An enzyme-linked immunosorbent assay for antibodies to Hepatozoon canis.

Canine hepatozoonosis is a tick-borne protozoal disease caused in the Old World and South America by Hepatozoon canis. An enzyme-linked immunosorbent assay (ELISA) using purified H. canis gamont antigen was applied for the detection of antibodies reactive with H. canis. Evaluation of the ELISA with sera from naturally infected parasitemic dogs indicated that it was sensitive (86%), specific (97%), and comparable to the indirect fluorescent antibody test (IFAT) for the detection of H. canis antibodies. A variable degree of serologic cross-reactivity was found between sera from H. americanum-infected dogs and the H. canis antigen. Dogs experimentally infected with H. canis seroconverted 1-4 weeks post-infection (PI). Antibody levels peaked at 7-9 weeks PI and gradually declined thereafter remaining above the cut-off value until the conclusion of the study 7 months PI. The ELISA will be valuable for serological evaluation of dogs suspected of exposure to H. canis and for epidemiological studies.

Treatment of dogs infected with Hepatozoon americanum: 53 cases (1989-1998).

OBJECTIVE: To determine clinical and pathologic findings before and after short-term (group 1) and long-term (group 2) treatment in dogs with Hepatozoon americanum infection. DESIGN: Retrospective study. ANIMALS: 53 dogs with H. americanum infection. PROCEDURE: Medical records of dogs that were treated for hepatozoonosis diagnosed on the basis of meront or merozoite stages in skeletal muscle were reviewed. RESULTS: Circulating gametocytes of H. americanum were identified in 12 of 53 dogs. Dogs were treated with various drugs, including toltrazuril, trimethoprim-sulfadiazine, clindamycin, pyrimethamine, and decoquinate. Mean WBC counts prior to treatment were 85,700 and 75,200 cells/microl in groups 1 and 2, respectively, and 1 month after initiation of treatment were 12,600 and 14,600 cells/microl, respectively. Initial response to treatment was excellent in all dogs. Twenty-three of 26 dogs in group 1 relapsed at least once and died within 2 years; mean (+/- SD) survival time was 12.6+/-2.2 months. Twenty-two of 27 group-2 dogs survived; 11 dogs had no clinical signs and were still receiving decoquinate (mean duration of treatment, 21 months), 11 dogs had no clinical signs after treatment for 14 months (range, 3 to 33 months; mean survival time, 39 months [range, 26 to 53 months]), 2 dogs were lost to follow-up, and 3 dogs were euthanatized because of severe disease. CONCLUSIONS AND CLINICAL RELEVANCE: Although no treatment effectively eliminated the tissue stages of H. americanum, treatment with trimethoprim-sulfadiazine, clindamycin, and pyrimethamine followed by long-term administration of decoquinate resulted in extended survival times and excellent quality of life.

Obstetrical emergencies.

This article discusses different techniques that can be used in the diagnosis and treatment of obstetrical emergencies. Female reproductive emergencies commonly encountered by small animal practitioners include pyometra, dystocia, cesarean section, mastitis, eclampsia, uterine torsion, and uterine prolapse. A thorough knowledge of normal and abnormal reproductive behavior will aid the emergency veterinarian in successfully managing such cases. Timely diagnosis and treatment of these emergencies will often give a good outcome.

Genetic and antigenic evidence supports the separation of Hepatozoon canis and Hepatozoon americanum at the species level.

Recognition of Hepatozoon canis and Hepatozoon americanum as distinct species was supported by the results of Western immunoblotting of canine anti-H. canis and anti-H. americanum sera against H. canis gamonts. Sequence analysis of 368 bases near the 3' end of the 18S rRNA gene from each species revealed a pairwise difference of 13.59%.

Intrathoracic and concurrent orthopedic injury associated with traumatic rib fracture in cats: 75 cases (1980-1998).

