If I Had To Fight Mange Again

Veterinarian

As I have already mentioned, the best treatment for a sick animal is to get to the veterinarian as soon as possible.

If I'm ever in this situation again, I hope that the vet is an option.

Quarantine

Mange can be very contagious. Infected animals must be isolated from other animals, in order to reduse the chances that all of them will become ill.

This wasn't an option with Bandit, because he is feral. For all I know, he went out on the town infecting other cats while I tried to treat him. But if it happens again, I hope to be able to quarantine the sick animal.

This means more than just "don't let them play together". It also includes:

Wash up throughly after contact with mangy animal.
Don't share brushes, combs, bedding, or toys between animals.

Human Infection

It is theoretically possible for humans to catch mange from animals. But it doesn't go far. Mange mites specialize in the species they attack and mange mites from a cat don't do too well on humans. They might get a start, but shouldn't thrive.

Still, I was probably quite lucky, because I had a lot of contact with Grimalkin before he died and before his condition was diagnosed.

I guess the lesson for next time is to wash up, thoroughly and frequently. Plenty of soap and hot water.

Washing goes for both people and clothing.

Environmental Surfaces

A reader of this web site e-mailed me to ask if there was anything that could be used around the house to kill mites that came off the infected animal.

I must admit to not thinking about that, probably because I didn't have to go through it. Bandit stayed outdoors, and that was part of the problem.

But if the next battle takes place indoors, I might try dusting around with Boric Acid powder. This is very commonly used in roach killer. I think it also kills fleas and ants. It might work on mites that escape from an infected animal. Either way, it's very inexpensive stuff, and probably qualifies as cheap insurance. In reasonable amounts, it is harmless to kids and pets, but I'll have to read the label, just to be sure.

Order Treatment Supplies

As soon as I found out that I would have to take desperate measures of a home mange cure, I should have ordered treatment supplies immediately. Time is of the essence. Unfortunately, I lost some time trying to figure out what to do last time.

Next time, I will immediately go to Pet Supplies 4 Less and order the following:

what order number price purpose

Eqvalan Paste 1.87% Ivermectin, 6.08 g 016MRK01-6.08 $12.65 active ingredient

Syringe-O Ring, 60 cc, Eccentric 011BAXOR-60 $2.00 measure glycerin (or vegetable oil); replaces graduated cylinder

And one of the following:

what order number price purpose

Syringe-O Ring, 1 cc 011BAXOR-1 $0.70 dispense solution - for small cats

Syringe-O Ring, 3 cc 011BAXOR-3 $0.70 dispense solution - for normal cats

Syringe-O Ring, 5 cc 011BAXOR-5 $0.70 dispense solution - for extreme cases

what	order number	price	purpose
Eqvalan Paste 1.87% Ivermectin, 6.08 g	016MRK01-6.08	$12.65	active ingredient
Syringe-O Ring, 60 cc, Eccentric	011BAXOR-60	$2.00	measure glycerin (or vegetable oil); replaces graduated cylinder

what	order number	price	purpose
Syringe-O Ring, 1 cc	011BAXOR-1	$0.70	dispense solution - for small cats
Syringe-O Ring, 3 cc	011BAXOR-3	$0.70	dispense solution - for normal cats
Syringe-O Ring, 5 cc	011BAXOR-5	$0.70	dispense solution - for extreme cases

Note:

These prices and order numbers are as of 6/2004. I'm sure that they will change by the time I need them again.
I'll probably use Eqvalan Paste again because that's what I used last time. Looking at the PetSupplies4Less web page now, I see some other products that seem to contain identical ingredients and might save a buck: [as of April 2005]
- Ivermectin Paste (1.87%, 6.08 g, 016PHX01-1, $6.65 each)
- Equimectrin Paste (6.08 g Syringe, 016MRK01-A, $7.95 each)
- Zimecterin (1.87%, 6.08 g Syringe, 016IVE, $11.95 each)
The big syringe replaces the graduated cylinder that I used in my first batch. A syringe seems like a cheap and accurate way to measure out the 22 ml glycerin (or vegetable oil). The 60 cc model is a compromise between too small and too big. I would resist the urge to use something like a smaller 5 cc, four+ times to measure out a total of 22 cc. Each measurement has a little error in it, and the errors add up.
A syringe seems the ideal way to precisely measure out the dose of Ivermectin solution. I envision doses between .5 cc and 1.8 cc, depending on the animal. The next standard size is 3 cc. Smaller animals would benefit from the accuracy of a smaller syringe. Extreme cases might need a larger one.
The fancy silicone O-Ring-seal syringe is overkill, but you can also buy just one - cheaper syringes usually come in multiple packs. If the next sick kitty isn't fat, I could probably get by with the Syringe-Monoject, 3cc LL, 25g x 5/8" (01101MON-3X25X5/8LL, $0.20 each)

[April 2005 update:]
The first few times I had to do this, I mixed the horse paste with vegetable oil. The paste doesn't really dissolve in the oil. The best that you can hope for is to stir for a long time, breaking up the horse paste into tiny bits that stay in suspension. Since then, I have experimented with mixing horse paste with glycerin, and it works a lot better. Glycerin is pretty easy to find at drug stores. It may be with the cosmetics. Make sure that the glycerin is pure, not some fancy stuff that just contains some glycerin.

