Rupture of collateral ligaments in metacarpophalangeal and metatarsophalangeal joints in horses: 17 cases (1999--2005)

OBJECTIVE: To characterize ruptures of collateral ligaments (CLs) in metacarpophalangeal and metatarsophalangeal joints in horses. DESIGN: Retrospective case series. ANIMALS: 17 horses with ruptured CLs. PROCEDURES: Data were obtained from medical records, including signalment, history, clinical signs, ultrasonographic and radiographic findings, treatment, and outcome. Additional follow-up information was obtained from owners or referring veterinarians. RESULTS: The lateral CL was ruptured in 11 horses; the medial CL was ruptured in 6 horses. Ultrasonography revealed ipsilateral rupture of the short and long components of the CL in 11 horses and rupture of only 1 component in 6 horses. No biaxial ruptures were detected, but 9 horses had desmitis of the CL on the nonruptured side of the affected joint. All horses were lame (lameness score range, 2/5 to 4/5). Joint instability was palpable in 9 horses; only 4 horses had episodes of joint luxation. Avulsion fractures were identified radiographically in 6 horses and ultrasonographically in another 2 horses. Stress radiography revealed joint instability in 10 horses. Horses were managed by stall confinement, limb immobilization, and gradual return to exercise. Eight horses returned to riding, 2 resumed breeding, 2 were retired, 2 were euthanized, and 3 were doing well 86 to 139 days after injury. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasonographic examination is indicated in horses with acute lameness and swelling at the metacarpophalangeal or metatarsophalangeal joint, particularly when stress radiography cannot be performed or findings are equivocal. Affected horses can be conservatively managed. Prognosis for athletic use may be better than originally believed.     

Next-generation sequencing capacity and capabilities within the National Animal Health Laboratory Network

With the cost of next-generation sequencing (NGS) decreasing, this technology is rapidly being integrated into the workflows of veterinary clinical and diagnostic laboratories nationwide. The mission of the U.S. Department of Agriculture–National Animal Health Laboratory Network (NAHLN) is in part to evaluate new technologies and develop standardized processes for deploying these technologies to network laboratories for improving detection and response to emerging and foreign animal diseases. Thus, in 2018, the NAHLN identified the integration of NGS into the network as a top priority. In order to assess the current state of preparedness across NAHLN laboratories and to identify which have the capability for performing NGS, a questionnaire was developed by the NAHLN Methods Technical Working Group and submitted to all NAHLN laboratories in December 2018. Thirty of 59 laboratories completed the questionnaire, of which 18 (60%) reported having some sequencing capability. Multiple sequencing platforms and reagents were identified, and limited standardized quality control parameters were reported. Our results confirm that NGS capacity is available within the NAHLN, but several gaps remain. Gaps include not having sufficient personnel trained in bioinformatics and data interpretation, lack of standardized methods and equipment, and maintenance of sufficient computing capacity to meet the growing demand for this technology.     

Clinical and scintigraphic findings in horses with a bone fragility disorder: 16 cases (1980-2006)

OBJECTIVE: To describe clinical and scintigraphic abnormalities in horses with a bone fragility disorder. DESIGN: Retrospective case series. ANIMALS: 16 horses with scintigraphic evidence of multiple sites of increased radiopharmaceutical uptake (IRU). Procedures-Medical records were reviewed for information on signalment; history; clinical, clinicopathologic, and diagnostic imaging findings; and treatment. Follow-up information was obtained through telephone interviews with owners. RESULTS: Horses ranged from 4 to 22 years old; there were 8 castrated males and 8 females. Foci of IRU most commonly involved the scapulae, ribs, sternebrae, sacral tubers, ilia, and cervical vertebrae. Most horses were examined because of chronic intermittent (n = 10) or acute (6) lameness involving a single (10) or multiple (6) limbs that could not be localized by means of regional anesthesia. Cervical stiffness (n = 3), scapular bowing (3), swayback (3), and ataxia (1) were also seen in more advanced cases. Signs of respiratory tract disease and exercise intolerance were evident in 4 horses. Ultrasonographic or radiographic evidence of bone remodeling or degeneration was seen in 19 of 33 affected bones. Histologic examination of bone biopsy specimens revealed reactive bone. Improvement was initially seen with conservative treatment in some horses, but the condition worsened in all horses, and 11 horses were euthanized within 7 years. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that horses may develop a bone fragility disorder characterized clinically by an unlocalizable lameness and scintigraphically by multiple sites of IRU involving the axial skeleton and proximal portion of the appendicular skeleton.     

