparoscopic surgery, cytology, histopathology, virology, and genetic (PCR) testing. Post-mortem examination after a bird dies may be recommended to determine the cause of death.

  • Addison’s disease or hypoadrenocorticism results from decreased corticosteroid and mineralocorticoid production from the adrenal glands. This results in non-specific signs of illness that mimic many other diseases. Laboratory changes consistent with Addison’s disease include anemia, absence of a stress leukogram (in a sick/stressed pet), hypoglycemia, elevated potassium, and low sodium causing a low sodium:potassium ratio, elevated kidney values and high urine specific gravity. Although an elevated resting blood cortisol level can rule out Addison’s disease, an ACTH stimulation test is needed to diagnose Addison’s disease. This requires a resting blood cortisol sample, administration of synthetic ACTH and a blood cortisol level 1-2 hours later to assess the adrenal response to ACTH. Consistently low levels of cortisol despite ACTH stimulation confirm the diagnosis. Primary Addison’s and secondary/atypical Addison’s can be differentiated by assessing the amount of endogenous ACTH in the blood.

  • Abdominal enlargement in cats may occur due to a simple cause such as obesity, pregnancy, or intestinal parasites; however, it can also be a symptom of different illnesses including heart disease, organ enlargement, cancer, FIP, trauma, and rarely hyperadrenocorticism or hypothyroidism. Identifying the cause of abdominal enlargement can take several steps starting with history and physical exam, progressing to screening tests including bloodwork and urinalysis. The CBC is assessed for signs of anemia, low platelets, or signs of inflammation. A biochemistry profile may reveal liver or kidney dysfunction, hypo- or hyperproteinemia, hypoglycemia, or other abnormalities. Urinalysis is used to fully interpret the biochemistry and check for abnormal urinary sediment. Based on the findings of the screening tests, additional diagnostics may include imaging, EKG, tissue biopsy, or fluid analysis.