ZOONOSES & VECTOR-BORNE DISEASES

 SIGNALMENT: ~6mth old neutered, male DSH  PRESENTING COMPLAINT: depression, feels “hot”, looks yellow, painful abdomen, and difficulty breathing. Cat began to act strange over the last week. Poor appetite, soft stool  Hx: indoor/outdoor cat, fully vaccinated, but not against FeLV and FIV, microchipped, often brings “gifts of mice” home

 PHYSICAL EXAM ◦ Temp: 104.1, HR:220, RR:40, shallow ◦ Depression ◦ Labored breathing ◦ Icteric mm, CRT: difficult to assess, >2sec ◦ Painful on abdominal palpation ◦ OS: signs of inflammation/uveitis

 CBC/SERUM CHEMISTRIES ◦ Elevated ALT. ALP, total bilirubin ◦ CBC WNL  FeLV/FIV Test ◦ Neg/Neg  Thoracic radiographs ◦ pneumonia  Paired titers  ELISA  FECAL ◦ See next slide

PNEUMONIA IS MOST COMMON IN NEONATALLY OR TRANSPLACENTALLY INFECTED CATS

THESE OOCYTS ARE DIFFICULT & RARE TO FIND

 TRANSMISSION: ◦ EATING CONTAMINATED MEAT  Ingestion of uncooked or undercooked meat is most likely the main route of infection in both cats and humans. ◦ Fecal – oral route ◦ Transplacental route  Cats are the definitive host for Toxoplasma gondii, but several animal can serve as intermediate hosts

CATS ONLY SHED OOCYTS IN THE FECES FOR 1-2 WEEKS THE OOCYTS BECOME INFECTIVE AFTER 1-5 DAYS TACHYZOITES ARE THE RAPIDLY DIVIDING STAGE OF THIS PARASITE THAT INFECTS THE TISSUES

 Clindamycin or Trimethoprim Sulfa for 2-3 weeks (may require 4 weeks treatment)  Prognosis is poor for young patients with hepatic or respiratory involvement, but good for the older cat with minimal or no signs of disease

 Exposure to Toxoplasma is common – 30%- 60% of adult humans are seropositive  Humans who are immunosuppressed should avoid contact with infected cats ◦ Have someone else clean the litter box  Avoid getting a new cat during pregnancy  Have antibody titers checked before getting pregnant ◦ Infection during the 1 st or 2 nd trimester can lead to birth defects  Cook all meat thoroughly  DON’T PANIC

 SIGNALMENT: 2yr old hound mix, intact male  PRESENTING COMPLAINT: dog is reluctant to move, has a stiff gait and seems painful, possibly ataxic, lethargic for the last week.  Hx: dog goes hunting with the owner about once month for the last 3 months. Dog is current on HW and flea preventive.

 PHYSICAL EXAM ◦ Temp: 103.5, HR: 116, RR:24 ◦ Mild mucopurulent ocular discharge ◦ Mm:pale pk, CRT: 2sec ◦ Animal is somewhat painful and ataxic ◦ Technician finds several ticks on the head and neck region

 CBC/SERUM CHEMISTRIES ◦ Anemia ◦ Leukocytosis w/left shift ◦ Thrombocytopenia ◦ Increased liver enzymes (ALT, ALP) ◦ Hypoproteinemia  SERUM TITERS – 4-fold increase between titers  TISSUE BIOPSY & FLUORESCENT STAINING

 DIAGNOSIS: TICK-BORNE DISEASE ◦ ROCKY MOUNTAIN SPOTTED FEVER – caused by Rickettsia rickettsii, a gram- obligate intracellular bacterial organism. ◦ This organism is carried in the saliva of the tick ◦ Clinical signs occur secondary to vasculitis of small blood vessels throughout the body. Other clinical signs include: edema, hemorrhage, seizures, coughing, vomiting, diarrhea, and more…

TICKS MUST BE ATTACHED TO HOST FOR 5-20 HOURS BEFORE TRANSMITTING INFECTIOUS ORGANISM

 TREATMENT ◦ Doxycycline ◦ Tetracycline ◦ Antibiotics only reduce the number of organisms, the animal must have a good immune system to eliminate them.

 Blood from infectious patients and from the tick can be infectious  Client should watch for signs of myalgia, headache, fever, or abdominal pain  Keep pets out of heavily infested tick areas and remove ticks quickly. Add tick prevention to the pet’s health regimen.  Incubation period is ~7days

 SIGNALMENT: 2yr old mixed breed, castrated male  PRESENTING COMPLAINT: lethargy, labored breathing, swollen neck, and swollen rt rear leg for about a week that seemed to resolve. About 6 weeks later developed bleeding from the nose, dyspnea, weakness, and “red spots” on the skin  Hx: outdoor dog, vaccinations current, on HW and flea preventive.

