Digital Cytology.

Microscopic evaluation of cytologic specimens can provide rapid diagnostic information and aid in formulating diagnostic and treatment plans. The primary benefit of cytologic evaluation is the rapid collection, processing, and evaluation of samples. However, physical transport of glass slides and body fluids to a diagnostic laboratory takes time and can negatively affect patient management. Digital cytology allows specimens to be processed in the clinic and immediately sent to pathologists. With technology becoming more affordable, digital cytology is revolutionizing the field of clinical pathology and patient care.

Subcutaneous Implantation of Hepatocellular Carcinoma in a Dog.

A 13-year-old male neutered Cocker Spaniel mixed-breed dog developed a subcutaneous mass 2 years after undergoing surgery to remove a hepatocellular carcinoma. An approximately 4 × 3 cm subcutaneous mass was found on the ventral abdomen at the cranial end of the abdominal incision from the previous surgery. The subcutaneous mass was surgically removed and histopathological examination determined that it was an implantation of the previously excised hepatocellular carcinoma. The diagnosis was confirmed by immunohistochemical labelling with hepatocyte paraffin 1 antibody and pancytokeratin. Based on the location of the subcutaneous mass at the cranial end of the abdominal incision associated with the previous hepatocellular carcinoma resection, it is likely there was iatrogenic metastasis from the primary tumour excision. Subcutaneous iatrogenic metastasis of hepatocellular carcinoma is well recognized in humans but has apparently never been reported in dogs. Clinicians should be aware of this potential surgical complication.

Utility of Thyroid Function Testing in the Inpatient Setting.

OBJECTIVE: Previous studies have reported a low value of ordering inpatient thyroid function tests (TFTs), with few changes in clinical management resulting from these tests. This study was designed to evaluate how often testing the thyroid function during hospitalization leads to medication initiation or adjustment and to determine whether the frequency of medication initiation or adjustment differs based on the indication for testing. METHODS: This is a retrospective observational study of 2278 patients who underwent TFTs tested while admitted to an academic hospital during a 5-month period. The indications for ordering TFTs were determined by reviewing clinical documentation, and those with abnormal test results were reviewed to assess whether thyroid medication was initiated or adjusted. RESULTS: The percentage of abnormal TFTs that led to medication initiation or adjustment was 15.1%, 12.2%, and 6.0%, for those tested based on a history of functional thyroid disease, suspicion of thyroid dysfunction, and reasons not directly related to thyroid dysfunction, respectively. Overall, 63 patients were started on thyroid medication or had their thyroid medication dose adjusted, which represented 10.1% of those with abnormal TFTs and only 2.8% of those tested. CONCLUSION: Abnormal TFTs are common, but a disproportionate number of tests are needed to find a small percentage of clinically significant thyroid dysfunction, of which only a low percentage leads to changes in management. Education on this topic should be provided to inpatient providers to limit thyroid function testing to instances in which they are clinically indicated and abnormal results would lead to changes in management.

Diversity and distribution of the tick-borne relapsing fever spirochete Borrelia turicatae.

Borrelia turicatae is a causative agent of tick-borne relapsing fever (TBRF) in the subtropics and tropics of the United States and Latin America. Historically, B. turicatae was thought to be maintained in enzootic cycles in rural areas. However, there is growing evidence that suggests the pathogen has established endemic foci in densely populated regions of Texas. With the growth of homelessness in the state and human activity in city parks, it was important to implement field collection efforts to identify areas where B. turicatae and its vector circulate. Between 2017 and 2020 we collected Ornithodoros turicata ticks in suburban and urban areas including public and private parks and recreational spaces. Ticks were fed on naïve mice and spirochetes were isolated from the blood. Multilocus sequence typing (MLST) was performed on eight newly obtained isolates and included previously reported sequences. The four chromosomal loci targeted for MLST were 16S ribosomal RNA (rrs), flagellin B (flaB), DNA gyrase B (gyrB), and the intergenic spacer (IGS). Given the complexity of Borrelia genomes, plasmid diversity was also evaluated. These studies indicate that the IGS locus segregates B. turicatae into four genomic types and plasmid diversity is extensive between isolates. Furthermore, B. turicatae and its vector have established endemic foci in parks and recreational areas in densely populated settings of Texas.

Retrospective study of canine endoparasites diagnosed by fecal flotation methods analyzed across veterinary parasitology diagnostic laboratories, United States, 2018.