Serum cannabidiol,tetrahydrocannabinol (THC), and their native acid derivatives after transdermal application of a low-THC Cannabis sativa extract in beagles

Cannabinoids hold promise for treating health problems related to inflammation and chronic pain in dogs, in particular cannabidiol (CBD), and its native acid derivative cannabidiolic acid (CBDA). Information regarding systemic delivery of cannabinoids through transdermal routes is sparse. The purpose of this study was to determine pharmacokinetics of transdermal administration of a low-THC Cannabis sativa extract in healthy dogs. Six purpose-bred research beagles were treated with a transdermal CBD-CBDA-rich extract, and serum concentrations of CBD, CBDA, tetrahydrocannabinol (THC), and its acid derivative tetrahydrocannabinolic acid (THCA) were examined prior to and at the end of weeks 1 and 2. A 4 mg/kg dose of total cannabinoids twice daily resulted in appx 10 ng/ml of CBD, 21–32 ng/ml of CBDA, trace amounts of THCA, and unquantifiable amounts of THC in serum at the end of weeks 1 and 2 of treatment. Results showed that CBDA and THCA were absorbed better systemically than CBD or THC.     

Changes in platelet function, hemostasis, and prostaglandin expression after treatment with nonsteroidal anti-inflammatory drugs with various cyclooxygenase selectivities in dogs

OBJECTIVE: To determine the effects of nonsteroidal anti-inflammatory drugs of various cyclooxygenase selectivities on hemostasis and prostaglandin expression in dogs. ANIMALS: 8 client-owned dogs with clinical signs of osteoarthritis. PROCEDURES: Dogs received aspirin (5 mg/kg, PO, q 12 h), carprofen (4 mg/kg, PO, q 24 h), deracoxib (2 mg/kg, PO, q 24 h), and meloxicam (0.1 mg/kg, PO, q 24 h) for 10 days each, with an interval of at least 14 days between treatments. On days 0 and 10, blood was collected for platelet aggregation assays, thrombelastography, and measurement of lipopolysaccharide-stimulated prostaglandin E(2), platelet thromboxane B(2) (TXB(2)), and free serum TXB(2) and 6-keto-prostaglandin F (PGF)-1alpha concentrations. RESULTS: Platelet aggregation decreased after treatment with aspirin and carprofen, whereas significant changes from baseline were not detected for the other drugs tested. Thrombelastograms obtained after treatment with carprofen revealed decreased maximum amplitude and alpha-angle, suggesting hypocoagulability. Maximum amplitude and coagulation index increased after treatment with deracoxib. Plasma concentrations of prostaglandin E(2) decreased after treatment with carprofen or deracoxib, and platelet TXB(2) production increased after treatment with aspirin. Serum concentrations of the prostacyclin metabolite 6-keto-PGF-1alpha did not change significantly after treatment with any of the drugs, although the ratio of free TXB(2) to 6-keto-PGF-1alpha decreased slightly after treatment with carprofen and increased slightly after treatment with deracoxib. CONCLUSIONS AND CLINICAL RELEVANCE: At the dosages tested, treatment with meloxicam affected platelet function minimally in dogs with osteoarthritis. Treatment with carprofen decreased clot strength and platelet aggregation. Clot strength was increased after treatment with deracoxib.     

Efficacy and toxicity of a dose-intensified doxorubicin protocol in canine hemangiosarcoma

The purpose of this study was to evaluate the efficacy and toxicity of a single-agent, dose-intensified doxorubicin protocol in canine hemangiosarcoma (HSA). Canine HSA is a highly malignant tumor, and most affected dogs die within 6 months of diagnosis. Doxorubicin is the most, and possibly the only, effective chemotherapeutic drug for this malignancy, but it provides only moderate improvement in survival. On the basis of previous studies reporting similar survival in dogs treated with doxorubicin as a single agent and doxorubicin-based combination chemotherapy and the concept of summation dose intensity, a dose-intensified single-agent doxorubicin protocol was initiated. Twenty dogs with HSA were recruited to participate in this study. Workup and staging were performed according to standard practice. Chemotherapy was initiated within 3 weeks of surgery. Doxorubicin was scheduled to be administered at 30 mg/m2 i.v. every 2 weeks for a total of 5 treatments. The dogs were monitored for toxicity and signs of recurrence during and at regular intervals after chemotherapy. The protocol was tolerated well. No dogs were hospitalized because of adverse effects or developed clinical signs consistent with doxorubicin-induced cardiomyopathy. There was a significant difference in survival in dogs with stage I and I1 HSA compared with dogs with stage III HSA. with median survival times of 257, 210, and 107 days, respectively. These results are slightly better than the historical control with respect to toxicity and efficacy but are not statistically different from what is achieved with standard treatments. There was no association between dose intensity and outcome.     

Evaluation of clinical characteristics, diagnostic test results, and outcome in horses with internal infection caused by Corynebacterium pseudotuberculosis: 30 cases (1995-2003)

