Tag Archives: Malocclusion

Holland Lop & Heat Tolerance

WARNING: Unverified Opinions Blog Content. Opinions expressed here is based on author’s observation and experience reader’s discretion needed.

During my younger days, I read a lot about dogs and I am a sucker for short snout/muzzle (or in short, Brachycephalic) dogs because they are cute and captivating. Recently I have read about airlines banning certain dogs from being allowed on board airplanes due to the many problems attributed to their short snout/muzzle.

One attribute that captured my attention recently is the heat tolerance in Brachycephalic dogs (reference article). Apparently, they are prone to overheating (heatstroke, collapse & death) . Dogs as we know, regulate body temperature through footpads but mostly through panting.

How does all these translates to rabbits?

Rabbits regulate body temperature through their ears where the major blood vessels are located. In extreme heat, rabbits can be seen panting (head banging) with moisture around their mouth, nose and when it gets bad, they lick their front feet at the region around the ankles in attempt to cool themselves down through moisture on the major blood vessels in that area. How many of you noticed matted fur with saliva stains on your rabbit’s front paws?

As  you can see, both dogs and rabbits do not sweat like how we humans do.

So is Holland Lop less heat tolerable compared to breeds like the Mini Rex?

I personally believe so because through my observation and experience, lop ear rabbits with regular snout/muzzle tend to thrive better than the Holland Lop in Malaysia. Being prey animal at the lower realm of the food chain, rabbits are highly adaptable and the most obvious physical change from one generation to the next in Holland Lop under the Malaysia weather is their ear length and overall flesh condition. The rule of thumb is, larger surface area to volume ratio in smaller animal means higher efficiency in losing and gaining heat.

I have written about “selective” breeding before and not to repeat myself, it means that we breed to retain the physical characteristics that is desirable which are clearly specified in a “standard” of some sort. I have not done extensive study or research on this but if I would to apply what happens to Brachycephalic dogs the same way I would apply on Holland Lop rabbits, there is indeed one very obvious similarity between the two – change in skull structure/shape.

I recently came across a sketch picture of a rabbit skull done by Isa Cunanan. At press time, I have yet to receive any confirmation if I could use her sketch for a graphical morph to illustrate the point I would like to put forth. The morphing process helps in my opinion in explaining how the rabbit skull changes and also explain probably how the malocclusion phenomenon happens. I have decided to share the morphing process until I receive a notice that I am not allowed to use the sketch.

A Mini Rex rabbit with a regular snout/muzzle.

A Mini Rex rabbit with a regular snout/muzzle. Long and pointy ears too!

A stumpy Holland Lop with short snout/muzzle. Short and rounded ears to adhere to standards.

A stumpy Holland Lop with short snout/muzzle. Short and rounded ears to adhere to standards.

Here are the morphs (Please click on image to see animation):-

Skull structure change through selective breeding to adhere to standard:

SkullMorphOpt

Click on image to view animation.

Skull development towards Malocclusion:

SkullMorphMaloclusionOpt

Click on image to view animation.

I am not making any statement whether selective breeding is good or bad. The Holland Lop breed thrives in many locations with “good” temperature/climate. Malaysia at press time is 81 degrees Fahrenheit or 27 degrees Celsius with the 89% humidity.

Is the Malaysia tropical climate suitable for the Holland Lop to be raised as is without any temperature control?

I believe that there are many approaches that can be taken.

1. Bring anything but Summer into your home. That means, you will need to simulate Autumn, Winter or Spring within your rabbits’ living quarters. Preferable Spring because that when most rabbits in the wild tend to be prolific.

2. Leave these rabbits where they truly belong. Anywhere but tropical climate.

3. Accept the fact that locally bred will eventually evolve into a different looking animal compared to its imported counterpart.

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The Undesirable 2

We all know that Holland Lops are one of the dwarf breeds. And being dwarfs, they were initially bred to have rounded skull. Just like the Netherland Dwarf, rounded skull poses a problem – Malocclusion. Which is the misalignment of the teeth. The classic example of this genetic problem is the bottom incisors outgrows over the top incisors. Breeders cull hard on this genetic trait. Sometimes this trait develops as the rabbit gets older. Malocclusion may start when the rabbit get old as well. Rabbits with Malocclusion could be extremely high in maintenance because they need regular trimming of the teeth by the vets and they must not be bred. The good news is, over the years “bigger” Holland Lops has been bred to spot the massiveness desired and their skulls are not too round anymore. This has lower the chances of getting Malocclusion greatly.

The history of Holland Lop tells us that they initially started off with solid colors and the broken was introduce by breeding them to the English Spots. While getting the broken patterns, breeders were unable to retain the rollback fur and therefore the French Angoras were used. That is the reason behind the occasional Fuzzy Holland Lops. The Fuzzy Holland Lops can be shown as American Fuzzy Lops but they can not be registered due to the reason that their pedigree will not show 3 generations of AFLs. And due to the reason that they cannot be registered with ARBA, although they can be shown as AFLs, they cannot be granded. To grand a rabbit, it has got to get 3 GC legs as we know and is registered with ARBA. This is another trait that breeders cull hard on as well.

I strongly believe that the Holland Lop is a breed that has many hidden recessive genes that certain combination of breedings may bring forth both desirable and undesirable traits. This is one of the reasons why they are a challenging breed to work with. They seemed to be like Pandora boxes opening up a whole new world with entirely new experiences for us.

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Filed under Rabbit Genetics