Bacillus anthracis is a spore-forming, facultative anaerobic, gram positive rod that is the causative agent of anthrax.  Spore formation occurs when the vegetative form of the bacteria, found within the animal, is exposed to air upon the animal’s death. The spores then settle into the ground under and around the carcass. The spores are highly resistant […]

A 10-year-old female quarter horse flipped over backwards onto its head after being spooked. Following the incident, the patient made multiple attempts to rise but would flail and progressed to having multiple seizure episodes and bilateral epistaxis. Due to the grave prognosis and perceived likelihood of potential traumatic injury to the brain and spinal cord, […]

Beetles found in a new batch of alfalfa hay were submitted to the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) for identification. TVMDL’s toxicology section can identify toxic and non-toxic beetles using microscopic examination. The beetles submitted were identified as Tiger beetles (Cicindelidae sp.) (Figure 1). Tiger beetles are characterized by having large, carnivorous mouth parts […]

Click to Skip Tips for Collecting Needle and Core Bone Biopsy | Tips for Submitting and Entire Leg | Clinical History Submitting samples of bone for histopathological analysis is essential to definitively diagnose most primary bone diseases (e.g., osteosarcoma). However, collecting representative bone biopsy specimens and their histopathological interpretations presents several challenges for the clinician […]

Click to Skip: Bone Marrow Aspirate Procedure | Bone Marrow Core Biopsy Procedure Bone marrow testing is used to diagnose and monitor bone marrow diseases and CBC abnormalities. Full evaluation of bone marrow requires a CBC the day of the bone marrow collection, bone marrow aspiration, and a bone marrow core biopsy.  Indications for bone […]

When horses ingest the cantharidin toxin through hay or alfalfa contaminated with “blister” beetles, the outcome is often fatal. Toxicosis occurs rapidly; as little as four grams of dried beetles may contain fatal levels of cantharidin. Cantharidin is extremely toxic and fast-acting, quickly affecting a horse’s ability to function. All blister beetles carry cantharidin and […]

Four partial biopsies of an infected hot brand skin lesion from a Quarter Horse stallion were submitted in 10% buffered formalin to the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) for histologic diagnosis. No clinical history was submitted. Histologically, the biopsies consisted of haired skin including epidermis, dermis, and subcutis. Two different lesions were identified […]

The Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) Analytical Chemistry Section has the ability to offer toxicology and drug testing services to livestock producers and practitioners. The lab offers a variety of tests to aid in diagnosing many conditions of both toxic and nutritional origin. Our highly trained and qualified personnel use state-of-the-art analytical techniques […]

Many Texans rely upon the weather for a variety of reasons. From crops to cattle, Texans are often at the mercy of Mother Nature. Although droughts can have a dire impact on animal health, floods can also contribute to widespread issues among animal owners. Excessive rainfall can contribute to mosquito-borne diseases, toxic plants, dermatologic conditions, […]

The Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) offers digital cytology to account-holding clients. Digital cytology provides rapid evaluation of photos taken with microscope cameras or smart phones. This service provides an official report and cytologic interpretation, typically within one hour of submission (during business hours). To enhance this service, submission of glass slides for […]

The Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) offers digital toxicology to account-holding clients. Digital toxicology provides evaluation of photos taken with smart phones, or other digital cameras, and an official report identifying items photographed (where possible) including an attachment with labeled photos for later reference – an advantage over shipping items to the laboratory […]

A 5-year-old Andalusian stallion was presented for necropsy at the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) after being euthanatized due to a history of colic, profuse nasogastric reflux, non-response to treatment, and poor prognosis. Upon opening the abdomen at necropsy, the stomach was found to be severely distended with gas. The duodenum and proximal […]

A 3-year-old, male Quarter horse became ataxic and kept falling over, eventually being unable to rise. The horse ultimately had to be euthanized. The onset and severity of clinical signs occurred over a two-hour period. Serum was submitted to the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) for an Equine Encephalitis Panel and corn and […]

With over 800,000 tests run annually, TVMDL encounters many challenging cases. Our case study series will highlight these interesting cases to increase awareness among veterinary and diagnostic communities. Infertility in the mare results in significant economic losses to the horse industry every year.  The causes are varied and include uterine infections and uterine inflammation, hormonal […]

A 23-year-old American Quarter Horse mare was presented to a veterinarian for chronic coughing and exercise intolerance. On physical examination, wheezing was heard during auscultation. Complete Blood Count (CBC) and chemistry profiles were unremarkable. Respiratory endoscopy revealed mildly increased airway mucus. A bronchoalveolar lavage (BAL) was performed and fluid was submitted to TVMDL for cytologic […]

Hair Sample Collection Preparation The collection of hair samples should be undertaken by a competent individual within a secure, contamination-free facility. The purpose of hair sampling is to collect a usable cross-section of hair to test for prohibited substances. Collection Supplies Collecting the Sample Samples should be stored at room temperature and protected from direct […]

