Tag Archives: research

09/6/14

The SA Story (Again)

selectcommitteesa

After hearing the ‘results’ of the Select Committee on Companion Animal Welfare in SA, I was hugely disappointed in the process and the recommendations. However, I was pleased to hear nothing further about it (it came out July last year!).

Until now.

A few articles (one | two | three) have come out quoting Ian Hunter (politician), Tammy Franks (politician), Tim Vasuedeva (RSPCA CEO), Steven Marshall (politician), and Jay Weatherill (politician).

The hot ideas are compulsory desexing (or just desexing puppies in pet shops), a code of practice, and a breeder licensing scheme, with some extra legislation thrown in for good measure. It’s not a surprise that this is mostly bad news, considering the spurious nature of the original Select Committee report.

 

Compulsory Desexing

The articles seem to be looking at both compulsory desexing, and compulsory desexing of all dogs sold in pet shops. The narrator in the first article describes the community as ‘divided’.

 

Compulsory Desexing of Petshop Puppies

Tammy Franks, in particular, supports the suggestion that all puppies from pet shops should be desexed.

Tim Vasudeva, from the RSPCA, says, “We’ve been desexing puppies between 3-4 months for years and years and we haven’t had any problems.”

The first article claims that the government will look at compulsory desexing of dogs sold in pet shop in light of a Select Committee’s report. While the report made many poor recommendations, desexing of dogs in pet shops before sale was not one of them! False reporting!

The problem with this is: We are desexing very young puppies and there is evidence that there are harms associated with desexing when it is done at a young age. These harms go beyond anaesthetic risks and immediate recovery (which is what Tim is referring to) and is more about long term acquisition of health problems including cancer. (You can read a recent study on golden retrievers, or a recent study on vizslas to learn more about this.)

Further, what is the point of this suggested legislation? Why should all puppies be desexed before sale? Especially because of the long term health risks?

If you wanted to get me on side with this suggestion, I would be more inclined to support the sterilisation of puppies before sale (including tubal ligation and vasectomies, that aren’t known to have these long-term health outcomes). However, I’d still be asking what the point of this was – surely there’s bigger issues for us to be dealing with.

 

Compulsory Desexing of Everything

Tim Vasudeva, from the RSPCA, says that the AVA’s research shows that desexed dogs are 2.6 times less likely to bite. This is not true: the AVA refers to others’ research, using 23 year old data, which suggests desexed dogs are 2.6 times less likely to bite.

Tim Vasudeva spoke about how desexing could be beneficial – in reducing wandering and hormone-driven behaviours and said “At the very least I don’t think can hurt”. While there is actually a study that indicates that this is the case, it is one old study. Anecdotally, I know of plenty of people who have non-humpy non-pissing non-wandering dogs that are entire.

Ian Hunter says that “In the ACT, desexing is compulsory and has led to a 47% decrease in dog attacks. It’s also reduced the number of unwanted dogs being euthanised.” Despite a lot of research on my part, I couldn’t find any evidence that this is the case. Any clues on this appreciated! While there might be a correlation (I stress might), this doesn’t indicate a causation.

 

Code of Practice

All three articles talk about the government introducing a Code of Practice to target puppy farms and makes sure dogs are kept and born into healthy and humane conditions.

But a Code of Practice will affect everyone, not just puppy farms! Such codes produced around Australia have pretty much banned dogs from being kept inside or on grass. Are puppy farms defined as those with lots of dogs? Those breeding many litters? Those producing many puppies? Anyone that breeds full stop? A ‘puppy farm’ is hard to define, and so Codes of Practice affect everyone instead.

Further, dogs already have to be kept in a humane way! The Animal Welfare Acts and similar legislation across Australia requires it. Anyone who is allowing their dogs to get matted, or not have water, or have medical treatments denied, is guilty of an offence. We can get puppy farmers for that! Code of Practice not required!

