Christine Navarre

Professor & Extension Veterinarian, School of Animal Sciences Louisiana State University

  • Baton Rouge LA

Dr. Navarre's clinical interests are in beef cattle preventive medicine.

Contact

Louisiana State University

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Biography

Dr. Navarre was in private practice in Texas following graduation from veterinary school. She joined the Food Animal Section at the Auburn University College of Veterinary Medicine Teaching Hospital in 1994 where she spent 11 years providing clinical service and teaching of food animal and camelid medicine and surgery. In 2005 she returned to LSU as the extension veterinarian.

Areas of Expertise

Beef Cattle Health
Food-Animal Welfare
Veterinary
Antimicrobial Stewardship
Livestock Management and Production
Animal Disease

Research Focus

Beef Cattle Health & Antimicrobial Stewardship

Dr. Navarre’s research centers on beef cattle health, antimicrobial stewardship, and food-animal welfare in Gulf Coast production systems. She combines field herd surveillance, clinical epidemiology, and producer education through LSU AgCenter outreach to craft evidence-based protocols that prevent disease, optimize drug use, and boost sustainable livestock productivity.

Spotlight

3 min

LSU Expert Christine Navarre on the Threat of New World Screwworms

The New World screwworm (NWS), also known as the primary screwworm, is the larvae of the fly Cochliomyia hominivorax. Unlike the larvae (maggots) of other flies that only feed on dead tissue, the NWS feeds on live tissue. This leads to more severe and potentially deadly consequences which threatens livestock and wildlife populations. Prior to their eradication form the United States, NWS were a major economic burden to the production of livestock, especially in the in the southwestern U.S. and Florida. The U.S. Department of Agriculture estimates that the U.S. livestock industry saves approximately $900 million a year as a result of NWS eradication. Other benefits of eradication and control are enhanced human and animal health and welfare and increased survival of endangered wild animal species. The NWS fly was eradicated from the U.S. in 1966 with the release of sterile male flies to control the population. This status is maintained through the Panama-U.S. Commission for the Eradication and Prevention of the Cattle Borer Worm (COPEG) which releases millions of sterile flies weekly along the Panama-Colombia border to create a barrier preventing the northward spread of screwworms. Due to these efforts, it is now found primarily in tropical areas of South America and some Caribbean Islands, including Cuba. In 2016 NWS were found in Key Deer in the Florida Keys. The source of the outbreak was never determined. Rapid recognition of the problem and response with the release of sterile flies quickly eradicated the problem but this incident illustrates the importance of remaining vigilant. In November, NWS was detected in Mexico near the Guatemala border. The USDA Animal and Plant Health Inspection Service (APHIS) has imposed immediate import restrictions on animal commodities from Mexico. They are also intensifying efforts to prevent the northward spread of NWS by collaborating with Mexican and Central American authorities and urging livestock producers along the southern U.S. border to monitor their livestock and pets for signs of NWS. Any suspected cases should be reported immediately. Clinical Signs NWS can infest any warm-blooded animal including livestock, pets, wildlife, birds and occasionally humans. Common sites of infestation are any fresh or old wounds, warts, tumors, tick bites and antlers in shedding. Wounds left from management procedures, such as dehorning, branding, ear tagging, tail docking and shearing, can become infested. The eyes, nose, vulva and prepuce are also vulnerable, as well as the umbilicus in newborn mammals. Animals infested with NWS may show the following signs: Presence of maggots in wounds or body openings Wounds with a foul odor, bloody drainage or white/cream-colored drainage (eggs) Depression, reduced appetite, weight loss Isolation and/or signs of discomfort, head shaking Fever and other signs of secondary infection Diagnosis and Reporting Maggots found on animals showing the above clinical signs should be sent to a veterinarian or veterinary diagnostic lab for identification to distinguish NWS larvae from other more common fly larvae. In Louisiana larvae can be sent to the Louisiana Animal Disease Diagnostic Laboratory (www.lsu.edu/vetmed/laddl). Larvae should be placed in 70% alcohol for submission to the diagnostic laboratory. It is very important to immediately report any NWS infestations to the Louisiana Department of Agriculture and Forestry. A reported case will not result in herd depopulation but will allow animal health officials to take steps to help you manage your animals and prevent spread. Early detection and rapid response are critical to controlling this parasite. Treatment Immediate veterinary care should be sought to remove larvae and properly treat with insecticides. Wound care is also important to speed healing and prevent reinfestation. Prevention Treatment of NWS can be difficult, and eradication is very costly, so prevention of infestations is essential. Adult NWS flies can travel up to 12 miles to lay eggs, and eggs can be transported by animals and people traveling from infested areas. This necessitates constant vigilance to ensure that reintroduction into the U.S. does not occur. Preventative steps include: Regularly inspect livestock and pets for cuts, wounds, scabs and tick infestations. Closely monitor the umbilicus of newborn livestock, vulva of females and prepuce of males. Use insect repellant and wound dressings to prevent fly strike. Report any unusual wildlife or bird deaths to the Louisiana Wildlife and Fisheries. Pay close attention to nasal passages and eyes for signs of larvae (maggot) infestation. Seek veterinary advice for immediate treatment of open wounds, including dehorning and castration sites and preventive use of topical and systemic insecticides. Review biosecurity plans with the farm or ranch veterinarian. Original article by the LSU AgCenter here.

