Livestock export testing safeguards human and animal health internationally. Testing helps mitigate the spread of diseases and ensures international commerce is sustainable. The Texas A&M Veterinary Medical Diagnostic Laboratory, TVMDL, is the only laboratory in Texas authorized to perform testing that meets United States Department of Agriculture, USDA, and international requirements. “The goal of export […]

Each test description in the online test catalog lists the proper sample submission, including collection container and shipping instructions. Follow the chart below and submit the sample in the correct tube.  Serum Plasma or Whole Blood Zinc Trace Material

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 […]

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 […]

“Lympho” and “Cheesy gland” are common names used by livestock owners and veterinarians for caseous lymphadenitis (CL), a bacterial disease that affects small ruminants such as sheep and goats. A worldwide problem, CL is caused by Corynebacterium pseudotuberculosis and once endemic on a farm is difficult to eradicate.  Primarily a disease of economic importance in […]

TVMDL maintains two laboratories dedicated to poultry diagnostics, located in Center, Texas and Gonzales, Texas. With the help of TVMDL, veterinarians can learn the best method to safely take a blood sample from poultry; the sample TVMDL uses to test for diseases like Avian Influenza, Salmonella or Mycoplasma. Veterinarians service the Texas animal health industry […]

TVMDL offers a range of tests to detect bovine viral diarrhea virus (BVDV). BVDV threatens the global cattle industry and negatively impacts producers in the form of decreased or lost productivity.  Despite vaccines and an array of diagnostic tests, this expensive disease continues to impact cattle producers. About 70 to 90% of all infections go […]

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) 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 […]

Vaccination programs are integral to the overall health and profitability of a cattle operation. Without vaccinations, diseases such as Bovine Respiratory Disease (BRD) and Bovine Viral Diarrhea (BVD) can decimate a cattle herd. The Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) team includes experienced veterinary diagnosticians available to help veterinarians and producers with a vaccination […]

Leishmania donovani/infantum Titer IFA testing was requested to assist in the clinical staging of a 6-year-old, neutered male, Spanish Galgo.   The dog was rescued in Spain and imported to the United States by a rescue group. Prior to importation, screening for Leishmania was negative.  Several months after being adopted, the dog presented with a peripheral […]

 In addition to managing two of the state’s poultry health programs, TVMDL helps keep Texas’ birds healthy through dedicated high-volume testing at the Center and Gonzales locations. In the five-year period between March 2019 and February 2024, TVMDL’s poultry laboratories performed over 1 million serologic tests for avian influenza, Mycoplasma, and Salmonella. While most of those tests […]

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 […]

Ten live 20-day-old, meat type chickens were submitted to the Texas A&M Veterinary Medical Diagnostic Laboratory’s (TVMDL) Center laboratory with a clinical history of leg problems and swollen tendons. At necropsy examination the birds exhibited outwardly deviated legs, moderately swollen hocks with an accumulation of a tannish, turbid exudate, and swollen gastrocnemius tendons. Serology for […]

Mycoplasmosis, caused by Mycoplasma gallisepticum and/or M. synoviae, is a group of bacterial diseases that are common maladies of backyard chicken flocks. Mycoplasma gallisepticum (MG) is the most common upper respiratory infection of backyard chicken flocks. The characteristic signs of naturally occurring infections are watery eyes, tracheal rales, nasal discharge, and coughing (Figure 1). Feed consumption is reduced, […]

Chlamydophilia psittaci is a bacterium that can be transmitted from pet birds to humans. In humans, the resulting infection is referred to as psittacosis and is also known as parrot disease, parrot fever, avian chlamydiosis, and ornithosis in avian species. This zoonotic disease can affect people after exposure to aerosolized organisms shed from the digestive or […]

The clinical pathology section at the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) received a digital cytology submission, with follow-up glass slides submission, of a prostate aspirate from a 7-year-old, male, small-breed canine. According to the referring veterinarian, the patient had a history of weight loss, diarrhea, and tenesmus. Rectal exam revealed an enlarged prostate. […]

A 10-year-old female dog presented to its veterinarian for routine exam, vaccination and heartworm testing. It was estimated that the dog had been off heartworm preventative for more than six months.  In-clinic testing revealed the presence of microfilariae on blood drop analysis, but was negative on an in-house antigen test. TVMDL received whole blood (EDTA) […]

An adult, mixed-breed dog was presented to their veterinarian for progressive lethargy, fever, and abdominal distension.  The dog had recently started treatment with prednisone and immunosuppressant medication for immune-mediated hemolytic anemia. Cytology of abdominal fluid revealed protozoal organisms. Abdominal fluid was submitted to the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) in College Station for Toxoplasma […]

A serum sample from a 1-year-old, male, American Staffordshire terrier was submitted to the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) in College Station for Brucella canis testing by the rapid slide agglutination test (RSAT – i.e. the card test). The medical history indicated the dog was febrile with a swollen left testicle and epididymis, slightly enlarged prostate, […]

We are all familiar with the saying that “cats are not small dogs”.  This is true when it comes to feline heartworm disease. While dogs are the typical host for Dirofilaria immitis, cats do become infected with heartworms, but confirming the disease antemortem can be quite difficult. Since cats typically have such a small worm burden […]

Anaplasmosis is a blood cell parasite of cattle with a worldwide distribution, but the disease is most common in tropical and subtropical areas. Anaplasma marginale is the most common organism involved in cattle, and it is transmitted through the bite of Dermacentor spp. ticks or tabanid flies, as well as through the use of blood-contaminated instruments. As a result, […]

Anaplasma marginale is a rickettsial bacterium that invades the red blood cells (RBCs) of ruminants, primarily cattle, and is considered the most common tick-borne infection of cattle.  In addition to tick vectors (Dermacentor spp., Rhipicephalus spp.), biting flies and blood-tainted fomites can also transmit this organism.  Anaplasma marginale is typically a clinical disease of adult cattle.  Calves infected with the organisms usually […]

Neospora caninum is a protozoal organism that is associated with abortion in cattle and the birth of weak calves.  Dogs are the definitive hosts for this organism, and the organism is spread in the feces of infected dogs.  Cattle become infected by ingesting the organism in feedstuffs contaminated with infected dog feces, but vertical transmission from […]

A veterinarian was called in to investigate the cause of abortion in a group of 60 well-managed 2-year-old brangus heifers. Four heifers aborted before the investigation was initiated. The herd is closed with a reportedly good biosecurity program and good nutrition. All of the animals are well-vaccinated. A fresh mid-term female fetus and fetal tissues […]