OBJECTIVE: To characterize rib, intrathoracic, and concurrent orthopedic injuries, and prognosis associated with traumatic rib fracture in cats. DESIGN: Retrospective study. ANIMALS: 75 cats. PROCEDURE: Medical records from January 1980 to August 1998 were examined for cats with traumatic rib fracture. Signalment, cause of trauma, interval from trauma to evaluation at a veterinary teaching hospital, referral status and date, method of diagnosis, duration of hospitalization, number and location of rib fractures, presence of flail chest, costal cartilage involvement, intrathoracic and concurrent orthopedic injury, and clinical outcome were reviewed. RESULTS: Median age was 3 years. Twenty-five (58%) cats with reported cause of trauma were injured by interaction with another animal. Forty-seven (78%) cats that were treated survived. Cats that died had a median duration of hospitalization of < 1 day. Ten (13%) cats had flail chest. Sixty-five (87%) cats had intrathoracic injury (median, 2 injuries). Nine (100%) cats without detected intrathoracic injury that were treated survived. Thirty-five (47%) cats had concurrent orthopedic injury. Cats with flail chest, pleural effusion, or diaphragmatic hernia were significantly more likely to die than cats without each injury. CONCLUSIONS AND CLINICAL RELEVANCE: Traumatic rib fracture in cats is associated with intrathoracic and concurrent orthopedic injury. Aggressive treatment of cats with traumatic rib fracture is warranted, because the prognosis is generally favorable. Diagnosis and treatment of intrathoracic injury associated with traumatic rib fracture in cats should precede management of concurrent orthopedic injury.

Pediatric intensive care.

To provide optimal care, a veterinarian in a pediatric intensive care situation for a puppy or kitten should be familiar with normal and abnormal vital signs, nursing care and monitoring considerations, and probable diseases. This article is a brief discussion of the pediatric intensive care commonly required to treat puppies or kittens in emergency situations and for canine parvovirus type 2 enteritis.

A new Hepatozoon species from dogs: description of the causative agent of canine hepatozoonosis in North America.

A new species of Adeleina, Hepatozoon americanum, is described from the skeletal muscle, cardiac muscle, visceral organs, and blood of dogs (Canis familiaris) in the Southern United States. The organism was previously identified as Hepatozoon canis (James, 1905) Wenyon, 1926; however, differences in clinical signs, histopathological and serological findings, gamont size, and ultrastructure define the new species of Hepatozoon. Attempts to transmit the protozoan from infected dogs to nymphal Rhipicephalus sanguineus ticks, the definitive host of H. canis, were not successful.

Assessment of current techniques for determining tracheal luminal stenosis in dogs.

OBJECTIVE: To assess the accuracy of current antemortem and postmortem techniques for determining tracheal luminal stenosis. ANIMALS: 15 dogs. PROCEDURE: Percentage of tracheal luminal stenosis (PTLS) was determined by 6 methods, using measurements obtained by radiography, tracheoscopy, and necropsy after selected tracheostomy techniques were performed. To calculate PTLS, dorsoventral tracheal diameter was measured from preoperative and postoperative lateral cervical radiographic views. Preoperative or normal tracheal segments adjacent to the stenotic area were used to obtain normal tracheal diameter measurements. Planimetrically determined cross-sectional area (CSA), obtained from pre- and postoperative tracheoscopic photographs, was used to calculate PTLS. The CSA of tracheal specimens obtained at necropsy was determined, using the formula for an ellipse. Percentage of luminal stenosis was calculated, using CSA of the stenotic site and of segments craniad and caudad to the site obtained at necropsy or at surgery. All methods were compared with the control method of planimetrically determined CSA of sections obtained at necropsy of the tracheostomy and segments craniad and caudad to the site. RESULTS: Correlation was poor for radiographic and tracheoscopic techniques (r = 0.146 to 0.458, P > 0.05) The formula for an ellipse accurately predicted PTLS when measurements obtained at surgery (r = 0.516, P = 0.049) or segments craniad and caudad (r = 0.853, P < 0.001) to the site were used. CONCLUSION: Antemortem methods of assessing PTLS did not correlate with control planimetric methods. Methods using CSA determined by tracheal diameter were weakly correlated to control planimetric techniques. CLINICAL RELEVANCE: Accurate measurement of the degree of tracheal stenosis cannot be made in clinical patients using current techniques.

Hepatozoonosis in dogs: 22 cases (1989-1994).