Christine Navarre

Answers

How can livestock owners prevent New World Screwworm infestations?
Christine Navarre

Prevention is essential. Regularly inspect animals for wounds, use insect repellents, and seek immediate veterinary care for any open wounds or signs of infestation.

What should livestock owners do if they suspect an infestation of New World Screwworms?
Christine Navarre

It is very important to immediately report any New World Screwworm infestations to the Louisiana Department of Agriculture and Forestry. Early detection and rapid response are critical.

What makes the New World Screwworm more dangerous than other maggots?
Christine Navarre

Unlike the larvae of other flies that only feed on dead tissue, the New World Screwworm feeds on live tissue. This leads to more severe and potentially deadly consequences, threatening livestock and wildlife populations.

Education

Louisiana State University

DVM

1990

Texas A&M University

M.S.

1994

Accomplishments

Louisiana Veterinary Medical Association Ralph C. Cooper Veterinarian of the Year

2023

Food Animal Speaker of the Year, 95th Annual Western Veterinary Conference

2023

Louisiana Cattlemen’s Association Beef Quality Assurance Educator of the Year

2023

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Media Appearances

Four sustainable deworming tips to battle parasite resistance

Beef Magazine  online

2025-02-01

“We’ve been thinking about parasites in the short term for 30 to 40 years,” shared Christine Navarre, DVM, Extension veterinarian at Louisiana State University Agricultural Center. “Parasite resistance is a real concern. We must think about deworming in the short term and the long term; otherwise, we’ll be left with nothing to combat parasites.”

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Worming a way out of a parasite predicament

High Plains Journal  online

2024-03-29

“Until you have a major stressor, usually nutritional stress, that allows parasites to cause severe health or mortality problems, it’s not noticed,” said Dr. Christine Navarre, DVM, MS, DACVIM and Extension veterinarian at the Louisiana State University AgCenter. “They are costing us money from subclinical problems long before we recognize them.”

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'Vicious little suckers': Massive clouds of mosquitoes kill cows, horses in Louisiana after Hurricane Laura

USA Today  online

2020-09-11

The species of mosquito doesn’t transmit human diseases easily, Christine Navarre, an extension veterinarian with LSU AgCenter, told USA TODAY on Thursday.

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Articles

Livestock fatalities attributed to a massive attack of dark rice field mosquitoes (Psorophora columbiae) following Hurricane Laura

The Bovine Practitioner

2022

The objective of this case report is to characterize the sudden fatality of livestock associated with a massive attack of dark rice field mosquitoes (Psorophora columbiae) after the passage of Hurricane Laura in southwest Louisiana late August 2020. In 3 days, approximately 30 deer, 600 beef cattle, 100 sheep and 30 horses died following a brief history of weakness or, in most cases, no clinical signs prior to death. Several on-site visits were performed by veterinarians to evaluate animals and perform necropsies. Two deer were received for necropsy, and tissue samples from 1 bull and 1 horse were evaluated at the Louisiana Animal Diagnostic Disease Laboratory.

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Epidemiology and Control of Gastrointestinal Nematodes of Cattle in Southern Climates

Veterinary Clinics of North America Food Animal Practice

2020

Control of gastrointestinal nematodes (GIN) can have both economic and health benefits for cattle operations in the southern United States. In the past several decades, GIN control has relied almost exclusively on the use of anthelmintics. With the increase in anthelmintic resistance new strategies must be developed. Anthelmintic use should be minimized by integrating grazing management and a good herd health program into GIN control programs. This takes knowledge of GIN biology and epidemiology in the region (climate and weather) combined with specific information from the ranch.

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Animal Contact in Public Settings-Risk Awareness of Enteric Pathogens and Hand Hygiene Behaviors

Food Control

2018

Contact with animals in public settings can provide education and entertainment opportunities for both adults and children. However, outbreaks have been associated with human-animal interactions at state, region or county fairs, petting zoos, educational farms, etc. Those outbreaks not only raised a public health concern, but also had substantial medical, legal, and economic impacts. In this study, we assessed the risk awareness of enteric pathogens associated with animal contact in public settings. Participants were asked whether they recognize the risk of spreading enteric pathogens through specific animal contact behaviors such as petting animals with hands or eating around farm animals. The results showed that the self-reported risk awareness was 4.0 ± 1.2 out of a total score of 6, which indicated a poor risk awareness.

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Affiliations

  • American Association of Bovine Practitioners : Past President
  • North American Veterinary Community : Past President and Treasurer

Event Appearances

Impact of Recruitment and Retention of Food Animal Veterinarians on the U.S. Food Supply

CAST Webinar  Virtual

2020-04-06

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