Serologic pattern of canine heartworm (Dirofilaria immitis) infection.

A total of 602 dogs at the Louisiana State University Veterinary Teaching Hospital were tested for antibodies to Dirofilaria immitis by enzyme-linked immunosorbent assay (ELISA), using a purified adult dirofilaria-derived antigen. Most dogs also were evaluated for heartworm infection by a complete WBC count and a Knott test for circulating microfilariae. The serologic prevalence of heartworm infection was 34.7%; prevalence increased significantly (P = 0.0003) with age up to 8 years and then decreased. Dogs usually kept indoors were significantly (P = 0.005) less likely to be infected, as were dogs given diethylcarbamazine therapy (P = 0.0004). Coat length, sex, breed, and presence of intestinal parasites were not associated (P greater than 0.05) with a positive heartworm ELISA result. The ELISA titers showed a positive relationship with both eosinophil and basophil counts. A total of 99 dogs evaluated radiographically were grouped according to results of the Knott test and radiographic examination as follows: (i) negative Knott test and negative radiographic examination (14 dogs), (ii) negative Knott test and positive radiographic examination (57 dogs), and (iii) positive Knott test and positive radiographic examination (28 dogs). The serologic prevalences of D immitis infection in each of these groups were 35.7%, 56.1%, and 85.7% for groups (i), (ii), and (iii), respectively. The ELISA, when used in conjunction with the Knott test results, record of exposure, clinical signs, laboratory results, and radiographic changes, was found to be useful for studying serologic patterns and identifying risk factors for canine heartworm infection.

Inappropriate secretion of antidiuretic hormone in a dog.

Hyponatremia with simultaneous renal sodium loss was associated with the inappropriate secretion of antidiuretic hormone in a dog with heartworm disease. Antidiuresis caused expansion of extracellular fluid volume, which induced renal salt wasting and a negative sodium balance. The combination of water retention, salt wasting, and inactivation of intracellular solute contributes to the decrease in serum sodium concentration. Water intoxication due to hypotonicity of body gluids induced anorexia, depression, weakness, and incoordination.

Multiple myeloma in a horse.

Multiple myeloma was diagnosed in a horse on the basis of clinical signs, protein electrophoresis pattern, Bence-Jones proteinuria, and radiographic changes in bone. The horse had mild depression, weight loss, edema of the distal portion of the left hind limb, anemia, hyperproteinemia, and monoclonal gammopathy in the beta 2 region. Radiographically, punctate cortical lysis of bone was seen. Specific treatment for the multiple myeloma was not attempted and the horse was euthanatized.

Clinical evaluation of American river otters in a reintroduction study.

Ten American river otters (Lutra canadensis) were evaluated clinically before release into Oklahoma waterways. Otters were immobilized for physical, radiographic, and electrocardiographic examinations and for collection of blood samples. Hematologic and serum biochemical analyses, urinalyses, parasitologic examinations, surgical omental biopsies, and necropsy findings were included. Respiratory tract disease, bacterial and parasitic infections, and starvation apparently were contributing causes of postrelease mortality in 4 of the otters.

Diagnostic imaging in companion animal theriogenology.

Clinical assessment of reproductive problems in companion animals is greatly enhanced by the availability of various imaging modalities. Specifically, survey radiography, contrast radiography, real-time ultrasonography, and ultrasound-guided biopsy and/or aspiration cytology, alone or in various combinations, offer sophisticated methods of extension of the physical examination of the reproductive systems of dogs and cats. In particular, real-time ultrasonography offers invaluable assistance. It is nonionizing, largely noninvasive, rapid, and capable of providing certain dynamic information that is not conveniently available in any other way. Judging from its rapid growth in recent years, it has apparently become an integral part of the complete reproductive assessment of domestic animals. This is not to slight the importance of some of the contrast radiographic procedures that have been developed and refined. Some of them, such as maximum distention retrograde urothrocystography, provide unique information not available with presently routinely used ultrasound techniques. Other imaging modalities, such as magnetic resonance imaging, have heretofore provided limited benefit to theriogenology; that will probably change in years to come.

Four cases of pulmonary nodular eosinophilic granulomatosis in dogs.

Four cases of pulmonary nodular eosinophilic granulomatosis are described in dogs. All dogs were presented for chronic respiratory disease. Three dogs had radiographic and pathologic evidence of heartworm disease. One dog had lesions suggestive of past heartworm disease; but adult worms were not found at necropsy. Radiographically, single or multiple pulmonary densities up to 10 cm in diameter were seen. Hemograms on 3 dogs indicated a leukocytosis, neutrophilia, and eosinophilia. A microfilaremia was not detected in any of these dogs. Transtracheal washes yielded eosinophils, neutrophils, and macrophages. Three dogs were euthanatized. A 7 cm pulmonary nodule was excised surgically from the other dog. The pulmonary nodules were grossly yellow to gray in color, well-circumscribed, and solid. In one case, several nodules surrounded major branches of the pulmonary artery. Histologically, these nodules were composed of dense accumulations of epithelioid cells, macrophages, and eosinophils. There was no evidence of thrombosis due to Dirofilaria immitis. Possible pathogenetic mechanisms are discussed. Differentiation of pulmonary nodular eosinophilic granulomatosis from other types of pulmonary nodules in the dog can be accomplished by histologic examination.

Effects of heartworm and intestinal parasitic infections on hematology and peripheral lymph node cytology in louisiana dogs.

Hookworm infected dogs had higher blood basophil counts than hookworm negative dogs. Dogs with occult heartworm infection (i.e., without microfilaremia) had higher blood neutrophil counts than heartworm negative dogs. The percentage of eosinophils in peripheral lymph nodes was higher in heartworm infected, microfilaremic dogs than in both occult infected dogs and heartworm negative dogs. Heartworm or intestinal parasitic infection had no other significant effects on hematologic parameters or peripheral lymph node cytology.