 

Licensing Scheme

I was excited in article two where there was the suggestion that there would be no licensing scheme… Then article three suggested there would be. I’ve repeatedly made arguments against breeder licensing (the most elaborate being here), but basically:

1) Breeder licensing hasn’t been shown to do much (like the Gold Coast scheme) – it doesn’t reduce pound intakes for sure. And puppy farmers don’t make a habit of signing up.

2) Why would we introduce a new license scheme, when the Animal Welfare Acts are not currently enforced?

3) How do we ensure that responsible and ethical home ‘hobby breeders’ are not discouraged from breeding wonderful pets?

4) Often, breeder licensing excludes ‘backyard breeders’, ‘working dog breeders’, and greyhound breeders. These breeders produce a lot of dogs and dogs that are, seemingly, more likely to end up in the pound system.

 

Other Matters

Tammy Franks wants shelters to reveal euthanasia rates publicly. I think this is great if shelters were to have such transparency.

Article two and three suggest that mandatory microchipping will come in, and be compulsory (presumably, hopefully, compulsory before sale). While I have no qualms with microchipping being mandatory, I look forward to the phone line that allows me to report in those selling animals without microchips illegally. I don’t look forward to my expensive phone bills from making such reports. What I’m saying is: I have no confidence that this legislation will be adequately enforced.

Interestingly, one article says that there will be a “requirement for pets to only be bought from registered breeders”. That would be interesting! No more RSPCA, AWL, rescue group sales. No more guide dog and assistant dog groups selling unsuitable animals. Does that mean private rehomings are no longer legal? Surely this must be some kind of error in reporting.

And still there’s continued bleating about a cooling off period, under the guise that it would “reduce impulse buying and cut the number of pets being abandoned or surrendered”. There is no evidence that this is the case! Firstly, it does not seem that pets acquired impulsively are at any greater risk of being surrendered than pets acquired with a lot of thought. Secondly, there is no evidence that a cooling off period would reduce abandonment of pets. I don’t know how this even gets attention!

 

How unfortunate that the Select Committee’s recommendations are now gaining media attention and potentially some momentum in SA.

I spent a great many hours researching and writing my 20 page submission to the Committee. When the Committee published its findings and suggestions, I was so angry that the recommendations made were based on an emotive community rather than evidence and science.

I had been peacefully thinking that the Select Committee was just a little media stunt, and that it was going to disappear. These recent media reports and troubling and upsetting.

It’s concerning that the Government is prepared to invest resources into plans with no evidence that they will have any impact on animal welfare.

It is just as concerning that the community is lapping it up.

 

Further reading:

Public Misconceptions

Is desexing a cult?

Companion Animal Taskforce in NSW – Feedback

09/3/14

A Link Between Desexing and Reactivity

ResearchBlogging.orgWhile desexing bitches is a common surgery, I was pleased to see Kim et al. take note that “the side effects of the operation, particularly any changes in behaviour, have been quantified in only few studies”.

That is to say, despite us commissioning vets to take the ovaries and uterus out of a great many bitches, we don’t really have much research about it. It’s a pretty scary state of play.

This particular study took 14 healthy German Shepherd bitches, between 5 and 10 months old. Half of these dogs were spayed, and the other half left entire. (The bitches were assigned to each group randomly, except for litter sisters, which were assigned opposite groups.)

After the spay, and having been given 4-5 months to recover from the surgery, the bitches were filmed in their kennel as a stranger and a dog approached. This footage was then scored based on how reactive the bitch was. A score of ’3′ indicated severe reactivity, and a score of ’0′ indicated no reactivity. The scorer was unaware of whether the bitch was spayed or not.

Photo courtesy of Rachel Willis.

Photo courtesy of Rachel Willis.

The reactivity of each bitch was recorded several times, and the reactivity of each bitch declined over the study. It’s likely that the bitches habituated to the novel stimuli. However, despite this affect, bitches in the ovary-hysterectomy group scored higher throughout the study.

Before generalising these results, there are some matters to consider:

  • Reactivity was only measured in a kennel setting, and how these dogs react in the ‘real world’ may be different. We can’t suppose that our pet dogs are going to respond in the same way as kennel dogs.
     
