Fever of unknown origin is a term used for persistent fever in pets. It has many causes including infection, immune-mediated disease and cancer. Initial steps in diagnosis are history and physical exam, followed by standard screening tests including CBC, biochemistry profile, and urinalysis. Based on the results of these tests, further testing may be indicated such as imaging (radiographs and/or ultrasound), fine needle aspiration, joint taps, bacterial or fungal cultures of affected fluid/tissue, and specific testing for diseases such as feline leukemia virus, feline immunodeficiency virus, or Lyme disease.
Heartworm disease is a parasitic disease that typically affects dogs but can occasionally occur in cats. Heartworm is usually diagnosed with a simple blood test. There are two main tests for detecting heartworm infection; one test detects adult worms and the other detects microfilaria. Unlike in dogs, treatment options are limited. Heartworm preventives are available for cats. Your veterinarian can advise you on the best prevention program for your cat.
Inappropriate urination happen in well-trained pets for many reasons, including inflammation, infection, estrogen deficiency, kidney failure, diabetes mellitus, diabetes insipidus, Cushing's disease, neurological disease, or behavioral issues. A number of screening tests will be performed by your veterinarian to determine the root cause of the inappropriate urination. These tests may include complete blood count, serum biochemistry, and urinalysis. Depending on the results of the screening tests, your veterinarian may recommend further testing including culture and sensitivity, cytology, X-rays or ultrasound, and stone analysis.
An increased appetite can be normal in an animal that has higher than normal energy requirements such as nursing, high energy sports, and growth in puppies or kittens. Many diseases can cause an increased appetite in the face of illness including hyperthyroidism in cats, Cushing’s disease, intestinal disease, diabetes or insulinoma, intestinal parasitism, and cancer. Increased appetite can also be caused by certain medications such as corticosteroids. Diagnosis generally requires a thorough history, physical exam, CBC, biochemistry panel, thyroxine (in cats), and urinalysis. Additional diagnostic testing may be required based on findings of the initial screening tests.
These clinical signs are non-specific and can be caused by many different diseases or conditions. Usually increased production of dilute urine results in a compensatory increase in water consumption, but occasionally the condition is one of increased water intake resulting in the production of large volumes of dilute urine.
Jaundice is caused by the build-up of bilirubin in the tissues due to high blood levels of bilirubin (hyperbilirubinemia). Hyperbilirubinemia occurs either due to increased red blood cell destruction (hemolysis), or the liver is unable to process or excrete bilirubin normally. CBC, biochemistry panel, and urinalysis are tests used to further define the cause of jaundice. Hemolysis will result in significant reduction of PCV/HCT but not affect plasma protein levels. Abnormal RBCs may be seen indicating IMHA or infectious causes of hemolysis. Liver disease severe enough to cause jaundice will result in significant increases in liver values: ALT and AST if the liver has been damaged by toxins, infection or tumors; ALP and GGT if there is a problem with bile flow out of the liver and/or gallbladder such as gallstones or pancreatitis. Obstruction of bile flow may also be detected in urine samples as a lack of urobilinogen. These tests only define where the problem is occurring, not what the problem is, so further diagnostics that may be needed and include ultrasound, X-ray, FNA, liver biopsy and/or bacterial culture from fluid found in or around the liver. More specific tests for infectious diseases include FeLV, feline coronavirus, and fungal testing.
Tests to diagnose kidney disease include complete blood count, serum biochemistry, and urinalysis. These blood tests will determine if your pet is anemic, determine white blood cell counts, measure blood urea nitrogen, creatinine, and electrolytes. A urinalysis is essential for the proper interpretation of the urea and creatinine values in the serum biochemistry profile and may also provide important clues to the possible underlying cause of kidney disease. A urinalysis will also determine the specific gravity, pH, presence of blood in the urine, and the amount of protein in the urine. An evaluation of the urine sediment will determine the presence of red blood cells, white blood cells, bacteria, crystalline material, and cellular casts all of which provide information to determine the underlying cause of kidney disease in your pet. Further diagnostic tests may be recommended based on the results of these initial screening tests.
The most common cause of lameness is trauma or injury to joints, ligaments, tendons, muscles, or bones. Other causes of lameness include developmental diseases in young animals, degenerative joint disease in older pets, immune-mediated joint disease, infectious joint diseases, neurological disorders, and cancer of the bones or joints. Finding the cause of a pet's lameness usually starts with a complete history and physical examination. Tests such as X-rays, joint fluid analysis, and blood testing may also be used to diagnose the lameness.
Initial screening tests for liver disease include a CBC, biochemistry panel, and urinalysis. A CBC can be used to differentiate hemolytic icterus from hepatic/post-hepatic icterus by measuring the PCV or HCT. Elevated WBC can also indicate presence of infection or cancer. ALP and GGT elevations can indicate a problem with bile flow through the liver. AST and ALT reflect liver cell damage. Bilirubinemia indicates a problem with the uptake, processing or excretion from the liver as long as hemolysis has been ruled out. Other serum indicators of liver disease include albumin, glucose, BUN, and cholesterol, as low numbers could suggest a reduced ability of the liver to manufacture these components. Certain parameters in urine can change before blood changes are seen making urinalysis a useful tool in diagnosing liver disease. Bile acid testing can be used to detect problems in liver function. More advanced diagnostics to determine the cause of liver disease include abdominal ultrasound, fine needle aspiration of the liver, or liver biopsy.
Hypoglycemia can be caused by many different things including liver failure, sepsis, Addison’s disease, and overdose of insulin in the treatment of diabetes mellitus. Clinical signs include weakness, tremors, and rarely seizures. After detecting hypoglycemia on a blood sample, determining the cause includes a full history, physical exam, CBC, biochemistry profile, and urinalysis. In some cases, more advanced testing such as imaging, biopsy, or ACTH stimulation testing will be recommended.