BACKGROUND: Companion animal endoparasites play a substantial role in both veterinary medicine and public health. Updated epidemiological studies are necessary to identify trends in occurrence and distribution of these parasites, and their associated risk factors. This study aimed to assess the occurrence of canine endoparasites  retrospectively, using fecal flotation  test data available through participating academic veterinary parasitology diagnostic laboratories across the United States of America (USA). METHODS: Canine fecal flotation records from ten veterinary diagnostic laboratories located in nine states in the USA acquired from January 1, 2018, to December 31, 2018, were included. RESULTS: A total of 4692 fecal flotation test results were obtained, with a majority comprised of client-owned dogs (3262; 69.52%), followed by research dogs (375; 8.00%), and shelter dogs (122; 2.60%). Samples from 976 (20.80%) dogs were positive for at least one parasite, and co-infections of two or more parasites were found in 3.82% (179/4692) of the samples. The five most commonly detected parasites were: Giardia sp., (8.33%; 391/4692), Ancylostomatidae (5.63%; 264/4692), Cystoisospora spp. (4.35%; 204/4692), Toxocara canis (2.49%;117/4692), and Trichuris vulpis (2.43%; 114/4692). Various other internal parasites, including gastrointestinal and respiratory nematodes, cestodes, trematodes, and protozoans were detected in less than 1% of samples. CONCLUSIONS: These data illustrate the importance of parasite prevention, routine fecal screening, and treatment of pet dogs. Additionally, pet owners should be educated about general parasite prevalence, prevention, and anthelmintic treatment regimens to reduce the risks of environmental contamination and zoonotic transmission.

Stray Mexico origin cattle captured crossing into Southern Texas carry Babesia bovis and other tick-borne pathogens.

Cattle fever ticks, Rhipicephalus microplus and R. annulatus have been eradicated from the United States and inspectors from the U.S. Department of Agriculture (USDA), Animal Plant Health Inspection Service (APHIS), Cattle Fever Tick Eradication Program (CFTEP) monitor the quarantine zone along the Texas border to prevent the introduction of livestock carrying cattle fever ticks from Mexico. Stray livestock apprehended by CFTEP in the zone are checked for ticks and tested for infectious disease-causing pathogens but are not evaluated for evidence of infection with tick-borne pathogens. We tested blood samples collected from stray cattle by CFTEP inspectors for evidence of infection with tick-borne pathogens. As a comparison group representing U.S. resident cattle, we tested blood samples that had been sent to the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) for unrelated testing. Both sets of blood samples were evaluated using the same specific and broad-spectrum PCR assays. For the border cattle the overall prevalence of infection with one or more tick-borne pathogen was 58.5 % (79/135) with many co-infections, including 30 cattle positive for Babesia bovis and/or Babesia bigemina (22.2 %) and 77 cattle positive for Anaplasma marginale (57 %), three of these animals were also positive for Borrelia theileri. No resident cattle represented by the TVMDL samples were infected with either of the Babesia spp., or with Borrelia theileri, but three were positive for Theileria orientalis and 7.3 % (7/96) were positive for A. marginale. These data show that cattle originating in Mexico have a higher prevalence of infection with tick-borne pathogens relative to resident U.S. cattle and specifically, a proportion are infected with bovine Babesia, which is absent from U.S. cattle populations. Consequently, these stray cattle may be a reservoir of tick-borne pathogens and if populations of Boophilus ticks become reestablished in areas where they had previously been eradicated, could pose a significant risk to the U.S. Cattle industry.

Systemic mastocytosis with subcutaneous hemorrhage and edema in a Greyhound dog: case report and review of diagnostic criteria.

Systemic mastocytosis, characterized by infiltration of multiple organs by neoplastic mast cells, is a well-described entity in human medicine with specific criteria for diagnosis, but is ill defined in veterinary literature. Hemostatic disorders are reported in humans affected by systemic mastocytosis but have not been well described in veterinary literature. A 5-y-old, spayed female Greyhound dog had a 1-mo history of progressive ventral cutaneous edema, hemorrhage, and pain. Cytology of an antemortem aspirate from the subcutis of the ventral abdomen was suggestive of mast cell neoplasia, but no discrete mass was present. The dog was euthanized and submitted for autopsy; marked subcutaneous edema and hemorrhage were confirmed. The ventral abdominal panniculus and dermis superficial to the panniculus carnosus were infiltrated by a dense sheet of neoplastic mast cells. The neoplastic cells contained toluidine blue-positive granules and formed aggregates within the bone marrow and several visceral organs, including the liver, spleen, heart, and kidney. Diffuse edema and hemorrhage is an unusual presentation of mast cell tumors in dogs. Antemortem tests, including complete blood count, coagulation profile, and viscoelastic coagulation testing, were suggestive of a primary hemostatic defect. We discuss here the diagnostic criteria used in humans, how these can be applied to veterinary patients, and the limitations of the current diagnostic framework.