  • The reactivity of these dogs was not measured at the start of the study. While it is unlikely, perhaps more reactive dogs happened to fall into the treatment group by chance. Without a ‘before desexing’ score, we cannot be sure of this.
     
  • The authors make note that these results are for German Shepherd bitches aged 5-10 months old. We can’t assume dogs of all breeds and ages would respond this way to spays.
     
  • Further, the bitches in this study are working lined German Shepherds, which may be more reactive than the typical pet dog.

 

However, this study notes that other studies on bitch spays have shown that as a group spayed bitches are:

  • More likely to gain weight
  • More aggressive than prior to spay (if they were aggressive prior to spay)
  • More active
  • More likely to have urinary incontinence
  • More likely to be reactive after surgery

 

The authors recommend:

[V]eterinary practitioners should inform owners that a bitch may become more reactive after spaying either because they have lost the calming effects of progesterone or because elevated gonadotropins stimulate release of adrenal androgens.

 
Source:
Kim HH, Yeon SC, Houpt KA, Lee HC, Chang HH, & Lee HJ (2006). Effects of ovariohysterectomy on reactivity in German Shepherd dogs. Veterinary journal (London, England : 1997), 172 (1), 154-9 PMID: 16772140

Further reading:
Desexing: It’s bad for Vizslas too
Is desexing a cult?
Desexed dogs – 2.6 times less likely to bite!
Why would you NOT desex your dog??
Golden Retrievers: Cancer if you do, cancer if you don’t

07/1/14

Desexed dogs – 2.6 times less likely to bite!

Australian Veterinary Association makes this claim, in its PDF “Dangerous Dogs – a sensible solution“:

Entire (undesexed) dogs are 2.6 times more likely to bite than those that are spayed or neutered (desexed)

Are undesexed dogs really that risky?

I decided to read the three studies referenced individually.

 

avadesexing

 

 

Messam, LL, Kass, PH, Chomel, BB, Hart, LA 2008, ‘The human-canine environment: a risk factor for non-play bites?’, Veterinary Journal, 177(2); 205-15.

This study used data from 2003 (11 years ago) collected in Kingston, Jamaica and San Fransico, USA. Participants were recruited from vet clinic waiting rooms where they were presented with a questionnaire, set to determine the nature of their dog’s biting behaviour (and differentiating it from play biting).

When it came to comparing entire and gonadectomised dogs, this research suggests:

  • Intact dogs are more likely to bite than desexed dogs
  • Intact males are 1.68 times more likely to bite than desexed males
  • Intact males were 0.8 times more likely to bite than intact females
  • Spayed females were the ‘least bitey’

 

Guy, NC, Luescher, UA, Dohoo, Se, Spangler, E, Miller, JB, Dohoo, IR and Bate, LA 2001, ‘Demographic and aggressive characteristics of dogs in general veterinary caseload’, Applied Animal Behaviour Science, vol 74, iss 1. 

This research is based on data collected in Cannada in 1996 (18 years ago), targeting owners with a questionnaire waiting for vet appointments in three Canadian provinces. Their results indicate:

  • The lowest level of aggression (biting and growling) was reported in intact female dogs
  • Intact male dogs were twice as likely to have bitten as intact female dogs
  • Intact male dogs and neutered females incidents of biting was reported at a similar level

And to quote:

“Relative to intact female dogs, neutered male dogs of at least 1 year of age were at the highest risk for having previously shown biting behaviour, followed by neutered female dogs, and intact males… [O]ur results indicate that the behavioural outcomes of [neutering] are worthy of further investigation.”

 

Gershman, KA, Sacks, JJ & Wright, JC 1994, ‘Which dogs bite? A case-control study of risk factors’, Pediatrics, 93 (6 pt 1), 913-7. 

This study used data from 1991 (23 years ago) using 178 dog bites requiring medical treatment of a non-household-member in Denver, USA. Data was only used for dogs that had not bitten before. The study itself recognises this is a small sample size.