A two-year-old, male, intact miniature donkey had a wound on the mandible that was associated with a large firm mass. Radiographs of the lesion showed large osseous spicules emanating from the parent bone. Additionally, the submitting veterinarian commented that the mass continued to grow.  A superficial edge biopsy from the surface and a deeper bone […]

This article was originally published in AgriLife Today. A Texas A&M Veterinary Medical Diagnostic Laboratory, TVMDL, expert advises horse owners to take proactive steps to protect their horses after cases of eastern equine encephalitis, EEE, infections in two Houston County horses were confirmed. These are the first reported cases of the mosquito-borne illness in Texas, according to […]

Recently, the brain of a 7-year-old Quarter horse mare was sent to the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) for histopathology. This horse was reported to have clinical neurological signs. Prior to histologic examination, the brain was determined to be rabies-negative by the Texas Department of State Health Services. Histologically, vessels in the brain […]

Blood was collected during a routine pre-purchase examination on a horse and submitted to the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) in College Station for drug testing. Serum was extracted using methyl tert-butyl ether (MTBE) and analyzed by liquid chromatography – tandem mass spectrometry (LC-MS/MS). Romifidine was confirmed in the sample by LC-MS/MS. Romifidine […]

Hundreds of samples arrive daily at the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) for testing. Testing accuracy often depends on the submission of the proper specimen for the assay, particularly for molecular diagnostics. With the proper sample, we can perform the assay and provide the most timely and accurate results without delay.  While results […]

Hundreds of samples arrive daily at the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) for testing. Testing accuracy often depends on submission of the proper specimen for the assay, particularly for molecular diagnostics.  To ensure the appropriate sample is submitted for molecular diagnostics at TVMDL, please consult the website for specific details associated with the […]

A forensic or legal necropsy as defined by the purposes of the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) is a necropsy done to attempt to determine the cause of death in cases where the death is known or suspected to be non-natural, there are suspicious circumstances, or there is evidence of foul play. They […]

Fumonisin B1 is the most prevalent of several fumonisin mycotoxins (B1, B2, B3) produced by Fusarium molds in corn. Corn contamination can occur at very high levels when permissive environmental conditions coincide with vulnerable points in corn kernel production. Equine Leukoencephalomalacia (ELEM) Horses and other equids, as well as rabbits, are the most fumonisin-sensitive species. […]

Vaginal/uterine discharge was submitted to the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) in College Station from an eight-year-old Warmblood mare for culture and a cytologic evaluation. Cytologically the discharge consisted of large numbers of degenerate neutrophils and marked numbers of yeast. The neutrophils were actively phagocytizing the yeast. There were no bacteria identified. The […]

The Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) was contacted by a client who was concerned a group of horses had potentially consumed gopher bait containing an anticoagulant (diphacinone) as the toxic agent. Providing treatment for large animals with the antidote for anticoagulant intoxication can be challenging, therefore the suggestion was made to submit samples […]

Anthrax is caused by a gram positive, rod-shaped bacteria called Bacillus anthracis. This is a spore forming bacteria that can persist in dry, alkaline soil of endemic areas such as southwest Texas. Cattle, sheep, goats, deer, and horses are more susceptible to infection than pigs, birds and carnivores, like dogs and cats. In herbivores, anthrax […]

Tissue samples from two ear masses on a 3-year-old American Quarter Horse were submitted to the Texas A&M Veterinary Diagnostic Lab (TVMDL) in College Station for histopathology and culture. Masses from both ears were histologically similar, consisting of severe, chronic, pyogranulomatous dermatitis. There was formation of discrete pyogranulomas with central aggregates of Splendore-Hoeppli material and […]

Diagnosing animal diseases frequently requires a veterinarian or a technician to collect specimens in the field. This can be difficult without having the right tools on hand. For these occasions, the Texas A&M Veterinary Medical Diagnostic Laboratory suggests assembling a necropsy field kit. The kit should include the following tools and materials, all of which […]

Prior to diagnostic testing, it’s important to determine what factors would lead to the most comprehensive assessment of an animal’s condition. Each case must be evaluated individually in order to establish the most practical diagnostic testing route.  Collection Guidelines What is an ideal serum sample? Since most serologic testing utilizes serum, blood should be collected […]

The Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) offers a variety of diagnostic tests that may be used as part of the breeding soundness examination of a mare. While this handout discusses bacterial culture, TVMDL also offers a uterine biopsy and cytology service.  Uterine culture is one of the more frequently requested tests to assess […]

Gastrointestinal, GI, parasites bring serious concern to equine health. Among the various types of parasites includes the most common nematodes from the Strongylidae family. In the last two years, the Texas A&M Veterinary Medical Diagnostic Laboratory, TVMDL, has detected parasites in approximately 49% of equine fecal samples submitted for parasitology testing. Of this group, 45% […]

