Reptile & Amphibian Forums

I am trying to switch my Red Tail from live rats that I kill myself to frozen rats. So this past weekend I went to a pet store that specializes in reptiles. I asked if they carry frozen rats and the young sales associate asked what it was for. I told him my boa, and he said that I shouldn't feed frozen prey to snakes because it will "rot" their stomach from the inside out and eventually kill them, even if they are thawed properly all the way through. Does any one know if this is true or not?

No, they will not cause any stomach problems, frozen rats are just frozen meat, nothing harmful in that. If the frozen prey has been properly thawed (all the way through, no cold spots) then you'll have no problems. From what I've heard, frozen prey that is not completely thawed can cause health issues due to the ice or cold spots - regurging and dropping the snake's body temperature, which can lead to other problems. I've been feeding frozen prey for roughly 2 years now, maybe more. Other breeders and keepers I know have been feeding frozen for much longer. That sales person, like so many we hear of in pet stores, is seriously uninformed. Personally I would call the store manager and let them know an employee is impacting sales by relaying false information.

The biggest drawback to feeding a diet of all frozen rodents is the loss of nutrients, with folic acid being the big one. Folic acid is needed for the neurological pathways needed in basic motor control. The folic acid is lost due to the cells bursting when frozen. Since animals have lots of water in tissue cells, and as it freezes water crystals form as sharp knife like projections growing in size thus bursting the cells. This is one thing the cryogenics researchers are still trying to work with. It is theorized that brewers yeast can help to counteract the effect by replacing some of the lost folic acid back into the animals system. We feed exclusively fresh killed food that we produce for peace of mind. Here is a little more info on frozen meats.

Warning------The following may put you to sleep, but we feel it is good information for everyone to read not only for herps.

Richter and al-Sheddy (1990)report that high microbial counts in meat may be caused by improper thawing.Delays in freezing,slow rates of freezing,and inadequate freezer temperatures also affect quality. The physical,chemical,and biological changes that occur during freezing are complex and not fully understood (Desrosier 1978). Changes in flavor,color,and texture,as well as losses in nutrients occur fairly rapidly at temperatures above 9 ° (48 °.Because of the physical nature of meat, the method of freezing affects quality and nutrient loss upon thawing.Meat frozen rapidly to 0 ° (32 °has less "drip " (nutrient loss due to water loss from cells)when thawed. Length of time for meat to freeze is dependent on temperature of the freezing chamber, temperature of food upon entering the freezing chamber,and type,shape,and size of packaging (Desrosier 1978). Freezing kills some microbes. Those not killed will grow upon thawing (Frazier and Westhoff 1988).Although most microorganisms do not grow well at temperatures below 0 ° (32 °,some yeasts and molds can grow in unfrozen foods with temperatures as low as 9 ° (48 °.Growth of microorganisms can be greatly influenced by the temperatures at which the food is thawed (Desrosier 1978). Some nutrients can be affected by freezing.Although there is little change in the nutritive value of proteins, they can be denatured by freezing, altering the appearance and quality of the product. Proteolysis can occur while animal tissue is frozen if the enzymes are not inactivated.Freezing only slows enzyme activity,which is usually optimum at higher temperatures (Desrosier 1978).
At a temperature of about 2 ° (36 °there is a reduction in rancidity of fatty tissue (Desrosier 1978). Rancid fats cause a lower nutritive value.Antioxidants,such as vitamin E,are utilized during fat breakdown and are therefore deficient in rancid fats (Oftedal and Boness 1983).Also, processing of foods,including the exposure of tissue to air and heat,allows oxidation and destruction of vitamins and the buildup of microbes (Desrosier 1978). Freezing temperatures may destroy parasites (Desrosier 1978).Molds and yeasts may grow at freezing or slightly below freezing temperatures (Frazier and Westhoff 1988). Some bacteria in meat (Salmonella spp.,Escherichia coli ,and Staphylococcus acromonas )can survive freezing temperatures and will resume growth when thawed (Frazier and Westhoff 1988,Richter and al- Sheddy 1990).At temperatures of 3 ° (37 °or above, spores of E.clostridium botulinum can survive, grow,and produce toxins (Frazier and Westhoff 1988)

Central Florida Reptile Breeders

due to freezing, the same is true of frozen meats for human consumption. The clerk is still incorrect...frozen prey will not 'rot' the snake's stomach strictly due to it being frozen/thawed prey. If improperly thawed, allowing bacteria growth to peak, yes, I'll agree to the potential for illness but not that it's intrinsic to the frozen meat itself.