Case Description—A 2-year-old captive-bred sexually intact female African pygmy hedgehog (Atelerix albiventris) was evaluated because of vague signs of illness including inappetence, weakness, lethargy, and weight loss over a 20-day period.
Clinical Findings—Abnormalities detected via initial clinicopathologic analyses included anemia, thrombocytopenia, leukopenia, hypoproteinemia, and hypoglycemia. Results of a fecal flotation test were negative. Three weeks after the initial evaluation, splenomegaly was detected via palpation and ultrasonography.
Treatment and Outcome—The hedgehog was treated with broad-spectrum antibacterial agents, resulting in an initially favorable response. Fenbendazole was also administered against possible occult parasitic infestation. After 3 weeks of illness, the hedgehog's condition had worsened and supportive care and administration of additional antibacterial agents were instituted. The hedgehog died, and pathologic examinations revealed severe splenomegaly; granulomatous infiltrates were evident in multiple organs, and Histoplasma capsulatum yeasts were detected intralesionally.
Clinical Relevance—Histoplasmosis can develop in a wide range of mammalian species. African pygmy hedgehogs are becoming increasingly popular as exotic pets, and vague signs of illness and splenomegaly are often attributed to hemolymphatic malignancies, which are somewhat common in this species. Practitioners should be aware that similar clinical signs may be associated with histoplasmosis in these animals. Although the hedgehog of this report was confined indoors, it originated from an area where histoplasmosis was endemic; this indicates that the disease should be included as a differential diagnosis for hedgehogs that develop vague signs of illness and are known to originate from such geographic regions.
CASE DESCRIPTION A 7-year-old castrated male Italian Greyhound (dog 1) and an approximately 1-year-old female Labrador Retriever (dog 2) were evaluated because of respiratory distress 8 and 10 days, respectively, after a tornado.
CLINICAL FINDINGS No obvious external injuries were identified auscultation revealed decreased bronchovesicular sounds in the affected hemithorax of both dogs. Clinicopathologic changes were mild, with evidence of inflammation in both dogs. Thoracic radiography of both dogs revealed pneumothorax and pleural effusion with effacement of the diaphragm; findings on CT included severe pulmonary atelectasis of affected lung lobes with normal bronchial tree configurtion and no evidence of diaphragmatic hernia.
TREATMENT AND OUTCOME Exploratory thoracotomy of both dogs confirmed CT findings Pulmonary parenchymal damage consistent with a large rupture was found in both patients. A large hematoma was adhered to the ruptured lung lobe of dog 1. Grossly affected lung tissue was removed; histologic examination revealed atelectasis, pulmonary fib osis, thrombosis, and minimal (dog 1) to marked (dog 2) inflammation Microbial culture of lung tissue yielded no growth for dog 1 and Streptococcus spp and Escherichia coli susceptible to amoxicillin-clavulanic acid for dog 2. Dog 1 had a recurrence of pneumothorax treated by drainage with a thoracostomy tube 1 month after surgery. Eighteen months after surgery, both dogs were reportedly doing well.
CLINICAL RELEVANCE Development of clinical signs after a tornado, together with clinical, diagnostic imaging, surgical, and histologic findings led to a presumptive diagnosis of pulmonary barotrauma for both dogs. Long-term outcome for these dogs, treated at a referral hospital, was good.
Case Description—A 14-year-old castrated male domestic shorthair cat was evaluated because of a large fluid-filled mass on the ventral aspect of the neck that failed to resolve after repeated draining.
Clinical Findings—Radiography and computed tomography revealed a fluid-filled mass 13 cm in diameter extending from the level of the first cervical vertebra to the manubrium. No evidence of metastasis was seen. Cytologic examination of the fluid revealed it to be a transudate with a T4 concentration considered to be normal. Incisional biopsy of the cyst wall was performed and led to a diagnosis of thyroglossal duct cyst.
Treatment and Outcome—The cyst was excised, and no recurrence was observed 15 months after surgery. Aside from temporary seroma formation, no complications developed after the surgery. A distinct tract through the hyoid apparatus to the base of the tongue, as has been described in humans, was not identified.
Clinical Relevance—Thyroglossal duct cyst should be considered as a differential diagnosis in cats with masses on the ventral aspect of the neck. Complete excision appeared to be curative in the cat of this report.
OBJECTIVE To compare clinical disease and lung lesions in calves experimentally inoculated with Histophilus somni 5 days after metaphylactic administration of tildipirosin or tulathromycin.