Their data concludes:

  • not-neutered dogs were 2.6 times more likely to bite
  • chained dogs were 2.8 times more likely to bite
  • dogs living with a baby were 3.5 times more likely to bite
  • male dogs were 6.2 times more likely to bite

 

So, are entire dogs 2.6 times more likely to bite?

If you are looking at the study in Denver, USA, in 1991 (23 years ago!) then, yes, their conclusions indicate that intact dogs are 2.6 times more likely to bite than desexed dogs.

But the other evidence referenced by the AVA does not make the exact same conclusions. The study conducted in 2003, using data from Jamaica and the USA, found that intact males were 1.68 times more likely to bite than castrated males, and 0.8 times as likely to bite as intact females. (This study is also old, with the data being collected 11 years ago.)

And that other article, with data from Canada in 1996 (18 years ago) makes pretty much the opposite conclusion. They found that neutered male dogs were the riskiest in terms of bites.

 

Questions to ask…

Why are we relying on data over a decade (or two decades) old? If aggression in entire dogs was a common phenomenon, surely we would have countless studies showing this problem.

Where is the Australian data-set?

Where is the study that controls for factors such as selection, socialisation, and socio-economic factors?

 

What the AVA should really be saying is:

According to one study conducted in Denver, USA, 23 years ago, entire dogs were found to be 2.6 times more likely to deliver a bite (that required medical treatment) to a stranger than desexed dogs.

06/23/14

Scottie Cramp

ResearchBlogging.orgWhile reading up on CECS in border terriers, I happened upon a condition called ‘Scottie Cramp’. I was keen to learn more, and found the article “Hyperkinetic episodes in Scottish Terrier dogs” (and, more importantly, the reproduction of its text on the Scottish Terrier Club of America website).

Scottish terriers. Photo courtesy of Argowan Scottish Terriers. (Photo for illustration purposes - these dogs do NOT have scottie cramp.)

Scottish terriers. Photo courtesy of Argowan Scottish Terriers. (Photo for illustration purposes – these dogs do NOT have scottie cramp.)

 

What is ‘Scottie Cramp?’

‘Scottie Cramp’ is the popular term for hyperkinetic episodes in scottish terriers. This is a central nervous system problem that causes the hindlegs of effected Scottish Terriers to ‘cramp up’ so they kind of ‘skip’ with their hindquarters.

This condition is often brought on by excitement or exercise, and gets worse as exercise progresses. Generally a walk of 90m-600m was enough to bring about symptoms in affected dogs in this study. (However, there was one badly effected dogs who displayed symptoms after 10m.)

Usually a dog will exhibit symptoms before 18 months of age, and this condition does not seem to affect the dog’s lifespan.

 

What does it look like?

The paper does a pretty good job of describing this disorder. So here’s what they say with some added emphasis from me:

During exercise, the onset of a hyperkinetic episode was usually indicated by a slight abduction of the front legs, resulting in an arclike motion of the limbs while extending.  The back then became arched in the lumbar region, and the hind legs were quickly over­flexed and then swiftly returned to the ground.  This motion has been appropriately described as a “stringhalt” gait.

The front legs became increasingly stiff, and while walking were quickly ex­tended then flexed. In rare cases where the back was not arched, the dog walked with a “goose step” gait. Forward movement was usually hindered, and in severe cases was completely absent, resulting in the dog walking in place. Facial muscles did not ap­pear to be affected at this time…

Occasionally, when the younger dogs were running, the hindquarters would suddenly and strongly become elevated, often to such a degree that the dog somersaulted. If the inducing stimulus was continued, the hind legs became increasingly resistant to flexion, which finally resulted in a pillarlike stance, with the dog unable to walk. If the dog fell down, it would curl into a ball with its head, limbs, and tail tucked in; breathing would ap­pear to cease. The severe seizure would last approximately 15 seconds, after which the dog appeared relaxed and panting. During or just preceding a severe episode, the facial muscles were often affected, and the dog was unable to open its jaws.

