Biology, Anatomy & Physiology Part 1
Ferrets are carnivores and belong to the Mustelidae family. They are related to weasels, otters, badgers and skunks and have been domesticated for many centuries. They are biologically very similar to cats and dogs. On average males weigh 1 - 2kg and females 0.5 - 1kg. Their average life span is 6 - 8 years.
|Rectal Temp (°C)||Heart Rate/min||Respiratory Rate/min||Urine Output (ml/day)|
|37.8 - 40||180 - 260||33 - 36||24|
Anatomy is similar as for the dog and cat, with the heart situated relatively caudally over the 6 - 8th rib. Ferrets are nasal breathers like rabbits, although oral respiration is possible. In males testicular descent occurs by 6 weeks old and the inguinal rings close after this. There is only one accessory sex gland in males - the prostate and males also have an os penis. The female reproductive tract is similar to that of dogs.
Ferret skin is extremely tough and seasonal alopecia is common during the summer, with a thicker coat developing over winter.
Sebaceous glands in the skin produce the charateristic ferret odour and may excrete a browny yellow substance which discolours the fur. Smell may be reduced by ovariohysterectomy or castration since this reduces secretions from these glands.
It is common for ferrets to sleep for up to 18 hours a day, which may make lethargy difficult to assess in an individual. Typically they show short energetic bouts of activity, followed by deep sleep. Seasonal weight loss is also common during the summer months, with as much as 40% in body weight reduction.
Most pet ferrets are easy to handle with gentle restraint around the neck and shoulders and support of the hindquarters. In fractious animals it may be necessary to scruff the animal, however the author [Anna Meredith] finds it easier to encircle the neck with one hand (acting as a neck brace). Body weight and hind limbs should be supported with your other hand, or may be tucked under your elbow to free up the other hand for clinical examination. Take care not to bring a fractious animal close to your face since ferrets have poor eyesight and reflex reactions may result in a bite to your face or nose. Ferret bites may be deep and once attached, the animal may be difficult to dislodge. If this occurs place the ferret on a table and attempt to pry open the mouth. Cold water applied to the head may encourage the animal to let go. Very fractious individuals may need sedation prior to clinical examination. These animals may appear frightened and hiss or scream, indicating that they are likely to be difficult to handle.
Clinical examination is basically the same as for cats and dogs, with the following exceptions:
Ferrets resent having their temperature taken rectally and this may prove difficult, resulting in an increased reading being recorded. An unbreakable, digital plastic thermometer is best and the ferret distracted by a treat.
Observe the animal initially at a distance. It may be placed on the consulting room floor and be allowed to investigate its surroundings whilst a history is being taken from the owner. A healthy animal will appear alert and should be active.
Hydration status should be assessed as in other mammals by skin turgidity. Teeth problems are common with similar lesions to cats developing, (dental tartar and gingivitis). Mucus membranes should be assessed for signs of anaemia in females. Cataracts occur in both adult and juvenile animals and the eyes should always be checked on clinical examination. Ear mites (Otodectes cynotis) are also common and infection is indicated by excessive brown waxy discharge.
Peripheral lymph nodes should be palpated for evidence of enlargement (which may indicate lymphoma). In fat animals these may be surrounded by fat and appear falsely enlarged.
The heart may be auscultated over the 6 - 8th ribs (more caudal than other species). Heart rate is rapid and may be difficult to record, particularly in an excited animal. There should be minimal lung sounds.
Palpation of the abdomen is aided by holding the ferret in a semivertical position. Splenic enlargement is commonly found in older animals and may be insignificant although further diagnostic tests are indicated if this is found.
Females should be examined for vulval swelling which may be associated in the intact animal with oestrus and in the neutered animal with adrenal disease or ovarian remnant. An intact female in oestrus should be examined for clinical signs of hyperoestrogenism. The testicles in males are only palpable in the scrotum during the breeding season (December - July)
Courtesy of Anna Meredith MA VetMB CertLAS DZooMed MRCVS Royal [Dick] School of Veterinary Studies