Buy Time

While I was waiting for the supplies to arrive, I engaged in certain measures intended to buy time.

I think that these measures helped, and I would go through them again.

Prepare The Solution

There are a wide variety of Ivermectin-based products that could be used for dosing cats.

All of my math is based on a diluted solution of 1.0 mg Ivermectin/ml. Ivermecting doesn't come this way, but it is a convenient dilution to work with.

It looks like Ivermectin-based "horse paste" is readily available in a standard strength: 1.87% (a 6.08 g Syringe intended to treat a 1250-pound horse). I would probably mix it with glycerin.

I would mix it according to my original method:

enough 1.87% Ivermectin horse paste to treat a 250 pound horse
22 ml of glycerin

In addition to horse paste, injectable Ivermectin seems fairly common in a standard strength of 1% (10 mg/ml). If I were working with this material, I would prepare my standard dilution using:

1 ml of 1% Ivermectin injectable solution
9 ml of glycerin

Weigh The Cat

The dose of Ivermectin solution is calculated based on the weight of the animal. A fat cat gets more; a skinny animal less. Ideally, I would weigh the animal.

Possible methods include:

Get the cat to stand alone on the bathroom scale.
Put the cat in a box or basket; weigh that. Then subtract the weight of the empty basket.
Stand on the scale while holding cat; weigh yourself. Then subtract your weight without the cat.

I don't know which of those methods produces the most accurate results. If possible, I would try all three and see how the results differ.

The smaller the cat, the more precise you have to be. If I had to treat a tiny cat, I would probably put her in a kitchen scale designed to weigh cooking ingredients.

When dealing with Bandit, I didn't have the option of any of these. Wild cats don't like being handled. I guessed a weight of 10 pounds. I hope I don't have to guess next time - overdoses can be dangerous!

The Merck Veterinary Manual recommends 0.2 mg/kg, and cautions that "Sudden death in association with the use of ivermectin in kittens has been reported." What age range should be considered a "kitten?" I don't know what Merck uses, but I would estimate from birth through 4 months.

Computing Dosage

All of my math is based on a diluted solution of 1.0 mg Ivermectin/ml. Ivermecting doesn't come this way; I prepare it myself.

Based on previous results:

0.2 mg/kg - oral Ivermectin does have a theraputic effect against mange
0.4 mg/kg - didn't do any visible harm, and may have resulted in a faster recovery

Since Ivermectin can be be dangerous, I would probably use the lowest dose that seems to work. That means 0.2 mg/kg next time.

This figure is for cats only and is based on my research and single experiment. Dogs would be a completely different situation because (a) they generally get a different species of mite and (b) certain breeds of dogs are sensitive to Ivermectin (I have seen warnings about collies and related breeds). I have seen dog web site recommend .2 mg/kg, daily, continued for 2 months after no mites are found. That dog mange must be tough stuff!

The computation is easy:

Get the cat's weight in kilograms. Since my bathroom scale reads in pounds, I will have to convert:
kilograms = pounds x .45
My standard dilution contains a concentration of 1.0 mg Ivermectin/ml.
My intended dose is 0.2 mg/kg.
Amount to use (ml) = Weight (kg) x dose (mg/kg) / concentration (mg/ml).
In Bandit's case: Amount to use (ml) = 4.5 kg x .2 mg/kg / 1.0 mg/ml = .9 ml.

I would get a 1 cc syringe, which would serve cats up to about 11 pounds. Larger standard sizes are 3 cc and 5 cc.

This table shows the hypothetical doses for various cat weights and treatment levels. As I mentioned, I would probably use the column "standard = .2 mg/kg". If the cat were elderly, injured, very young, or had other illnesses, I would probably use the column "weak = .1 mg/kg". I would avoid higher treatment levels unless I had a reliable diagnosis of the less common (and harder to cure) Demodectic Mange. This table is based on my standard dilution, containing a concentration of 1.0 mg Ivermectin/ml. [Veterinarians have access to pre-diluted Ivermectin, which is usually 10 mg/ml.]

Notoedric Mange (Feline Scabies) or Sarcoptic Mange (Scabies) Demodectic Mange (Demodicosis; Red Mange)

cat weight weak = .1 mg/kg standard = .2 mg/kg strong = .3 mg/kg .4 mg/kg .5 mg/kg .6 mg/kg

pounds kilos dose, ml (cc) dose, ml (cc) dose, ml (cc) dose, ml (cc) dose, ml (cc) dose, ml (cc)

