Category: Timely Topics

Submitted by Kelly Foster, DVM

Brucellosis is a rising concern in Hawaiʻi. Commercial swine and nearly all U.S. cattle herds are certified free, but Hawaiʻi’s feral swine are a persistent reservoir for Brucella suis, with documented spillover to cattle and ongoing risk to dogs, horses, and people — including hunters and the veterinary team. Feral swine here test positive at roughly three times the mainland rate; seroprevalence is highest on Maui, then Oʻahu, then Hawaiʻi Island, running about 10–25% on most main islands but staying low on Kauaʻi and Molokaʻi.

Feral swine are usually subclinical carriers. In symptomatic pigs, expect the classic reproductive picture — infertility, abortion, orchitis, and sometimes lameness — and note that there is no effective treatment and no vaccine, so an infected herd is a management problem rather than a treatment one. Cattle are most often exposed at the wildlife–livestock interface, so a brucellosis-positive cow should prompt questions about feral swine pressure on that property.

 Among companion animals, hog-hunting dogs are the main local concern, acquiring B. suis through contact with feral pig blood, urine, saliva, or tissue; it’s worth asking owners about hunting exposure when reproductive or nonspecific signs arise. B. canis is a separate entity, mostly relevant in breeding kennels and imported dogs.

Report suspected animal cases to the State Veterinarian. Human brucellosis is an urgent-category reportable condition in Hawaiʻi — exposed people should be reported promptly by phone to the Disease Outbreak Control Division (Oʻahu) or the District Health Office on the neighbor islands.  The feral reservoir isn’t going away, so surveillance, biosecurity counseling for cattle producers, and education for owners of hunting dogs remain the practical tools available.

What Is Brucellosis?

By Clayton Foster, MDAli‘i Health Center

• Brucellosis (brew-sell-OH-sis) is an infection caused by a bacterium (germ) called Brucella (brew-SELL-ah)
• Brucella is most often carried by pigs, goats, sheep and cows
• In Hawai‘i, wild pigs are most likely to carry Brucella, and pig hunters are at higher risk for getting brucellosis

How do I know if I have brucellosis?

Symptoms of brucellosis usually develop gradually over months. They may include:

• Persistent, unexplained fever
• Night sweats (soaking through clothes, sheets)
• Fatigue
• Muscle or joint pain
• Weight loss and poor appetite
• Headaches
• Pain and swelling in the testicles

How do I protect myself from brucellosis?

• If you are a hunter, at a minimum, you should wear arm-length waterproof gloves and avoid touching your face while field dressing
• Ideally, you should use waterproof gloves, eye protection and a mask when working with raw meat or body fluids from pigs, goats, sheep and cows
• If you are not a hunter, try to avoid contact with wild pigs. When cleaning up after wild pigs (removing a dead pig or repairing an area dug up by pigs, for example), use waterproof gloves and a mask
• Wash your hands with soap and water after handling raw meat or animal body fluids
• Cook all wild game thoroughly. Don’t eat any part of wild game raw
• Don’t feed raw animal parts to dogs. Dogs can get brucellosis and pass it to humans
• Don’t drink unpasteurized milk

How serious is brucellosis?

• Fortunately, brucellosis is rarely life-threatening. However, it does not go away on its own and requires a long course of antibiotics.
• If you think you might have brucellosis, ask your healthcare provider to test for it.

AVMA One Health article on brucellosis in humans and animals:
https://avmajournals.avma.org/view/journals/javma/261/4/javma.23.01.0033.xml

Submitted by Erika Sox, DVM, DACVIM

While we enjoy a low prevalence of Canine distemper virus in Hawaii, we do occasionally see cases here and it is important to remain vigilant to protect pets that may be vulnerable to infection.

Canine distemper is a highly contagious and often fatal viral disease of domestic dogs. Young puppies and unvaccinated adult dogs in high density housing are at highest risk. Acutely affected dogs commonly exhibit clinical signs of fever, lethargy and inappetence, respiratory signs (nasal discharge, coughing and labored breathing due to pneumonia), ocular signs (uveitis, KCS), and GI signs (anorexia, vomiting, diarrhea with or without blood). In severe cases, these may be followed by central neurologic signs such as clonic muscle tremors and seizures. Neurologic signs can take up to 3 months to develop and sometimes do so without other preceding clinical signs.  ^{1, 2}

Diagnosis is made by recognition of compatible clinical signs, along with confirmation through testing, ideally with quantitative RT-PCR which can distinguish between natural and vaccine-derived distemper. Testing is readily available through commercial veterinary labs but take several days to return, making clinical suspicion and proper handling of suspect cases imperative while awaiting results. Distemper should be considered in any febrile dog exhibiting symptoms of the GI, respiratory and neurological systems, especially if unvaccinated or incompletely vaccinated. ^{1, 2}

Distemper is shed in all body secretions of acutely infected animals and can be spread by both direct contact and via respiratory droplets. Isolation of both clinically ill and unvaccinated exposed dogs requires designated airspace and is crucial to preventing spread. The virus is fragile in the environment and readily killed with most cleaning agents but can survive at least several hours. Staff handling affected animals should wear appropriate PPE and practice proper hygiene protocols. Detailed isolation and clearance protocols are available online. ¹

There is no specific treatment or cure for Distemper virus. Treatment is generally supportive in nature and may include IV fluid therapy, anti-emetics, nutritional support, antibiotics for secondary infections, and anti-convulsant medications. ^{1, 2}

Vaccination is highly effective in preventing disease and is considered core for all puppies and dogs worldwide. Initial vaccination should be administered at 6 to 8 weeks of age and repeated every 2 to 4 weeks until 16 weeks of age, followed by a 1-year booster and then boosters every 3 years. ³

1. https://sheltermedicine.wisc.edu/library/resources/canine-distemper-cdv
2. https://www.merckvetmanual.com/infectious-diseases/canine-distemper/canine-distemper
3. https://www.aaha.org/resources/2022-aaha-canine-vaccination-guidelines/canine-distemper-virus-cdv/