Cytologic appearance of hibernoma in two dogs.

Hibernomas are rare benign tumors of brown fat (adipose tissue) that have been reported in several different species. The cytologic characterization of these tumors has not been described in dogs. In this case report, we describe two dogs with hibernomas, focusing on the cytologic appearance of these unique neoplasms. Both cytologic specimens were highly cellular and predominated by vacuolated neoplastic cells with no evidence of concurrent inflammation. The cells contained a moderate to large number of variably sized cytoplasmic vacuoles, with occasional, irregularly shaped pink granular material. Most cells contained a single nucleus; however, cells displayed moderate anisokaryosis. A biopsy with histologic examination was performed in both cases, confirming the cytologic suspicion of hibernoma. Immunohistochemistry revealed that both tumors were positive for UCP1 and vimentin, and negative for cytokeratin. Hibernoma is an important differential diagnosis in dogs with conjunctival and periocular swellings that exfoliate numerous, mildly atypical, vacuolated cells.

Molecular prevalence and ecoregion distribution of select tick-borne pathogens in Texas dogs.

Tick-borne diseases (TBD), caused by borrelial, rickettsial and babesial pathogens, are common across the United States and can cause severe clinical disease in susceptible hosts, such as domestic dogs. However, there are limited TBD molecular epidemiological reports for dogs in Texas, and none for the non-Lyme borrelial pathogen responsible for causing tick-borne relapsing fever (TBRF). Therefore, data to support the prevalence of TBRF in the canine population is inadequate. This study aimed to characterize the molecular prevalence of 11 causative agents responsible for three TBD groups within domestic dogs with an emphasis on pathogen distribution within Texas ecoregions. A total representative number of 1,171 whole-blood samples were collected opportunistically from two Texas veterinary diagnostic laboratories. A layerplex real-time PCR assay was utilized to screen the dog samples for all 11 pathogens simultaneously. The overall molecular infection prevalence of disease was 0.68% borrelial, 1.8% rickettsial and 0.43% babesial pathogens, for a TBD total of 2.73% across Texas. Higher molecular prevalence was observed when analysed by ecoregion distinction, including 5.78% rickettsial infections by Ehrlichia canis and Anaplasma platys in the Rolling Plains ecoregion, and an average of 1.1% Borrelia turicatae and 1.0% Babesia gibsoni across detected ecoregions. To our knowledge, our findings indicate the first molecular detection of A. platys in Texas, and the first report of coinfections with E. canis and A. platys in dogs of Texas. The zoonotic concerns associated with TBDs, in conjunction with dogs' implication as an effective sentinel for human disease, highlight the importance of characterizing and monitoring regions associated with active infections in dogs. Surveillance data obtained from this study may aid public health agencies in updating maps depicting high-risk areas of disease and developing preventative measures for the affected areas.

Molecular identification of Ehrlichia ewingii in a polyarthritic Texas dog.

An 8-year-old, neutered male, Golden Retriever presented for bilateral carpal joint effusion. A complete blood count revealed mild leukopenia and marked thrombocytopenia. Samples were sent to the Texas A&M Veterinary Medical Diagnostic Laboratory for blood smear review and serologic testing for tick-borne diseases. Numerous morulae were observed within neutrophils, and antibodies against Ehrlichia canis were detected at a 1:512 dilution via the indirect fluorescent antibody (IFA) test. As neutrophilic morulae are morphologically indistinguishable between Ehrlichia ewingii and Anaplasma phagocytophilum, and genus-wide cross-reactivity is possible with serologic testing, additional molecular testing was performed. Quantitative real-time polymerase chain reaction (qPCR) followed by conventional PCR and Sanger sequencing were performed on serum identified with E ewingii as the sole disease-causing agent. Three months after diagnosis and treatment, no morulae were found, molecular testing for E ewingii detected no DNA, and convalescent IFA testing demonstrated a continued detection of antibodies for E canis at a 1:512 dilution. To the authors' knowledge, this is the first reported case of E ewingii confirmed with molecular diagnostics in a Texas dog. The zoonotic transmission potential of E ewingii should be noted as Texas supports competent tick vectors, and dogs represent effective sentinels for human ehrlichiosis. This report also highlights the utility of molecular diagnostics when serologic and microscopic evaluations are not sufficient in providing the species-level identity of a causative agent.

