Diagnosis

The medical history should include information related to the patient’s diet as well as travel history of the patient and other household pets. Any available medical information on the pa­tient’s parents or siblings could also prove helpful.

The dietary history should include major dietary components and whether the diet is commercially formulated or home made. Also, the type and quantity of any treats, commercial or table scraps, should be determined. The storage conditions and expiration date of any commercial diet should be noted. If the clinician is unfamiliar with a particular diet, the label indicat­ing the dietary ingredients should be reviewed. It should also be determined if the patient is receiving any dietary supple­ments or medications. This includes commercially available, holistic, over-the-counter, or prescription medications. This information may help establish if a nutritionally imbalanced diet or a drug interaction is a potential cause for the weight loss. In certain situations, consultation with a veterinary phar-

macist, nutritionist, or a veterinarian certified in the practice of complementary medicine may be necessary.

Obtaining an accurate travel history of the patient and house­mates is important when infectious diseases are being consi­dered. Diseases indigenous to an area of travel should be iden­tified. This component of the history should also include if the patient has access to the outdoors and, if so, determine if it is in an enclosed area or free roaming. It should also be deter­mined if the patient frequents local parks, has access to bodies of water, and if the potential exists for contact with local wild­life giving consideration to endemic diseases.

Ascertaining previous episodes of ectoparasitism is important especially in areas where tick-borne diseases are endemic. Also, it should be noted whether other pets are kept in the house­hold, especially exotic species and their complete medical his­tory should be recorded.

If the diagnosis is not apparent after obtaining the signalment and history and performing a thorough physical examination, a minimum data base should be obtained. This includes a CBC, serum biochemistry profile, urinalysis, and feces for floatation and direct smear examination.

Further diagnostics could include fecal assays for the presence of Giardia organisms and Clostridium enterotoxin, and cyto­logic examination of a rectal scraping. Finding a suppurative response on cytologic examination of the rectal scraping would support bacterial culture of the feces for specific enter- opathogenic organisms. Malignant lymphocytes may be iden­tified suggestive of alimentary LSA. Fungal or algae organisms may be detected indicating systemic infection. A rectal scrap­ing is safe, non-invasive, inexpensive, and easy to perform. Ad­ditionally, a presumptive diagnosis can often be made follow­ing cytologic examination by the clinician.

Additional tests may include bacterial culture of a urine sam­ple and quantification of the urine albumin concentration. Based on these results more specific tests can be ordered. Depending upon the clinical data of the specific patient, these may include thoracic and abdominal radiographs, a cardiac evaluation (i. e., echocardiogram, ECG), abdominal ultrasound with performance of a fine needle aspiration or a biopsy pro­cedure if indicated, or determining the function of organs such as the liver (see 1.4.3), pancreas (see 1.4.4), adrenal gland (ACTH stimulation test), or kidney (nuclear scintigraphy). Detection of gastrointestinal disease may require determina­tion of serum cobalamin and folate concentrations (1.4.2), fecal alpha-1-protease inhibitor (α₁-PI) concentrations (1.4.2), or endoscopic examination of the gastrointestinal tract with tissue samples obtained for cytological and histopathological examination (see 1.7 and 1.8).

Key Facts

■ Obtaining a complete and detailed history in conjunction with performance of a thorough and comprehensive physical examination is imperative.

■ Weight loss occurs when the metabolic demand for energy or the loss of nutrients exceeds energy intake.

■ Weight loss is considered clinically significant when it equals or exceeds 10% of the patient's normal body weight.