OBJECTIVE: To document hepatozoonosis in dogs from Alabama and Georgia and to report associated clinical signs, method of diagnosis, response to treatment, and course of disease. DESIGN: Retrospective case series. ANIMALS: 22 dogs in which Hepatozoon canis was identified by microscopic examination of skeletal muscle. PROCEDURE: We reviewed medical records of all dogs with a definitive diagnosis of hepatozoonosis that were referred to the Auburn University Small Animal Clinic between 1989 and 1994. RESULTS: Diagnoses were confirmed by microscopic identification of H canis schizont or merozoite stages in skeletal muscle. The gametocyte stage was not detected in smears of blood obtained from a peripheral vein, buffy-coat smears, or bone marrow evaluation. Common clinical signs included fever, cachexia, ocular discharge, pain, stiffness, and paresis. Laboratory abnormalities included marked leukocytosis, hypoglycemia, hypoalbuminemia, mild anemia, hyperphosphatemia, and high alkaline phosphatase activity. Periosteal bone proliferation was evident radiographically in 18 of 22 dogs. Renal lesions included amyloidosis (1 dog), interstitial nephritis (3), and mesangioproliferative glomerulonephritis (4). Treatment with the anticoccidial drug toltrazuril, despite an initial favorable response, failed to prevent relapse in all but 3 of 21 treated dogs. Mean survival time was 12.6 +/- 2.2 months, with a mean time of remission before recurrence of clinical signs of 6 months. CLINICAL IMPLICATIONS: H canis infection in dogs can be associated with a distinct clinical syndrome that involves chronic myositis, debilitation, and death. The dogs of this report represent the first substantial number of domestic dogs naturally infected with H canis in the United States outside of the Texas Gulf Coast. Hepatozoon canis appears to be a serious pathogen in the United States that is becoming more widespread geographically.

Heat-induced illness in dogs: 42 cases (1976-1993).

OBJECTIVE: To determine the typical history of and physical and clinicopathologic findings in dogs with heat-induced illness, and to correlate these findings with outcome. DESIGN: Retrospective study. ANIMALS: 42 dogs with heat-induced illness. PROCEDURE: Dogs were included in the study if other medical problems had not been previously diagnosed and if clinical signs of illness developed after exposure to a warm environment. Information obtained from each record included time of year heat-induced illness developed, signalment, history, clinical signs, physical examination findings, results of clinicopathologic tests, treatment, clinical course, outcome, and necropsy results. RESULTS: Overall, 27 dogs survived and 15 died or were euthanatized. Time of year was recorded for 40 dogs. Thirty-one of the 40 were examined before July. Hypothermia and coma at the time of initial examination were associated with a poor outcome. Serum cholesterol, albumin, and total protein concentrations were significantly lower, serum total bilirubin and creatinine concentrations were significantly higher, and ventricular arrhythmias were detected significantly more frequently in dogs that did not survive than in dogs that did.

Use of streptokinase in four dogs with thrombosis.

Four dogs with thrombosis were referred for diagnostic testing and were subsequently treated by the use of streptokinase. The range of duration of clinical signs associated with thrombosis was 6 to 120 days. Causes of thrombosis were heart disease (1 dog), protein-losing nephropathy and hyperadrenocorticism (1), hyperadrenocorticism (1), and idiopathic (1). Possible factors that predisposed dogs to hypercoagulability included hypertension (2 dogs) and diabetes mellitus (1). All dogs were treated for underlying disease by use of supportive care. The first dog was treated with a loading dose of 250,000 U of streptokinase, i.v., with a subsequent maintenance dosage of 100,000 U/h, i.v., and also was treated with anticoagulant. The subsequent 3 dogs were treated with a loading dose of 90,000 U of streptokinase, i.v., and maintenance dosage of 45,000 U/ h, i.v., at various intervals. These dogs also were treated with anticoagulant. Three dogs had minor hemorrhage as an adverse effect to streptokinase infusion, but they did not require treatment for the hemorrhage. Complete resolution of the thrombus was observed in 3 dogs, and partial resolution of the thrombus was observed in the other dog. In all dogs, partial or complete resolution of clinical signs associated with thrombosis was seen. Streptokinase may be an effective treatment for dogs with thrombosis.

Budd-Chiari syndrome in a kitten, caused by membranous obstruction of the caudal vena cava.