OBJECTIVE: To determine clinical signs, results of diagnostic testing, and outcome in horses with internal Corynebacterium pseudotuberculosis infection. DESIGN: Retrospective study. ANIMALS: 30 horses. PROCEDURE: Information pertaining to clinical data, results of diagnostic tests, and costs of hospitalization and treatment was extracted from medical records of affected horses. RESULTS: Internal C. pseudotuberculosis infection was diagnosed on the basis of clinical signs, diagnostic imaging, and clinicopathologic data, including results of serologic tests and bacterial culture. The most common clinical signs were concurrent external abscesses, anorexia, fever, lethargy, weight loss, and signs of respiratory tract disease or abdominal pain. Clinicopathologic abnormalities included a geometric mean reciprocal serum synergistic hemolysin inhibition titer > or = 512, leukocytosis with neutrophilia, hyperglobulinemia, hyperfibrinogenemia, and anemia. Specific organ involvement was diagnosed in 27 of 30 horses. Affected organs included the liver (18 horses), lungs (12), kidneys (7), and spleen (3); multiple organs were affected in 10 horses. Treatment with antimicrobials for a median of 36 days (range, 7 to 97 days) was usually successful, yielding an overall survival rate of 71%. CONCLUSIONS AND CLINICAL RELEVANCE: Early diagnosis and long-term antimicrobial treatment were important for a successful outcome in horses with internal C. pseudotuberculosis infection. Ultrasonographic imaging was an important technique for identifying specific organs affected, aiding in obtaining samples for a definitive diagnosis, and monitoring response to treatment. Pregnant mares with internal infections are at risk for fetal loss. Preexisting chronic organ disease may be associated with a poor prognosis.     

The Effect of Cholesterol Addition,Buffer, and pH on Equine Sperm Stored at 5°C

Cooled stallion semen has a short viable life, which ranges with acceptable motility and viability from 24 up to 48 hours. The purpose of this study was to compare the effects of storage pH, the ability of three different zwitterionic buffers, and cholesterol-loaded cyclodextrins (CLC) to preserve the motility and integrity of stallion sperm cooled to 5°C for 48 hours. Fourteen ejaculates were collected and split to receive CLC or not (control group). After incubation, each sample was split into six subsamples and diluted in KMT extender containing 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES), N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES), or 2-(N-morpholino)ethanesulfonic acid (MES) buffers, and the final pH was adjusted to either 7.0 or 6.6, totalizing 12 experimental groups as a function of CLC, buffer, and pH variables (2 × 3 × 2 factorial). The motility parameters and integrity of plasma and acrosome membranes (live cell index) were determined using computer-automated semen analysis and epifluorescence microscopy at 3, 6, 24, and 48 hours of cooling period. According to results, pH was not a significant source of variation for motility and live sperm over different cooling periods. However, samples diluted in BES exhibited higher progressive motility within 3 hours and higher percentages of total motile cells after 48 hours of incubation at 5°C (P < .05). After 24 hours of storage, CLC-treated sperm samples presented higher motility than control group (P < .05), and after 48 hours of incubation, CLC-treated sperm exhibited higher percentages of live, motile, and progressively motile sperms (P < .05). We inferred that equine semen diluted in KMT containing BES as buffer and CLC treatment improve the equine sperm survival during storage at 5°C for 48 hours.     

Prevalence of neoplasia in llamas and alpacas (Oregon State University, 2001-2006).

Prevalence and type of neoplastic disease were determined in 551 camelid submissions (368 alpacas [Lama pacos], 180 llamas [Lama glama], and 3 cases in which species was not identified) over a 5-year period. Forty neoplasms were identified in 38 animals (6.9%). Prevalence of neoplasia in llamas was higher (11%) than in alpacas (4.9%). Mean age of camelids with neoplasia was 9.42 +/- 4.9 years. Mean age of alpacas with neoplasia (5.48 +/- 3.7 years) was significantly less than of llamas with neoplasia (12.53 +/- 3.2 years; P < 0.001). Cutaneous and mucocutaneous fibroma/fibropapilloma was most common (10 animals), followed by cutaneous and mucocutaneous squamous cell carcinoma (6 animals), disseminated lymphoma (5 animals), and fibrosarcoma (4 animals). Four of 5 animals with lymphoma were alpacas, aged 0.21 to 4 years. Lymphoma occurred in 1 aged llama (15 years). Disseminated carcinoma and adenocarcinoma occurred in 4 llamas and 2 alpacas, and included biliary (2), gastrointestinal (2), mammary gland (1), and unknown (1) origin. Mean age of camelids with any type of carcinoma or adenocarcinoma (12.36 +/- 2.8 years) was significantly greater than that of camelids with lymphoma (4.24 +/- 6.2 years; P = 0.02). Results indicate that neoplasia is relatively common in camelids and that there are differences between llamas and alpacas as regards prevalence of neoplasia, tumor types, and age at diagnosis.     

IMAGING DIAGNOSIS—AORTIC ANEURYSM AND URETERAL OBSTRUCTION SECONDARY TO UMBILICAL ARTERY ABSCESSATION IN A 5‐WEEK‐OLD FOAL

A 5‐week‐old foal was evaluated for fever and hematuria of 3 days duration. Cystoscopy localized the blood to be originating from the left ureter. Abdominal ultrasonography revealed left hydronephrosis, hydroureter, and omphaloarteritis of the left umbilical artery with abscess formation that communicated with an arterial structure. Computed tomography (CT) revealed a large aortic aneurysm within the center of the abscess. An exploratory celiotomy was performed and the infection was nonresectable. The prognosis for life was grave; therefore the colt was euthanized. Necropsy findings confirmed the antemortem diagnosis. Ultrasound and CT imaging in this case provided an accurate antemortem diagnosis.