ANIMALS Twenty-four 3-month-old Holstein and Holstein-crossbreed steers.
PROCEDURES Calves were randomly allocated to 3 groups of 8 calves. On day 0, calves in group 1 received tildipirosin (4 mg/kg, SC), calves in group 2 received tulathromycin (2.5 mg/kg, SC), and calves in group 3 received isotonic saline (0.9% NaCl) solution (1 mL/45 kg, SC; control). On day 5, calves were inoculated with 10 mL of a solution containing H somni strain 7735 (1.6 × 109 CFUs/mL, intrabronchially; challenge). Calves were clinically evaluated on days 5 through 8 and euthanized on day 8. The lungs were grossly evaluated for evidence of pneumonia, and bronchial secretion samples underwent bacteriologic culture.
RESULTS The mean clinical score for each group was significantly increased 12 hours after challenge, compared with that immediately before challenge, and was significantly lower for tildipirosin-treated calves on days 6, 7, and 8, compared with those for tulathromycin-treated and control calves. The mean percentage of lung consolidation for tildipirosin-treated calves was significantly lower than those for tulathromycin-treated and control calves. Histophilus somni was isolated from the bronchial secretions of some tulathromycin-treated and control calves but was not isolated from tildipirosin-treated calves.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that metaphylactic administration of tildipirosin to calves 5 days prior to H somni challenge prevented subsequent culture of the pathogen from bronchial secretions and was more effective in minimizing clinical disease and lung lesions than was metaphylactic administration of tulathromycin.
Objective—To develop a repeatable model for studying colonization with streptomycin-resistant Escherichia coli O157:H7 in adult cattle.
Animals—5 adult mixed-breed beef cattle.
Procedures—Cattle were surgically cannulated in the duodenum, treated daily with streptomycin (33 mg/kg) via the duodenal cannula prior to and during experimental colonizations, and colonized with 1010 CFUs of streptomycin-resistant E coli O157:H7 via the duodenal cannula. Colonization of rectal mucus and shedding in feces were monitored. Antimicrobials were administered to eliminate the colonizing strain so that 5 repeated colonization experiments could be performed. A comprehensive analysis of colonization was performed at necropsy.
Results—Streptomycin treatment resulted in improved experimental colonization variables, compared with untreated controls, during initiation (days 2 to 6) and early maintenance (days 7 to 12) of colonization. Elimination of the colonizing strain followed by 5 repeated colonizations in the same animals indicated the repeatability of the protocol. Positive results of bacteriologic culture of feces 7 and 12 days after colonization were obtained in 100% and 84% of samples, respectively, across all animals and trials. At necropsy, highest magnitude recovery was in terminal rectal mucus.
Conclusions and Clinical Relevance—The model was highly repeatable and novel with respect to streptomycin treatment, use of duodenal cannulas, and repeated colonizations of the same animals. Its use in adult cattle, from which most bovine-derived food originates, is critical to the study of preharvest food safety. The findings have implications for understanding intermittency of shedding in the field and for proposed vaccine-based interventions.
Objective—To determine whether antemortem core needle biopsy and fine-needle aspiration of enlarged peripheral lymph nodes could be used to distinguish between inflammation and lymphosarcoma in cattle.
Animals—25 cattle with enlarged peripheral lymph nodes.
Procedures—Antemortem biopsies of the selected lymph nodes were performed with an 18-gauge, 12-cm core needle biopsy instrument. Fine-needle aspirates were performed with a 20-gauge, 4-cm needle. Specimens were analyzed by pathologists who were unaware of clinical findings and final necropsy findings, and specimens were categorized as reactive, neoplastic, or nondiagnostic for comparison with necropsy results.
Results—Sensitivity and specificity of core needle biopsy ranged from 38% to 67% and from 80% to 25%, respectively. Sensitivity of fine-needle aspiration ranged from 41% to 53%, and specificity was 100%. Predictive values for positive test results ranged from 77% to 89% for core needle biopsy and were 100% for fine-needle aspiration. Predictive values for negative test results were low for both core needle biopsy and fine-needle aspiration.
Conclusions and Clinical Relevance—Results indicated that core needle biopsy and fineneedle aspiration can aid in the antemortem diagnosis of bovine enzootic lymphosarcoma. Results of fine-needle aspiration of enlarged peripheral lymph nodes were more specific and more predictive for a positive test result than were results of core needle biopsy.