Iron is an essential element for nearly all living organisms and disruption of iron homeostasis can lead to a number of clinical manifestations. Iron is used in the formation of both hemoglobin and myoglobin, as well as numerous enzyme systems of the body. Disorders of iron in the body include iron deficiency anemia, anemia of inflammatory disease, and iron overload. This article reviews normal iron metabolism, disease syndromes of iron imbalance, diagnostic testing, and treatment of either iron deficiency or excess. Recent advances in diagnosing iron deficiency using reticulocyte indices are reviewed.

Surveillance data indicate that failures have been reported for virtually all heartworm prevention product categories. Resistance of third and fourth stage larvae of Dirofilaria immitis to macrocyclic lactones, lack of compliance, other unknown factors, or a combination of these reasons may be the cause of failure. A survey of members of a national hunting dog club was conducted to identify practices used to prevent canine heartworm infections. Questionnaires were completed by 708 dog owners. Year-round administration of heartworm preventive medication was reported by 208 (88%) respondents residing north of the 37th parallel. Dosing was based on the estimated weight of the dog by 54 (7%) respondents, 389 (55%) did not record the date prophylaxis was administered, and 89 (13%) observed the dogs spit out pills. Heartworm testing at least once per year was done by 556 (79%) respondents and test dates were spread throughout the year. Only 448 (64%) respondents tested newly acquired dogs for heartworm. These findings suggest that veterinarians should place a greater emphasis on the frequency and timing of heartworm diagnostic tests, the importance of weighing dogs, duration of administration, recording the date monthly heartworm prophylaxis is given, and observing dogs to ensure that oral medication is retained.

Hemangiosarcoma (HSA) is an aggressive disease that is fairly common in the dog. The authors evaluated a doxorubicin, dacarbazine, and vincristine (DAV) combination protocol in dogs with nonresectable stage II and stage III HSA. Twenty-four dogs were enrolled in this prospective, phase 2 study. Doxorubicin and dacarbazine were administered on day 1 while vincristine was administered on days 8 and 15. The protocol was repeated every 21 days for a maximum of six cycles or until disease progression. Toxicity and efficacy were assessed by clinical and laboratory evaluation and by questionnaires completed by the owners. Of the 24 included dogs, 19 were evaluable for response. The response rate (including five complete responses and four partial responses) was 47.4%. Median time to tumor progression was 101 days and median overall survival was 125 days. Significant toxicities were noted, including 41 high-grade hematologic and 12 high-grade gastrointestinal toxic events. Five dogs discontinued treatment due to chemotherapy-related toxicities, but no treatment-related deaths occurred. Multivariate analysis identified patient age (relative risk [RR], 2.3, P=0.049) to be negatively associated with time to progression whereas dacarbazine dose reductions (RR, 0.06, P=0.031) were positively associated with time to progression. Dacarbazine dose reduction was the sole factor positively associated with overall survival (RR, 0.28, P=0.015). In conclusion, the DAV combination appears to offer clinical responses and may prolong survival in dogs with advanced-stage HSA.

Blood samples from 1,822 dogs residing on Native American reservations in 10 states were collected between February 2004 and August 2007. Samples were examined using a commercial enzyme-linked immunosorbent assay (ELISA) antigen capture test. All ELISA-positive samples were subsequently examined for microfilaremia. All dogs were asymptomatic for Dirofilaria immitis infection, resided outside (except for winter in the Northern latitudes), not on prophylaxis for D. immitis, and had not traveled off of the reservation. Reservations were characterized by degrees of north latitude, true prevalence of D. immitis, and a reproductive index calculated by multiplying the number of months of the year in which infective stage larvae (L₃) could develop in 30 days or less for each reservation by the 30 yr mean annual rainfall in centimeters recorded for that community. The prevalence of heartworm was directly related to the reproductive index on each reservation.

The purpose of this study was to determine the experimental side effects of liposome-encapsulated hydromorphone (LE-Hydro) in beagles and to evaluate LE-Hydro analgesia in dogs undergoing ovariohysterectomies (OVH). Beagles were injected subcutaneously with 1–3 mg/kg LE-Hydro or 0.1 mg/kg hydromorphone. Dogs were evaluated for sedation, temperature, respiratory rate, and heart rate. OVH dogs were injected with 2 mg/kg LE-Hydro subcutaneously or 0.2 mg/kg morphine and 0.05 mg/kg acepromazine intramuscularly. Side effects of LE-Hydro were within clinically acceptable limits. The analgesic efficacy was superior in dogs administered LE-Hydro at 12 hr postsurgically. LE-Hydro provided adequate, durable analgesia in dogs undergoing OVH.

Factors that predict postoperative continence and incontinence were evaluated in 33 female dogs with surgically corrected ectopic ureters. The current study found that intramural or extramural, left- or right-sided, and unilateral or bilateral ectopic ureters were not significant factors influencing postoperative incontinence in affected dogs. The presence of either hydroureter or urinary tract infection was also not significantly associated with postoperative incontinence. Dogs with ectopic ureters that were incontinent postsurgically tended to remain unresolved.