None of the dogs lost consciousness during an episode, nor did they appear to be in pain. A short period of rest would alleviate the hyper­kinetic episode in most dogs, but the signs would quickly reappear if the inducing factors were not eliminated.

Here’s a video showing a scottie with this cramping disorder, and a ‘normal’ scottie:


 

What causes it?

This was a small study of only 10 dogs, but the results seem to indicate: “Excitement and fear facilitated the hyperkinetic episodes, whereas anxiety and apprehension were often inhibitory”. (Personally, I am not sure that fear and anxiety are different enough to form this kind of conclusion.)

They also found that amphetamine sulfate, when injected intramuscularly, caused symptoms within 15 minutes.

There was a lot of variation between dogs and symptoms, but it seemed that frequent exposure to the trigger, the dogs tended to build tolerance. However, no dog ‘recovered’ (i.e. ceased to display symptoms).

 

What fixes it?

As this is a Central Nervous System problem, drugs that target the CNS, naturally, are effective.

Symptoms can be alleviated by some drugs (such as chlorpromazine, acepromazine, and diazepam) injected intramuscularly. In the case of chlorpromazine, injection intramuscularly during a seizure caused cessation of symptoms within 15 minutes.

Diazepam worked to stop dogs seizing, and also to prevent seizures (given twice daily to affected dogs).

While Vitamin E has been anecdotally suggested as a preventative, this study did not find it to be effective.

 

How is Scottie Cramp diagnosed?

3 criteria for scottie cramp:

1) abnormal gait or seizures during excitement,

2) injected amphetamine should induce an episode, and

3) administering diazepam or promazine during a seizure should cause prompt remission.

 

Reference:
Meyers KM, Lund JE, Padgett G, & Dickson WM (1969). Hyperkinetic episodes in Scottish Terrier dogs. Journal of the American Veterinary Medical Association, 155 (2), 129-33 PMID: 5816228

02/25/14

Vaccinations Last At Least Three Years

ResearchBlogging.orgWhen reading Terrierman he made reference to the work Schultz has done on the duration of vaccines. Intrigued, I decided to read one of his articles. I dug up a review Shultz wrote on the duration of vaccines. It looks at available research on vaccines and their ‘duration of vaccinal immunity’ (i.e. how long they last).

Whether a dog has immunity can be determined either by antibody titres (a ‘titre test’) or a challenge study (e.g. deliberately exposing the dogs to the pathogen).

 

For distemper, parvovirus, and adenovirus the published data suggests an immunity period of 3 years or longer minimum.

Using blood products to test immunity, it seems that vaccines last 3 years or longer.  When using challenge studies, dogs that were vaccinated 11 years ago did not contract the virus.

According to this article, if a cat or dog is:

  • Vaccinated with core vaccines at 12 weeks of age or older,
  • Is revaccinated at 1 year old, and
  • Receives a vaccination “not more often than every 3 years”

then this would be as protective to the pet as annual vaccination.

However, non-core vaccinations last a year or less.

Table 1 shows estimated minimum duration of immunity for the 4 core canine vaccines.

How long does a dog vaccination last?

Shultz concludes, “Extending the revaccination intervals for canine and feline core vaccines does not place the animal at increased risk to developing vaccine preventable disease, but it does reduce the potential for adverse reactions”

He also recommends using titre tests to ensure that a puppy’s final vaccine enduces an immune response – and to revaccinate if the titre does not indicate that an immune response was produced.

Oh, and on cats? According to this paper, feline vaccines less researched, but feline parvovirus, calcivirus and herpes seems to last at least 7.5 years. Exception is feline leukemia which provides immunity for 1 year or less.

 

Reference:
Ronald D. Schultz (2006). Duration of immunity for canine and feline vaccines: A review Veterinary Microbiology, 117 (1), 75-79 DOI: 10.1016/j.vetmic.2006.04.013