1 0.45 0.05 0.09 0.14 0.18 0.23 0.27

2 0.90 0.09 0.18 0.27 0.36 0.45 0.54

3 1.35 0.14 0.27 0.41 0.54 0.68 0.81

4 1.80 0.18 0.36 0.54 0.72 0.90 1.08

5 2.25 0.23 0.45 0.68 0.90 1.13 1.35

6 2.70 0.27 0.54 0.81 1.08 1.35 1.62

7 3.15 0.32 0.63 0.95 1.26 1.58 1.89

8 3.60 0.36 0.72 1.08 1.44 1.80 2.16

9 4.05 0.41 0.81 1.22 1.62 2.03 2.43

10 4.50 0.45 0.90 1.35 1.80 2.25 2.70

11 4.95 0.50 0.99 1.49 1.98 2.48 2.97

12 5.40 0.54 1.08 1.62 2.16 2.70 3.24

13 5.85 0.59 1.17 1.76 2.34 2.93 3.51

14 6.30 0.63 1.26 1.89 2.52 3.15 3.78

15 6.75 0.68 1.35 2.03 2.70 3.38 4.05

16 7.20 0.72 1.44 2.16 2.88 3.60 4.32

17 7.65 0.77 1.53 2.30 3.06 3.83 4.59

18 8.10 0.81 1.62 2.43 3.24 4.05 4.86

19 8.55 0.86 1.71 2.57 3.42 4.28 5.13

20 9.00 0.90 1.80 2.70 3.60 4.50 5.40

likely safe likely safe
for healthy adults stronger than necessary I haven't tried it

	Notoedric Mange (Feline Scabies) or Sarcoptic Mange (Scabies)	Demodectic Mange (Demodicosis; Red Mange)
cat weight	weak = .1 mg/kg	standard = .2 mg/kg	strong = .3 mg/kg	.4 mg/kg	.5 mg/kg	.6 mg/kg
pounds	kilos	dose, ml (cc)	dose, ml (cc)	dose, ml (cc)	dose, ml (cc)	dose, ml (cc)	dose, ml (cc)
1	0.45	0.05	0.09	0.14	0.18	0.23	0.27
2	0.90	0.09	0.18	0.27	0.36	0.45	0.54
3	1.35	0.14	0.27	0.41	0.54	0.68	0.81
4	1.80	0.18	0.36	0.54	0.72	0.90	1.08
5	2.25	0.23	0.45	0.68	0.90	1.13	1.35
6	2.70	0.27	0.54	0.81	1.08	1.35	1.62
7	3.15	0.32	0.63	0.95	1.26	1.58	1.89
8	3.60	0.36	0.72	1.08	1.44	1.80	2.16
9	4.05	0.41	0.81	1.22	1.62	2.03	2.43
10	4.50	0.45	0.90	1.35	1.80	2.25	2.70
11	4.95	0.50	0.99	1.49	1.98	2.48	2.97
12	5.40	0.54	1.08	1.62	2.16	2.70	3.24
13	5.85	0.59	1.17	1.76	2.34	2.93	3.51
14	6.30	0.63	1.26	1.89	2.52	3.15	3.78
15	6.75	0.68	1.35	2.03	2.70	3.38	4.05
16	7.20	0.72	1.44	2.16	2.88	3.60	4.32
17	7.65	0.77	1.53	2.30	3.06	3.83	4.59
18	8.10	0.81	1.62	2.43	3.24	4.05	4.86
19	8.55	0.86	1.71	2.57	3.42	4.28	5.13
20	9.00	0.90	1.80	2.70	3.60	4.50	5.40
	likely safe	likely safe for healthy adults	stronger than necessary	I haven't tried it

Monitor Dosage

In Bandit's case, I mixed the Ivermectin with canned cat food. I need to do more research on the best way to get a cat to eat this stuff.

Since Ivermectin tastes bitter, the cat might not eat all the the medicated food. In some cases, another animal might eat some of the medicated food. Either way, it means the sick animal is not getting the medication he needs.

With Bandit, I tried to estimate how much he was really eating. If he didn't eat most of the medication, I gave him some more the next day, so the total adds up to the intended dose. This is probably a reasonable approach.

Next time, I'll watch him to make sure that the right cat is eating the food.

Treatment Schedule

I like the results I got with 3 doses, about a week apart.

I also think it was a good idea to dose the cat at night, so he could sleep off any side-effects.

Ideally, I would watch him for adverse side effects, but Bandit is a stray who eats the food we offer, and then disappears.

With three treatments, about a week apart, I would just mix up one batch of diluted Ivermectin and keep it in the refrigerator until the last dose has been administered. The two weeks that elapse between the first and last treatment should be sufficient to see some significant visible improvement.

Disposal

So, how does one dispose of the leftover Ivermectin? Note: Ivermectin is harmful to fish. Don't dump concentrated material someplace where it could get into ocean or stream.

The diluted solution of Ivermectin in oil, I would flush down the toilet. There is unlikely to be enough there to bother whatever treats your sewage.

The tube of horse paste still contains a lot of medicine that, if I am careful, is uncontaminated. I would probably keep it in the refrigerator in case of future need. It should be disposed of when the expiration date is reached. I suspect that the best method is to wrap it in plastic and put it in the trash.

The syringes - I would pull out the plunger, wash thoroughly with soap and water, then air dry, and put away in case of later need. Make sure that you put them in a container clearly marked as veterinary supplies. You don't want kids playing with them.