Thoracolumbar intervertebral disc extrusion is a common disease in dogs. Surgical decompression of the spinal cord is the preferred treatment. Localization of the compressive material is critical for surgical planning. Myelography has been used for localizing extruded disc material, but this procedure carries risk of complications. Computed tomography (CT) is becoming more available for use in veterinary medicine and CT myelography is used for localization of extruded disc material. This report compares CT with intravenous contrast medium and CT myelography for identifying extruded intervertebral discs. CT with intravenous contrast medium is as effective as CT myelography for determining level and laterality of compressive disc extrusions.

Certain breeds are known to be overrepresented among mast cell tumor (MCT) patients, but other risk factors have not been evaluated. This study presents results from a case-control study of 252 dogs with grade 2 or grade 3 cutaneous MCT. Increased risk for MCT development was found in spayed females (adjusted odds ratio [OR], 4.11), boxers (adjusted OR, 6.09), Labrador retrievers (adjusted OR, 3.95), pugs (adjusted OR, 3.17), golden retrievers (adjusted OR, 2.12), the mastiff and terrier phylogenetic cluster (adjusted OR, 3.19), and breeds classified as large (adjusted OR, 2.10) or giant (adjusted OR, 5.44). Additional studies are needed to evaluate the role of these and other potential risk factors in MCT development.

This is the first description of a left ventricular inflow tract obstruction secondary to a myxoma in a dog. A 4 yr old, male fox terrier presented with a 1 mo history of cough and exercise intolerance. Expiratory dyspnea, pulmonary crackles, irregular cardiac rhythm, and a grade 4/6 pansystolic cardiac murmur over the left cardiac apex were the most important features on physical examination. The electrocardiogram revealed atrial fibrillation. Thoracic radiographs showed left-sided cardiac enlargement and mild pulmonary edema, especially in the hilar area. Two-dimensional transthoracic echocardiography showed severe left atrial dilation and a homogenous, echodense mass involving both leaflets of the mitral valve and the posteromedial papillary muscle, inducing mitral stenosis. Spectral Doppler echocardiography was consistent with severe left ventricular inflow tract obstruction secondary to a mass. Therapy for congestive heart failure was prescribed. Follow-up examinations of the dog 1 mo, 2 mo, and 6 mo after diagnosis showed an improvement in clinical signs, but similar echocardiographic features. Eleven months after diagnosis, the dog was euthanized at the owner's request because of recurrent congestive heart failure. The postmortem examination showed the cardiac tumor was consistent with a myxoma.

A 7 yr old, neutered female vizsla underwent an exploratory thoracotomy after diagnosis of recurrent hemorrhagic pericardial effusion and a right auricular mass. Staging tests were negative for metastasis. The patient underwent a right, fourth intercostal thoracotomy, subtotal pericardectomy, right auricular mass excision, and pericardial free patch graft. The patient experienced blood loss during surgery, which required a packed red blood cell transfusion. The patient experienced transient arrhythmias postoperatively, but was discharged from the hospital 48 hr later. Histopathologic diagnosis of the mass was hemangiosarcoma. The patient was treated with carboplatin single-agent chemotherapy and palliative radiation therapy. The patient died at home, presumably from metastatic disease 260 days postoperatively. Surgical mass removal or debulking along with pericardial free patch grafting may be considered as palliative treatment options for dogs diagnosed with right auricular masses. In this case report, other techniques failed to repair the defect in the heart and a free patch graft offered a good rescue procedure with a favorable outcome without the need for inflow and outflow occlusion when used in conjunction with adjunctive therapies.

Disseminated histoplasmosis and disseminated intravascular coagulopathy were diagnosed in a 7 mo old, female spayed mixed-breed dog. The dog improved transiently with supportive care, but deteriorated shortly after initiation of antifungal therapy. The dog was subsequently euthanized. At necropsy, marked granulomatous vasculitis was identified in all affected organs. The tunicae and laminae of the arteries and arterioles were obscured by epithelioid macrophages and multinucleated giant cells admixed with necrotic material. Intracytoplasmic yeast were present within some of these macrophages. To the authors' knowledge, this is the first reported case of granulomatous vasculitis associated with Histoplasma capsulatum in a dog.

A 4 yr old, castrated male dachshund was presented for lethargy, restlessness, a “hunched” posture, and a painful abdomen. A gastric foreign body had been surgically removed 24 mo previously. Exploratory celiotomy revealed a devitalized segment of jejunum with twisted mesentery. Several adhesions and fibrous bands were present within the abdomen, presumptively from the previous gastric foreign body surgery. Histopathology determined that a fibrous tissue band caused entrapment of the segment of intestine and its mesentery resulting in volvulus and ischemic necrosis of the intestine. This case is unique because it involved a focal area of the jejunum that was incarcerated in fibrous adhesions.

A 4 yr old, spayed female domestic shorthair was referred with a 2 mo history of weight loss, anorexia, and diarrhea. Skin fragility was noted on presentation and a large skin tear measuring 5 cm × 5 cm was obvious over the dorsal cervical region. The patient was previously treated with short-term prednisone that was discontinued 6 wk before presentation. Initial diagnostics (complete blood count and biochemistry) did not indicate an endocrine disorder, the most common cause of acquired feline skin fragility. Necropsy revealed diffuse histoplasmosis (most significantly affecting the skin), epidermal atrophy, dermal collagen separation, and infiltration in the dermis and subcutis by inflammatory cells containing yeast organisms consistent with Histoplasma spp. Infiltrative fungal infection should be considered as a potential cause of acquired feline skin fragility.