Beware of toxoplasmosis in venison


A recent study in the journal EcoHealth connects white-tailed deer and free-roaming cats to the disease toxoplasmosis. In an email, lead author Gregory Ballash, Ohio State University’s Department of Veterinary Preventive Medicine, explained that cats are the definitive host of Toxoplasma gondii, the protozoan parasite that causes toxoplasmosis.

Toxoplasma reproduces only in cats, but can infect any warm-blooded mammal, including deer and humans. Cats release millions of eggs into the environment through their feces, where they remain infectious for up to 18 months. Where wild and feral cats occur, these infectious eggs are abundant and contaminate the environment. Deer pick up the eggs from the soil where deer and cats coexist.

In the EcoHealth field study in Northeast Ohio, Ballash and colleagues found that more than 50 percent of 444 deer and 200 cats tested positive for toxoplasma. Deer are most likely to be infected in areas with abundant free-roaming cat populations.

Humans and toxoplasma

According to the Centers for Disease Control and Prevention, more than 60 million people in the United States carry the toxoplasma parasite. Symptoms vary, but young children, infants infected during pregnancy and people with weakened immune systems are at greatest risk. Human infections have been linked to miscarriages, memory loss and even death. Ballash continued, humans can become infected by consuming undercooked venison that contains toxoplasma tissue cysts.

Cooking venison to appropriate temperatures is the safest way to prevent foodborne transmission. Kitchen hygiene is also important to prevent cross-contamination from venison to other food such as uncooked vegetables or fruits.

To avoid toxoplasmosis, the CDC recommends cooking venison to at least 145 degrees Fahrenheit for whole cuts of meat and 160 degrees F for ground venison. The temperature should be measured by a food thermometer placed in the thickest part of the meat, then allowing the meat to rest for three minutes before carving.

Ballash adds, consuming any meat product carries an inherent risk of getting a foodborne infection, and venison is no different. However, this should not deter individuals from consuming venison because cooking venison to the correct internal temperature and proper kitchen hygiene (washing contaminated surfaces and separating utensils used for meat from other foods) will allow safe consumption of venison, and meat in general.

Indoor cats

The cat-deer-toxoplasma connection is yet another reason that all cats should be kept indoors. It is unlikely that indoor cats will eat infected mice or other small mammals, so their risk of infection is very low. But all cat owners should be careful when disposing of cat litter or working in soils that cats frequent. Always wash hands thoroughly after working outdoors or handling cat litter. This is especially true for children responsible for cleaning the litter box.

Suet recipe

Last week I referred readers to my website for my favorite suet recipe, but based on some mail I’ve received, not everyone has internet access. So here it is. Martha Sargent’s No-melt Peanut Butter Suet comes from an Alabama friend, who shared it with me years ago.


  • One cup crunchy peanut butter (use a cheap generic type)
  • Two cups of quick cook oats
  • Two cups of cornmeal
  • One cup of lard (available in bulk in most grocery stores)
  • One cup of white flour
  • 1/3 cup sugar


  1. Melt and blend the lard and peanut butter in a large pan over low heat, and then stir in the remaining ingredients. Pour into a flat container about 1 1/2 inches thick.
  2. Place in the freezer for about an hour, then cut blocks sized to fit your suet basket.
  3. Place a piece of wax paper between the blocks, then stack, and store in the freezer. It keeps for months.
  4. For more suet, just double or triple the recipe. And to make the recipe even more irresistible, add a handful of sunflower chips, peanuts, and/or raisins.


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Scott Shalaway, who holds a Ph.D. in wildlife ecology from Michigan State University, writes from his home in rural West Virginia. A former faculty member at Oklahoma State University and the University of Oklahoma Biological Station, he has been writing a weekly nature column for newspapers and freelancing for magazines since 1986. He can be heard on Birds & Nature from 3-4 p.m. Sunday afternoons on 620 KHB Radio, Pittsburgh, or live online anywhere at, or on the Tune-In radio app. Visit his website at or contact him directly at or 2222 Fish Ridge Road, Cameron, WV 26033.



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