The Birds and the Bees…..

downloadAs many shelters have encountered, hoarding situations are often not limited to cats and dogs.  So staff can sometimes be faced with determining housing based on sex to avoid adding to the pet population. Although some exotic species are very social and being housed together can reduce stress, it’s important to be able to sex them to prevent unwanted litters, advise potential adopters, and avoid possible fighting. Sexing different species can be challenging to say the least. Internet searches can be a powerful tool with images and videos to help. But here are some tips all in one place that may be useful:


Rabbits can be tricky. A relaxed male can have obvious testicles. But if nervous, they have an ability to keep them in their abdomen rather than allowing them to descend and be easily identified. If already neutered, it is essential to extrude the genitals to determine sex. There are sometimes only subtle differences between an extruded penis and an extruded vulva. It’s also important to remember proper handling techniques when sexing rabbits since any kind of a struggle can lead to a back injury. 0e55aa8e4a5f6afac5b1cb4ee200e512

Guinea Pigs

Guinea Pigs are somewhat easier. Males will have obvious testicles usually becoming more prominent after 4 weeks of age. If altered, the penis can be extruded to verify sex.

Small Rodents

In some instances males can keep their testicles retracted like rabbits. Otherwise, males can have prominent testicles. Other tips include using the distance between the anus and genitals (where males will have a greater distance), and observing nipples (only in females) to determine sex.

Reptiles and Birds

Laszlo probing drawingThese animals can be the most difficult to sex. Some species have different coloring or physical characteristics that differentiate the sexes (Eclectus parrots have red females and green males). Lizards and snakes can sometimes have sex determined by inserting a probe into the cloaca (the probe will go in further in males). Some species can only be sexed with DNA testing. It’s recommended to involve an exotics veterinarian or specialist to aid in sexing.

With Spring in the air, it may be a good time to brush up on sexing different species because you never know when you may have hundreds of rats on your hands.


Variety is the Spice of Life

RatJust when you think you’ve got the routine down, a very small patient shows up on your surgery list. Next thing you know you find yourself researching anesthetic protocols for rats. Most shelters require dogs and cats to be spayed or neutered prior to adoption. Should we have the same recommendation for rats? Well, when you consider how prolific rats are, it could be argued that overpopulation is a concern. Rats can go into heat as early as 5 weeks, they have a heat cycle every 4-6 days, their gestation period is 22-23 days, their average litter size can vary from 2-20 kittens, and they have a postpartum estrus cycle 24 hours later …..well you do the math. Before you know it, an uneducated owner could go from two rats to rat hoarder.rat2

Studies have also shown that spaying rats can reduce the risk of developing mammary tumors and pituitary tumors. Pituitary tumors are hormonally induced, so by removing the source of estrogen, their development can be decreased. In turn, mammary tumors are avoided as they are usually a result of the pituitary tumor. This may provide a longer life span and higher quality of life. Although studies haven’t been conclusive for male rats, neutering could still be performed if there was a chance of co-housing with females.

Surgically, the procedures are very similar to kittens. So surgeons experienced in high-quality, high volume, spay and neuter (HQHVSN) and pediatric spay/neuter may feel a natural segue into rat surgery. However, rats can have a higher anesthetic risk creating the need to keep surgery time as short as possible. Drug doses are very different from dogs and cats so calculations need to be exact. Also, rats are chewers. So avoiding tissue glue or anything overtly irritating along the incision is essential to prevent self- trauma and dehiscence. But one of the biggest considerations is providing safe and low stress handling of rats before, during and after the procedure.  Therefore, the comfort level of the veterinarian, technicians and staff are of the utmost importance.rat surgery

References are essential and two very good ones to have on hand are:

Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery, 3e Paperback

by Katherine Quesenberry DVM MPH Diplomate ABVP (Author), James W. Carpenter MS DVM Dipl ACZM (Author)

Exotic Animal Formulary, 4e

by James W. Carpenter (Author)

Acquainting yourself with local exotic veterinarians and rat rescue groups can also be a valuable resource. Along with advice, they may be able to assist with adoption, or provide help if rat intake is not an option. If there is a veterinary teaching hospital in your area they most likely have an exotics department. The Association of Exotic Mammal Veterinarians website allows you to search by state to find a member veterinarian at Also, and have helpful rescue links and allow you to search for rescue groups by state.

Rats are social and intelligent companions who, unlike other rodents, don’t have a strong desire to latch onto your fingers when handling. This, along with their hardiness, make them ideal pets for children and adults and are definitely worth the added research.svd