An eight-month-old, male domestic shorthair kitten developed progressive abdominal distension over a six-week period. Abdominocentesis revealed a fluid with high protein (3.8 g/dl) and moderate cellularity. Infectious, cardiovascular, and neoplastic causes of posthepatic obstruction were ruled out. Partial obstruction and stenosis of the caudal vena cava (CVC) at the level of the diaphragm were detected on a contrast venogram. Exploratory surgery revealed a fibrous, web-like membrane at the site of obstruction. Resection of the stenotic segment of the CVC was not possible because of the junction of the left hepatic veins and CVC just caudal to the lesion. A 3 by 6-mm, oval Dacron patch graft was sutured into the venotomy site. Postoperative complications included fever and leukocytosis, eosinophilic pleural effusion, and transient congestive heart failure associated with volume overload. The cat is normal 16 months after surgery, with no recurrence of ascites. This is the first reported case of Budd-Chiari syndrome (BCS) in a domestic kitten. Documented herein is the first successful treatment of BCS in a small animal using a vascular, prosthetic patch graft.

Emergency therapy of diabetic crises: insulin overdose, diabetic ketoacidosis, and hyperosmolar coma.

Three types of diabetic crises occur: insulin overdose, diabetic ketoacidosis, and hyperosmolar coma. Neurologic signs may accompany each of these syndromes, and each must be differentiated quickly by the emergency clinician so that an appropriate treatment plan can be initiated. The basic goal is to restore metabolic derangements and to stabilize the patient so that it can then be managed more routinely as an uncomplicated diabetic.

Emergencies of the female reproductive tract.

Emergencies of the female reproductive tract are common in small animal practice. The veterinarian must be familiar with normal and abnormal reproductive behaviors, as well as medical and surgical options available. Emergencies of the reproductive tract can be life-threatening for both dam and off-spring, requiring rapid diagnosis and assessment as well as aggressive treatment. With effective management, most of these conditions warrant a good prognosis.

Treatment of diabetic ketoacidosis in dogs by continuous low-dose intravenous infusion of insulin.

In a prospective clinical trial, low-dose, continuous, IV infusion of insulin (dosage, 2.2 U/kg of body weight, q 24 h) was used to treat 21 dogs with diabetic ketoacidosis. Mean (+/- SD) blood glucose concentration at the onset of treatment was 550 +/- 150 mg/dl and after 6 hours, was 350 +/- 106 mg/dl, with a mean decline of 34 +/- 16 mg/dl/h. By 12 hours, mean blood glucose was 246 +/- 85 mg/dl, with a mean decline of 28 +/- 14 mg/dl/h during the second 6 hours of treatment. Mean duration of treatment required to reach a blood glucose concentration < or = 250 mg/dl was 10 +/- 4 hours, with a range of 4 to 24 hours. Ketonuria was observed for 26 +/- 14 hours (range, 6 to 72 hours). Hypoglycemia developed in 3 of 21 dogs during treatment, but responded to IV administration of a glucose solution and to a reduction in rate of insulin delivery. Potassium supplementation was required in 15 of 21 dogs. Mean bicarbonate concentration was 11.6 +/- 3.4 mEq/L before treatment and was 18.2 +/- 0.7 mEq/L after 24 hours. Fifteen of 21 dogs (71%) survived to be discharged. Mean duration of treatment with the insulin infusion was 50 +/- 30 hours (range, 7 to 124 hours). In this series of dogs, continuous, low-dose, IV infusion of insulin provided a gradual and consistent reduction in blood glucose concentration while ketoacidosis, electrolyte balance, and dehydration were corrected.(ABSTRACT TRUNCATED AT 250 WORDS)

Reversal of atrial tachycardia with intravenous administration of verapamil in a dog.

Intravenous administration of verapamil at low dosage was effective in reversal of atrial tachycardia of unknown origin in a dog. The sinus rhythm remained normal for 24 hours before it reverted back to atrial tachycardia. A second IV administration of verapamil was effective in reversal of the atrial tachycardia, and a tapering dosage of verapamil, PO, was used to maintain normal sinus rhythm.

Cardiac arrhythmias associated with multiple trauma in dogs.

Premature ventricular contractions and ventricular tachycardia were detected in 10 dogs 1 to 48 hours after trauma. All dogs were treated aggressively if the arrhythmias became severe. One dog died, 8 were discharged with stable cardiac rhythm, and 1 was euthanatized. Necropsy revealed gross and microscopic lesions of acute myocardial necrosis, probably of ischemic origin. Cardiac arrhythmias were associated with thoracic trauma, neurologic injury, severe shock, and/or extensive tissue trauma.