 PHYSICAL EXAM ◦ Temp: 103.8, HR: 120, RR: 28 ◦ Mild epistaxis ◦ Petechial hemorrhages ◦ Edema of the extremities ◦ Ticks found in the coat

 CBC/SERUM CHEMISTRY ◦ 25% have pancytopenia ◦ Anemia ◦ Thrombocytopenia ◦ Hyperglobulinemia  Blood smear  Observe morula in mononuclear cells  IFA

 DIAGNOSIS: TICK-BORNE DISEASE ◦ CANINE MONOCYTIC EHRLICHIOSIS, caused by Ehrlichia canis transmitted by the tick Rhipicephalus sanguineus ◦ After infection, E. canis causes acute, subclinical, and chronic stages of the disease ◦ ACUTE: lasts 2-4 weeks  Organisms multiplies in mononuclear cells  Mononuclear cells carry the organism to other organs including the lungs, kidneys, and meninges.  Vasculitis develops ◦ SUBCLINICAL PHASE  Few clinical signs if any ◦ CHRONIC PHASE  Bone marrow suppression  Bleeding tendencies

 CANINE GRANULOCYTIC EHRLICHIOSIS caused by Ehrlichia ewingii or Ehrlichia equi  Clinical signs associated with Ehrlichia ewingii infection: ◦ Fever ◦ Lethargy ◦ Lameness ◦ Muscle stiffness ◦ CBC: Thrombocytopenia ◦ Blood smear: morulae found in neutrophils ◦ Transmitted by the Amblyomma americanum tick

 CANINE GRANULOCYTIC EHRLICHIOSIS caused by Ehrlichia ewingii or Ehrlichia equi  Clinical signs of Ehrlichia equi infection: ◦ Fever ◦ Debilitating lethargy ◦ Anorexia ◦ CBC: thrombocytopenia ◦ Serum chemistries: Increased ALP ◦ Transmitted by the Ixodes dammini tick

 ANTIBIOTICS ◦ Doxycycline ◦ Tetracycline ◦ +/- blood transfusions  CLIENT INFO: ◦ Ticks can be a threat to pets and humans  Owners should avoid exposure to the blood of the tick ◦ The prognosis is good – Improvement often seen within 48 hours ◦ Check pets frequently for ticks and remove them when found.

 SIGNALMENT: 3yr old castrated male, English Setter  Hx: Moved from the northeast about 3 weeks ago. Prior to moving, owner pulled off a few ticks. Some of the areas have a red rash. In the last few days, the dogs is showing some lameness in the rear legs

 PHYSICAL EXAM ◦ Temp:103.5, HR: 100, RR: 24 ◦ Lethargic ◦ Swollen lymph nodes ◦ Wt. bearing lameness on the rt. Rear limb that seems to come and go.

 Radiographs ◦ Would be normal  ELISA TEST ◦ Lyme Positive  SYNOVIAL FLUID ANALYSIS ◦ Increased nucleated cells

LYME DISEASE is caused by the spirochete Borrelia Burgodorferi, passed by an Ixodes tick – The tick must be attached to the host for more than 48 hours Other clinical signs: – Fever – Anorexia – Lymphadenopathy – Chronic flare-ups – Myocardial abnormalities – Nephritis, esp in Labs

 ANTIBIOTICS ◦ Doxycycline is the treatment of choice for Borreliosis  Treatment may not completely eliminate the organism and some animals may remain permanently infected.  CLIENT INFO ◦ Vaccination is effective, unless dog has already been exposed. ◦ Animal infection should alert owners to the possibility of human infection from ticks in the area. ◦ Use a tick preventive regularly

 SIGNALMENT: 4 yr old, neutered male mixed breed.  HISTORY: owner saw dog playing with remains of a dead bat out in the back yard yesterday. The owner brings the dead bat into the clinic in a box and wants to know what to do. ◦ The dog is current on all vaccinations including rabies. He is on HW and flea prevention.

 The bat should be sent to a laboratory for analysis and rabies testing ◦ This requires a sample of brain tissue that has NOT been frozen. ◦ There is no antemortem test available  The dogs should be examined and handled carefully. He should be quarantined until the results from the bat are known.

 Rabies virus is spread through the saliva of an infected animal ◦ Bite, open wound, or mucous membranes  It travels up the nerve endings at the site of infection until it reaches the brain where it multiplies. It then enters the salivary glands where it can be transmitted through saliva. ◦ This may take 3-8 weeks

 RABIES IS CHARACTERIZED BY 3 STAGES: ◦ PRODROMAL STAGE – people are greatest risk during this phase. It is associated with behavior changes ◦ EXCITATIVE/FURIOUS STAGE- Infected animals may attack inanimate objects or appear hyperreactive. Some animals may appear “dumb” ◦ PARALYTIC STAGE - characterized by ascending paralysis of the hind limbs which may progress to respiratory paralysis and death. ◦ Death will occur between 2 and 10 days from the onset of clinical signs

 CLINICAL SIGNS: ◦ Behavioral changes ◦ Difficulty swallowing ◦ Voice changes ◦ CNS signs (seizures, ataxia) ◦ hypersalivation

 CLIENT INFO: ◦ Never handle wild animals that appear tame or friendly  Leave wild life in the wild ◦ Wear glove when examining a pet’s oral cavity, esp if rabies is suspected ◦ Promote vaccination against rabies ◦ If your pet bites someone, it must be quarantined for 10 days to observe for signs of clinical rabies ◦ Vaccinated animals exposed to a rabid animal should be revaccinated and observed for 90 days.