Punch biopsies of an ulcerated plaque in the nasal mucosa of a male-castrated, 12-year-old, Quarter horse were submitted to the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) in 10% buffered formalin for histopathologic examination. History noted that the ulcerated plaque was a squamous cell carcinoma or an infection. Histologically, there was no evidence of neoplasia […]

Most known information on Corynebacterium pseudotuberculosis, or pigeon fever, does not reflect current disease trends. In recent years, the disease that was once considered endemic in California and dry, arid climates in the west has spread as far north as Washington state and has been reported in such eastern states as Kentucky and Florida.  Cases […]

A 7-year-old pastured mare suffered an acute onset of hemolytic anemia and hematuria. The blood drawn for analysis was hemolyzed and dark. The mare died about three hours after intravenous fluid therapy was begun. Whole blood, serum and a blood smear were submitted to the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) for evaluation. Clinical […]

Strangles is a highly contagious respiratory disease in horses caused by the bacterium Streptococcus equi subspecies equi. Horses of all ages can be affected by the infection, but younger horses are especially vulnerable. Although the mortality rate for strangles is low, the disease can develop into more complicated problems if untreated. In rare cases, the […]

Although there have been substantial advances in benchtop hematology instrumentation for veterinary species, manual evaluation of a blood smear remains a vital part of a complete blood count (CBC). At the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL), all CBCs include manual blood smear examination by a highly skilled clinical pathology technician, a clinical pathologist, […]

In January, an animal owner in northwestern Washington State contacted the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) regarding possible blister beetles on their property. Specifically, the animal owner was interested in measuring the amount of cantharidin in a sampling of the beetles. Cantharidin is a very potent blistering agent, causing colic, heart arrhythmias and […]

Fixed tissue samples from nostril masses of three horses were received at the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) for histopathologic examination. The animals were a 23-year-old Quarter Horse gelding, an 18-year-old Appaloosa mare, and an adult American Quarter Horse gelding of unspecified age. The histories provided with the specimens were brief, but described […]

The Texas A&M Veterinary Medical Diagnostic Laboratory’s (TVMDL) Analytical Chemistry Section offers a screen for the detection of beta-adrenergic agonist drugs, including albuterol, bambuterol, clenbuterol, ractopamine, and zilpaterol, in hair. Certain drugs bind to melanin in hair and can be detected months, and in some cases years, following drug administration. This provides horse racing regulators […]

The Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) performs numerous tests using serum. Proper collection, preparation, and packaging for transportation is imperative to obtaining a quality serum sample. Serum samples that arrive at TVMDL which are hemolyzed and/or lipemic may not be acceptable for testing. Accurate results start with an ideal sample. Ideal Sample Clear […]

Dermatology cases are one of the most common types of cases seen by general practitioners. A crucial diagnostic tool in these cases is the skin biopsy. They are indicated in cases that do not respond to normal therapy, pustular, or ulcerative disease, and suspected neoplasia.  Before Taking a Skin Biopsy Prior treatment should also be […]

A six-year-old mixed breed gelding experienced a sudden onset of neurologic signs including a stiff jaw, body tremors, dilated pupils, photophobia, and ataxia.  Symptomatic treatment was unsuccessful, and the horse was euthanized after becoming intractable.  The attending veterinarian performed a field necropsy and noted icterus, subcutaneous hemorrhages (attributed to trauma), acute pleural hemorrhage, agonal endocardial […]

Analytical Testing Analytical testing capabilities for drug testing have evolved significantly over the years. Historically, techniques such as thin layer chromatography (TLC), gas chromatography (GC) and gas chromatography – mass spectrometry (GC/MS) were used to detect drugs. More modern day tests include enzyme-linked immunosorbent assay (ELISA), high-pressure liquid chromatography (HPLC) and liquid chromatography – mass […]

Canine Diagnostic Testing Canine Basic Thyroid Panel (T4, TSH, Free T4)The two most frequent thyroid disorders in dogs are primary hypothyroidism and euthyroid sick syndrome (repressed pituitary-thyroid axis due to non-thyroid illness). Additionally, some medications can induce hypothyroxinemia in dogs (i.e. phenobarbital, sulfa drugs, glucocorticoids). Other variables that may affect T4 and TSH include diestrus, […]

Click to Skip: Autolysis | Cautery Artifact | Freezing Artifact | Crush Artifact | Sponge Artifact Pathologic artifacts are any structures or features that are not normally present in the living animal. Some are minor, easy to distinguish from normal or diseased tissue, and/or do not interfere with the pathologists’ ability to provide an accurate […]

Late summer is when the West Nile virus (WNV) poses the greatest threat to the health of horses in the United States. It’s important for veterinarians to educate horse owners concerning the prevention, detection and accurate diagnose of WNV. Yearly, TVMDL tests between 500 and 1,000 horses for West Nile virus. In 2016, TVMDL confirmed […]