Iron homeostasis and disorders in dogs and cats: a review.

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.

Systemic hypertension in a dog with a functional thyroid gland adenocarcinoma.

CASE DESCRIPTION: A 12-year-old 21.9-kg (48.48-lb) spayed female Alaskan Malamute with a long-term history of panting, polydypsia and polyuria, weight loss, hind limb weakness, and a decrease in appetite was evaluated for hypertension. CLINICAL FINDINGS: Use of Doppler sphygmomanometry revealed a systolic blood pressure of 250 mm Hg (mean value for 5 consecutive measurements). Palpation of the ventral cervical region revealed a fixed asymmetric mass in the area of the lobes of the thyroid gland. The portion of the mass on the right side was approximately 2 x 2 cm, whereas the portion of the mass on the left side was approximately 1 x 1.5 cm. Hyperthyroidism was diagnosed on the basis of high serum thyroxine concentrations. Thyroidectomy of both lobes of the gland was performed. Histologic examination revealed a bilateral, multilobulated, and encapsulated thyroid gland adenocarcinoma. TREATMENT AND OUTCOME: Thyroidectomy of both lobes of the gland was performed with clinical resolution of hypertension. The dog was treated postoperatively with chemotherapeutics, including doxorubicin and carboplatin, and external beam radiation. Calcium and thyroxine homeostasis fluctuated; however, the dog finally achieved concentrations within the respective reference ranges through the administration of calcitriol, calcium carbonate, and levothyroxine. CLINICAL RELEVANCE: This report describes concurrent hypertension in a dog with a functional thyroid gland adenocarcinoma with subsequent return of blood pressure values to within reference ranges after thyroidectomy.

Suspected albuterol toxicosis in a dog.

CASE DESCRIPTION: A 6-year-old male castrated Shetland Sheepdog was evaluated because of severe hypokalemia and progressive paresis. CLINICAL FINDINGS: Physical examination revealed fever, tachypnea, mydriasis, hyperemic mucous membranes, severe forelimb paresis, and hind limb paraplegia. The dog had superficial and deep pain sensation in all 4 limbs. Forelimb spinal reflexes were considered normal, but hind limb reflexes were normal to slightly hyperreflexive. The panniculus reflex was considered to be normal, and cranial nerve reflexes were intact. A CBC revealed mild leukocytosis and erythrocytosis, and serum biochemical analysis revealed severe hypokalemia. Thoracic and abdominal imaging did not reveal relevant findings. Blood pressure and ECG findings were within reference limits. Questioning of the owner revealed possible exposure to albuterol via ingestion of medication intended for the owner's horse. Results of serum testing via immunoassay were suggestive of albuterol toxicosis. TREATMENT AND OUTCOME: Treatment included IV administration of an electrolyte solution and supplemental potassium chloride. The rate of potassium chloride supplementation was slowly decreased as serum potassium concentration increased. No other medical intervention was required, and the dog made a rapid and complete recovery. CLINICAL RELEVANCE: Ingestion of albuterol can lead to profound physical and serum biochemical abnormalities. Appropriate historical information should be obtained to identify possible sources and routes of exposure to intoxicants. Albuterol-induced hypokalemia can be successfully managed medically.

Effect of antivenin dose on outcome from crotalid envenomation: 218 dogs (1988-2006).

OBJECTIVE: To determine whether the dose of antivenin administered is associated with a difference in survival of crotalid-envenomated dogs. A secondary objective was to determine whether other covariables affect survival. DESIGN: Retrospective study (1988-2006). SETTING: Private referral center and university small animal teaching hospital. ANIMALS: Two hundred and eighteen dogs with evidence of crotalid envenomation and treatment with equine-derived antivenin. INTERVENTIONS: Administration of antivenin. MEASUREMENTS AND MAIN RESULTS: Patient signalment, physical and clinicopathologic data at time of presentation, treatments, complications of antivenin therapy, length and cost of hospitalization, and outcome were recorded. Confidence intervals were determined for the difference in median number of vials administered and for median dosage for patients that lived versus died. Penalized logistic regression was performed to evaluate the effect of other covariables on survival. The median age of affected dogs was 3 years (range 6 w-12 y) with a median weight of 25.7 kg (range 1.95-86.4 kg). The median number of antivenin vials administered was 1.0 (range 1.0-10.0). Acute and chronic reactions were reported in 7% (16/218) and 0.9% (2/218) of dogs, respectively. Nine of 218 dogs (4.1%) died. The median number of vials administered to the nonsurvivors and survivors were 2.0 (range 1-5 vials) and 1.0 (range 1-10 vials), respectively. The median number of vials received was significantly different in dogs that died versus those that lived (P<0.05). Increased heart rate (P=0.02) and petechiation (P=0.04) were associated with decreased likelihood of survival, while diphenhydramine (P=0.02) and fluoroquinolone (P=0.046) administration was associated with increased likelihood of survival. The median duration of hospitalization was 1.0 day (range 2 h-22 d). The median cost of hospitalization was US$1592.00 (range US$267.20-US$6738.00). CONCLUSION: The administration of more vials of antivenin is potentially associated with negative outcome; however, a causal relationship has not been established. Controlled, prospective studies are needed to optimize antivenin administration.