Novel real-time PCR assays for genomic group identification of tick-borne relapsing fever species Borrelia hermsii.

Borrelia hermsii is a non-Lyme borreliosis pathogen that is responsible for causing tick-borne relapsing fever in humans and animals in the western United States. B. hermsii has been described to encompass two divergent genomic groups, GGI and GGII, which have been suggested to maintain a unique geographical distribution and potential range of pathogenicity. Though the genomic groups have been extensively documented in the literature, a real-time PCR tool for identifying these genomic groups is lacking. This study describes the development and validation of two flaB-based quantitative real-time PCR assays for differentiating between the two genomic groups of B. hermsii while also maintaining specificity against other closely related Borrelia species. The diagnostic specificity of the assays were evaluated using a large panel of various Borrelia species, including a collection of 22 B. hermsii culture isolates purified from various hosts. The high sensitivity and specificity of the assays provide a useful tool for supporting future studies aimed at evaluating the geographical distribution as well as potential intraspecies pathogenicity within arthropod vectors and mammalian hosts.

Serological detection of Tick-Borne Relapsing Fever in Texan domestic dogs.

Tick-Borne Relapsing Fever (TBRF) is caused by spirochetes in the genus Borrelia. Very limited information exists on the incidence of this disease in humans and domestic dogs in the United States. The main objective of this study is to evaluate exposure of dogs to Borrelia turicatae, a causative agent of TBRF, in Texas. To this end, 878 canine serum samples were submitted to Texas A&M Veterinary Medical Diagnostic Laboratory from October 2011 to September 2012 for suspected tick-borne illnesses. The recombinant Borrelial antigen glycerophosphodiester phosphodiesterase (GlpQ) was expressed, purified, and used as a diagnostic antigen in both ELISA assays and Immunoblot analysis. Unfortunately, due to significant background reaction, the use of GlpQ as a diagnostic marker in the ELISA assay was not effective in discriminating dogs exposed to B. turicatae. Nevertheless, immunoblot assays showed that 17 out of 853 samples tested were considered to be seropositive, which constitutes 1.99% of all Texas samples tested in this study. The majority of positive samples were from central and southern Texas. Exposure to TBRF spirochetes may be seasonal, with 70.59% (12 out of 17) of the cases detected between June and December. In addition, 2 out of the 17 sero-reactive cases (11.76%) showed reactivity to both B. burgdorferi (causative agent of Lyme disease) and B. turicatae (a causative agent of TBRF). This is the first report of TBRF sero-prevalence in companion animals in an endemic area. Our findings further indicate that B. turicatae is maintained in domestic canids in Texas in regions where human disease also occurs, suggesting that domestic dogs could serve as sentinels for this disease.

Agreement between microscopic examination and bacterial culture of bile samples for detection of bactibilia in dogs and cats with hepatobiliary disease.

OBJECTIVE To evaluate the agreement between results of microscopic examination and bacterial culture of bile samples from dogs and cats with hepatobiliary disease for detection of bactibilia. DESIGN Cross-sectional study. ANIMALS 31 dogs and 21 cats with hepatobiliary disease for which subsequent microscopic examination and bacterial culture of bile samples was performed from 2004 through 2014. PROCEDURES Electronic medical records of included dogs and cats were reviewed to extract data regarding diagnosis, antimicrobials administered, and results of microscopic examination and bacterial culture of bile samples. Agreement between these 2 diagnostic tests was assessed by calculation of the Cohen κ value. RESULTS 17 (33%) dogs and cats had bactibilia identified by microscopic examination of bile samples, and 11 (21%) had bactibilia identified via bacterial culture. Agreement between these 2 tests was substantial (percentage agreement [positive and negative results], 85%; κ = 0.62; 95% confidence interval, 0.38 to 0.89) and improved to almost perfect when calculated for only animals that received no antimicrobials within 24 hours prior to sample collection (percentage agreement, 94%; κ = 0.84; 95% confidence interval, 0.61 to 1.00). CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that agreement between microscopic examination and bacterial culture of bile samples for detection of bactibilia is optimized when dogs and cats are not receiving antimicrobials at the time of sample collection. Concurrent bacterial culture and microscopic examination of bile samples are recommended for all cats and dogs evaluated for hepatobiliary disease.